The present disclosure provides a method of detecting the existence of a printed code on a product.
Printing systems are often used to print images or codes on a product, such as lot codes, bar codes, use by dates, and the like. It is often desired to automatically verify that a code has been printed, so that if the printer malfunctions, for example, an operated is notified so that he or she can fix the malfunction to both catch the products that have not been marked and minimize the amount of product that has to be reworked.
The present disclosure provides a method of detecting the existence of a printed code on a product. In particular, the system includes a camera and a mounting system to ensure that the camera is located in the proper place and does not require adjustment.
In one aspect, a printer system includes a print head, the print head oriented with a first end at a height above a substrate. A support arm extends laterally with respect to the print head. A camera is disposed on the support arm a fixed height above the substrate, such that the camera can be adjusted laterally with respect to the print head. The camera is disposed at an angle with respect to vertical to the substrate. A product detect mechanism is disposed laterally on the support arm with respect to the print head. A controller is in communication with the camera and the product detect mechanism, wherein the system is configured so that the camera can verify the printing of an image on the substrate.
A method of verifying an image printed on a substrate includes disposing a print head with a first end at a height above a substrate. A camera is disposed on a support at a fixed height above the substrate. The camera is adjusted laterally with respect to the print head, wherein the camera is disposed at an angle with respect to vertical to the substrate. A product detect mechanism is disposed laterally with respect to the print head. An image is printed on the substrate. Communication with the camera and the product detect mechanism is controlled to use the camera to verify the printing of the image on the substrate.
The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The presently preferred embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.
The invention is described with reference to the drawings in which like elements are referred to by like numerals. The relationship and functioning of the various elements of this invention are better understood by the following detailed description. However, the embodiments of this invention as described below are by way of example only, and the invention is not limited to the embodiments illustrated in the drawings.
The present disclosure provides a printer system for detecting whether a code was printed on a product. In particular, the system includes a camera and a mounting system to ensure that the camera is located in the proper place relative to a substrate and does not require adjustment. An embodiment of the system is shown in
The product detect mechanism 60 is disposed laterally in the direction of substrate movement with respect to the print head 30. A controller (not shown) is in communication with the camera 50 and the product detect mechanism 60. The system 10 is configured so that the camera 50 can verify the printing of an image on the substrate, or in other words, to identify products that are not marked by the print head. For example, if a code is not detected as printed on the substrate, the system 10 can alert an operator, stop the production line, or take other corrective action.
The camera 50 preferably has a field of view of at least 1″×3″. In one embodiment, the camera 50 is a Microscan Hawk Mini camera model. The presence of an image may be detected by any suitable methodology. The image may be detected by a machine vision methodology selected from OCR, OCV, barcode reader, pattern match, pixel counting, and presence/absence detect. The camera 50 preferably takes a snapshot image, rather than a continuous video of the substrate. In one embodiment, the system counts the number of pixels and uses a threshold to determine if the image is acceptable. For example, if X pixels are expected, the system may be set to trigger an alarm if the detected number of pixels is less than 85% of X.
The print head 30 has a feature for attaching the support arm 20 to the print head 30 such that the support arm 20 is disposed a fixed distance above the substrate 40. In one embodiment, the support arm 20 is connected to a collar 26 that encircles the print head 30. The collar 26 may rest in a circumferential groove in the print head 30 to control the fixed height of the support arm 20 (and thus camera 50) about the substrate. This arrangement ensures that the camera 50 is maintained at the proper height. Mount 22 is used to connect the camera 50 to the support arm 20 and preferably provides sliding movement with respect to the support arm 20. Mount 24 is used to connect the product detect 60 to the support arm 20 and preferably provides sliding movement with respect to the support arm 20.
The camera 50 has a fixed angle offset of between 4 degrees and 30 degrees with respect to vertical, preferably between 8 degrees and 20 degrees. In one embodiment, the camera has a fixed angle offset of 12.5 degrees with respect to vertical. In the embodiment shown in
The product detect mechanism 60 is positioned on a support arm such that it can provide a zero-delay trigger. In other words, the print head 50 is able to respond immediately once the product detect mechanism is triggered by the substrate moving beneath. This eliminates the need for the system to compensate for any delays between triggering and image capture. The trigger can be actuated by either the leading or the trailing edge of the product. Both the print head and the camera may be activated by the same product detect, or there may be separate product detects for the print head and the camera (as disclosed below).
A second embodiment 14 of the system is shown in
A third embodiment of a system 16 is shown in
A further variation of the embodiment shown in
A fourth embodiment 18 of the system is shown in
Each of the systems 10, 14, 16, 18 may be used as follows. The print head 30 is disposed with end 32 at a height above the substrate 40. The camera 50 is disposed at an angle with respect to vertical to the substrate 40. The product detect 60 detects the presence of the substrate 40 and the print head 30 prints an image on the substrate. The products detect 60 (or 62 if present) also is used to activate the camera 50 to view the substrate 40 after printing to verify the presence of a printed image on the substrate 40. Communication between the camera 50 and the product detect mechanism 60 thus allows the camera 50 to verify the printing of the image on the substrate 40.
Although examples are shown using the system with a continuous inkjet system, it will be apparent that the code detect and other features of the system can be used with other types of printing technology, such as thermal inkjet, piezo inkjet, laser marking, thermal transfer printing, and the like.
An example of the inventive system is described as follows. A system is set up on a production line for printing on moving substrates. Various orientations of the product detect, camera, and printer are illustrated in
The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the scope of the inventions as defined in the claims are desired to be protected. It should be understood that while the use of words such as “preferable”, “preferably”, “preferred” or “more preferred” in the description suggest that a feature so described may be desirable, it may nevertheless not be necessary and embodiments lacking such a feature may be contemplated as within the scope of the invention as defined in the appended claims. In relation to the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
Filing Document | Filing Date | Country | Kind |
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PCT/US2014/043780 | 6/24/2014 | WO | 00 |
Number | Date | Country | |
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61840270 | Jun 2013 | US |