Optical inspection method and apparatus

An apparatus for optical inspection of an object, having upper and lower faces, so as to detect defects existing on the object, the apparatus comprising:

• i. an illumination system providing first and second beams of radiation simultaneously directed respectively onto a first area of the object and a second, different area of the object;
• ii. a sensing system mounted in the vicinity of the object and simultaneously sensing a light component of the first beam reflected from the upper face of the object and a light component of the second beam transmitted through the upper and lower faces of the object and providing output signals representative thereof;
• iii. a light directing system directing the reflected and transmitted light components onto the sensing system;
• and
• iv. a processor coupled to the sensing system for receiving the output signals;
• representative of the reflected and transmitted light components and for analyzing the signals so as to provide data indicative of said defects.

A method for inspecting an object having upper and lower faces for detecting defects existing on the object, said method comprising:

• a) providing first and second beams of radiation;
• b) directing the first beam of radiation onto the object and sensing a light component reflected from one face of the object;
• c) directing the second beam of radiation onto the object and sensing a light component transmitted through the upper and lower faces of the object;
• d) simultaneously acquiring first and second images of the object, wherein the first image is formed by directing the reflected light component to a first sensor located on a first side of the object and the second image is formed by directing the transmitted light component to a second sensor located on said first side of the object;
• and
• e) analyzing said first and second images so as to provide data indicative of said defects.

An apparatus for optical inspection of an object, having upper and lower faces, so as to detect defects existing on the object, the apparatus comprising:

• i. an illumination system providing first and second beams of radiation simultaneously directed onto the object;
• ii. a sensing system mounted in the vicinity of the object and comprising a first sensor located on a first side of the object and a second sensor located on said first side of the object for simultaneously sensing a light component of the first beam reflected from the upper face of the object and a light component of the second. beam transmitted through the upper and lower faces of the object and providing output signals representative thereof;
• iii. a light directing system directing the reflected and transmitted light components;
• onto the sensing system;
• and
• iv. a processor coupled to the sensing system for receiving the output signals representative of the reflected and transmitted light components and for analyzing the signals so as to provide data indicative of said defects.

A method for inspecting an object having upper and lower faces for detecting defects existing on the object, said method comprising:

• a) providing first and second beams of radiation;
• b) directing the first beam of radiation onto the object and sensing a light component reflected from one face of the object;
• c) directing the second beam of radiation onto the object and sensing a light component transmitted through the upper and lower faces of the object;
• d) simultaneously acquiring first and second images of the object, wherein the first image is formed by directing the reflected light component to a first multi-element sensor and the second image is formed by directing the transmitted light component to a second multi-element sensor;
• and
• analyzing said first and second images so as to provide data indicative of said defects.

An apparatus for optical inspection of an object, having upper and lower faces, so as to detect defects existing on the object, the apparatus comprising:

• i. an illumination system providing first and second beams of radiation simultaneously directed onto the object;
• ii. a sensing system mounted in the vicinity of the object and comprising first and second sensors each comprising a respective multi-element sensor, said first and second sensors respectively and simultaneously sensing a light component of the first beam reflected from the upper face of the object and a light component of the second beam transmitted through the upper and lower faces of the object and providing output signals representative thereof;
• iii. a light directing system directing the reflected and transmitted light components onto the sensing system;
• and
• iv. a processor coupled to the sensing system for receiving the output signals representative of the reflected and transmitted light components and for analyzing the signals so as to provide data indicative of said defects.