Focusable, color corrected, high performance projection lens systems
First Claim
1. A projection lens system for use with a cathode ray tube, said lens system having an overall optical power Φ
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0 consisting in order from its long conjugate to its short conjugate of;
(a) a first lens unit having an optical power Φ
1 and consisting in order from the lens system'"'"'s long conjugate to its short conjugate of;
a first lens subunit having an optical power Φ
S1 ; and
a second lens subunit having an optical power Φ
S2 ;
(b) a second lens unit having an optical power Φ
2 ; and
(c) a third lens unit which has an optical power Φ
3, is associated with the cathode ray tube during use of the lens system, and provides correction to the field curvature of the lens system;
wherein each of the first, second, and third lens units has at least one aspherical surface and wherein Φ
1, Φ
S1, Φ
S2, Φ
2, and Φ
3 satisfy the following conditions;
(i) Φ
1 >
0;
(ii) Φ
1 /Φ
0 <
0.3;
(iii) Φ
S1 <
0;
(iv) |Φ
S1 |/Φ
0 >
0.4;
(v) Φ
S2 >
0;
(vi) Φ
S2 /Φ
0 >
0.3;
(vii) Φ
2 >
0;
(viii) Φ
2 /Φ
0 >
0.4; and
(ix) Φ
3 <
0.
1 Assignment
0 Petitions
Accused Products
Abstract
Focusable, color corrected, high performance projection lens systems are provided which include three lens units (U1, U2, U3), the first lens unit being composed of two subunits (US1, US2). The lens systems can have f/190 '"'"'s less than 1.0, total fields of as much as 90°, low vignetting losses, and MTF values greater than 0.5 at 10 cycles/mm through 0.85 of the full field. By varying the space between the first and second lens units, these performance levels can be maintained as the lens system is focused over a range of conjugates of approximately ±7.5% from a center value of about 4 meters. The lens systems can be used in such demanding applications as flight simulators.
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Citations
20 Claims
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1. A projection lens system for use with a cathode ray tube, said lens system having an overall optical power Φ
-
0 consisting in order from its long conjugate to its short conjugate of;
(a) a first lens unit having an optical power Φ
1 and consisting in order from the lens system'"'"'s long conjugate to its short conjugate of;a first lens subunit having an optical power Φ
S1 ; anda second lens subunit having an optical power Φ
S2 ;(b) a second lens unit having an optical power Φ
2 ; and(c) a third lens unit which has an optical power Φ
3, is associated with the cathode ray tube during use of the lens system, and provides correction to the field curvature of the lens system;wherein each of the first, second, and third lens units has at least one aspherical surface and wherein Φ
1, Φ
S1, Φ
S2, Φ
2, and Φ
3 satisfy the following conditions;(i) Φ
1 >
0;(ii) Φ
1 /Φ
0 <
0.3;(iii) Φ
S1 <
0;(iv) |Φ
S1 |/Φ
0 >
0.4;(v) Φ
S2 >
0;(vi) Φ
S2 /Φ
0 >
0.3;(vii) Φ
2 >
0;(viii) Φ
2 /Φ
0 >
0.4; and(ix) Φ
3 <
0. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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0 consisting in order from its long conjugate to its short conjugate of;
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17. A projection lens system for use with a cathode ray tube, said lens system having an overall optical power Φ
-
0 and comprising in order from its long conjugate to its short conjugate;
(a) a first lens unit having an optical power Φ
1 and comprising in order from the lens system'"'"'s long conjugate to its short conjugate;a first lens subunit having an optical power Φ
S1 ; anda second lens subunit having an optical power Φ
S2 ;(b) a second lens unit having an optical power Φ
2 ; and(c) a third lens unit which has an optical power Φ
3, is associated with the cathode ray tube during use of the lens system, and provides correction to the field curvature of the lens system;wherein each of the first, second, and third lens units has at least one aspherical surface, each of the first and second lens units comprises at least one plastic lens element and at least one glass lens element, and wherein Φ
1, Φ
S1, Φ
S2, Φ
2, and Φ
3, satisfy the following conditions;(i) Φ
1 >
0;(ii) Φ
1 /Φ
0 <
0.3;(iii) Φ
S1 <
0;(iv) |Φ
S1 |/Φ
0 >
0.4;(v) Φ
S2 >
0;(vi) Φ
S2 /Φ
0 >
0.3;(vii) Φ
2 >
0;(viii) Φ
2 /Φ
0 >
0.4; and(ix) Φ
3 <
0. - View Dependent Claims (18, 19, 20)
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0 and comprising in order from its long conjugate to its short conjugate;
Specification