Browse Prior Art Database

Tilted Vertical Illumination for Linear Detctor Arrays

IP.com Disclosure Number: IPCOM000062262D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Goodman, DS: AUTHOR

Abstract

A vertical illumination optical inspection system is provided and comprises an imaging system having a linear detector array which is tilted at a first small angle from the normal to the object of interest, and an illuminating system for illuminating the object, where the illuminating system is tilted at an angle from the normal to the object which is an equal but opposite angle to said first small angle. The disclosed system eliminates the need for beam splitters which typically reduce the light reaching the image by a factor of four in vertical illuminators, as well as causing polarization effects and aberrations. The system also eliminates the need for light trap.

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Tilted Vertical Illumination for Linear Detctor Arrays

A vertical illumination optical inspection system is provided and comprises an imaging system having a linear detector array which is tilted at a first small angle from the normal to the object of interest, and an illuminating system for illuminating the object, where the illuminating system is tilted at an angle from the normal to the object which is an equal but opposite angle to said first small angle. The disclosed system eliminates the need for beam splitters which typically reduce the light reaching the image by a factor of four in vertical illuminators, as well as causing polarization effects and aberrations. The system also eliminates the need for light trap.

The vertical illumination optical inspection system of the invention is seen in the figure. Light from a source 10 is sent through a condenser 15 to illuminate an object 20. The illuminating system (10 and 15) are tilted at a small angle A rela to the normal to the object. The light hitting object 20 is specularly reflected into an imaging system which includes lens 25 and a linear detector array 30. The lens 25 and linear detector array 30 are likewise tilted at an angle (-A) relative to the normal to the object 20, with the angle between the imaging system and the normal being equal and opposite the angle between the illuminating system and the normal. Such a tilt is permitted because a linear detector array is used in the imaging system rather...