Lens system for scanning laser apparatus
AssigneeInternational Business Machines Corporation
InventorsThomas Ainsworth, Jr., George Chiu, Rama N. Singh, Janusz S. Wilczynski
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Abstract
A lens system for a laser scanning apparatus which incorporates two transfer lenses in tandem. The transfer lenses include angular reflecting mirrors, correction lenses, and concave mirrors. The transfer lenses are located between the projection mask and the target of the scanning apparatus wherein the laser beam passed through the projection mask is reflected by an angularly disposed mirror through the first correction lens onto the first concave mirror where it is reflected back through the first correction lens and onto another angularly disposed mirror where the beam is sent to and back from the second concave mirror through the second correction lens and then onto the target.
Claims5
In a laser scanning apparatus of the type including a laser beam source and an optical system including a projection mask wherein said laser beam is directed through said projection mask onto a target, the improvement comprising:
- a projection mark means in the path of a laser beam,
- a target means,
- a double lens system disposed in the path of said laser beam between said projection mask means and said target means, said double lens system including a multiple mirror element consisting of a first lens having first and second angularly disposed mirrors and a second lens having third and fourth angularly disposed mirrors,
- first and second correction lenses,
- first and second concave mirrors, and
- wherein first and second mirrors of said multiple mirror element, said first correction lens and said first concave mirror form a first optical lens system path for reflecting said laser beam from said projection mask back and forth between said first and second mirrors of said multiple mirror element and said first concave mirror through said first correction lens, and wherein said third and fourth mirrors of said multiple mirror element, said second correction lens and said second concave mirror form a second optical lens system path for reflecting said laser beam back and forth between said third and fourth mirrors of said second concave mirror through said second correction lens and onto said target.
Dependencies are inferred from the claim text.