Process and device for detecting the presence of an object, preferably a leaf sheet-shaped or sheet-shaped object for printing

Abstract

Detecting the presence of an object, preferably a leaf sheet-shaped or sheet-shaped object on a transport path, especially for preparation and/or control of a processing of the object, preferably for printing the object in a printing machine, especially a digital printer, where the object is transported on the transport path past a sensor device, preferably a photoelectric barrier, for detection and registration of the front edge of the object in the transport direction. After detecting the front edge of the object and/or its entrance into the measurement area, it is checked at least once to determine whether the object continues to be present in the measurement area of the sensor device.

What is claimed is:  
     
         1 . Process for detecting the presence of an object, preferably a leaf sheet-shaped or sheet-shaped object on a transport path, especially for preparation and/or control of a processing of the object, preferably for printing the object in a printing machine, especially a digital printer, where the object is transported on the transport path past a sensor device, preferably a photoelectric barrier, for detection and registration of the front edge of the object in the transport direction, characterized in that after detecting the front edge of the object, it is checked at least once to determine whether the object continues to be present in the measurement area of the sensor device.  
     
     
         2 . Process according to  claim 1 , characterized in that the check is done multiple times in a clock-pulsed manner.  
     
     
         3 . Process according to  claim 2 , characterized in that a certain time interval pulsing is specified.  
     
     
         4 . Process according to  claim 2 , characterized in that a transport distance covered by the object is measured and that a certain path section clock-pulsing is specified for the sensor device.  
     
     
         5 . Process according to  claim 2 , characterized in that the position of the measurement area of the sensor device is defined and specified on the transport path with regard to a reference point.  
     
     
         6 . Process according to  claim 2 , characterized in that for the check of the presence of the object, a minimum length of an object in the transport direction is taken into consideration, in such a way that only upon the presence of the object even after the minimum length has been covered in the measurement area past the sensor device, a detected object is recognized as such.  
     
     
         7 . Process according to  claim 6 , characterized in that when using formatted objects, the length of the smallest format provided for possible use is considered as a minimum length.  
     
     
         8 . Process according to  claim 2 , characterized in that the clock pulsing, when using a time interval clock pulsing taking into account the transport speed, is used for a measurement of the length of the object.  
     
     
         9 . Device for detecting the presence of an object, preferably a leaf sheet-shaped or sheet-shaped object on a transport path, especially for preparation and/or control of a processing of the object, preferably for printing the object in a printing machine, especially a digital printer, where the transport path passes by a sensor device, preferably a photoelectric barrier, for detection and registration of the front edge of the object in the transport direction, characterized in that the sensor device ( 4 ) is set up to check at least once to determine whether the object ( 3 ) continues to be present in the measurement area ( 5 ) after first detecting the object ( 3 ).  
     
     
         10 . Device according to  claim 9 , characterized in that the sensor device ( 4 ) is clock-pulsed for multiple checking.  
     
     
         11 . Device according to  claim 10 , characterized in that a certain time interval clock-pulsing is specified for the sensor device ( 4 ).  
     
     
         12 . Device according to  claim 10 , characterized by a measurement device ( 10 ) for measuring a transport path that is covered by the object ( 3 ) is in connection with the sensor device ( 4 ) to specify a certain path section clock-pulsing for the sensor device ( 4 ).  
     
     
         13 . Device according to  claim 12 , characterized in that the sensor device ( 4 ) and the measurement device ( 10 ) are connected to each other to measure the transport distance via a computational unit and/or a signal output unit ( 6 ).  
     
     
         14 . Device according to  claim 9 , characterized in that the position of the measurement area ( 5 ) of the sensor device ( 4 ) on the transport path is defined and specified with regard to a reference point ( 9 ).  
     
     
         15 . Device according to  claim 9 , characterized in that to transport the object ( 3 ) along the transport path, a transparent conveyor belt ( 1 ) is provided, on which the object ( 3 ) can be placed.