Method and apparatus for detecting defects in a surface regardless of surface finish

Claim 1

A method of inspecting the surface of a running object comprising the steps of scanning the surface of a running object with a spot light source through an optical scanning means, condensing said light reflected on said surface of said running object, detecting a regularly reflected component of said light at the point of said condensation, simultaneously detecting irregularly reflected light components at a plurality of predetermined positions in the vicinity of said condensation point, summing the detected light components derived at said respective positions, comparing said sum with a predetermined reference value, and producing an output representing a defect when said total deviates from said reference value, thereby making it possible to detect said defect discriminatively without being affected by the manner in which said surface of said object is finished.

Claim 2

A method of inspecting the surface of a running object comprising the steps of scanning the surface of a running object with a spot light source through an optical scanning means, condensing said light reflected on said surface of said running object, detecting a regularly reflected component of said light at the point of said condensation, simultaneously detecting irregularly reflected light components at a plurality of predetermined positions in the vicinity of said condensation point, summing the detected light components derived at said respective positions, comparing said sum with a predetermined reference value, and producing an output representing a defect when said total deviates from said reference value, thereby making it possible to detect said defect discriminatively without being affected by the manner in which said surface of said object is finished.

Claim 3

A method of inspecting the surface of a running object comprising the steps of scanning the surface of a running object with a spot light source, condensing said light reflected on said surface of said running object, detecting a regularly reflected component of said light at the point of said condensation, simultaneously detecting irregularly reflected light components at a plurality of predetermined positions in the vicinity of said condensation point, comparing a predetermined reference value with the absolute value of the difference between the output current of at least two of said irregularly reflected light receiving photoelectric converter elements disposed punctually symmetric with respect to said condensation position, and producing an output representing a defect when said difference exceeds said reference value, thereby making it possible to detect a defect discriminatively.

Claim 4

A method of inspecting the surface of a running object comprising the steps of scanning the surface of a running object with a spot light source, condensing said light reflected on said surface of said running object, detecting a regularly reflected component of said light at the point of said condensation, simultaneously detecting irregularly reflected light components at a plurality of predetermined positions in the vicinity of said condensation point, comparing a predetermined reference value with the absolute value of the difference between the output current of at least two of said irregularly reflected light receiving photoelectric converter elements disposed punctually symmetric with respect to said condensation position, and producing an output representing a defect when said difference exceeds said reference value, thereby making it possible to detect a defect discriminatively.

Claim 5

A method of inspecting the surface of a running object comprising the steps of scanning the surface of a running object with a spot light source, condensing said light reflectd on said surface of said running object, detecting a regularly reflected component of said light at the point of said condensation, simultaneously detecting irregularly reflected light components at a plurality of predetermined positions in the vicinity of said condensation point, comparing individual components of said irregularly reflected light with a predetermined reference value, and producing a signal representing a defect when an individual value of a light component exceeds said reference value without any change in the absolute value of the light components at least at two of said irregularly reflected light positions which are symmetric with respect to said condensation point, thereby making it possible to detect a defect discriminatively.

Claim 6

A method of inspecting the surface of a running object comprising the steps of scanning the surface of a running object with a spot light source, condensing said light reflectd on said surface of said running object, detecting a regularly reflected component of said light at the point of said condensation, simultaneously detecting irregularly reflected light components at a plurality of predetermined positions in the vicinity of said condensation point, comparing individual components of said irregularly reflected light with a predetermined reference value, and producing a signal representing a defect when an individual value of a light component exceeds said reference value without any change in the absolute value of the light components at least at two of said irregularly reflected light positions which are symmetric with respect to said condensation point, thereby making it possible to detect a defect discriminatively.

Claim 7

An apparatus for inspecting the surface of a running object for defects comprising means for continuously scanning a spot of light over the surface of said running object, means for condensing the light reflected from said surface as a result of such scanning, a first detector positioned at a point at which regularly reflected light will be projected by said condensing means, a plurality of second detectors disposed at predetermined positions in the vicinity of said first detector so as to detect irregularly reflected light, and control means responsive to the outputs from said first and second detectors for generating a flaw indicating signal, said control means including first means for detecting a difference between the outputs of at least two of said second detectors which are disposed symmetrically on diametrically opposite sides of said first detector and second means responsive to an output of said first means in excess of a predetermined threshold for generating a first flaw indicating signal.

Claim 8

An apparatus for inspecting the surface of a running object for defects comprising means for continuously scanning a spot of light over the surface of said running object, means for condensing the light reflected from said surface as a result of such scanning, a first detector positioned at a point at which regularly reflected light will be projected by said condensing means, a plurality of second detectors disposed at predetermined positions in the vicinity of said first detector so as to detect irregularly reflected light, and control means responsive to the outputs from said first and second detectors for generating a flaw indicating signal, said control means including first means for detecting a difference between the outputs of at least two of said second detectors which are disposed symmetrically on diametrically opposite sides of said first detector and second means responsive to an output of said first means in excess of a predetermined threshold for generating a first flaw indicating signal.

Claim 22

An apparatus for inspecting the surface of a running object for defects comprising means for continuously scanning a spot of light over the surface of said running object, means for condensing the light reflected from said surface as a result of such scanning. a first detector positioned at a point at which regularly reflected light will be projected by said condensing means, a plurality of second detectors disposed at predetermined positions in the vicinity of said first detector so as to detect irregularly reflected light, and control means responsive to the outputs from said first and second detectors for generating a flaw indicating signal, said control means including first means for comparing the output of at least one of said second detectors with a predetermined threshold and third means for generating a first flaw indicating signal in response to the detection by said first means of the output of said second detector exceeding said predetermined threshold.

Claim 23

An apparatus for inspecting the surface of a running object for defects comprising means for continuously scanning a spot of light over the surface of said running object, means for condensing the light reflected from said surface as a result of such scanning. a first detector positioned at a point at which regularly reflected light will be projected by said condensing means, a plurality of second detectors disposed at predetermined positions in the vicinity of said first detector so as to detect irregularly reflected light, and control means responsive to the outputs from said first and second detectors for generating a flaw indicating signal, said control means including first means for comparing the output of at least one of said second detectors with a predetermined threshold and third means for generating a first flaw indicating signal in response to the detection by said first means of the output of said second detector exceeding said predetermined threshold.

Claim 28

An apparatus for inspecting the surface of a running object for defects comprising means for continuously scanning a spot of light over the surface of said running object, means for condensing the light reflected from said surface as a result of such scanning, a first detector positioned at a point at which regularly reflected light will be projected by said condensing means, a plurality of second detectors disposed at predetermined positions in the vicinity of said first detector so as to detect irregularly reflected light, and control means responsive to the outputs from said first and second detectors for generating a flaw indicating signal, said control means including first means for adding the outputs of at least two detectors of the group of first and second detectors and second means for comparing the output of said first means to a predetermined reference value to generate a first flaw indicating signal when said output exceeds said reference value.

Claim 29

An apparatus for inspecting the surface of a running object for defects comprising means for continuously scanning a spot of light over the surface of said running object, means for condensing the light reflected from said surface as a result of such scanning, a first detector positioned at a point at which regularly reflected light will be projected by said condensing means, a plurality of second detectors disposed at predetermined positions in the vicinity of said first detector so as to detect irregularly reflected light, and control means responsive to the outputs from said first and second detectors for generating a flaw indicating signal, said control means including first means for adding the outputs of at least two detectors of the group of first and second detectors and second means for comparing the output of said first means to a predetermined reference value to generate a first flaw indicating signal when said output exceeds said reference value.