Die stamping press having CCD camera system for automatic 3-axis die registration

A method of successively aligning a die unit of a die cutting press with defined areas of elongated material, the material including area indicia provided in predetermined positions relative to each of the defined areas, the method comprising the steps of:

• longitudinally advancing the material along a path of travel to successively feed the defined areas of the material toward the die unit;
• providing at least one camera for receiving images;
• focusing the at least one camera on predetermined locations relative to the die unit corresponding to the predetermined positions of the area indicia relative to the defined areas of the material and receiving images of the material at the predetermined locations;
• providing reference means which generates reference image data representative of the desired position of the area indicia within each image received by the camera;
• interrupting successive movement of the areas toward the die unit when a corresponding area indicia is substantially at said predetermined location relative to the die unit and said camera;
• comparing the reference image data with an image received by the camera after movement of the material has been interrupted with a corresponding area indicia in said predetermined location thereof;
• generating longitudinal, lateral and angular difference data representative of the difference in position between the area indicia within the image and the desired position of the area indicia;
• and
• moving the material in the longitudinal direction to compensate for the difference in longitudinal position between the indicia within the image and the desired longitudinal position of the indicia, moving the die unit relative to the material along a direction of travel transverse to the path of travel of the material to compensate for the difference in lateral position between the indicia within the image and the desired lateral position of the indicia, and rotating the die unit relative to the material about a reference axis perpendicular to a plane containing the material to compensate for the difference in angular position between the indicia within the image and the desired angular position of the indicia so that one of the defined areas of the material is in register with the die unit.

In a die cutting press for elongated material having a planer surface provided with defined, successive areas and area indicia provided in predetermined positions relative to each of the defined areas, the press including a base platen, a ram platen shiftable toward and away from the base platen, a removable die unit positionable in the space between the base platen and the ram platen, and longitudinal shifting means for longitudinally advancing the material along a path of travel to successively feed the defined areas of the material toward the die unit, a registration system for successively positioning the die unit in predetermined relationship to the defined areas of the material as successive defined areas are brought into a position to be processed by the die unit, the registration system comprising:

• lateral shifting means for moving the die unit relative to the base platen along a direction of travel transverse to the path of travel of the material;
• angular shifting means for rotating the die unit relative to the base platen about a reference axis perpendicular to a plane containing the material;
• a first camera for receiving images, the first camera being attachable to the die init at a position laterally disposed from the elongated material;
• first image directing means fixed to the die unit for directing an image from a first region of the die unit toward the first camera, the first region including a first preset location of the die unit corresponding to the position of a first area indicium when the elongated material is in the predetermined relationship relative to the die unit, the first image directing means including a reference indicium which appears within the directed image at a fixed position relative to the first preset location;
• first focusing means for focusing the first camera on the first image directing means;
• reference means for providing reference image data representative of the position of the first preset location within the images received by the first camera;
• means for interrupting successive movement of the areas toward the die unit when a corresponding area indicia is substantially at said predetermined location relative to the die unit and said camera;
• comparison means for comparing the reference image data with an image received by the first camera after movement of the material has been interrupted with a corresponding area indicia in said predetermined location thereof and for generating longitudinal, lateral and angular difference data representative of the difference between the position of the first indicium within the image and the position of the first preset location within the image;
• and
• control means for receiving the longitudinal, lateral and angular difference data and operating the longitudinal, angular and lateral shifting means to change the position of the material relative to the die unit to compensate for the difference in position between the first indicium and the first preset location so that the die unit is in the predetermined relationship with one of the defined areas of the material.