Inspection apparatus with improved detection of surface defects over large and curved surfaces

A surface defect inspection apparatus comprising:

• light radiation means, arranged to oppose a surface to be inspected serving as a mirror surface, for radiating light having a predetermined change pattern toward said surface to be inspected;
• imaging means for imaging an image of said light radiation means reflected by said surface to be inspected and forming a received-light image corresponding to the change pattern of said light radiation means;
• and
• image processing means for detecting a surface defect portion on said surface to be inspected by discriminating a portion whose change pattern is different from the change pattern on the basis of the received-light image formed by said imaging means,
• wherein said light radiation means radiates light having a luminous intensity distribution including high-level and low-level portions toward said surface to be inspected,
• wherein said light radiation means radiates, toward said surface to be inspected, light having the luminous intensity distribution which is set so that a luminous intensity is gradually changed from high level to low-level along a predetermined direction,
• wherein said imaging means images the image of said light radiation means reflected by said surface to be inspected, and forms the received-light image corresponding to the luminous intensity distribution of said light radiation means, and
• wherein when the change state of the luminous intensity distribution of the portion detected as the surface defect portion is the same as the change state of the luminous intensity distribution of the surrounding portion, said image processing means discriminates that the surface defect portion is formed in a convex shape, and when the change state of the luminous intensity distribution of the portion detected as the surface defect portion is opposite to the change state of the luminous intensity distribution of the surrounding portion, said image processing means discriminates that the surface defect portion is formed in a concave shape.

A surface defect inspection apparatus comprising:

• light radiation means, arranged to oppose a surface to be inspected serving as a mirror surface, for radiating light having a predetermined change pattern toward said surface to be inspected;
• imaging means for imaging an image of said light radiation means reflected by said surface to be inspected and forming a received-light image corresponding to the change pattern of said light radiation means;
• and
• image processing means for detecting a surface defect portion on said surface to be inspected by discriminating a portion whose change pattern is different from the change pattern on the basis of the received-light image formed by said imaging means,
• wherein said imaging means comprises a camera having a view field which is set to image the image of said light radiating means reflected by said surface to be inspected over an entire formation range of the received-light image,
• wherein said imaging means comprises video signal generation means for converting the received-light image into a video signal, and
• wherein said image processing means processes the video signal output from said video signal generation means, and discriminates a position and a three-dimensional pattern of the surface defect portion on the basis of a timing at which the processed value exceeds a predetermined value, and a change state of the processed value.

A surface defect inspection apparatus comprising:

• light radiation means, arranged to oppose a surface to be inspected serving as a mirror surface, for radiating light having a predetermined change pattern toward said surface to be inspected;
• imaging means for imaging an image of said light radiation means reflected by said surface to be inspected and forming a received-light image corresponding to the change pattern of said light radiation means;
• image processing means for detecting a surface defect portion on said surface to be inspected by discriminating a portion whose change pattern is different from the change pattern on the basis of the received-light image formed by said imaging means,
• wherein said light radiation means radiates, toward said surface to be inspected, light having a wavelength distribution which is set such that a wavelength is gradually changed from a long wavelength to a short wavelength in a predetermined direction,
• wherein said imaging means images the image of said light radiation means reflected by said surface to be inspected, and forms the received-light image having a wavelength distribution corresponding to the wavelength distribution of said light radiation means,
• wherein said image processing means discriminates a portion whose change state of the wavelength distribution is considerably different from a change state of a surrounding portion on the basis of the received-light image formed by said imaging means so as to detect the discriminated portion as the surface defect portion on said surface to be inspected, and
• wherein when the change state of the wavelength distribution of the portion detected as the surface defect portion is the same as the change state of the wavelength distribution of the surrounding portion, said image processing means discriminates that the surface defect portion is formed in a convex shape, and when the change state of the wavelength distribution of the portion detected as the surface defect portion is opposite to the change state of the wavelength distribution of the surrounding portion, said image processing means discriminates that the surface defect portion is formed in a concave shape.

A surface defect inspection apparatus comprising:

• light radiation means, arranged to opposite a surface to be inspected serving as a mirror surface, for radiating light having a predetermined change pattern toward said surface to be inspected;
• imaging means for imaging an image of said light radiation means reflected by said surface to be inspected and forming a received-light image corresponding to the change pattern of said light radiation means;
• image processing means for detecting a surface defect portion on said surface to be inspected by discriminating a portion whose change pattern is different from the change pattern on the basis of the received-light image formed by said imaging means,
• wherein said light radiation means radiates, toward said surface to be inspected, light having a color pattern in which colors are sequentially changed in a predetermined order along a predetermined direction,
• wherein said imaging means images the image of said light radiation means reflected by said surface to be inspected, and forms the received-light image having a color pattern corresponding to the color pattern of said light radiation means,
• wherein said image processing means discriminates a portion whose change state of the color pattern is different from a change state of a surrounding portion on the basis of the received-light image formed by said imaging means so as to detect the discriminated portion as the surface defect portion on said surface to be inspected, and
• wherein when the change state of the color pattern of the portion detected as the surface defect portion is the same as the change state of the color pattern of the surrounding portion, said image processing means discriminates that the surface defect portion is formed in a convex shape, and when the change state of the color pattern of the portion detected as the surface defect portion is opposite to the change state of the color pattern of the surrounding portion, said image processing means discriminates that the surface defect portion is formed in a concave shape.