Anamorphic lens for a CCD camera apparatus

摘要

The present invention relates to an anamorphic lens for a CCD camera apparatus used for inspecting a semiconductor chip during the manufacturing process. The reduced image of the semiconductor chip being inspected is formed at a magnification of 0.25 times in the horizontal direction and a magnification ratio of 1:1 in the vertical direction. The anamorphic lens system for the CCD camera apparatus includes two spherical lens sets each having five lenses, and an afocal cylindrical lens system through which the image is formed in different ratios between its length and width. The spherical lens sets are positioned face-to-face on the same axis line. The afocal lens system includes an indefinite distance in its focus point, and the different magnification between length and width is positioned in a space between the two spherical lens sets. As a result, the image of the semiconductor chip being inspected is formed on a general CCD element 6.6 mmx8.8 mm in size after it is reduced by 0.25 times.