Projection lens for mask pattern printing

Abstract

A projection lens for mask pattern printing comprising a photographic lens arrangement which is used for both the alignment and the printing. The arrangement includes a plurality of fixedly positioned lenses and two interchangeable lens elements which are interchangeably insertable into the arrangement. One interchangeable lens element is designed for the alignment, and is inserted into the arrangement during aligning, and the other interchangeable lens element is designed for the printing, and is inserted into the arrangement during the printing.

What is claimed is: 
     
       1. A projection lens for mask pattern printing, .Iadd.corrected for chromatic aberration with respect to at least three wave lengths, .Iaddend.comprising a photographic lens arrangement which is interposed between .[.an image plane.]. .Iadd.a photo-sensitive means .Iaddend.and an object plane and used for both the alignment and the printing, and including at least one group of fixedly spaced lenses .[.corrected for chromatic aberrations with respect to at least four wavelengths,.]. and a pair of interchangeable lens elements which are interchangeably inserted into said arrangement at identical axial positions therein, .Iadd.the photographic lens arrangement, with .Iaddend.one of said interchangeable lens elements.Iadd., .Iaddend.being corrected for chromatic aberrations for .[.at least two of said wavelengths.]. .Iadd.an alignment light which does not sensitize said photo-sensitive means .Iaddend.and being designed for the alignment and .[.inserted.]. .Iadd.used .Iaddend.during alignment; .Iadd.the photographic lens arrangement, with .Iaddend.the other of said interchangeable lens elements.Iadd., .Iaddend.being corrected for chromatic aberrations for .[.at least the other.]. two wavelengths, .Iadd.among those of the printing light, which sensitize said photo-sensitive means .Iaddend.and being designed for the printing and .[.inserted.]. .Iadd.used .Iaddend.during printing; the axial spacing between said photographic lens arrangement .[.image plane.]. .Iadd.and the photo-sensitive means .Iaddend.remaining the same during both alignment and printing, and the axial spacing between the object plane and the .[.image plane.]. .Iadd.photosensitive means .Iaddend.remaining the same during both alignment and printing. 
     
     
       2. The projection lens according to claim 1, which is constructed of a lens arrangement of the substantially symmetric type. 
     
     
       3. The projection lens according to claim 2, in which the interchangeable lens elements, which are interchanged between the alignment operation and the printing operation, are inserted substantially at the center of the projection lens. 
     
     
       4. A projection lens according to claim 3, in which each interchangeable lens element inserted substantially at the center of the projection lens is a concave lens element. 
     
     
       5. A projection lens according to claim 1, wherein said fixedly spaced lenses include a pair of meniscus lenses having their concave surfaces facing toward each other, and convergent lens elements disposed axially outwardly of said meniscus lenses, each interchangeable lens element being a concave lens insertable between the two meniscus lenses. 
     
     
       6. A projection lens according to claim 5, wherein said interchangeable concave lenses are double concave cemented lenses. 
     
     
       7. A mask pattern printing projection lens, corrected for chromatic aberration with respect to at least three wave lengths, comprising a photographic lens arrangement which is interposed between an image plane and an object plane and used for both the alignment and the printing, and including at least one group of fixedly spaced lenses and a pair of interchangeable lens elements which are interchangeable inserted into said photographic lens arrangement at identical axial positions therein, one of said interchangeable lens elements being inserted into said photographic lens arrangement during alignment, and the other lens element being inserted into said photographic lens arrangement during printing; the photographic lens arrangement, with said one lens element inserted therein, being corrected for chromatic aberration with respect to two of said wave lengths and being designed for the alignment; the photographic lens arrangement, with said other lens element inserted therein, being corrected for chromatic aberration with respect to another two of said wave lengths and designed for printing, the axial spacing between said photographic lens arrangement and the image plane remaining the same during both alignment and printing, and the axial spacing between the object plane and the image plane remaining the same during both alignment and printing.