Surface inspection system and method of inspecting surface of workpiece

Claim 2

A surface inspection system for detecting particles or defects on a surface of a workpiece, the surface inspection system comprising: means for translationally transporting a workpiece along a material path; means associated with said transporting means for rotating a workpiece during translational travel along the material path; a scanner positioned and arranged to scan a surface of a workpiece during rotational and translational travel along the material path, said scanner including a light source arranged to generate a light beam therefrom and means positioned to receive the light beam and arranged for scanning the light beam along a predetermined scan path across a surface of the workpiece as the workpiece rotationally and translationally travels along the material path; and a collector arranged for collecting light reflected and scattered from the surface of the workpiece during rotational and translational travel along the material path, said collector comprising: a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned closely adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece.

Claim 3

A surface inspection system as defined by claim 1, wherein said translational transporting means and said rotating means are synchronized and arranged with said scanner so as to form a substantially spiral-shaped angle scan of the surface of the workpiece during rotational and translational travel along the material path.

Claim 4

A surface inspection system as defined by claim 2, wherein the predetermined scan path comprises a relatively narrow scan path of no greater than 0.1 radians along the surface of the workpiece.

Claim 5

A surface inspection system as defined by claim 2, wherein the predetermined scan path comprises a relatively narrow scan path in a range between about 0.025 to 0.040 radians.

Claim 6

A surface inspection system as defined by claim 1, wherein said scanning means comprises a deflector arranged to repetitively deflect the light beam along a predetermined narrow scan path along the surface of the workpiece.

Claim 7

A surface inspection system as defined by claim 1, wherein said plurality of collectors of said dark channel detector comprises a small angle collector arranged to collect light components scattered forwardly from the surface of the workpiece at a relatively small angle, a medium angle collector positioned adjacent said small angle collector and arranged to collect light components scattered substantially normal from the surface of the workpiece at a relatively medium angle, and a large angle collector positioned adjacent said medium angle collector and arranged to collect light components scattered backwardly from the surface of the workpiece at a relatively large angle, and wherein said dark channel detector further includes a small angle detector, a medium angle detector, and a large angle detector each respectively positioned in optical communication with a corresponding collector for detecting collected light, and means electrically connected to said small, medium, and large angle detectors and responsive to electrical signals from said detectors for determining the presence of a particle on the surface of the workpiece.

Claim 8

A surface inspection system for detecting particles or defects on a surface of a workpiece, the surface inspection system comprising: a transporter arranged to translationally transport a workpiece along a material path; a rotator associated with said transporter and arranged to rotate a workpiece during translational travel along the material path; a scanner positioned and arranged to scan a surface of a workpiece during rotational and translational travel along the material path, said scanner including a laser source arranged to generate a laser light beam therefrom and a deflector positioned to receive the light beam and arranged to deflect the light beam along a relatively narrow scan path toward a surface of the workpiece as the workpiece rotatively and translationally travels along the material path; a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece.

Claim 9

A surface inspection system for detecting particles or defects on a surface of a workpiece, the surface inspection system comprising: a transporter arranged to translationally transport a workpiece along a material path; a rotator associated with said transporter and arranged to rotate a workpiece during translational travel along the material path; a scanner positioned and arranged to scan a surface of a workpiece during rotational and translational travel along the material path, said scanner including a laser source arranged to generate a laser light beam therefrom and a deflector positioned to receive the light beam and arranged to deflect the light beam along a relatively narrow scan path toward a surface of the workpiece as the workpiece rotatively and translationally travels along the material path; a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece.

Claim 10

A surface inspection system as defined by claim 7, wherein said transporter and said rotator are synchronized and arranged with said scanner so as to form a spiral-shaped narrow angle scan of the surface of the workpiece during rotational and translational travel along the material path.

Claim 11

A surface inspection system as defined by claim 8, wherein the rotator includes means for varying the speed of rotating the workpiece during translational travel along the material path during the scan of the surface of the workpiece so as to provide a substantially constant scanning speed of the surface of the workpiece.

Claim 12

A surface inspection system as defined by claim 8, wherein the relatively narrow scan path along the surface of the workpiece is no greater than 0.1 radians.

Claim 13

A surface inspection system as defined by claim 10, wherein said deflector is arranged to repetitively deflect the light beam along a predetermined narrow scan path along the surface of the workpiece, and wherein said scanner further includes means for directing the light beam from the narrow scan path toward a surface of the workpiece at a relatively low angle of incidence as the workpiece rotatively and translationally travels along the material path.

Claim 14

A surface inspection system as defined by claim 11, wherein the relatively low angle of incidence is greater than 45 degrees from normal to the workpiece.

Claim 15

A surface inspection system as defined by claim 12, wherein said plurality of collectors of said dark channel detector comprises a small angle collector arranged to collect light components scattered forwardly from the surface of the workpiece at a relatively small angle, a medium angle collector positioned adjacent said small angle collector and arranged to collect light components scattered substantially normal from the surface of the workpiece at a relatively medium angle, and a large angle collector positioned adjacent said medium angle collector and arranged to collect light components scattered backwardly from the surface of the workpiece at a relatively large angle, and wherein said dark channel detector further includes a small angle detector, a medium angle detector, and a large angle detector each respectively positioned in optical communication with a corresponding collector for detecting collected light, and means electrically connected to said small, medium, and large angle detectors and responsive to electrical signals from said detectors for determining the presence of a particle on the surface of the workpiece.

Claim 16

A surface inspection system as defined by claim 8, wherein the relatively narrow scan path along the surface of the workpiece is in a range between about 0.025 to 0.040 radians.

Claim 17

A surface inspection system for detecting particles or defects on a surface of a workpiece, the surface inspection system comprising: a transporter arranged to translationally transport a workpiece along a material path; a rotator associated with said transporter and arranged to rotate a workpiece during translational travel along the material path; a scanner positioned and arranged to scan a surface of a workpiece during rotational and translational travel along the material path, said scanner including a laser source arranged to generate a laser light beam therefrom, a deflector positioned to receive the light beam and arranged to deflect the light beam along a relatively narrow scan path, the relatively narrow scan path being no greater than 0.1 radians and directionally corresponding to the translational travel of the workpiece, and means positionally aligned with said deflector and arranged for directing the light beam from the narrow scan path toward a surface of a workpiece at a relatively low angle of incidence as a workpiece rotatively and translationally travels along the material path; a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned adjacent each other and at different respective predetermined angles from the surface of the workpiece.

Claim 18

A surface inspection system for detecting particles or defects on a surface of a workpiece, the surface inspection system comprising: a transporter arranged to translationally transport a workpiece along a material path; a rotator associated with said transporter and arranged to rotate a workpiece during translational travel along the material path; a scanner positioned and arranged to scan a surface of a workpiece during rotational and translational travel along the material path, said scanner including a laser source arranged to generate a laser light beam therefrom, a deflector positioned to receive the light beam and arranged to deflect the light beam along a relatively narrow scan path, the relatively narrow scan path being no greater than 0.1 radians and directionally corresponding to the translational travel of the workpiece, and means positionally aligned with said deflector and arranged for directing the light beam from the narrow scan path toward a surface of a workpiece at a relatively low angle of incidence as a workpiece rotatively and translationally travels along the material path; a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned adjacent each other and at different respective predetermined angles from the surface of the workpiece.

Claim 19

A surface inspection system as defined by claim 15, wherein said transporter and said rotator are synchronized and arranged with said scanner so as to form a spiral-shaped narrow angle scan of the surface of the workpiece during rotational and translational travel along the material path.

Claim 20

A surface inspection system as defined by claim 16, wherein the rotator includes means for varying the speed of rotating the workpiece during translational travel along the material path and the transporter includes means for varying the speed of translationally transporting the workpiece along the material path during the scan of the surface of the workpiece so as to provide a substantially constant scanning speed of the surface of the workpiece.

Claim 21

A surface inspection system as defined by claim 17, wherein the relatively low angle of incidence is greater than 45 degrees from normal to the workpiece.

Claim 22

A surface inspection system as defined by claim 18, wherein said plurality of collectors of said dark channel detector comprises a small angle collector arranged to collect light components scattered forwardly from the surface of the workpiece at a relatively small angle, a medium angle collector positioned adjacent said small angle collector and arranged to collect light components scattered substantially normal from the surface of the workpiece at a relatively medium angle, and a large angle collector positioned adjacent said medium angle collector and arranged to collect light components scattered backwardly from the surface of the workpiece at a relatively large angle, and wherein said dark channel detector further includes a small angle detector, a medium angle detector, and a large angle detector each respectively positioned in optical communication with a corresponding collector for detecting collected light, and means electrically connected to said small, medium, and large angle detectors and responsive to electrical signals from said detectors for determining the presence of a particle on the surface of the workpiece.

Claim 23

A surface inspection system as defined by claim 19, wherein said directing means includes a mirror and a plurality of optical lenses positioned between said laser source and the material path and arranged to direct the light beam toward the surface of the workpiece to be inspected.

Claim 24

A surface inspection system arranged for scanning a surface of a workpiece, the surface inspection system comprising: a light source arranged to generate a light beam therefrom; means for receiving the light beam and scanning a relatively narrow scan path toward a surface of a workpiece; and means for imparting a rotational and translational scan of the workpiece, and means for varying the speed of rotating the workpiece during translational travel along the material path during the scan of the surface of the workpiece so as to provide a substantially constant scanning speed of the surface of the workpiece.

Claim 25

A surface inspection system arranged for scanning a surface of a workpiece, the surface inspection system comprising: a light source arranged to generate a light beam therefrom; means for receiving the light beam and scanning a relatively narrow scan path toward a surface of a workpiece; and means for imparting a rotational and translational scan of the workpiece, and means for varying the speed of rotating the workpiece during translational travel along the material path during the scan of the surface of the workpiece so as to provide a substantially constant scanning speed of the surface of the workpiece.

Claim 26

A surface inspection system as defined by claim 21, wherein the relatively narrow scan path along the surface of the workpiece is no greater than 0.1 radians.

Claim 27

A surface inspection system as defined by claim 22, wherein said scanning means comprises a deflector arranged to repetitively deflect the light beam along a predetermined narrow scan path along the surface of the workpiece.

Claim 28

A surface inspection system as defined by claim 22, further comprising means positionally aligned with said scanning means for directing the light beam toward the surface of the workpiece at a relatively low angle of incidence, said directing means including a mirror and a plurality of optical lenses.

Claim 29

A surface inspection system as defined by claim 21, wherein the relatively narrow scan path is in a range between about 0.025 to 0.040 radians.

Claim 30

An optical scanner arranged for detecting particles or defects on a surface of a workpiece, the optical scanner comprising: a laser arranged to generate a laser light beam therefrom; an acousto-optical deflector arranged to receive the light beam and to deflect the light beam along a relatively narrow scan path, the relatively narrow scan path being no greater than 0.1 radians; means associated with said laser and said acousto-optical deflector for directing the light beam toward a surface of a workpiece at a relatively low angle of incidence as the workpiece rotatively and translationally travels along a material path, said directing means including a mirror and a plurality of optical lenses arranged to direct the light beam toward the surface of the workpiece to be inspected; a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector arranged for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned closely adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece.

Claim 31

An optical scanner arranged for detecting particles or defects on a surface of a workpiece, the optical scanner comprising: a laser arranged to generate a laser light beam therefrom; an acousto-optical deflector arranged to receive the light beam and to deflect the light beam along a relatively narrow scan path, the relatively narrow scan path being no greater than 0.1 radians; means associated with said laser and said acousto-optical deflector for directing the light beam toward a surface of a workpiece at a relatively low angle of incidence as the workpiece rotatively and translationally travels along a material path, said directing means including a mirror and a plurality of optical lenses arranged to direct the light beam toward the surface of the workpiece to be inspected; a light channel detector arranged for detecting light specularly reflected from the surface of a workpiece; and a dark channel detector arranged for detecting light scattered from the surface of a workpiece, said dark channel detector including a plurality of collectors positioned closely adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece.

Claim 32

An optical collector for collecting light reflected from a surface of a workpiece and for providing information about particles detected on a surface of a workpiece, the optical collector comprising dark channel detection means for detecting light scattered from a surface of a workpiece, said dark channel detection means including a plurality of collectors positioned adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece, said plurality of collectors including at least a collector arranged for collecting forwardly scattered light from the surface of the workpiece and a collector arranged for collecting backwardly scattered light from the surface of the workpiece.

Claim 33

An optical collector for collecting light reflected from a surface of a workpiece and for providing information about particles detected on a surface of a workpiece, the optical collector comprising dark channel detection means for detecting light scattered from a surface of a workpiece, said dark channel detection means including a plurality of collectors positioned adjacent each other and arranged for collecting components of the scattered light at different respective predetermined angles from the surface of the workpiece, said plurality of collectors including at least a collector arranged for collecting forwardly scattered light from the surface of the workpiece and a collector arranged for collecting backwardly scattered light from the surface of the workpiece.

Claim 34

An optical collector as defined by claim 27, wherein said plurality of collectors of said dark channel detector comprises a small angle collector arranged to collect light components scattered forwardly from the surface of the workpiece at a relatively small angle, a medium angle collector positioned adjacent said small angle collector and arranged to collect light components scattered substantially normal from the surface of the workpiece at a relatively medium angle, and a large angle collector positioned adjacent said medium angle collector and arranged to collect light components scattered backwardly from the surface of the workpiece at a relatively large angle, and wherein said dark channel detector further includes a small angle detector, a medium angle detector, and a large angle detector each respectively positioned in optical communication with a corresponding collector for detecting collected light, and means electrically connected to said small, medium, and large angle detectors and responsive to electrical signals from said detectors for determining the presence of a particle on the surface of the workpiece.

Claim 35

An optical collector arranged for collecting light reflected from a surface of a workpiece and for providing information about particles detected on a surface of a workpiece, the optical collector comprising: a light channel detector arranged to detect light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector to detect light scattered from the surface of a workpiece, said dark channel detector including a small angle collector arranged for collecting light components forwardly scattered from the surface of the workpiece at a relatively small angle, a medium angle collector positioned closely adjacent said small angle collector and arranged for collecting light components scattered substantially normal from the surface of the workpiece at a relatively medium angle, and a large angle collector positioned closely adjacent said medium angle detector and arranged for collecting light components scattered backwardly from the surface of the workpiece at a relatively large angle, a small angle detector, a medium angle detector, and a large angle detector each respectively positioned in optical communication with a corresponding collector for respectively detecting the collected light, and a particle classifier electrically connected to said small, medium, and large angle detectors and responsive to electrical signals from said detectors to determine the presence of a particle on the surface of a workpiece.

Claim 36

An optical collector arranged for collecting light reflected from a surface of a workpiece and for providing information about particles detected on a surface of a workpiece, the optical collector comprising: a light channel detector arranged to detect light specularly reflected from the surface of a workpiece; and a dark channel detector positioned adjacent said light channel detector to detect light scattered from the surface of a workpiece, said dark channel detector including a small angle collector arranged for collecting light components forwardly scattered from the surface of the workpiece at a relatively small angle, a medium angle collector positioned closely adjacent said small angle collector and arranged for collecting light components scattered substantially normal from the surface of the workpiece at a relatively medium angle, and a large angle collector positioned closely adjacent said medium angle detector and arranged for collecting light components scattered backwardly from the surface of the workpiece at a relatively large angle, a small angle detector, a medium angle detector, and a large angle detector each respectively positioned in optical communication with a corresponding collector for respectively detecting the collected light, and a particle classifier electrically connected to said small, medium, and large angle detectors and responsive to electrical signals from said detectors to determine the presence of a particle on the surface of a workpiece.

Claim 37

An optical collector as defined by claim 29, wherein said dark channel collector further comprises a scratch detector positioned adjacent said light detector and said small angle detector for detecting a scratch in the surface of a workpiece.

Claim 40

A method as defined by claim 31, wherein the step of rotatively and translationally transporting a workpiece along a material path is synchronized with the step of scanning of a surface of the workpiece so as to impart a substantially spiral-shaped scan of the surface of the workpiece.

Claim 43

A method as defined by claim 32, further comprising varying the optical gain of the scanned light during the scanning of the surface of the workpiece.

Claim 46

A method as defined by claim 35, wherein the step of scanning a path of light across a surface of a workpiece comprises a relatively narrow angle scan, and wherein the step of varying at least the speed of rotating the workpiece further comprises varying the speed of translationally transporting the workpiece during the scanning of the surface thereof.

Claim 51

A method as defined by claim 38, wherein the plurality of collectors further comprises a collector positioned to collect substantially normal scattered light from the surface of the workpiece.

Claim 52

A method as defined by claim 38, further comprising identifying a defect in or on a surface of a workpiece responsive to light detected at a plurality of predetermined scattering angles.