DE102016118520B4 - Testing device for testing a workpiece - Google Patents

Abstract

Inspection device (1) for testing a workpiece (5), with a lighting device (2) for illuminating the workpiece (5) and an image generating device (3, 3A-3C) for imaging the workpiece (5), characterized in that the Illumination device (2) has a light-emitting foil arrangement (22) with a light-emitting, first side (220) for emitting a diffuse light radiation (L) and with at least one opening (20, 20A-20C), wherein the image-generating device (3, 3A-3C) on a first side (220) facing away from the second side (221) of the light-emitting foil assembly (22) is arranged and formed through the opening (20) of the light-emitting foil assembly (22) to image the workpiece (5).

Description

The invention relates to a testing device for testing a workpiece, in particular a connector part, according to the preamble of the claim 1 ,

Such a testing device comprises a lighting device for illuminating a workpiece and an image generating device for imaging the workpiece.

In the development or production of workpieces, such as connector parts with contact elements for electrically contacting lines, a functional and wear test is generally required. For example, it may be specified that a connector part of a certain type has to survive a predetermined number of plug-in operations without wear, that is to say without impairing its functionality. Such a function and wear test can be done, for example, in an automated manner by repeated plugging on a wear tester, which is to determine in the test, and if and when wear occurs, which could possibly affect the functionality of the connector part.

The examination for defects on a workpiece to be tested is carried out by means of an imaging device, such as a camera, for example, equipped with a microscope objective for recording greatly enlarged images of the workpiece to be tested under microscopic resolution. By means of the image generation device and an image analysis on the recorded images, a workpiece can be examined, for example, for microscopically fine material fractures. In addition, the material and surface properties, for example the presence of different materials on the workpiece surface, can be tested.

For the examination of workpieces - in particular those workpieces which consist of solid materials, for example metal materials - the most homogeneous possible illumination of the workpiece is required. Inhomogeneous illumination, for example, in reflective workpieces (made, for example, of metal) may result in localized illumination peaks in a captured image, resulting in image analysis and, accordingly, detection of a functionally impairing error, e.g. may make difficult due to a defect, misalignment, damage, wrong condition (e.g., on the surface or in the material), or even due to wear.

At one of the DE 10 2007 025 524 A1 known opto-electric detection system, a lighting device is provided with a plurality of light-emitting elements in the form of light emitting diodes (LEDs) for illuminating a beverage container. The opto-electrical detection system has a camera assembly to receive images of the beverage container.

From the DE 10 2009 035 369 A1 is a flexible LED strip light known.

At one of the DE 602 09 591 T2 known system for the production testing of blister packs, a lighting device with an electroluminescent luminescent layer is provided which surrounds a test room with a camera arranged therein.

In the DE 196 13 082 C2 a lighting device is disclosed, which has a V-shaped cross-section in the transport direction, which means that the lighting device is designed as a V-shaped box. This box has two legs, on each of which light exit surfaces are formed. The light exit surfaces consist of frosted glass panes, under each of which a plurality of diffused light sources are arranged. The light sources can be designed as individual flash tubes. Placed on the frosted glass panes are a plurality of parallel running in the transport direction guide webs. An angle of inclination of these guide webs with respect to the light exit surfaces is adapted approximately parallel to a light beam running.

The DE 41 23 916 A1 discloses a lighting device which is formed from a plurality of individually arranged, point-shaped light sources. A similar lighting device is from the DE 10 2013 108 722 A1 known.

From the DE 20 2013 104 938 U1 For example, a device for optically inspecting a mouth region of a container is known which comprises an illumination device having a plurality of light sources, wherein the light sources are arranged in angular segments around the mouth region.

Object of the present invention is to provide a test device available, which allows a cost-effective design reliable testing of a workpiece for errors.

This object is achieved by an article having the features of claim 1.

Accordingly, the illumination device has a light-emitting foil arrangement with a light-emitting, first side for emitting a diffuse Light radiation and with at least one opening. The image generating device is arranged on a second side of the luminous film arrangement facing away from the first side and is designed to image the workpiece through the opening of the luminous film arrangement.

Accordingly, the illumination device comprises a light-emitting foil arrangement. The luminescent film arrangement can be formed, for example, by an electroluminescent film element or by an OLED film element which realizes a (single) arealuminous organic light-emitting diode or an arrangement of a plurality of areally radiating organic light-emitting diodes (OLEDs) and can preferably be flexible at least in sections. This makes it possible to arrange the light-emitting-foil arrangement in a flexible manner around a workpiece to be tested while flexibly adapting the shape of the light-emitting-foil arrangement in order to obtain optimum illumination for testing a specific workpiece. Film elements in the form of electroluminescent films or films having organic light-emitting diodes are available inexpensively, can be handled easily, for example, cut in shape and provide a diffused light that can cause an advantageous homogeneous illumination of an object.

An electroluminescent film (in short EL film, also luminescent or plasma film, light film or capacitor luminescent film) is understood as meaning a film which converts electrical energy into light. Such an electroluminescent film may comprise, for example, an electroluminescent phosphor, for example zinc sulfide. Such an electroluminescent film may have a thickness of less than 1 mm and is e.g. flexible bendable. By applying an alternating voltage, the electroluminescent phosphor can be excited to electroluminescence, so that the luminous film emits an undirected, diffused light over a large area.

In contrast, an organic light-emitting diode arranged on a flexible film (OLED for short) is made up of several layers of organic layers which can realize a pn junction and can be excited to create a surface by applying a current flow.

The light-emitting foil arrangement can be designed to emit a white light. However, it is also conceivable and possible for the light film arrangement to emit a light of a specific wavelength, for example green, blue or red light, or even to trigger different light colors.

The light-emitting foil arrangement has at least one opening. While diffuse light radiation is emitted at the first side of the light-emitting foil arrangement, the image generation device, for example a camera for imaging the workpiece, is arranged on a second side of the light foil arrangement facing away from the first side. The image generating device can thus be arranged outside of a test room in which the workpiece is located and in which the workpiece is to be illuminated. For examination, the image-forming device picks up images from the workpiece through the opening in the luminous film arrangement from the outside, which has the advantage that the image-forming device does not cast shadows on the workpiece and thus does not affect the illumination of the workpiece.

The image generating device may be formed by a camera or comprise a camera. The image generating device can be designed, for example, to take pictures of greatly enlarged images of the workpiece to be tested. For example, the image generating device may comprise a CCD camera.

The light film arrangement is, in one embodiment, at least partially curved for the purpose of testing a workpiece. With a curved shape, the light film arrangement can be at least partially placed around the workpiece to be tested, so that the workpiece can be illuminated from different sides with diffuse light radiation.

For example, the light-emitting foil arrangement can surround a test space in which the workpiece is arranged. For this purpose, the light film arrangement can be formed, for example, to a tunnel or cylinder surrounding the test space or to a dome surrounding the test space. The light-emitting foil arrangement may, for example, be formed into a horizontal or stationary cylinder, which surrounds the test space like a tunnel and in which a workpiece can be arranged for testing.

Because the imaging device is located outside the inspection space, one or more apertures in the light sheet assembly are required to receive images from the workpiece located in the inspection space by the imaging device. Each opening may be cut into the light-emitting-foil arrangement as a hole, for example, and may have a circular, square or rectangular shape or else a slot shape.

By providing a plurality of openings in the light-emitting foil arrangement, images of the workpiece to be tested can be recorded from different directions and perspectives. For this purpose, the image generating device be movable, for example, so that the image forming device can be brought into different positions to successively record different images of the workpiece through different openings.

In one embodiment, it is also conceivable and possible for the checking device to have a plurality of image-generating devices which are each assigned to an opening. By means of the image-forming devices, images of the workpiece can be obtained from different perspectives in order, by means of an image analysis of the recorded images, to scan the workpiece for an error, e.g. as a result of faulty surface or material properties or as a result of wear.

In one embodiment, the luminous foil arrangement has a plurality of foil sections, which can be formed by spatially separated sections of a uniform foil or else by separate foils. The film sections are preferably separately controllable to emit light radiation. By spatial offset between the film sections is possible in this way to illuminate a workpiece from different directions to record pictures, for example, with a side lighting, a top light or a backlight.

It is also conceivable and possible that the different foil sections are designed for emitting light of different light colors, that is to say different wavelengths. For example, one foil section can be designed to emit a red light and another foil section to emit a blue light. It is also conceivable and possible that one or more foil sections can optionally emit different light colors, for example white, blue or red light, and can be activated separately for this purpose. For this purpose, one or more foil sections can be switched, for example, between different light colors, or the light color can be varied steplessly by controlling the respective foil section.

Apertures may be formed between adjacent film sections over which one or more imaging devices may receive images from the workpiece. For example, a slot opening can be provided between adjacent, rectangular film sections, through which an associated image-forming device can take pictures of the workpiece to be tested. Additionally or alternatively, of course, one or more openings can be formed directly into one or more of the film sections.

In one embodiment, the checking device has a control and evaluation device for controlling the illumination device and the image-generating device and for evaluating images recorded by the image-generating device. The control and evaluation device can serve, for example, to trigger the illumination device in order to effect illumination when an image is to be taken. The illumination of the workpiece and the recording of an image by the image generating device can thus take place in a timely manner. Likewise, the control and evaluation device, for example, a movement of the image forming device - for example, to capture images through different openings of the light-emitting foil arrangement - control. In addition, the control and evaluation device can also be designed to perform an image analysis of recorded images in order to check the condition of a workpiece from the images and to determine an error, e.g. as a result of faulty manufacture or wear.

A test device of the type described here can be used for example on a system, for example a production line, which has a conveyor for conveying workpieces. Workpieces are moved along the conveyor, the test apparatus e.g. is arranged on the conveyor to check conveyed workpieces on their nature, such as their quality and operational readiness.

• 1 einen schematische Darstellung einer Prüfeinrichtung mit einer Leuchtfolienanordnung;
• 2A die Prüfeinrichtung gemäß 1, bei diffuser Lichtabgabe durch die Leuchtfolienanordnung;
• 2B eine Seitenansicht der Anordnung gemäß 2A;
• 3 ein Ausführungsbeispiel einer Prüfeinrichtung, mit einer zu einem Tunnel geformten Leuchtfolienanordnung und einer Bilderzeugungseinrichtung zum Aufnehmen eines Bildes eines in dem Tunnel befindlichen Werkstücks;
• 4 die Ansicht gemäß 3, bei diffuser Lichtabgabe der Leuchtfolienanordnung;
• 5 eine andere Ansicht der Anordnung gemäß 4;
• 6 eine schematische Ansicht einer an einer Fördereinrichtung angeordneten Prüfeinrichtung;
• 7 eine schematische Ansicht eines Ausführungsbeispiels einer Prüfeinrichtung, bei der eine Leuchtfolienanordnung eine Mehrzahl von Folienabschnitten aufweist;
• 8 eine schematische Ansicht einer Leuchtfolienanordnung, mit einer Mehrzahl von anhand eines Rasters ausgerichteten Öffnungen;
• 9 eine schematische Ansicht einer Prüfeinrichtung, mit einer zu einem Dom geformten Leuchtfolienanordnung; und
• 10 eine Seitenansicht der Anordnung gemäß 9.

The idea underlying the invention will be explained in more detail with reference to the embodiments illustrated in the figures. Show it:

• 1 a schematic representation of a test device with a light-emitting foil assembly;
• 2A the test device according to 1 , with diffuse light emission through the light-emitting foil arrangement;
• 2 B a side view of the arrangement according to 2A ;
• 3 an embodiment of a test device, comprising a tunnel-shaped luminous foil arrangement and an image forming device for receiving an image of a workpiece located in the tunnel;
• 4 the view according to 3 , with diffuse light emission of the light-emitting foil arrangement;
• 5 another view of the arrangement according to 4 ;
• 6 a schematic view of a arranged on a conveyor tester;
• 7 a schematic view of an embodiment of a test device in which a light-emitting plate assembly having a plurality of foil sections;
• 8th a schematic view of a light-emitting panel assembly having a plurality of aligned with a grid openings;
• 9 a schematic view of a test device, with a molded into a dome luminous film assembly; and
• 10 a side view of the arrangement according to 9 ,

1 and 2A . 2 B show in schematic views an embodiment of a test device 1 that is a lighting device 2 with a light-emitting foil arrangement 22 has in the form of a flat, thin luminescent film. The luminescent film can be formed, for example, as an electroluminescent film or as an OLED film and can be so flexible that the luminescent film arrangement 22 can be flexibly bent and curved.

The illuminated foil arrangement 22 For example, it may have a thickness of less than 1 mm and, for example, it may easily be cut with a knife, scissors or other cutting tool to match the shape of the luminescent film assembly 22 to suit a desired use.

As in an embodiment in 3 to 5 shown, the test device 1 serve a workpiece 5 to test its nature. The testing device 1 can for example be used for error checking to on a workpiece 5 For example, determine whether and if so when an error (eg as a result of wear) occurs. Is the workpiece 5 For example, a connector part for plug-in connection with an associated mating connector part for electrically contacting electrical lines with each other, the connector part can be repeatedly inserted for testing (for example, several 1000 or even 10,000 times) to check at regular intervals when plugging, if an error has occurred which could possibly impair the function of the connector part.

In addition, by means of such a test device 1 For example, a quality test of a workpiece 5 in manufacturing, for example, on a production line, to ensure that finished workpieces 5 have a certain quality and quality.

By means of the test device 1 Workpieces to be tested 5 For example, they can be manufactured as solid bodies, in particular from a metal material. By means of the test device 1 can such a workpiece 5 For example, be checked for microscopic fractures or on a material condition on the surface.

The illuminated foil arrangement 22 serves to a workpiece to be tested 5 to illuminate, so by means of an image forming device 3 , for example in the form of a camera, an image of the workpiece 5 can be included. The image forming device 3 is with a control and evaluation 4 connected to the imaging device 3 and also the light film arrangement 22 can control, for example, the illumination of the workpiece 5 and the image capture by the imaging device 3 to coordinate with each other in time and / or to perform an image analysis based on captured images to provide information about the nature of the workpiece 5 to obtain.

The image forming device 3 can be configured for example by an electronic camera, in particular a CCD camera. By means of the imaging device 3 can eg greatly enlarged images of the workpiece 5 , for example, under microscopic resolution of the workpiece 5 to be recorded.

The illuminated foil arrangement 22 gives a diffuse light radiation L which allows a workpiece to be tested 5 to illuminate in an advantageous manner. Due to the fact that the light film arrangement 22 in its shape to the workpiece to be tested 5 adjusted and (eg by bending) around the workpiece 5 In addition, a homogeneous illumination, for example, for a material analysis and / or wear tracking on the workpiece 5 possible.

In the embodiment according to 3 to 5 is the light-emitting foil arrangement 22 formed into a cylindrical tunnel that has a testing room 21 surrounds in which the workpiece to be tested 5 is arranged. As schematically in 4 and 5 shown, there is the light-emitting foil assembly 22 on a first, inward side 220 light radiation L by means of which in the test room 21 located workpiece 5 is illuminated in a homogeneous way from all sides. Due to the homogeneous diffuse illumination, light peaks in a recorded image can be avoided.

The image forming device 3 is outside the testing room 21 So outside of one Tunnel laid luminous foil arrangement 22 on one of the first page 220 opposite, second side 221 the light-emitting foil arrangement 22 arranged. In the light-emitting foil arrangement 22 is an opening 20 formed, for example, with a rectangular, square, round or slot-shaped cross-section, through which the image forming device 3 into the interior of the test room 21 look into it and through it the imaging device 3 thus pictures of the workpiece 5 in the test room 21 can record.

Because the imaging device 3 outside the testing room 21 is placed throws the image forming device 3 no shadows on the workpiece 5 and thus affects the homogeneous illumination of the workpiece 5 Not. Because the clear width of the opening 20 small compared to the total area of the light radiation L dispensing luminous film arrangement 22 is the effect of the opening 20 negligible on the lighting and on the workpiece 5 barely noticeable.

In the embodiment according to 3 to 5 is the light-emitting foil arrangement 22 shaped into a cylindrical tunnel. The shape of the light-emitting foil arrangement 22 is here, with flexible design of the light-emitting foil arrangement 22 , flexible a desired insertion, in particular a workpiece to be tested 5 , customizable. For example, the light-emitting foil arrangement 22 also be placed to an oval tube or the like.

At the in 6 illustrated embodiment is a tester 1 with a planar, flat luminous film arrangement 22 above a conveyor 50 arranged, by means of which a plurality of workpieces 5 For example, in the context of a production line, in a conveying direction B can be moved. The testing device 1 can in this case to check the condition of manufactured workpieces 5 serve, wherein the image forming device 3 , the lighting device 2 and the conveyor 50 by a common control and evaluation device 4 can be controlled to depend on the position of a workpiece 5 to carry out a test and if necessary - if the quality of a tested workpiece differs from that of a specified quality 5 - initiate countermeasures, eg to interrupt production.

7 shows an embodiment in which a light-emitting foil arrangement 22 a plurality of mutually spatially offset film sections 22A-22D having. Some of these foil sections 22A - 22C can in this case adjoin one another along a lateral surface of a cylinder, wherein the film sections 22A - 22C for example, through slit-shaped openings 20A-20C can be separated from each other. A lower foil section 22D is flat in the illustrated embodiment and forms the bottom of a test room 21 out.

The different film sections 22A-22D For example, they can be controlled separately from each other. This allows the workpiece 5 to selectively illuminate from different sides. For example, by means of the upper film sections 22A a lighting from above, by means of the adjoining film sections 22B a lighting obliquely from above, by means of the adjoining film sections 22C a lighting obliquely from below and by means of the lower film section 22D a lighting can be effected from below.

With this light film arrangement 22 Different tests are possible. So can all foil sections 22A-22D for homogeneous illumination of the workpiece 5 be controlled to work together the workpiece 5 to be homogeneously illuminated from all sides with diffused light. When controlling only the upper film sections 22A a test can be carried out in incident light. When controlling the lateral film sections 22B . 22C can be a test with side lighting of the workpiece 5 respectively. And when controlling the lower film section 22D may be a test, for example by means of an upper imaging device 3A , under transmitted light (the workpiece 5 is in this case under the backlight of the film section 22D generated light tested).

In the embodiment according to 7 are several imaging devices 3A-3C provided by different openings 20A-20C in the test room 21 look into it. By means of different imaging devices 3A-3C Thus, images can be taken from different perspectives, resulting in an examination of the workpiece 5 from different sides.

It is also conceivable and possible, in a modified embodiment, only an imaging device 3A-3C to use that between different openings 20A-20C can be moved to temporally successively with the one image forming device 3A-3C Pictures of the workpiece 5 from different directions.

The illuminated foil arrangement 22 can, in the embodiment according to 7 , oblong, tunnel-shaped extending (similar to the embodiment according to 3 to 5 ). The foil sections 22A - 22C thus form a cylinder through the lower film section 22D flattened at the bottom.

The foil sections 22A-22D may be formed by different sections of a single film or by separate, separate films.

At an in 8th illustrated embodiment, the light-emitting foil assembly 22 a variety of openings 20 on, which are arranged to a grid. The illuminated foil arrangement 22 thus has a lattice structure that provides imaging through a plurality of apertures 20 through it.

At the in 9 and 10 illustrated embodiment, the light-emitting foil assembly 22 the lighting device 2 the test facility 1 shaped into a dome (comparable to the shape of a fallen glass), which is a test room 21 limited, within which a workpiece 5 to check. Through an opening 20 For example, at the top of the dome, an image forming device 3 in the test room 21 look into it for pictures of the workpiece to be tested 5 take.

The idea underlying the invention is not limited to the embodiments described above, but can basically be realized in a completely different manner.

A test device of the type described here can be used to test very different workpieces. Such workpieces, such as connector parts, are preferably at least partially made of a solid, such as a metal material.

For example, connector parts have contact elements in the form of metal contact pins or metal contact sockets, which are to be connected for establishing an electrical connection. The test device can serve in this case for error checking on the contact elements.

A light film arrangement may have any shape. For example, round, square, rectangular or otherwise cut to size film plates can be used, which can be placed in very different shapes, such as cylindrical tubes or the like.

LIST OF REFERENCE NUMBERS

1

test equipment

2

lighting device

20, 20A-20C

opening

21

testing room

22

Luminous film arrangement

22A-22D

film section

220

First page

221

Second page

3, 3A-3C

Imaging device (camera)

4

Control and evaluation device

5

workpiece

50

Conveyor

B

conveying direction

L

(Diffused) light

Claims (13)

Inspection device (1) for testing a workpiece (5), comprising - a lighting device (2) for illuminating the workpiece (5) and - an image forming device (3, 3A-3C) for imaging the workpiece (5), characterized in that the Illumination device (2) has a light-emitting foil arrangement (22) with a light-emitting, first side (220) for emitting a diffuse light radiation (L) and with at least one opening (20, 20A-20C), wherein the image-generating device (3, 3A-3C) on a first side (220) facing away from the second side (221) of the light-emitting foil assembly (22) is arranged and formed through the opening (20) of the light-emitting foil assembly (22) to image the workpiece (5). Test device (1) after Claim 1 , characterized in that the light-emitting foil arrangement (22) is formed by an at least one electroluminescent foil element or by at least one organic light-emitting diode foil element (OLED foil element). Test device (1) after Claim 1 or 2 , characterized in that the light-emitting foil arrangement (22) is flexible at least in sections. Test device (1) according to one of Claims 1 to 3 , characterized in that the light-emitting foil arrangement (22) is curved at least in sections. Test device (1) according to one of the preceding claims, characterized in that the light film arrangement (22) completely or partially surrounds a test space (21) in which the workpiece (5) is arranged. Test device (1) after Claim 5 , characterized in that the light-emitting foil arrangement (22) to a test room (21) surrounding tunnel, cylinder or to a test room (21) surrounding dome is formed. Test device (1) according to one of the preceding claims, characterized in that the light-emitting foil arrangement (22) has a plurality of openings (20, 20A-20C). Test device (1) according to one of the preceding claims, characterized in that the test device (1) has a plurality of image generating devices (3, 3A-3C). Test device (1) according to one of the preceding claims, characterized in that the light film arrangement (22) has a plurality of film sections (22A-22D), which are separately controllable for emitting light radiation (L) and spatially offset from each other to illuminate the workpiece are arranged from different directions. Test device (1) after Claim 9 , characterized in that between adjacent film sections (22A-22D) an opening (20A-20C) for imaging of the workpiece by the image forming device (3) is arranged. Test device (1) according to one of the preceding claims, characterized by a control and evaluation device (4) for controlling the illumination device (2) and the image generating device (3) and for evaluating images taken by the image generation device (3). Test device (1) according to one of the preceding claims, characterized in that the light-emitting foil arrangement (22) can be actuated for emitting light of different light colors. Plant comprising a conveying device (50) for conveying workpieces (5) along a conveying direction (B) and having a testing device (1) arranged on the conveying device (50) according to one of the preceding claims for testing the conveyed workpieces (5).

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