DE102010061559A1 - Device for recognizing film web processing errors, has detection device that detects processing error based on film web error if film web and processing errors are determined for film web region - Google Patents

Abstract

The device has a comparing device for comparing an accommodating image with a reference image stored in a memory. An error recognition device (2) determines a film web error of a film web region before processing a film web (1). Another recognition device (3) determines a processing error of a processed film web region. A detection device (4) detects the processing error based on the film web error if the film web and processing errors are determined for the film web region. An illumination device illuminates the film web. A polarization filter polarizes light. An independent claim is also included for a method for recognizing film web processing errors.

Description

The present invention relates to an apparatus and method for detecting film processing errors.

From the publication DE 103 01 931 A1 For example, there is known a method of optically controlling color patterned surfaces provided with a transparent, planar or embossed protective layer. The surface of cameras with different orientation and lighting is checked.

Furthermore, in the published patent application DE 10 2007 043 408 A1 describes a method for detecting carrier film residues or carrier film defects. In this method, the surface of a carrier film is checked by a camera with a downstream image processing unit. In addition, a second camera can be provided, which supplies reference values for the check for the first camera. However, the detection of a processing error based on a defect of the raw material is not possible by these devices and methods.

The invention is based on the object to provide a device which is able to detect processing errors of a film, which are based on errors of the starting film material.

This object is achieved by a device for detecting film processing errors having the features specified in claim 1 and by applying the method steps indicated in the method claim 7. Advantageous embodiments of the device are specified in claims 2 to 6 and advantageous further method steps in claims 8 to 11.

The device according to the invention is characterized by a first error detection device for detecting a film defect of a film area prior to processing. a film of a second error detection device for detecting a processing error of the processed film area and a detecting device for detecting a film error based processing error when the film area detects both a film defect and a processing error. By this device processing errors of a film material are detected, which may be due to manufacturing defects of the film or incurred during winding of the film after manufacture, so that these errors can be distinguished from later processing errors of the film material, for example, when back molding.

In a further embodiment, the device comprises a camera for the first or second error detection device for capturing an image of the film region. By using cameras for fault detection, he has the advantage that can be detected with simple technical means and little effort film defects.

In a further embodiment, the apparatus comprises a comparison device for comparing a captured image with a stored image to detect the film defect and / or processing error. The stored image can be a previously recorded image, but it can also be a target image previously stored for the target / actual comparison. For example, if the target image does not contain a single defect and the film is detected as it passes through the camera and contains a pixel that z. B. is led dark in transparent film or a different color than the foil color, so this error is detected and not assigned to the subsequent processing. Is taken as a target image of the film section with the camera, z. B. a CCD camera, and stored as a target image and with the image that after processing, for. B. the back molding with a plastic mass, compared and found no further pixel error, so also this proves that no processing error has occurred. If, on the other hand, an additional pixel error is detected in the images, this proves that a manufacturing error has led to the additional errors. In this way, a perfect error assignment can be made, so that resulting recourse claims are attributable to the cause of the error.

By comparing a recorded image with a target image stored in a memory, the advantage is achieved that film defects and / or processing errors can be detected with high accuracy.

In a further embodiment, the device comprises a polarization filter for polarizing light. By a special choice of the polarization properties of the light used for recording by the polarizing filter, the advantage is achieved that reflections can be suppressed by the film material, so that the accuracy of error detection is improved.

In a further embodiment, the device comprises a lighting device for illuminating the film during the recording by the first or second camera. By using a lighting device, the advantage is achieved that the error detection can be improved by specially set lighting conditions and defects of the film can be detected safely before or after processing.

• – Feststellen eines Folienfehlers eines Folienbereichs vor einer Verarbeitung einer Folie (1),
• – Feststellen eines Verarbeitungsfehlers des verarbeiteten Folienbereichs und
• – Erfassen eines auf einem Folienfehler beruhenden Verarbeitungsfehlers, wenn für den Folienbereich sowohl ein Folienfehler als auch ein Verarbeitungsfehler festgestellt ist.

The process according to the invention is characterized by the following process steps:

• Determining a film defect of a film area before processing a film ( 1 )
• - detecting a processing error of the processed film area and
• - Detecting a film defect-based processing error if the film area has detected both a film defect and a processing error.

In another embodiment of the method, the method comprises the step of capturing an image by a camera to detect a film defect prior to further processing or a processing error after processing.

In another embodiment of the method, this includes the step of comparing the captured image to a stored image to determine the film defect or processing error.

In a further embodiment of the method, it is provided that the light thrown by a light source for recording on the foil is polarized.

The method steps indicated result in technical advantages which are identical to those of the corresponding device.

Basically, based on the error analysis, care can be taken to ensure that faulty film sections are not back-injected at all. However, there are mistakes that may not be visible after the injection, so they can be accepted. On the other hand, other defects that are already on the film are also visible after the back injection process, possibly with further defects that can be attributed to the injection molding process. Such typical errors should be recorded and evaluated in order to be able to control the back-injection process as a function of this. In order to detect such typical film defects, the images before and after the injection molding in an evaluation circuit, the z. B. has a microprocessor, also evaluated to determine whether the error is repeated. Thus, a sufficient number of film sections are checked. If it turns out that it is a recurring error that can only be attributed to the foil, this is registered as a typical error and, when this typical error occurs, it is immediately prompted that no back-injection takes place. The film section is a film scrap and is suitably wound up for recourse claims. This saves in particular superfluous injection molding and the processing of plastic for the injection process. In addition, it is easy to prove film defects in this way; an error source allocation is made possible.

The invention will be described in more detail below with reference to the exemplary embodiments illustrated in the drawings.

In the drawings show:

1 a first embodiment of the device according to the invention and

2 a second embodiment of the device according to the invention.

The following is the explanation of the invention with reference to the drawings according to structure and mode of operation of the illustrated invention.

1 shows a first embodiment of the device according to the invention for detecting film processing errors.

A foil web 1 runs in the direction of the arrow on rollers or rollers 7 through the apparatus for detecting film processing errors. The rollers 7 serve to transport or guide the film web 1 and may be made of a material that is particularly suitable for use in combination with the film used, for example, to adhere the film material to the rollers 7 to prevent. In addition, the roles 7 include other devices for cooling or heating the material.

During the passage of the film web 1 finds a processing process of the film web 1 instead of. For example, the film web 1 through an injection device 5 with a sprayed layer 6 Mistake. In addition, the surface of the film can with a shaping tool 10 are processed, which moves up and down along the arrow shown.

However, to process the film web 1 Other methods may be considered, such as those of the prior art for processing a film web 1 are known. For example, an in-mold decoration process (IMD process) or in-mold labeling process (IML process) can be used.

In these methods, films and components made of a variety of plastics, such as polypropylene (PP), acrylonitrile-butadiene-styrene (ABS), Polycarbonate (PC), blends of acrylonitrile-butadiene-styrene and polycarbonate (ABS / PC), acrylic ester-styrene-acrylonitrile (ASA), styrene-acrylonitrile (SAN) and polymethylmethacrylate (PMMA). Furthermore, it is possible with these methods to apply additional lacquer layers or films to the film web.

It is not essential that the film web 1 leaves the device as a film web, but instead it is also possible to use within the device a method by which the inserted film web 1 is processed into individual parts, for example by shaping. The items thus produced may, for example, be conveyed out of the apparatus by any suitable conveyor.

The apparatus for detecting film processing errors comprises a first error detection apparatus 2 for detecting material defects of the introduced film web 1 before processing.

A film defect can be any irregularity in the starting material, such as variations in film thickness, chromatic aberrations, cracks, voids, adhesions or embedding of film residue, dust or other materials, variations in film width, defects in a protective layer.

The first error detection device 2 may use different methods to detect a film defect. In general, any known method suitable for detecting a film defect can be used for this purpose. These methods may include, in particular, optical methods, X-ray methods, ultrasonic methods, electrical methods or mechanical methods.

Furthermore, the device for detecting film processing errors comprises a second error detection device 3 for detecting processing errors of the film web 1 after processing has taken place. Here, the first and the second error detection device 2 and 3 synchronized so that they allow an assignment of an identical film area before and after processing.

Processing defects can generally be any irregularity in the material being processed, such as variations in a sprayed coating, molding defects, cracks, embedding, folds of the film material, defects in a protective layer, or material defects.

The second error detection device 3 may use different methods to detect a film defect. In general, any known method suitable for detecting a processing error can be used for this purpose. These methods may also include optical methods, X-ray methods, ultrasonic methods, electrical methods or mechanical methods.

Since not every processing error is due to a film defect, the apparatus for detecting film processing errors comprises a detection device 4 for detecting a processing error based on a film defect. This detecting device detects a processing error based on a film defect when both a film defect by the first defect detecting device is caused to a film area 2 as well as a processing error second error detection device 3 has been found. The detection device may be, for example, an electronic circuit or a computer with which the two error detection devices 2 and 3 are coupled via electrical lines or wirelessly.

In an advantageous embodiment, the first and / or second error detection device comprise 2 and 3 one camera each. As a result, the advantage is achieved that errors in the film web 1 easy to detect before and after processing by taking pictures. In particular, it is advantageous to use electronic cameras (CCD cameras) coupled to a computer or storage system. As a result, images of the film web and the defects can be stored and analyzed.

To do this, a picture is first taken of a specific area of the film before processing to detect a defect in the source material. After processing, another image is taken of the processed film area to detect a processing error. If both a film defect and a processing error are detected, there is a processing error based on a film defect.

In a particularly advantageous embodiment, the recognition of an error is made in such a way that an actual image of the film area recorded by a camera is compared with a desired image located in a memory. For this purpose, the device comprises a memory of target images. This memory can include desired images of different film webs and / or processed film webs, so that a simple conversion to other starting materials can be made.

If the difference between the recorded actual image and the stored target image exceeds a certain limit, the error recognition device recognizes 2 in that there is a film defect in the recorded area. The error detection device 3 can work in a similar way and recognize a processing error by a target-actual comparison.

Lying in two image comparisons each by the first and second error detection device 2 and 3 both a film defect and a processing error, recognizes the detection device 4 this error as a processing error based on an error of the source material.

This device has the advantage that rejects generated during a processing process and based on errors in a source material can be detected particularly precisely.

2 shows another embodiment for detecting film processing errors.

The device of this embodiment has lighting devices 9 for illuminating a film area during error detection. At the lighting devices 9 These may be, for example, incandescent lamps, halogen lamps, fluorescent tubes or flash lamps. By means of these illumination devices, for example, the film area can be illuminated by a camera during a recording. This improves the accuracy of error detection.

In an alternative optical method, the illumination devices may be 9 also act on lasers. In particular, when using lasers, there is the advantage that defects can be detected simply by taking advantage of interference effects by reflection on the front and back of the film.

The lighting devices 9 can is on the same side of the film web 1 like the error detection devices 2 and 3 be arranged. This can be one of the lighting devices 9 emitted light from the film are reflected and scattered and by the error detection devices 2 and 3 be recorded.

However, it is also possible to use the lighting fixtures 9 and the recognition devices 2 and 3 to arrange on different sides of the film web, so that the error detection devices 2 and 3 from the lighting device 9 receive emitted light that passes through the film. This is particularly advantageous in the detection of variations in a film thickness since a change in film thickness causes a change in the intensity of the light passing through.

In addition, in the apparatus for detecting film processing errors, polarizers 8th be arranged. By the use of polarizers 8th For example, the detection of a film defect can be further improved because of proper alignment of the polarizers 8th suppress unwanted light reflexes.

For example, in front of the light source 9 a polarizer 8th for linearly polarizing the light source 9 be emitted light emitted. This linearly polarized light is emitted from the film web 1 thrown back and through a second linear polarizer 8th in front of the lens of the error detection device 2 guided. In this case, the polarization directions of the polarizer in front of the light source 9 and the polarizer before the error detection device 2 are orthogonal to each other, so that upon rotation of the linearly polarized light due to a film defect, an error is detected by light in the error detection device 2 falls. Alternatively, however, it is also possible here, which is provided with a polarizer light source 9 and the polarizer-provided error detection device 2 to be arranged on different sides of the film web, so that a taking place during the passage of the light through the film web rotation of the polarization direction is detected due to a film defect.

In addition, a polarizing filter can only be used in front of the error detection device 3 be arranged. In addition, the use of color filters or indifference filters is advantageous because they can detect both film defects and processing errors particularly effectively. These color and interference filters can be matched in particular to the special properties of the film web. Especially when using a color filter can be color deviations of a film web 1 particularly easy to identify.

Further, the apparatus for detecting film processing errors may include a marking apparatus capable of marking a film area on which a processing error based on a film defect has been detected.

This has the advantage that errors can easily be found in a processed material again.

As a marker comes, for example, a color marker, a magnetic marker, a mark by labels, a mark by imprinting or any other marking that can be used to determine the position of the film defect based processing error in a later. Method to locate.

In particular, an identifier may be applied to the film by the marking device, for example a number or a file name that allows the assignment of an error to data generated by the error detection devices 2 and 3 been recorded. For example, an identifier, such as a number or a file name, for a recorded image can be printed on the film web, so that after processing the detected error by cameras 2 and 3 recorded images can be assigned.

This has the advantage of allowing a subsequent optical inspection and analysis of the processing error and its previous cause.

All of the devices and means illustrated in the first and second embodiments may be suitably combined together to achieve the advantages of the present invention.

LIST OF REFERENCE NUMBERS

1

sheet

2

Error detection device

3

Film detection device

4

detection device

5

Back injection device

6

spray layer

7

roll

8th

polarizers

9

Illumination device / light source

10

shaping tool

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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 10301931 A1 [0002]
• DE 102007043408 A1 [0003]

Claims (11)

Device for detecting film processing errors, comprising: - a first error detection device ( 2 ) for detecting a film defect of a film area prior to processing a film ( 1 ), - a second error detection device ( 3 ) for detecting a processing error of the processed film area and - a detection device ( 4 ) for detecting a processing error based on a film defect, if the film area has detected both a film defect and a processing defect. Apparatus according to claim 1, characterized in that a camera for the first or second error detection device ( 2 . 3 ) is provided for capturing an image of the film area. Apparatus according to claim 2, characterized by comparing means for comparing a captured image with a stored image to detect the film defect and / or processing error. Device according to one of the preceding claims, characterized in that a lighting device ( 9 ) for illuminating the film ( 1 ) is provided during recording and that a polarizing filter ( 8th ) for polarizing light during the shooting of the image or such is not provided. Device according to claim 1, characterized in that the detection device ( 4 ) is connected to an evaluation circuit, which determined the errors of a sufficient number of film sections before and after the injection molding process and compared and examined to determine typical defects in the film or typical errors of the subsequent injection molding process, wherein the detection of typical film defects of the injection process stopped and the film section is pulled as a film scrap through the back injection tool. Device according to one of the preceding claims, characterized in that a lighting device ( 9 ) for illuminating the film ( 1 ) is provided during the recording. A method of detecting film processing errors, comprising the steps of: - detecting a film defect of a film area prior to processing a film ( 1 ), - detecting a processing error of the processed film area, and - detecting a processing error based on a film defect if the film area has detected both a film defect and a processing defect. Method according to claim 7, characterized by the further method step: - Taking a picture by a camera to detect a film defect and / or a processing error. Method according to claim 7, characterized by the further method step: Comparing the captured image with a stored image to determine the film defect and / or processing error. Method according to one of claims 7 to 9, characterized by the further method step: - Illuminate the film with polarized or unpolarized light. Method according to one of claims 7 to 9, characterized in that with the error detection device, an error analysis is performed, in which the number of defects counted on the film or the back-sprayed film section and the errors are compared with each other, a typical error at least in the film The detection circuit, upon detection of a typical fault in or on the foil, outputs a control signal which suspends the back-injection process.

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