Single mirror projection optical system

Claim 2

A ring field optical system, comprising: refractive element means comprised of the same optical material providing a well corrected virtual image of an object at the optical axis; said refractive element means comprising; first lens means correcting for axial color in the system; second lens means correcting for field aberrations in the system; third lens means for providing telecentricity in object and image space of the system; and spherical mirror means positioned relative to said refractive element means such that its center of curvature is nearly coincident with said virtual image for projecting a real image of said virtual image at an off axis position.

Claim 3

A ring field optical system according to claim 1 wherein said first lens means includes means for increasing power in the object field to make the object real.

Claim 4

A ring field optical system according to claim 2 wherein said first lens means comprises: positive lens means; negative lens means; said positive and negative lens means together correcting for axial color in the system; and field lens means disposed between said positive and negative lens means correcting for lateral color in the system.

Claim 5

A ring field system according to claim 3 wherein said second lens means comprises an airspaced doublet.

Claim 6

A ring field system according to claim 4 wherein said optical system provides demagnification between object and image.

Claim 7

A ring field system according to claim 5 wherein said spherical mirror means doubles the axial color correction of said negative lens means.

Claim 8

A ring field system according to claim 6 further comprising: a first fold mirror disposed before said positive lens means; a second fold mirror disposed before said negative lens means; and said fold mirrors providing easy accessibility to said real image.

Claim 9

A ring field optical system according to claim 7 characterized by the following construction data for the case N.A.=0.33; ______________________________________ SINGLE MIRROR PROJECTION SYSTEM N.A. = 0.33 AT IMAGE DISTANCE SURFACE TO NEXT NO. FROM RADIUS SURFACE OBJECT (MM) (MM) MATERIAL ______________________________________ 0 PLANE 15.0106 AIR 1 250.7601 20.0000 FUSED SILICA 2 495.7365 220.1050 AIR 3 1316.0222 7.0000 FUSED SILICA 4 256.8690 17.0000 AIR 5 2094.2528 20.0000 FUSED SILICA 6 -440.3327 300.0000 AIR 7 PLANE -316.9289 AIR 8 3427.7484 -25.0000 FUSED SILICA 9 388.2743 -1.0000 AIR 10 -381.6655 -25.0000 FUSED SILICA 11 -1439.2312 -136.0369 AIR 12 -219.7194 -30.0000 FUSED SILICA 13 -553.6858 -50.0369 AIR 14 -125.2624 -10.0000 FUSED SILICA 15 -103.1942 -25.0000 AIR 16 190.2020 -30.0000 FUSED SILICA 17 205.2266 -103.7988 AIR 18 -145.9760 -20.0000 FUSED SILICA 19 1300.6540 -50.6144 AIR 20 -101.4453 -20.0000 FUSED SILICA 21 -561.9992 -72.5311 AIR 22 PLANE 180.0000 AIR 23 -111.2179 10.0000 FUSED SILICA 24 -238.5001 250.0000 AIR 25 -400.0000 -250.0000 AIR 26 - 238.5001 -10.0000 FUSED SILICA 27 -111.2179 -185.0000 AIR 28 479.8622 -10.0000 FUSED SILICA 29 182.4330 -6.9982 AIR 30 PLANE AIR ______________________________________ STOP IS 3.5 MM AFTER SURFACE 13

Claim 10

A ring field system according to claim 7 having the following construction data for the condition N.A.=0.40; ______________________________________ SINGLE MIRROR PROJECTION SYSTEM N.A. = 0.40 AT IMAGE DISTANCE SURFACE TO NEXT NO. FROM RADIUS SURFACE OBJECT (MM) (MM) MATERIAL ______________________________________ 0 PLANE 15.0034 AIR 1 191.1886 20.0000 FUSED SILICA 2 380.6867 156.2513 AIR 3 -7886.6829 7.0000 FUSED SILICA 4 193.8456 19.0000 AIR 5 -1841.8397 20.0000 FUSED SILICA 6 -288.5379 300.0000 AIR 7 PLANE -219.4054 AIR 8 1910.4091 -25.0000 FUSED SILICA 9 380.8600 -1.0000 AIR 10 -372.7529 -25.0000 FUSED SILICA 11 -1055.4615 -259.5532 AIR 12 -261.0379 -30.0000 FUSED SILICA 13 -34966.4670 -29.9486 AIR 14 -113.1974 -10.0000 FUSED SILICA 15 -100.0095 -32.0000 AIR 16 229.8248 -30.0000 FUSED SILICA 17 275.3900 -49.9961 AIR 18 -190.6421 -20.0000 FUSED SILICA 19 1336.8166 -91.1971 AIR 20 -85.2476 -20.0000 FUSED SILICA 21 -1424.8770 -65.7494 AIR 22 PLANE 180.0000 AIR 23 -113.1155 10.0000 FUSED SILICA 24 -244.2444 150.0000 AIR ______________________________________

Claim 11

A virtual relay comprising first, second, and third positive lenses; a negative lens; first and second field lenses disposed between said third positive lens and said negative lens; said positive lenses and said negative lenses constructed and arranged to correct axial color of the system; said field lenses constructed and arranged to cause the chief ray through the system to pass through the center of said negative lenses thereby correcting for lateral color in the system; all of said lenses being made of the same optical material; said relay having the following construction data; ______________________________________ 0.4X VIRTUAL RELAY N.A. AT OBJECT 0.1143 N.A. AT IMAGE 0.2857 SURFACE DISTANCE TO NO. FROM RADIUS NEXT SUR- OBJECT (MM) FACE (MM) MATERIAL ______________________________________ 0 PLANE -509.3784 AIR 1 146.8335 40.0000 FUSED SILICA 2 437.5290 3.0000 AIR 3 97.8688 25.0000 FUSED SILICA 4 74.8220 87.5000 AIR 5 706.1405 5.0000 FUSED SILICA 6 63.5693 113.9107 AIR 7 849.0004 20.0000 FUSED SILICA 8 -125.8509 8.1384 AIR 9 110.5940 20.0000 FUSED SILICA 10 -719.2014 276.6173 AIR 11 -85.6669 10.0000 FUSED SILICA 12 -197.8643 -150.0000 AIR 13 INF 0.0 AIR ______________________________________ STOP IS 4.0 MM AFTER SURFACE 6

Claim 12

A virtual relay comprising first, second, and third positive lenses; a negative lens; first and second field lenses disposed between said third positive lens and said negative lens; said positive lenses and said negative lenses constructed and arranged to correct axial color of the system; said field lenses constructed and arranged to cause the chief ray through the system to pass through the center of said negative lenses thereby correcting for lateral color in the system; all of said lenses being made of the same optical material; said relay having the following construction data; ______________________________________ 0.4X VIRTUAL RELAY N.A. AT OBJECT 0.1143 N.A. AT IMAGE 0.2857 SURFACE DISTANCE TO NO. FROM RADIUS NEXT SUR- OBJECT (MM) FACE (MM) MATERIAL ______________________________________ 0 PLANE -509.3784 AIR 1 146.8335 40.0000 FUSED SILICA 2 437.5290 3.0000 AIR 3 97.8688 25.0000 FUSED SILICA 4 74.8220 87.5000 AIR 5 706.1405 5.0000 FUSED SILICA 6 63.5693 113.9107 AIR 7 849.0004 20.0000 FUSED SILICA 8 -125.8509 8.1384 AIR 9 110.5940 20.0000 FUSED SILICA 10 -719.2014 276.6173 AIR 11 -85.6669 10.0000 FUSED SILICA 12 -197.8643 -150.0000 AIR 13 INF 0.0 AIR ______________________________________ STOP IS 4.0 MM AFTER SURFACE 6