Automatic system for detecting printing faults on metallized strips or any other printing support comprising a predominance of specular color surfaces
First Claim
1. An automatic system (1) for detecting printing faults on metallised strips (3) or any other printing support comprising a predominance of specular colour surfaces, characterised in that the said system, arranged in a blackout casing (2), comprises an arm (30) on which there can move automatically a lighting unit (10) provided with a video camera (55) having a variable-focus lens (56) which, through a semi-transparent filter (57) disposed in an oblique position in front of the lens, continuously films a portion of the strip (3) of a format (7) of variable size, and in that the illumination of this strip portion is provided by two direct-illumination flashlights (12, 14), provided primarily to illuminate the non-specular surfaces of the strip, and by two other indirect-illumination flashlights (11, 13), advantageously provided to illuminate the specular colour surfaces, one of the two flashlights (11, 13) comprising a translucent flat diffuser (27) disposed on its leading front surface and oriented preferentially in the direction of the semi-transparent filter (57), while the other flashlight (11) is oriented in the direction of the surface of a concave and opaque diffuser (25) enclosing the semi-transparent filter (57), and which is mounted at its centre on a sleeve (26) which provides the mechanical and optical connection between the diffuser (25) and the lens (56) of the camera (55).
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Accused Products
Abstract
This automatic system (1) detects printing faults on metallized strips (3) or any other printing support comprising a predominance of specular color surfaces. The said system, arranged in a blackout casing (2), comprises an arm (30) on which there can move automatically a lighting unit (10) provided with a video camera (55). The camera has a variable-focus lens (56) which, through a semi-transparent filter (57) disposed in an oblique position in front of the lens, continuously films a portion of the strip (3) of a format (7) of variable size. The illumination of this strip portion is provided by two direct-illumination flashlights (12, 14), provided primarily to illuminate the non-specular surfaces of the strip, and by two other indirect-illumination flashlights (11, 13), advantageously provided to illuminate the specular color surfaces. One of the two flashlights (11, 13) comprises a translucent flat diffuser (27) disposed on its leading front surface and oriented preferentially in the direction of the semi-transparent filter (57), while the other flashlight (11) is oriented in the direction of the surface of a concave and opaque diffuser (25). Enclosing the semi-transparent filter (57), the diffuser (25) is mounted at its center on a sleeve (26) which provides the mechanical and optical connection between the diffuser (25) and the lens (56) of the camera (55).
20 Citations
10 Claims
- 1. An automatic system (1) for detecting printing faults on metallised strips (3) or any other printing support comprising a predominance of specular colour surfaces, characterised in that the said system, arranged in a blackout casing (2), comprises an arm (30) on which there can move automatically a lighting unit (10) provided with a video camera (55) having a variable-focus lens (56) which, through a semi-transparent filter (57) disposed in an oblique position in front of the lens, continuously films a portion of the strip (3) of a format (7) of variable size, and in that the illumination of this strip portion is provided by two direct-illumination flashlights (12, 14), provided primarily to illuminate the non-specular surfaces of the strip, and by two other indirect-illumination flashlights (11, 13), advantageously provided to illuminate the specular colour surfaces, one of the two flashlights (11, 13) comprising a translucent flat diffuser (27) disposed on its leading front surface and oriented preferentially in the direction of the semi-transparent filter (57), while the other flashlight (11) is oriented in the direction of the surface of a concave and opaque diffuser (25) enclosing the semi-transparent filter (57), and which is mounted at its centre on a sleeve (26) which provides the mechanical and optical connection between the diffuser (25) and the lens (56) of the camera (55).
Specification