Method and apparatus for detecting product defects during the production of mailing products, hygiene products, or folded paper products

Abstract

To detect product defects during the production of mailing products, hygiene products or folded paper products, optical imaging sensors or capacitive sensors monitor at least one characteristic parameter or feature of the products successively moving through the production machine, to detect an actual value of each characteristic parameter or feature of each product. The detected actual value is compared with a stored nominal value for the respective characteristic parameter or feature. The result of the comparison is used to initiate or control a further measure, such as ejecting a defective product from the production line, marking a defective product so that it can be visually recognized and manually removed from the production line, or initiating corrective measures to correct the cause of the defect. The characteristic parameters or features relate to the dimensions, the position, and/or the form of the product or parts of the product.

What is claimed is:  
     
         1 . A method for detecting product defects of products selected from mailing products, hygiene products, and folded paper products, during producing or packaging of said products, comprising the steps: 
 a) producing or packaging said products in a machine including plural machine components;    b) storing a respective nominal value respectively for each one of at least one characteristic parameter or characteristic feature of said products, with respect to at least one of a dimension, a form, and a position of said products or respective parts of said products;    c) during said producing or packaging of said products, detecting a respective actual value of each said characteristic parameter or characteristic feature of said products, respectively for each individual one of said products;    d) respectively comparing each said actual value with said nominal value for each said respective characteristic parameter or characteristic feature, to provide a respective comparison result indicative of how said actual value compares to said nominal value, for each said individual one of said products; and    e) in response to and dependent on said comparison result, carrying out a further measure with respect to any defective product among said products for which said comparison result indicates that a defect exists.    
     
     
         2 . The method according to  claim 1 , further comprising detecting a plurality of said actual values with respect to a dimension, a form, or a position of said product or of a part of said product, relative to each other.  
     
     
         3 . The method according to  claim 1 , used for detecting said product defects of said mailing products during said producing of said mailing products.  
     
     
         4 . The method according to  claim 1 , wherein said further measure of said step e) comprises at least one of indicating said comparison result, carrying out a corrective measure for correcting said defect, marking said defective product, documenting said comparison result, and ejecting said defective product out of said machine.  
     
     
         5 . The method according to  claim 1 , wherein said detecting of said actual value is carried out electrically or electronically, using at least one of a line camera and a capacitive sensor.  
     
     
         6 . The method according to  claim 1 , wherein said detecting of said actual value is carried out using an optical sensor or a line camera, and at least one mirror, so as to deflect an image beam of an image of said characteristic parameter or characteristic feature of said product via said at least one mirror to be received by said optical sensor or said line camera.  
     
     
         7 . The method according to  claim 1 , wherein said characteristic parameter or characteristic feature of said product comprises at least one of a size, dimensions, a position, and a shape of a contour of a cut blank for said product, or of at least one glue strip of said product.  
     
     
         8 . The method according to  claim 1 , used for detecting said defects in said folded paper products or said hygiene products during said producing of said folded paper products or said hygiene products, or for detecting said defects in said mailing products or said hygiene products during said packaging of said mailing products or said hygiene products.  
     
     
         9 . The method according to  claim 1 , further for detecting defects in printed matter that is printed onto said products by a printing machine during said producing of said products.  
     
     
         10 . An apparatus for producing mailing products, hygiene products, or folded paper products, and for detecting product defects of said products, comprising: 
 a plurality of machine components forming plural machine stations for performing successive steps in producing said products;    evaluation electronics; and    at least one of an imaging sensor and a capacitive sensor arranged to monitor said products in at least one of said machine stations and connected for signal transmission to said evaluating electronics.    
     
     
         11 . The apparatus according to  claim 10 , wherein said sensor is arranged to monitor at least one of a size, dimensions, and a position of a contour of at least one of a cut blank for said products and glue strips for said products.  
     
     
         12 . The apparatus according to  claim 10 , further comprising a housing and at least one mirror, wherein said sensor is arranged in said housing together with said at least one mirror which is arranged to deflect an image beam path from said product to said sensor.  
     
     
         13 . The apparatus according to  claim 10 , comprising at least two of said sensors grouped together to form a monitoring device.