DE102022110476A1 - Lighting module and coordinate measuring machine - Google Patents

Abstract

The present invention relates to an illumination module (24) for a coordinate measuring machine (10) for measuring a measurement object (60), wherein the coordinate measuring machine (10) carries a measuring head (16) with an optical sensor (18) which has a lens (56) and a light-sensitive detector (58), wherein the lens (56) defines a detection beam path (64) from the measurement object (60) to the light-sensitive detector (58), and wherein the lighting module (24) has: a module housing (26) with a module-side interchangeable interface (30), which is designed to attach the module housing (26) to the measuring head (16) in an operationally releasable manner in a defined position; at least one light source (40) designed to generate light; an optical element (48) which is designed to direct the light onto the measurement object (60) when the module housing (26) is attached to the measuring head (16) in the defined position, the optical element (48) having a Illumination beam path (62) from the light source (40) to the measurement object (60) is defined; and a first polarization device (42), which is arranged in the illumination beam path between the light source (40) and the measurement object (60) and which is designed to polarize the light in at least one defined, first polarization direction, the first polarization device having at least one first polarizer (44) for polarizing the light. The present invention further relates to a coordinate measuring machine (10) with such an illumination module (24).

Description

The present invention relates to a lighting module for a coordinate measuring machine for measuring a measurement object. The present invention further relates to a coordinate measuring machine for measuring a measurement object.

Coordinate measuring machines are well known in the art. They are used, for example, to check workpieces or measurement objects as part of quality assurance or to completely determine the geometry of a measurement object as part of so-called “reverse engineering”. In addition, a variety of other possible applications are conceivable.

Different types of sensors can be used in such coordinate measuring machines to record the coordinates of a measurement object to be measured. For example, tactile measuring sensors and optical sensors are known for this purpose.

The sensors can then be used in different types of measurement setups. An example of such a measurement setup is the applicant’s “O-INSPECT” product. In such a device, both an optical sensor and a tactile sensor are used to carry out various testing tasks on a machine and ideally with a single clamping of a measurement object to be measured.

Sensor systems with optical sensors are becoming increasingly important in coordinate measurement technology. Optical sensors are characterized in particular by their high speed of measurement. Typically, a coordinate measuring machine has a measuring head that has an optical sensor or to which an optical sensor is attached. The coordinate measuring machine can also have a carrier system that carries the measuring head. In particular, the measuring head can be moved by means of the carrier system. Various carrier systems are known in the prior art, for example gantry systems, stand, horizontal arm and arm systems, and all types of robot systems. The carrier systems can also have system components that enable the measuring head to be positioned as flexibly as possible. In addition, various adapters can be provided in order to connect the different system components of the carrier system to one another and to the sensor system.

Optical sensors can, for example, have a light-sensitive detector (such as a camera) for measuring a measurement object. Furthermore, it is common practice to provide lighting for the measurement object in order to illuminate the measurement object, preferably evenly, during the optical measurement. Furthermore, fixed imaging optics (for example a lens) can be provided, which images the measurement object to be measured onto the light-sensitive detector.

The lighting can, for example, be permanently installed on the coordinate measuring machine. Such coordinate measuring machines with fixed lighting are, for example, from the publications DE 10 2006 035 179 B4 , US 10 337 991 B2 and DE 10 2007 025 306 A1 known.

Furthermore, it is known in coordinate measuring technology that different types of lighting can be used when measuring objects. For example, the different lighting for a coordinate measuring machine can be provided using different lighting modules. For this purpose, for example, the measuring head of a coordinate measuring machine can have an interchangeable interface to which a lighting module can optionally be attached. Such lighting modules are, for example, from the publications DE 10 2014 215 952 A1 and EP 2 847 539 B1 known.

In optical measurement technology it is also known to use polarized light to illuminate measurement objects to be measured. In the field of dimensional optical measurement technology, the use of polarized light to illuminate a measurement object is known, for example, from the publications US 10 337 991 B2 , DE 10 2007 025 306 A1 , DE 10 2014 215 952 A1 , DE 2112229 A , WO 2011/099404 A1 and EP 2 847 539 B1 known. Furthermore, it is also known to use polarization components to couple in a coaxial reflected light in order to suppress unwanted reflections from the interior of the optical beam path.

So-called polarization microscopes are also known, particularly in the field of microscopy. These have a polarization filter in the condenser optics or illumination and an additional polarization filter (also called an analyzer) in the imaging optics. In this way, a measurement object can be examined with a specific polarization contrast. Classically or historically, polarization contrast is used in microscopy, particularly with transmitted light illumination, but can also be used with reflected light illumination. The adjustment of the polarization contrast in microscopes is usually done manually or partially automatically Introducing appropriate filters or polarization-optical components.

In the field of dimensional optical measurement technology - an area in which full automation plays a much larger role - the use of polarization contrast is largely unknown.

The known lighting for coordinate measuring machines still leaves room for improvements, particularly with regard to the use of polarized light for measuring a measurement object using an optical sensor.

Against this background, it is an object of the present invention to provide an improved lighting module and an improved coordinate measuring machine. In particular, it is an object of the present invention to provide an improved illumination module and an improved coordinate measuring machine which enables a controlled provision of polarized illumination light.

• - ein Modulgehäuse mit einer modulseitigen Wechselschnittstelle, die dazu eingerichtet ist, das Modulgehäuse betriebsmäßig lösbar in einer definierten Position an dem Messkopf zu befestigen;
• - zumindest eine Lichtquelle, die dazu eingerichtet ist, Licht zu erzeugen;
• - ein optisches Element, das dazu eingerichtet ist, das Licht auf das Messobjekt zu richten, wenn das Modulgehäuse in der definierten Position an dem Messkopf befestigt ist, wobei das optische Element einen Beleuchtungsstrahlengang von der Lichtquelle zu dem Messobjekt definiert; und
• - eine erste Polarisationseinrichtung, die in dem Beleuchtungsstrahlengang zwischen der Lichtquelle und dem Messobjekt angeordnet ist und die dazu eingerichtet ist, das Licht in zumindest einer definierten, ersten Polarisationsrichtung zu polarisieren, wobei die erste Polarisationseinrichtung zumindest einen ersten Polarisator zum Polarisieren des Lichts aufweist.

According to a first, second and third aspect of the invention, an illumination module for a coordinate measuring machine for measuring a measurement object is provided, wherein the coordinate measuring machine carries a measuring head with an optical sensor which includes a lens and a light-sensitive detector, the lens having a detection beam path from the measurement object to the light-sensitive detector, and wherein the lighting module comprises:

• - a module housing with a module-side interchangeable interface, which is designed to attach the module housing to the measuring head in a defined position in an operationally releasable manner;
• - at least one light source that is designed to generate light;
• - an optical element that is designed to direct the light onto the measurement object when the module housing is attached to the measurement head in the defined position, the optical element defining an illumination beam path from the light source to the measurement object; and
• - a first polarization device, which is arranged in the illumination beam path between the light source and the measurement object and which is set up to polarize the light in at least one defined, first polarization direction, the first polarization device having at least one first polarizer for polarizing the light.

The lighting module is used to illuminate the measurement object that is measured using the coordinate measuring machine. To measure the measurement object, the coordinate measuring machine has the measuring head, which carries the optical sensor. For example, a two-dimensional image of the measurement object can be recorded using the optical sensor. For this purpose, the optical sensor has the lens and the light-sensitive detector. The lens images the measurement object or at least part of the surface of the measurement object onto the light-sensitive detector. The objective thus defines a detection beam path from the measurement object to the light-sensitive detector. The light-sensitive detector can be, for example, an image sensor, in particular a CCD sensor or CMOS sensor.

The coordinate measuring machine can also have a carrier system that carries the measuring head and by means of which the measuring head can be moved, i.e. moved. In this way, images can be recorded from different positions during a measurement process using the optical sensor.

The module housing of the lighting module defines an interior and has an exterior. The components (such as the light source, the optical element, the first and the second polarization device) of the lighting module are arranged in and/or on the module housing (i.e. in the interior and/or on the outside). The module housing has an interchangeable interface on the module side. The module-side interchangeable interface is arranged on the outside. The module-side interchangeable interface is used to attach the module housing, i.e. the lighting module, to the measuring head of the coordinate measuring machine. In particular, the module housing can be operationally detachably (optionally) attached to the measuring head in a defined position via the module-side interchangeable interface.

The lighting module has at least one light source. A light source can be a device or a body that generates or emits light. A light source can in particular comprise a plurality of thermal or non-thermal emitters, such as a lamp, a laser or a light-emitting diode. The light source can be arranged in or on the module housing. Preferably, the light source is an unpolarized light source that is designed to generate unpolarized light.

By means of the optical element, the light generated by the light source is directed onto the measurement object when the module housing is attached to the measuring head in the defined position. The optical element thus defines an illumination beam path from the light source to the measurement object. The optical element can in particular be a lens (for example a Fresnel lens) or a neutral conductor (for example a beam splitter). A Fresnel lens can be used, for example, in a ring light illumination. A beam splitter can be used, for example, in coaxial lighting.

The lighting module can also have multiple light sources. The light from several light sources can be combined to illuminate the measurement object, for example via lighting optics. Alternatively, each light source can also be directed at the measurement object using a corresponding optical element.

The first polarization device is arranged in the illumination beam path between the light source and the measurement object. The first polarization device can in particular be arranged in the illumination beam path between the light source and the optical element. Alternatively, the first polarization device can also be arranged in the illumination beam path between the optical element and the measurement object. The first polarization device serves to polarize the light in at least one defined, first polarization direction. In other words, the first polarization device is used for polarization filtering of the light in the illumination beam path in order to illuminate the measurement object only with light of a specific polarization (corresponding to the first polarization direction). For this purpose, the first polarization device has at least one first polarizer. The first polarizer can be a linear polarizer. The first polarization device can also be set up to polarize the light from the light source in several polarization directions.

According to the first aspect of the invention, a second polarization device is arranged in the detection beam path between the measurement object and the objective when the module housing is attached to the measuring head in the defined position, the second polarization device being designed to direct the light in a defined, second polarization direction to analyze, wherein the second polarization device has a second polarizer for polarizing the light, and wherein the second polarization device is controllable to adjust the second polarization direction.

The second polarization device is arranged in the detection beam path between the measurement object and the objective. The second polarization device is used to analyze the light in a defined, second polarization direction. In other words, the second polarization device is used for polarization filtering of the light in the detection beam path in order to detect only with light of a specific polarization (corresponding to the second polarization direction) with the light-sensitive sensor or to analyze light for the proportion of a specific polarization. The second polarization device can also be called an analyzer device. To polarize or filter the light, the second polarization device has a second polarizer. The second polarizer can be a linear polarizer. The second polarizer can also be called an analyzer. The lighting module preferably has the second polarization device. In other words, the second polarization device is preferably arranged on the module side. Alternatively, the optical sensor or the measuring head can also have the second polarization device. In other words, the second polarization device is arranged on the sensor side. As a further alternative, the second polarization device can be arranged partly on the module side and partly on the sensor side. For example, the lighting module and the optical sensor can have different components of the second polarization device. For example, the second polarizer can be arranged on the sensor side. In particular, the second polarizer can be permanently installed in the lens.

The second polarization device can be controlled, preferably electronically, in order to set the second polarization direction. The second polarization direction can thus be flexibly adjusted using the second polarization device. In particular, the second polarization device can be controlled in order to change the second polarization direction. In other words, the second polarization device can be controlled in order to set a desired second polarization direction. In particular, the lighting module has at least the components of the second polarization device, which serve to control and adjust the second polarization direction. The second polarization device is preferably controlled by the coordinate measuring machine. In particular, the second polarization device can be controlled by means of a control device of the coordinate measuring machine.

In this way, the polarization or filtering of the light in the detection beam path can be regulated or controlled, in particular by the coordinate measuring machine. In particular, the lighting module according to the first aspect enables the setting of polarization-optical configurations (polarizer-analyzer states) in combination with imaging systems, whereby the adjustment can be carried out without manual intervention and, in particular, completely electronically, controlled.

According to the second aspect of the invention, the first polarization device is controllable to adjust the first polarization direction.

The first polarization device can be controlled, preferably electronically, in order to set the first polarization direction. In particular, the first polarization device can be controlled in order to change the first polarization direction. In other words, the first polarization device can be controlled in order to set a desired first polarization direction. The first polarization device is preferably controlled by the coordinate measuring machine. In particular, the first polarization device can be controlled by means of a control device of the coordinate measuring machine. In this way, the polarization of the light in the illumination beam path can be regulated or controlled, in particular by the coordinate measuring machine. In particular, this structure allows the polarization direction of the lighting to be rotated as desired. This allows the polarization of the lighting to be adapted to the geometry and orientation of the measurement object.

According to the third aspect of the invention, the light source has a plurality of lighting elements for generating the light, the first polarization device having a plurality of first polarizers, the plurality of first polarizers having a first group of polarizers and a second group of polarizers, wherein the polarizers of the first group are assigned to first lighting elements of the plurality of lighting elements, wherein the polarizers of the second group are assigned to second lighting elements of the plurality of lighting elements, wherein the polarizers of the first group are designed to reflect the light of the first lighting elements with a first defined polarization direction to polarize, and wherein the polarizers of the second group are set up to polarize the light of the second lighting elements with a second, first defined polarization direction, the light source being controllable in order to supply the light either by means of the first lighting elements and/or by means of the second lighting elements generate.

The lighting elements generate the light from the light source. The lighting elements are preferably light-emitting diodes (LEDs). The lighting elements are preferably all identical in construction. The light source can in particular be a ring light source. The lighting elements are preferably evenly distributed along the circumferential direction of the ring light source. The plurality of lighting elements has at least first and second lighting elements. The number of first lighting elements preferably corresponds to the number of second lighting elements.

The first polarization device has the plurality of first polarizers. The first polarizers are preferably linear polarizers. Each lighting element is assigned a corresponding polarizer of the plurality of first polarizers. Each first polarizer is designed to polarize the light that is generated with the corresponding associated lighting element. The first polarization device is designed such that the light generated by the light source can be polarized in a plurality of first polarization directions. In other words, the first polarization device can polarize the light that is generated by the luminous elements of the light source in at least two different first polarization directions, i.e. in at least a first first polarization direction and a second first polarization direction. In the case of two first polarization directions, these are preferably orthogonal to one another.

The majority of first polarizers have at least two groups, i.e. at least a first and a second group. The first group of the first polarizers is assigned to the first lighting elements. The second group of first polarizers is assigned to the second lighting elements. Each group polarizes the light from the lighting elements assigned to it in a different first polarization direction. The number of groups corresponds to the number of intended first polarization directions. The first group polarizes the light generated by the first lighting elements in the first polarization direction. The second group polarizes the light generated by the second lighting elements in the second first polarization direction.

The light source can be controlled, preferably electronically, in order to generate the light at least selectively by means of the first lighting elements and/or by means of the second lighting elements. The first lighting elements and the second lighting elements can preferably be controlled separately or independently of one another. In particular, the light source can be controllable in such a way that light is selectively generated by means of lighting elements that are assigned to a specific group of the first polarizers. This allows the light of a specific polarization direction of the first polarization directions to be generated.

When the light from the light source is generated with the first lighting elements, the light from the light source is polarized in the first first polarization direction. When the light from the light source is generated with the second lighting elements, the light from the light source is polarized in the second first polarization direction. When the light from the light source is generated with the first and second lighting elements, the light of both polarizations is mixed. If the first two polarization directions are orthogonal to one another and the lighting elements are operated at the same intensity, the mixing produces unpolarized lighting.

The light source is preferably controlled by the coordinate measuring machine. In particular, the light source can be controlled by means of a control device of the coordinate measuring machine.

In this way, the polarization of the light in the illumination beam path can be regulated or controlled, in particular by the coordinate measuring machine.

• - einer Werkstückaufnahme zur Aufnahme des Messobjekts;
• - einem Messkopf, der relativ zu der Werkstückaufnahme verfahrbar ist und einen optischen Sensor trägt;
• - einer Steuereinrichtung, die dazu ausgebildet ist, dimensionelle und/oder geometrische Eigenschaften an dem Messobjekt in Abhängigkeit von einer Position des Messkopfes relativ zu der Werkstückaufnahme und in Abhängigkeit von Sensordaten des optischen Sensors zu bestimmen; und
• - einem Beleuchtungsmodul nach dem ersten, zweiten oder dritten Aspekt zum selektiven Beleuchten des Messobjekts,

wobei der Messkopf eine sensorseitige Wechselschnittstelle aufweist, die dazu eingerichtet ist, das Beleuchtungsmodul betriebsmäßig lösbar an dem Messkopf zu befestigen, wobei der optische Sensor ein Objektiv und einen lichtempfindlichen Detektor beinhaltet, der dazu ausgebildet ist, ein Bild des Messobjekts durch das Objektiv aufzunehmen, und wobei das Objektiv einen Strahlengang von dem Messobjekt zu dem lichtempfindlichen Detektor definiert.According to a fourth aspect of the invention, a coordinate measuring machine for measuring a measurement object is provided, with:

• - a workpiece holder for holding the measurement object;
• - a measuring head which can be moved relative to the workpiece holder and carries an optical sensor;
• - a control device which is designed to determine dimensional and/or geometric properties on the measurement object as a function of a position of the measuring head relative to the workpiece holder and as a function of sensor data from the optical sensor; and
• - a lighting module according to the first, second or third aspect for selectively illuminating the measurement object,

wherein the measuring head has a sensor-side interchangeable interface which is designed to operationally releasably attach the lighting module to the measuring head, the optical sensor including a lens and a light-sensitive detector which is designed to record an image of the measurement object through the lens, and wherein the lens defines a beam path from the measurement object to the light-sensitive detector.

The workpiece holder is used to hold the measurement object in order to provide the measurement object in a defined position during measurement, i.e. during a measurement process. The workpiece holder can, for example, comprise a work table on which the measurement object can be arranged. The workpiece holder can also include a holder by means of which the measurement object can be held in the defined position.

The measuring head has at least one sensor-side interchangeable interface. The sensor-side interchangeable interface is used to attach the lighting module to the measuring head of the coordinate measuring machine. In particular, the lighting module can be operationally detachably (optionally) attached to the measuring head in a defined position via the sensor-side interchangeable interface. For this purpose, the module-side change interface can be coupled to the sensor-side change interface, preferably mechanically.

The control device of the coordinate measuring machine is designed to determine dimensional and/or geometric properties on the measurement object as a function of a position of the measuring head relative to the workpiece holder and as a function of sensor data from the optical sensor.

The control device of the coordinate measuring machine can also be referred to as an evaluation and control unit. The control device can have an evaluation unit (also called a data processing unit) and a control unit (also called a control unit). The evaluation unit can, for example, carry out calculation steps to determine the dimensional and/or geometric properties on the measurement object. The control unit can, for example, generate control commands or control signals by means of which the measurement of the measurement object is controlled. In particular, the movement of the measuring head and/or the illumination of the measurement object by means of the lighting module and/or the detection by means of the light-sensitive sensor can be controlled by means of the control signals or control commands.

The first polarization device and/or the second polarization device and/or the light source are preferably controlled by the coordinate measuring machine. In particular, the first polarization device can be controlled by means of the control device of the coordinate measuring machine. In this way, the polarization of the light in the illumination beam path and/or in the detection beam path can be regulated or controlled, in particular by the coordinate measuring machine.

The new lighting modules and the new coordinate measuring machine according to the described aspects of the invention thus enable the controlled provision of polarized illumination light for a coordinate measuring machine. In particular, the polarization of the light, in particular the polarization contrast, can be better controlled and adjusted using the new lighting modules and the new coordinate measuring machine. In particular, the polarization can be controlled or regulated via the coordinate measuring machine.

Furthermore, by means of the new lighting modules and the new coordinate measuring machine, the setting or regulation of the polarization can also take place during operation of the coordinate measuring machine, in particular in a fully automated manner, which is not possible, for example, with manual or partially automated control. The polarization, in particular the polarization contrast, can be set, for example, as a control variable in a measuring process (CNC sequence) for measuring the measurement object and can also be regulated or changed over time. In this way, in particular, the measuring process for measuring the measurement object can be improved, in particular made more flexible.

Using the new lighting modules and the new coordinate measuring machine, the possibility of polarization contrast is made available during imaging (particularly in incident light situations). In particular, the new lighting modules can be adapted or retrofitted by the operator in order to be able to flexibly adapt a standard coordinate measuring machine to corresponding applications.

Polarization contrast is particularly suitable for incident light illumination in order to highlight fine edges on very shiny or reflective surfaces, without having to compromise on the working distance restrictions that are associated with the typically used dark field illumination.

Polarization contrast is also suitable for visualizing polarizing components or features such as liquid crystals or crystal grain boundaries. This also makes it possible to inspect stresses in, for example, transparent plastics due to stress birefringence.

The new lighting modules and the new coordinate measuring machine thus create new contrast possibilities in the imaging of optical measurement technology. In this way, new measurement options can be implemented or improved compared to existing imaging methods in terms of the stability of the measurement results.

The task set at the beginning is thus completely solved.

In a first embodiment according to the second, third or fourth aspect, the illumination module further has a second polarization device, which is arranged in the detection beam path between the measurement object and the objective when the module housing is attached to the measuring head in the defined position, and the is set up to analyze the light in a defined, second polarization direction, the second polarization device having a second polarizer for polarizing the light.

The second polarization device is arranged in the detection beam path between the measurement object and the objective. The second polarization device is used to analyze the light in a defined, second polarization direction. In other words, the second polarization device is used for polarization filtering of the light in the detection beam path in order to only detect light of a specific polarization (corresponding to the second polarization direction) with the light-sensitive sensor or to analyze light for the proportion of a specific polarization. The second polarization device can also be called an analyzer device. To polarize or filter the light, the second polarization device has a second polarizer. The second polarizer can be a linear polarizer. The lighting module preferably has the second polarization device. In other words, the second polarization device is preferably arranged on the module side. Alternatively, the optical sensor or the measuring head can also have the second polarization device. In other words, the second polarization device is arranged on the sensor side. As a further alternative, the second polarization device can be arranged partly on the module side and partly on the sensor side. For example, the lighting module and the optical sensor can have different components of the second polarization device. For example, the second polarizer can be arranged on the module side or on the sensor side.

In a further embodiment according to the second, third or fourth aspect, the second polarization device can be controlled in order to set the second polarization direction.

The second polarization device can be controlled, preferably electronically, in order to set the second polarization direction. In particular the second polarization device can be controlled to change the second polarization direction. In other words, the second polarization device can be controlled in order to set a desired second polarization direction. In particular, the lighting module has at least the components of the second polarization device, which serve to control and adjust the second polarization direction. The second polarization device is preferably controlled by the coordinate measuring machine. In particular, the second polarization device can be controlled by means of a control device of the coordinate measuring machine. In this way, the polarization or filtering of the light in the detection beam path can be regulated or controlled, in particular by the coordinate measuring machine.

In a further embodiment according to one of the aspects, the second polarization device has a second polarization rotator, wherein the second polarizer is arranged in the detection beam path beam downstream of the second polarization rotator.

A polarization rotator is an optical device that is designed to rotate the polarization axis, i.e. the polarization direction, of a linearly polarized light beam by a certain angle. Such optical devices are based on the Faraday effect, birefringence or total reflection. For example, Faraday rotators, birefringence rotators (for example wave plates, in particular A/2 plates) or prismatic rotators can be used as polarization rotators. By means of the second polarization rotator, the polarization direction of the light in the detection beam path can be rotated before the light is polarized, i.e. filtered, in the second polarizer. The second polarization rotator is arranged in particular on the module side. The second polarizer can be arranged on the sensor side or on the module side.

In a further embodiment according to one of the aspects, the second polarization rotator is controllable in order to adjust the second polarization direction, in particular wherein the second polarization rotator is a liquid crystal polarization rotator.

In this way, the second polarization direction can be set in conjunction with a fixed, downstream polarizer (i.e. the second polarizer). This allows the light to be detected to be analyzed for the desired, second polarization direction. The second polarization rotator is preferably electronically controllable in order to adjust the second polarization direction. For example, the second polarization rotator can be voltage controlled. The second polarization rotator can be designed in such a way that it rotates the polarization direction of the light that passes through the second polarization rotator depending on an applied electric field, i.e. depending on an external applied voltage. The applied voltage can also be referred to as the control voltage. The rotation depends on the applied voltage. A liquid crystal polarization rotator, for example, can be used as the voltage-controlled polarization rotator.

In a further embodiment according to one of the aspects, the second polarizer is mounted rotatably about a second axis of rotation, wherein the second polarization device has a second drive device which is set up to rotate the second polarizer about the second axis of rotation in order to adjust the second polarization direction.

In this way, the second polarizer can be rotated, in particular micromechanically. The second axis of rotation is preferably parallel or coaxial to the detection beam path. The second drive device can have an electric motor by means of which the second polarizer can be rotated about the second axis of rotation. The second drive device is preferably voltage-uncontrolled. The second polarizer is arranged in particular on the module side.

In a further embodiment according to one of the aspects, the second polarization device is set up to set the second polarization direction based on a second control signal, in particular wherein the second control signal is a control signal of a control device of the coordinate measuring machine.

In particular, the second drive device can be set up to rotate the second polarizer based on the second control signal. Alternatively, the second polarization rotator can be set up to rotate the polarization of the light in the detection beam path based on the second control signal. The second control signal can be, for example, an analog or a digital signal. Alternatively, the second control signal can also be a control voltage. The second polarization device can have a voltage control unit that is set up to generate or provide a control voltage for the second polarization rotator or the drive device based on the second (analog or digital) control signal. The second control signal can in particular be provided by a control device of the coordinate measuring machine become. In this way, the control device of the coordinate measuring machine can control or regulate the second polarization direction.

In a further embodiment according to the first, third or fourth aspect, the first polarization device can be controlled in order to set the first polarization direction.

The first polarization device can be controlled, preferably electronically, in order to set the first polarization direction. In particular, the first polarization device can be controlled in order to change the first polarization direction. In other words, the first polarization device can be controlled in order to set a desired first polarization direction. The first polarization device is preferably controlled by the coordinate measuring machine. In particular, the first polarization device can be controlled by means of a control device of the coordinate measuring machine. In this way, the polarization of the light in the illumination beam path can be regulated or controlled, in particular by the coordinate measuring machine. In particular, this structure allows the polarization direction of the lighting to be rotated as desired. This allows the polarization of the lighting to be adapted to the geometry and orientation of the measurement object.

In a further embodiment according to one of the aspects, the first polarization device has a first polarization rotator, wherein the first polarizer is arranged in the illumination beam path beam upstream of the first polarization rotator.

By means of the first polarization rotator, the polarization direction of the light in the illumination beam path can be rotated after the light has been polarized, i.e. filtered, in the first polarizer.

In a further embodiment according to one of the aspects, the polarization rotator is controllable in order to adjust the first polarization direction, in particular wherein the first polarization rotator is a liquid crystal polarization rotator.

In this way, the first polarization direction can be set. The first polarization rotator is preferably electronically controllable in order to set the first polarization direction. For example, the first polarization rotator can be voltage controlled. The first polarization rotator can be designed in such a way that it rotates the polarization direction of the light that passes through the first polarization rotator depending on an applied electric field, i.e. depending on an external applied voltage. The applied voltage can also be referred to as the control voltage. The rotation depends on the applied voltage. A liquid crystal polarization rotator, for example, can be used as the voltage-controlled polarization rotator.

In a further embodiment according to one of the aspects, the first polarizer is rotatably mounted about a first axis of rotation, wherein the first polarization device has a first drive device which is set up to rotate the first polarizer about the first axis of rotation in order to adjust the first polarization direction.

In this way, the first polarizer can be rotated, in particular micromechanically. The first axis of rotation is preferably parallel or coaxial to the illumination beam path. The first drive device can have an electric motor by means of which the first polarizer can be rotated about the first axis of rotation. The first drive device is preferably voltage-uncontrolled.

In a further embodiment according to one of the aspects, the first polarization device is set up to set the first polarization direction based on a first control signal, in particular wherein the first control signal is a control signal of a control device of the coordinate measuring machine.

In particular, the first drive device can be set up to rotate the first polarizer based on the first control signal. Alternatively, the first polarization rotator can be set up to rotate the polarization of the light in the illumination beam path based on the first control signal. The first control signal can be, for example, an analog or a digital signal. Alternatively, the first control signal can also be a control voltage. The first polarization device can have a voltage control unit that is set up to generate or provide a control voltage for the first polarization rotator or for the drive device based on the first (analog or digital) control signal. The first control signal can in particular be provided by a control device of the coordinate measuring machine. In this way, the control device of the coordinate measuring machine can control or regulate the first polarization direction.

In a further embodiment according to one of the aspects according to the first, second or fourth aspect, the light source has a plurality of lighting elements for generating the light, wherein the first polarization device has a plurality of has first polarizers, each first polarizer being assigned to a corresponding lighting element of the plurality of lighting elements and polarizing the light of the respective lighting element.

The lighting elements generate the light from the light source. The lighting elements are preferably light-emitting diodes (LEDs). The lighting elements are preferably all identical in construction. The light source can in particular be a ring light source. The lighting elements are preferably evenly distributed along the circumferential direction of the ring light source. The plurality of lighting elements has at least first and second lighting elements. The number of first lighting elements preferably corresponds to the number of second lighting elements. The first polarization device has the plurality of first polarizers. The first polarizers are preferably linear polarizers. Each lighting element is assigned a corresponding polarizer of the plurality of first polarizers. Each first polarizer is designed to polarize the light that is generated with the corresponding associated lighting element. The first polarization device is designed such that the light generated by the light source can be polarized in a plurality of first polarization directions. In other words, the first polarization device can polarize the light that is generated by the luminous elements of the light source in at least two different first polarization directions, i.e. in at least a first first polarization direction and a second first polarization direction. In the case of two first polarization directions, these are preferably orthogonal to one another.

In a further embodiment according to the first, second or fourth aspect, the plurality of first polarizers has a first group of polarizers and a second group of polarizers, wherein the polarizers of the first group are assigned to first luminous elements of the plurality of luminous elements, wherein the polarizers of second group are assigned to second lighting elements of the plurality of lighting elements, wherein the polarizers of the first group are designed to polarize the light of the first lighting elements with a first defined polarization direction, and wherein the polarizers of the second group are designed to polarize the light of the second To polarize lighting elements with a second, first defined polarization direction.

The majority of first polarizers have at least two groups, i.e. at least a first and a second group. The first group of the first polarizers is assigned to the first lighting elements. The second group of first polarizers is assigned to the second lighting elements. Each group polarizes the light from the lighting elements assigned to it in a different first polarization direction. The number of groups corresponds to the number of intended first polarization directions. The first group polarizes the light generated by the first lighting elements in the first polarization direction. The second group polarizes the light generated by the second lighting elements in the second first polarization direction.

In a further embodiment according to the first, second or fourth aspect, the light source can be controlled in order to generate the light either by means of the first lighting elements and/or by means of the second lighting elements.

In this way, the polarization of the light in the illumination beam path can be regulated or controlled, in particular by the coordinate measuring machine. The light source can be controlled, preferably electronically, in order to generate the light at least selectively by means of the first lighting elements and/or by means of the second lighting elements. The first lighting elements and the second lighting elements can preferably be controlled separately or independently of one another. In particular, the light source can be controllable in such a way that light is selectively generated by means of lighting elements that are assigned to a specific group of the first polarizers. This allows the light of a specific polarization direction of the first polarization directions to be generated. When the light from the light source is generated with the first lighting elements, the light from the light source is polarized in the first first polarization direction. When the light from the light source is generated with the second lighting elements, the light from the light source is polarized in the second first polarization direction. When the light from the light source is generated with the first and second lighting elements, the light of both polarizations is mixed. If the first two polarization directions are orthogonal to one another and the lighting elements are operated at the same intensity, the mixing produces unpolarized lighting. The light source is preferably controlled by the coordinate measuring machine. In particular, the light source can be controlled by means of a control device of the coordinate measuring machine.

In a further embodiment according to one of the aspects, the light source is set up to generate the light based on at least a third control signal either by means of the first lighting elements and/or by means of the second lighting elements, in particular wherein the third control signal is a control signal from a control device of the coordinate measuring machine.

One or more third control signals can be provided to control the light source. The third control signal can be, for example, an analog or a digital signal. Alternatively, the third control signal can also be a control voltage. Using the one or more third control signals, the first and second lighting elements can be selectively switched on and off. In particular, several third control signals can be provided for controlling the light source. For example, one for controlling the first lighting elements and another for controlling the second lighting elements can be provided. Alternatively, a third control signal can also be provided for each lighting element of the light source for individual control of each lighting element. The light source can further have switching elements for switching the lighting elements, the switching elements being controlled by means of the third control signals. For example, the light source can have a first switching element for switching the first lighting elements and a second switching element for switching the second lighting elements.

In a further embodiment according to one of the aspects, the module housing has a passage for the detection beam path, with the plurality of lighting elements being arranged around the passage.

The passage extends through the module housing. The detection beam path therefore runs through the module housing. The second polarization device can be arranged in the passage. In particular, the lighting module can be designed as a ring lighting. The module housing then has an annular body with a recess in the middle, which serves as a passage for the detection beam path. The light source is then designed as a ring light source. The ring light source preferably has light-emitting diodes (LEDs) as lighting elements. The optical element is preferably a Fresnel lens.

In a further embodiment according to one of the aspects, the first lighting elements and the second lighting elements are arranged alternately along a circumferential direction around the passage.

In other words, the lighting elements are arranged alternately around the detection beam path. In this way, the most uniform possible illumination of the measurement object is achieved, regardless of the selected polarization of the light. The first and second lighting elements are preferably evenly distributed, in particular arranged at regular intervals around the detection beam path.

In a further embodiment according to one of the aspects, the module-side interchangeable interface has at least one mechanical contact element which is designed to fasten the module housing to the measuring head in a defined position.

The lighting module can be attached to the measuring head by means of the at least one mechanical contact element. The mechanical contact element can be arranged on the outside of the module housing. For this purpose, the mechanical contact element of the module-side interchangeable interface can, for example, mechanically couple with a corresponding mechanical contact element of the coordinate measuring machine.

In a further embodiment according to one of the aspects, the module-side changeover interface has at least one first electrical contact element, which is set up to electrically connect the first polarization device to the measuring head, in particular wherein the first polarization device is set up to transmit the first control signal via the first electrical Receive contact element.

In this way, the first polarization device can be electrically controlled via the coordinate measuring machine. The electrical connection between the first polarization device and the coordinate measuring machine is established when the module housing is attached to the measuring head in the defined position. The first polarization device can receive the first control signal via this electrical connection. The first control signal can in particular be sent by the control device of the coordinate measuring machine. In this way, the first polarization device can be electrically controlled by means of the control device of the coordinate measuring machine.

In a further embodiment according to one of the aspects, the module-side changeover interface has at least one second electrical contact element, which is set up to electrically connect the second polarization device to the measuring head, in particular wherein the second polarization device is set up to transmit the second control signal via the second electrical Receive contact element.

In this way, the second polarization device can be electrically controlled via the coordinate measuring machine. The electrical connection Connection between the second polarization device and the coordinate measuring machine is established when the module housing is attached to the measuring head in the defined position. The second polarization device can receive the second control signal via this electrical connection. The second control signal can in particular be sent by the control device of the coordinate measuring machine. In this way, the second polarization device can be electrically controlled by means of the control device of the coordinate measuring machine.

In a further embodiment according to one of the aspects, the module-side interchangeable interface has at least one third electrical contact element, which is set up to electrically connect the at least one light source to the measuring head, in particular wherein the light source is set up to transmit the at least one third control signal via the to receive third electrical contact element.

In this way, the light source can be operated electrically and in particular controlled via the coordinate measuring machine. The electrical connection between the light source and the coordinate measuring machine is established when the module housing is attached to the measuring head in the defined position. The light source can receive the at least one third control signal via this electrical connection. In particular, the module-side interchangeable interface can have a plurality of third electrical contact elements, with a first number of the third electrical contact elements serving to supply voltage to the light source and a second number of the third electrical contact elements serving to provide the at least one third control signal. The at least one third control signal can in particular be sent by the control device of the coordinate measuring machine. In this way, the light source can be electrically controlled using the control device of the coordinate measuring machine.

In a further embodiment according to the fourth aspect, the control device is set up to control the light source and/or the first polarization device and/or the second polarization device.

This allows the coordinate measuring machine to adjust the polarization of the light in the illumination beam path and/or in the detection beam path. In particular, the control device can be set up to send the first control signal to the first polarization device in order to regulate or set the first polarization direction. The control device can also be set up to send the second control signal to the second polarization device in order to regulate or set the second polarization direction. The control device can also be set up to send the at least a third control signal to the light source in order to control the first and second lighting elements.

In a further embodiment according to the fourth aspect, the sensor-side interchangeable interface has at least one mechanical contact element, wherein the mechanical contact element of the module-side interchangeable interface can be coupled to the mechanical contact element of the sensor-side interchangeable interface in order to fasten the module housing in the defined position on the measuring head.

In this way, the lighting module can be attached to the measuring head.

In a further embodiment according to the fourth aspect, the sensor-side interchangeable interface has at least one first electrical contact element, which can be connected to the first electrical contact element of the module-side interchangeable interface in order to electrically connect the first polarization device to the measuring head.

The at least one first electrical contact element of the sensor-side interchangeable interface can be connected to the first electrical contact element of the module-side interchangeable interface when the module housing is attached to the measuring head in the defined position. The first polarization device can then be electrically controlled by the coordinate measuring machine via this electrical connection. In particular, the control device can send the first control signal to the first polarization device via this electrical connection.

In a further embodiment according to the fourth aspect, the sensor-side interchangeable interface has at least one second electrical contact element, which can be connected to the second electrical contact element of the module-side interchangeable interface in order to electrically connect the second polarization device to the measuring head.

The at least one second electrical contact element of the sensor-side interchangeable interface can be connected to the second electrical contact element of the module-side interchangeable interface when the module housing is attached to the measuring head in the defined position. The second polarization device can then be electrically controlled by the coordinate measuring machine via this electrical connection. In particular, the control device can transmit the second control signal send this electrical connection to the second polarization device.

In a further embodiment according to the fourth aspect, the sensor-side interchangeable interface has at least one third electrical contact element, which can be connected to the third electrical contact element of the module-side interchangeable interface in order to electrically connect the light source to the measuring head.

The at least one third electrical contact element of the sensor-side interchangeable interface can be connected to the third electrical contact element of the module-side interchangeable interface when the module housing is attached to the measuring head in the defined position. The light source can then be electrically operated and controlled by the coordinate measuring machine via this electrical connection. In particular, the control device can send the at least one third control signal to the light source via this electrical connection.

It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or alone, without departing from the scope of the present invention.

• 1 eine isometrische Darstellung eines Ausführungsbeispiels des neuen Koordinatenmessgeräts;
• 2 eine schematische Darstellung eines ersten Ausführungsbeispiels eines Beleuchtungsmoduls;
• 3 zwei Darstellungen eines Beleuchtungsmoduls und eines Messkopfs in einem gekoppelten Zustand und in einem nicht gekoppelten Zustand;
• 4 eine schematische Darstellung eines zweiten Ausführungsbeispiels eines Beleuchtungsmoduls;
• 5 eine schematische Darstellung eines dritten Ausführungsbeispiels eines Beleuchtungsmoduls;
• 6 eine schematische Ansicht einer Ausführungsform einer Lichtquelle des Beleuchtungsmoduls aus 5; und
• 7 eine schematische Darstellung eines vierten Ausführungsbeispiels eines Beleuchtungsmoduls.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

• 1 an isometric representation of an exemplary embodiment of the new coordinate measuring machine;
• 2 a schematic representation of a first embodiment of a lighting module;
• 3 two representations of a lighting module and a measuring head in a coupled state and in a non-coupled state;
• 4 a schematic representation of a second embodiment of a lighting module;
• 5 a schematic representation of a third embodiment of a lighting module;
• 6 a schematic view of an embodiment of a light source of the lighting module 5 ; and
• 7 a schematic representation of a fourth embodiment of a lighting module.

1 shows an exemplary embodiment of the new coordinate measuring machine in its entirety with the reference number 10. In this exemplary embodiment, the coordinate measuring machine 10 has a workpiece holder 12, a carrier system 14, a measuring head 16, an optical sensor 18, a separate tactile sensor 20 and a control device 22. The coordinate measuring machine is used to measure a measurement object.

In this exemplary embodiment of the coordinate measuring machine 10, the workpiece holder 12 is designed in the form of a cross table. The workpiece holder 12 is used to hold the measurement object. The carrier system 14 is arranged above the workpiece holder 12. The carrier system 14 carries the measuring head 16. The carrier system 14 is set up to move the measuring head 16. The optical sensor 18 and the separate tactile sensor 20 are attached to the measuring head 16. In principle, the measuring head 16 can be purely a holding plate to which various sensors can be attached. With the optical sensor 18, the coordinate measuring machine 10 can optically measure a measurement object in a known manner. For this purpose, for example, measuring images can be taken from different positions relative to the measurement object using the optical sensor 18, with the optical sensor 18 being moved accordingly relative to the measurement object using the workpiece holder 12 and the carrier system 14. With the tactile sensor 20, the coordinate measuring machine 10 can touch a measuring point on a measurement object in a known manner, which is arranged on the workpiece holder 12 for this purpose. The tactile sensor 20 is moved relative to the measurement object with the help of the workpiece holder 12 and the carrier system 14 in order to touch the measurement point. Based on the respective positions of the workpiece holder and the carrier system, spatial coordinates of the measured measuring point can then be determined in a known manner.

The coordinate measuring machine 10 is a preferred example of a multi-sensor coordinate measuring machine in which, in addition to the optical sensor 18, a tactile sensor 20 can be used to measure a measurement object. Alternatively, in other exemplary embodiments, the new coordinate measuring machine can only have one or more optical sensors.

Furthermore, the present invention can be used not only with coordinate measuring machines that meet the requirements in 1 have the machine structure shown. In principle, the new coordinate measuring machine can be designed in a bridge design, portal design, horizontal arm design or any other mechanical design.

The coordinate measuring machine 10 also has a lighting module (in 1 not shown). In particular, the measuring head 16 of the coordinate measuring machine 10 is designed such that the lighting module can be attached to it. The lighting module serves to illuminate the measurement object, in particular while the measurement object is being measured with the optical sensor 18. Examples of embodiments of the new lighting module are described below in connection with 2 until 7 described.

The control device 22 of the coordinate measuring machine 10 is set up to control the components of the coordinate measuring machine 10 and to process data. The control device 22 can, for example, control the drives (for example of the carrier system or the workpiece holder) of the coordinate measuring machine 10 in order to move the measuring head 16 relative to a measurement object. Furthermore, the control device 22 can also control the lighting of the new lighting module, for example. Furthermore, the control device 22 can, for example, also read in sensor data from the optical and/or tactile sensor 18, 20 and, depending on this sensor data and depending on the respective position of the measuring head and the workpiece holder, determine spatial coordinates for one or more measuring points on the measurement object. The basic operation of such a coordinate measuring machine is known to the relevant experts and is therefore not explained in detail.

The control device 22 can preferably have various subunits, each of which controls a component and/or processes data. For example, the control device 22 can have a control unit that controls the movement of the measuring head 16 relative to the measurement object and/or the lighting of the lighting module. Furthermore, the control device 22 can have a data processing unit that is set up to evaluate the recorded sensor data of the sensors 18 and 20.

The control device 22 can be connected to or have a non-volatile data memory in which a computer program is stored. In some embodiments, the controller 22 is a general purpose computer, such as a commercially available personal computer running Windows 0, Linux, or MacOS, and the computer program in memory includes program code used to implement functions (particularly control and determination steps). of the new coordinate measuring machine is designed and trained. In an alternative embodiment, the controller 22 is a logic circuit, such as a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a microcontroller, or any other appropriate programmable electrical circuit. The functions of the new coordinate measuring machine can be implemented with the logic circuit. Any appropriate programming language or hardware description language may be used to implement the functions of the new coordinate measuring machine in the logic circuit, such as C, VHDL, and the like.

2 shows a first exemplary embodiment of the new lighting module with the reference number 24. The lighting module 24 can be operationally releasably attached to the measuring head 16 of the coordinate measuring machine 10 in a defined position. The lighting module 24 serves to illuminate a measurement object 60 while the measurement object 60 is measured using the optical sensor 18 of the coordinate measuring machine 10.

The optical sensor 18, which is attached to the measuring head 16, has a lens 56 and a light-sensitive detector 58. The light-sensitive detector 58 is designed to record an image or a measurement recording of the measurement object 80 through the lens 56. The objective 56 defines a detection beam path 64 from the measurement object 60 to the light-sensitive detector 58.

The lighting module 24 has at least one light source 40. The light source 40 is designed to generate light. The light source 40 can, for example, have one or more lighting elements to generate the light.

The lighting module 24 further has an optical element 48. The optical element 48 is set up to direct the light that is generated by the light source 40 onto the measurement object 60. The optical element 48 thus defines an illumination beam path 62 from the light source 40 to the measurement object 60.

The lighting module 24 further has a first polarization device 42. The first polarization device 42 is arranged in the illumination beam path between the light source 40 and the optical element 48. Alternatively, the first polarization device 42 can also be arranged after the optical element 48 (in particular if the light source 40 is a ring light source). The first polarization device 42 is set up to reflect the light in at least one to polarize in the defined, first polarization direction.

The first polarization device 42 has at least a first polarizer 44. The first polarizer 44 is set up to polarize the light in the illumination beam path. The first polarization device 42 can also have a plurality of first polarizers 44. The first polarization device 42 can further have a first polarization rotator 46. The first polarizer 44 is arranged in the detection beam path 62 in line with the first polarization rotator 46.

The first polarization device 42 can be controllable to adjust the first polarization direction. For example, the first polarization device 42 can be set up to set the first polarization direction based on a first control signal. The first control signal can in particular be a control signal from the control device 22 of the coordinate measuring machine 10.

In a preferred embodiment, the first polarization rotator 46 is controllable to adjust the first polarization direction. In particular, the first polarization rotator 46 can be designed as a liquid crystal polarization rotator.

In an alternative embodiment, the first polarizer 44 is rotatably mounted about a first axis of rotation (coaxial to the illumination beam path 62), the first polarization device 42 having a drive device (not shown) which is designed to rotate the first polarizer 44 about the first axis of rotation to set the first polarization direction.

The lighting module 24 can further have a second polarization device 50. The second polarization device 50 is arranged in the detection beam path between the measurement object 60 and the objective 56 when the illumination module 24 is attached to the measuring head 16 in the defined position. The second polarization device 50 is set up to analyze the light in the detection beam path with respect to a defined, second polarization direction.

The second polarization device 50 has a second polarizer 54. The second polarizer 54 is set up to polarize the light in the detection beam path 64. The second polarization device 50 may further have a second polarization rotator 52. The second polarizer 54 is arranged in the detection beam path 64 downstream of the second polarization rotator 52.

The second polarization device 50 can be controllable to adjust the second polarization direction. For example, the second polarization device 50 can be set up to set the second polarization direction based on a second control signal. The second control signal can in particular be a control signal from the control device 22 of the coordinate measuring machine 10.

In a preferred embodiment, the second polarization rotator 52 is controllable to adjust the second polarization direction. In particular, the second polarization rotator 52 can be designed as a liquid crystal polarization rotator.

In an alternative embodiment, the second polarizer 54 is mounted rotatably about a second axis of rotation (coaxial to the detection beam path 64), the second polarization device 50 having a drive device (not shown) which is designed to rotate the second polarizer 54 about the second axis of rotation to set the second polarization direction.

In a preferred embodiment, the light source 40 can have a plurality of lighting elements for generating the light, the first polarization device 42 having a plurality of first polarizers 44, each first polarizer 44 being assigned to a corresponding lighting element of the plurality of lighting elements and the light of the respective lighting element polarized.

In particular, the plurality of first polarizers 44 may have a first group of polarizers and a second group of polarizers, wherein the polarizers of the first group are assigned to first luminous elements of the plurality of luminous elements, wherein the polarizers of the second group are assigned to second luminous elements of the plurality of luminous elements , wherein the polarizers of the first group are designed to polarize the light of the first lighting elements with a first polarization direction, and wherein the polarizers of the second group are designed to polarize the light of the second lighting elements with a second first polarization direction.

The light source 40 can be controllable to generate the light either by means of the first lighting elements and/or by means of the second lighting elements. For example, the light source 40 can be set up to generate the light based on at least a third control signal either by means of the first lighting elements and/or by means of the second lighting elements. In particular can the third control signal can be a control signal from the control device 22 of the coordinate measuring machine 10.

In other words, the control device 22 of the coordinate measuring machine can be set up to control the light source 40 and/or the first polarization device 42 and/or the second polarization device 50. The control device 22 can in particular send the first control signal to the first polarization device 42 in order to set the first polarization direction. The control device 22 can in particular send the second control signal to the second polarization device 50 in order to set the second polarization direction. The control device 22 can in particular send the third control signal to the light source 40 in order to generate light selectively with the first and/or the second lighting elements.

In 3 is shown as an example of how the new lighting module 24 is on the measuring head 16 of the coordinate measuring machine 10 1 can be attached.

The lighting module 24 has a module housing 26. The components 40-54 of the lighting module 24 are preferably arranged in and/or on the module housing 26. The measuring head 16 has an interchangeable interface 28 on the sensor side. The module housing 26 has a module-side interchangeable interface 30. The two interchangeable interfaces 28, 30 can be coupled to one another in order to attach the lighting module 24 (in particular the module housing 26) to the measuring head 16 in a defined position in an operationally detachable manner.

In representation (A) the 3 the two interchangeable interfaces 28, 30 are not coupled to one another. In representation (B) the 3 the two interchangeable interfaces 28, 30 are coupled to one another.

The sensor-side interchangeable interface 28 can have at least one mechanical contact element 32 and a plurality of electrical contact elements 34. Accordingly, the module-side interchangeable interface 30 can also have a mechanical contact element 36 and a plurality of electrical contact elements 38. In 3 In particular, three electrical contact elements are shown per interchangeable interface. However, each interchangeable interface can also have only two or more than three electrical contact elements.

The mechanical contact element 32 of the sensor-side interchangeable interface 28 can be coupled to the mechanical contact element 36 of the module-side interchangeable interface 30 in order to fasten the module housing 26 in the defined position on the measuring head 16.

Each electrical contact element 34 of the sensor-side interchangeable interface 28 can be connected to a corresponding electrical contact element 38 of the module-side interchangeable interface 30 (in particular when the module housing 26 is attached to the measuring head 16 in the defined position) in order to establish an electrical connection between the measuring head 16 (in particular the control device 22) and the lighting module 24.

For example, at least a first electrical contact element 38 'of the module-side interchangeable interface 30 can be connected to a corresponding first electrical contact element 34' of the sensor-side interchangeable interface 28 in order to electrically connect the first polarization device 42 to the measuring head 16. The first polarization device can then be electrically controlled by the coordinate measuring machine via this electrical connection. In particular, the control device 22 can send the first control signal to the first polarization device 42 via this electrical connection.

Furthermore, for example, at least a second electrical contact element 38" of the module-side interchangeable interface 30 can be connectable to a corresponding second electrical contact element 34" of the sensor-side interchangeable interface 28 in order to electrically connect the second polarization device 50 to the measuring head 16. The second polarization device 50 can then be electrically controlled by the coordinate measuring machine 10 via this electrical connection. In particular, the control device 22 can send the second control signal to the second polarization device 50 via this electrical connection.

Furthermore, for example, at least a third electrical contact element 38''' of the module-side interchangeable interface 30 can be connectable to a corresponding third electrical contact element 34''' of the sensor-side interchangeable interface 28 in order to electrically connect the light source 40 to the measuring head 16. The light source 40 can then be electrically operated and controlled by the coordinate measuring machine 10 via this electrical connection. In particular, the control device 22 can send the at least a third control signal to the light source 40 via this electrical connection.

4 shows a second exemplary embodiment of the new lighting module 24. The lighting module 24 of the second exemplary embodiment essentially corresponds to the lighting module 24 of the first exemplary embodiment. The same elements are marked with the same reference numbers and are not explained in more detail. In the second exemplary embodiment of the lighting module 24, the lighting is designed as coaxial lighting.

In the second exemplary embodiment of the lighting module 24, the light source 40 is any light source 40′. For example, the light source 40' may have a lamp or a light-emitting diode (LED) to generate the light.

The first polarization device 42 is provided in the second exemplary embodiment of the lighting module 24 as a first polarization device 42', which has a first polarizer 44' and a first polarization rotator 46'. The first polarization device 42 'is, as already described in the first exemplary embodiment of the lighting module 24, controllable by the control device 22 in order to set the first polarization direction.

In the second exemplary embodiment of the lighting module 24, the optical element 48 is designed as a beam splitter 48 ', which directs the light from the light source 40' onto the measurement object 60. The detection beam path 64 also runs through the beam splitter 48', but without deflection. In other words, the beam splitter 48' redirects the light from the light source 40' onto the measurement object 60 coaxially with the detection beam path 64. In the section between the beam splitter 48 'and the measurement object 60, the illumination beam path 62 and the detection beam path 64 thus run coaxially to one another.

Further optical means (such as lenses, mirrors, etc.) can also be provided along the illumination beam path 62, which serve to shape the beam, focus the beam and/or redirect the light in the illumination beam path. In 4 Two lenses are shown in the illumination beam path 62 as an example.

The second polarization device 50 is arranged in the detection beam path 64 downstream of the beam splitter 48 '. As already described in the first exemplary embodiment of the lighting module 24, the second polarization device 50 can be controlled by the control device 22 in order to set the second polarization direction.

5 shows a third exemplary embodiment of the new lighting module 24. The lighting module 24 of the third exemplary embodiment essentially corresponds to the lighting module 24 of the first exemplary embodiment. The same elements are marked with the same reference numbers and are not explained in more detail. In the third exemplary embodiment of the lighting module 24, the lighting is designed as ring light lighting.

In the third exemplary embodiment of the lighting module 24, the light source 40 is designed as a ring light source 40". The light source 40" has a plurality of lighting elements 66 for generating the light.

The first polarization device 42 is provided in the third exemplary embodiment of the lighting module 24 as a first polarization device 42" which has a plurality of first polarizers 44". Each first polarizer 44" is assigned to a corresponding lighting element 66 and polarizes the light of the assigned lighting element 66. The lighting elements 66 are, preferably identical, light-emitting diodes (LEDs).

The lighting elements 66 and the first polarizers 44" are arranged next to the detection beam path 64, in particular around the detection beam path 64.

In the third exemplary embodiment of the lighting module 24, the optical element 48 is designed as a Fresnel lens 48", which directs or directs the light from the light source 40" onto the measurement object 60. The Fresnel lens 48" has a recess 68 or an optically neutral area through which the detection beam path 64 runs.

In the third exemplary embodiment of the illumination module 24, the second polarization device 50 is arranged in the detection beam path 64 downstream of the Fresnel lens 48" (in particular downstream of the recess 68). However, the second polarization device 50 can also be in the detection beam path 64 upstream of the Fresnel lens 48". (in particular upstream of the recess 68). As already described in the first exemplary embodiment of the lighting module 24, the second polarization device 50 can be controlled by the control device 22 in order to set the second polarization direction.

In 6 An embodiment of the light source 40" is shown in the third exemplary embodiment of the lighting module 24. The plurality of lighting elements 66 has first lighting elements 70 and second lighting elements 72. The plurality of first polarizers 44" has a first group of polarizers and a second group of polarizers on. The polarizers of the first group are assigned to the first lighting elements 70. The polarizers of the second group are assigned to second lighting elements 72. The polarizers of the first group are designed to reflect the light from the first lighting elements 70 with a first to polarize in the first polarization direction. The polarizers of the second group are designed to polarize the light from the second lighting elements with a second, first polarization direction. The first first polarization direction and the second first polarization direction are preferably orthogonal to one another. In other words, the light generated with the first lighting elements 70 is polarized in the first polarization direction and the light generated with the second lighting elements 72 is polarized in the second first polarization direction.

The light source 40" is, as already described in the first exemplary embodiment of the lighting module 24, controllable by the control device 22 in order to generate the light either by means of the first lighting elements 70 and/or by means of the second lighting elements 72.

The module housing 26 of the third exemplary embodiment of the lighting module 24 can have an annular body with a recess in the middle, which serves as a passage for the detection beam path 64. The first lighting elements 70 and the second lighting elements 72 are arranged alternately along a circumferential direction around the passage. The lighting elements 70, 72 are arranged evenly distributed around the passage, with adjacent lighting elements 70, 72 always being at the same distance from one another. The second polarization device 50 can be arranged in or in front of the passage.

In other words, the third exemplary embodiment of the lighting module 24 provides selectively polarized ring light illumination. The lighting elements 70, 72 are placed in a ring around the optical axis (the detection beam path 64). The light from the first and second lighting elements 70, 72 is polarized with two different polarization directions (for example x and y polarization), with the first and second lighting elements 70, 72 being arranged alternately in the circumferential direction.

7 shows a fourth exemplary embodiment of the new lighting module 24. The fourth exemplary embodiment of the new lighting module 24 essentially corresponds to a combination of the second and third exemplary embodiments of the lighting module 24. The same elements are marked with the same reference numerals and are not explained in more detail.

The lighting module 24 in the fourth embodiment thus has two lights, namely the coaxial lighting of the second exemplary embodiment of the lighting module 24 and the ring light lighting of the third exemplary embodiment of the lighting module 24. In particular, the lighting module 24 of the fourth exemplary embodiment has both light sources 40 ', 40 ", both of which can generate light. The light from the light source 40' is directed through the beam splitter 48' onto the measurement object 60, so that the beam splitter 48' defines an illumination beam path for the light from the light source 40'. The light from the light source 40" becomes directed through the Fresnel lens 48" onto the measurement object 60, so that the Fresnel lens 48" defines an illumination beam path for the light from the light source 40". In the detection beam path, the beam splitter 48' is beam downstream of the Fresnel lens 48" (in particular beam downstream of the recess 68) arranged.

The light sources 40' and 40" can be controlled separately, so that light can be generated either by means of the light source 40' and/or the light source 40". In particular, the control device 22 of the coordinate measuring machine 10 can be set up to control the light sources 40 'and 40" in order to expose the measurement object either to coaxial illumination (i.e. with the light from the light source 40') or to ring light illumination (i.e. with the light the light source 40").

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006035179 B4 [0007]
• US 10337991 B2 [0007, 0009]
• DE 102007025306 A1 [0007, 0009]
• DE 102014215952 A1 [0008, 0009]
• EP 2847539 B1 [0008, 0009]
• DE 2112229 A [0009]
• WO 2011/099404 A1 [0009]

Claims (22)

Illumination module (24) for a coordinate measuring machine (10) for measuring a measurement object (60), the coordinate measuring machine (10) carrying a measuring head (16) with an optical sensor (18) which has a lens (56) and a light-sensitive detector (58 ), wherein the lens (56) defines a detection beam path (64) from the measurement object (60) to the light-sensitive detector (58), and wherein the lighting module (24) has: - a module housing (26) with a module-side interchangeable interface (30 ), which is designed to attach the module housing (26) to the measuring head (16) in an operationally detachable manner in a defined position; - at least one light source (40) which is designed to generate light; - an optical element (48) which is designed to direct the light onto the measurement object (60) when the module housing (26) is attached to the measuring head (16) in the defined position, the optical element (48) defines an illumination beam path (62) from the light source (40) to the measurement object (60); and - a first polarization device (42), which is arranged in the illumination beam path between the light source (40) and the measurement object (60) and which is set up to polarize the light in at least one defined, first polarization direction, the first polarization device being at least has a first polarizer (44) for polarizing the light, characterized in that a second polarization device (50) is arranged in the detection beam path (64) between the measurement object (60) and the objective (56) when the module housing (26) is in the defined position is attached to the measuring head (16), the second polarization device (50) being set up to analyze the light in a defined, second polarization direction, the second polarization device (50) having a second polarizer (54) for polarizing the Light, and wherein the second polarization device (50) is controllable to adjust the second polarization direction. Lighting module (24). Claim 1 , wherein the second polarization device (50) has a second polarization rotator (52), the second polarizer (54) being arranged in the detection beam path (64) beam downstream of the second polarization rotator (52). Lighting module (24). Claim 2 , wherein the second polarization rotator (52) is controllable to adjust the second polarization direction, in particular wherein the second polarization rotator (52) is a liquid crystal polarization rotator. Lighting module (24). Claim 1 , wherein the second polarizer (54) is rotatably mounted about a second axis of rotation, wherein the second polarization device (50) has a second drive device which is designed to rotate the second polarizer (54) about the second axis of rotation, about the second polarization direction to set. Lighting module (24) according to one of the Claims 1 until 4 , wherein the second polarization device (50) is set up to set the second polarization direction based on a second control signal, in particular wherein the second control signal is a control signal of a control device (22) of the coordinate measuring machine (10). Lighting module (24) according to one of the Claims 1 until 5 , wherein the first polarization device (42) can be controlled to set the first polarization direction. Lighting module (24). Claim 6 , wherein the first polarization device (42) has a first polarization rotator (46), the first polarizer (44) being arranged in the illumination beam path (62) beam upstream of the first polarization rotator (46). Lighting module (24). Claim 7 , wherein the first polarization rotator (46) can be controlled to adjust the first polarization direction. in particular, wherein the first polarization rotator (46) is a liquid crystal polarization rotator. Lighting module (24). Claim 6 , wherein the first polarizer (44) is rotatably mounted about a first axis of rotation, wherein the first polarization device (42) has a drive device which is designed to rotate the first polarizer (44) about the first axis of rotation in order to adjust the first polarization direction . Lighting module (24) according to one of the Claims 6 until 9 , wherein the first polarization device (42) is set up to set the first polarization direction based on a first control signal, in particular wherein the first control signal is a control signal of a control device (22) of the coordinate measuring machine (10). Lighting module (24) according to one of the Claims 1 until 10 , wherein the light source (40) has a plurality of lighting elements (66, 70, 72) for generating the light, wherein the first polarization device (42) has a plurality of first polarizers (44), each first polarizer (44) having a corresponding lighting element (66, 70, 72) of the plurality of lighting elements (66, 70, 72) is assigned and the light of the respective lighting element (66, 70, 72) is polarized. Lighting module (24). Claim 11 , wherein the plurality of first polarizers has a first group of polarizers and a second group of polarizers, the polarizers of the first group being assigned to first luminous elements (70) of the plurality of luminous elements (66, 70, 72), the polarizers of the second Group of second lighting elements (72) of the plurality of lighting elements (66, 70, 72) are assigned, the polarizers of the first group being designed to polarize the light of the first lighting elements (70) with a first polarization direction, and wherein the polarizers of the second group are designed to polarize the light of the second lighting elements (72) with a second, first polarization direction. Lighting module (24). Claim 12 , wherein the light source (40) can be controlled to generate the light either by means of the first lighting elements (70) and / or by means of the second lighting elements (72). Lighting module (24). Claim 13 , wherein the light source (40) is set up to generate the light based on at least a third control signal either by means of the first lighting elements (70) and/or by means of the second lighting elements (72), in particular wherein the third control signal is a control signal of a control device ( 22) of the coordinate measuring machine (10). Lighting module (24) according to one of the Claims 1 until 14 , wherein the module-side interchangeable interface (30) has at least one mechanical contact element (36) which is designed to fasten the module housing (26) in a defined position on the measuring head (16). Lighting module (24) according to one of the Claims 1 until 15 , wherein the module-side interchangeable interface (30) has at least one first electrical contact element (38 '), which is set up to electrically connect the first polarization device (42) to the measuring head (16), in particular wherein the first polarization device (42) is set up for this purpose is to receive the first control signal via the first electrical contact element (38 '). Lighting module (24) according to one of the Claims 1 until 16 , wherein the module-side interchangeable interface (30) has at least one second electrical contact element (38"), which is designed to electrically connect the second polarization device (50) to the measuring head, in particular wherein the second polarization device (50) is designed to do so to receive the second control signal via the second electrical contact element (38''). Lighting module (24) according to one of the Claims 1 until 17 , wherein the module-side interchangeable interface (30) has at least one third electrical contact element (38'''), which is designed to electrically connect the at least one light source (40) to the measuring head (16), in particular wherein the light source (40) is set up to receive the at least one third control signal via the third electrical contact element (38'''). Illumination module (24) for a coordinate measuring machine (10) for measuring a measurement object (60), the coordinate measuring machine (10) carrying a measuring head (16) with an optical sensor (18) which has a lens (56) and a light-sensitive detector (58 ), wherein the lens (56) defines a detection beam path (64) from the measurement object (60) to the light-sensitive detector (58), and wherein the lighting module (24) has: - a module housing (26) with a module-side interchangeable interface (30 ), which is designed to attach the module housing (26) to the measuring head (16) in an operationally detachable manner in a defined position; - at least one light source (40) which is designed to generate light; - an optical element (48) which is designed to direct the light onto the measurement object (60) when the module housing (26) is attached to the measuring head (16) in the defined position, the optical element (48) defines an illumination beam path (62) from the light source (40) to the measurement object (60); and - a first polarization device (42) which is arranged in the illumination beam path (62) between the light source (40) and the measurement object (60) and which is designed to polarize the light in at least one defined, first polarization direction, wherein the first polarization device (42) has at least one first polarizer (44) for polarizing the light, characterized in that the first polarization device (42) is controllable in order to set the first polarization direction. Illumination module (24) for a coordinate measuring machine (10) for measuring a measurement object (60), the coordinate measuring machine (10) carrying a measuring head (16) with an optical sensor (18) which has a lens (56) and a light-sensitive detector (58 ), wherein the lens (56) defines a beam path from the measurement object (60) to the light-sensitive detector (58), and wherein the lighting module (24) has: - a module housing (26) with a module-side interchangeable interface (30), which is designed to attach the module housing (26) to the measuring head (16) in an operationally releasable manner in a defined position; - at least one light source (40) which is designed to generate light; - an optical element (48) which is designed to direct the light onto the measurement object (60) when the module housing (26) is attached to the measuring head (16) in the defined position, the optical element (48) defines an illumination beam path (62) from the light source (40) to the measurement object (60); and - a first polarization device (42) which is arranged in the illumination beam path (62) between the light source (40) and the measurement object (60) and which is designed to polarize the light in at least one defined, first polarization direction, wherein the first polarization device (42) has at least one first polarizer (44) for polarizing the light, characterized in that the light source (40) has a plurality of lighting elements (66, 70, 72) for generating the light, wherein the first polarization device (42) has a plurality of first polarizers (44), the plurality of first polarizers (44) having a first group of polarizers and a second group of polarizers, the polarizers of the first group being first luminous elements (70) of the plurality of luminous elements (66, 70, 72), the polarizers of the second group being assigned to second lighting elements (72) of the plurality of lighting elements (66, 70, 72), the polarizers of the first group being designed to reflect the light of the first lighting elements (70). to polarize with a first, first defined polarization direction, and wherein the polarizers of the second group are designed to polarize the light of the second lighting elements (72) with a second, first defined polarization direction, wherein the light source (40) is controllable to selectively emit the light by means of the first lighting elements (70) and/or by means of the second lighting elements (72). Coordinate measuring machine (10) for measuring a measurement object (60), with: - a workpiece holder (12) for holding the measurement object (60); - a measuring head (16), which can be moved relative to the workpiece holder (12) and carries an optical sensor (18); - a control device (22) which is designed to determine dimensional and/or geometric properties on the measurement object (60) depending on a position of the measuring head (16) relative to the workpiece holder (12) and depending on sensor data from the optical sensor ( 18) to determine; and - a lighting module (24) according to one of the Claims 1 until 20 for selectively illuminating the measurement object (60), the measuring head (16) having a sensor-side interchangeable interface (28) which is designed to operationally releasably attach the lighting module (24) to the measuring head (16), the optical sensor (18 ) includes a lens (56) and a light-sensitive detector (58), which is designed to record an image of the measurement object (60) through the lens (56), and wherein the lens (56) has a beam path from the measurement object (60) to the light-sensitive detector (58). Coordinate measuring machine (10). Claim 21 , wherein the control device (22) is set up to control the light source (40) and / or the first polarization device (42) and / or the second polarization device (50).

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