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US 4,232,943 AGranted
Modified Petzval lens
AssigneePilkington P. E. Limited
InventorPhillip J. Rogers
Life of this patent
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AssigneePilkington P. E. Limited
InventorPhillip J. Rogers
Estimating the term…
A collimating magnifier lens which may be used in a head-up display has a focal length of F. The lens has a front part comprising at least one positive element with a focal length between +1 F and +3 F and a negative element with a focal length between -1.2 F and infinity, the focal length of the front part as a whole being between +1 F and +6 F and the negative element of the front part not being cemented to any other element, a rear part comprising a single positive element with a focal length between +0.4 F and +1.2 F, and a field flattener behind the rear part and comprising a single negative element with a focal length between -0.4 F and -1.1 F. The negative element of the front part may have a refractive index less than or equal to 0.13 greater than that of any positive element of the front part and may be meniscus in shape having a focal length of at least 2.8 times that of the positive component and which produces overcorrect spherical aberration. A single positive element with a focal length between +1.4 F and infinity may be used as a middle part. The air gap in front of the rear part is preferably between 0.6 F and 1.1 F, and the air gap between the rear part and the field flattener is preferably between 0.01 F and 0.5 F. The front part of the lens may have two positive elements. A mirror may be interposed in the gap between the rear and front, or rear and middle.
A modified Petzval lens having a focal length F, the lens having a front part comprising at least one positive element with a focal length between +1F and +3F and a negative element with a focal length between -1.2F and infinity, the focal length of the front part as a whole being between +1F and +6F and the negative element of the front part not being cemented to any other element and having a refractive index less than or equal to 0.13 greater than the refractive index of any positive element of the front part, a rear part comprising a positive singlet element with a focal length between +0.4F and +1.2F, and a field flattener behind the rear part and comprising a single negative element with a focal length between 0.4F and -1.1F.
A modified Petzval lens having a focal length F, the lens having a front part comprising a positive component consisting of at least one positive element with a focal length between +1F and +3F and a relatively weak meniscus shape negative element having a focal length at least 2.8 times that of said positive component and which produces overcorrect spherical aberration, the focal length of the front part as a whole being between +1F and +6F and the negative element of the front part not being cemented to any other element, a rear part comprising a positive singlet element with a focal length between +0.4F and +1.2F, and a field flattener behind the rear part and comprising a single negative element with a focal length between -0.4F and -1.1F.
A modified Petzval lens comprising lens elements 1 to 5 having faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, substantially in accordance with the following table:
A modified Petzval lens comprising lens elements 6 to 10, and having a prism 12 with associated lens element 17 interposed between the lens elements 9 and 10, wherein the elements have faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, which substantially accord with the following table:
A modified Petzval lens comprising lens elements 18 to 21, and having a prism 22 interposed between the lens elements 20 and 21, wherein the elements have faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, which substantially accord with the following table:
A modified Petzval lens comprising elements 23 to 26 having faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, substantially in accordance with the following table:
A modified Petzval lens comprising lens elements 35 to 39 having faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, substantially in accordance with the following table:
A modified Petzval lens comprising lens elements 45 to 48 and 51, and having a prism 49 and block 50 interposed between the lens elements 48 and 51, wherein the elements have faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, which substantially accord with the following table:
A modified Petzval lens comprising lens elements 45 to 48 and 51, and having a prism 49 and block 50 interposed between the lens elements 48 and 51, wherein the elements have faces with radii of curvature, axial thicknesses and separations, refractive indices Nd, and Abbe numbers Vd, substantially in accordance with the following table:
A modified Petzval lens having a focal length F, the lens having a front part comprising at least one positive element with a focal length between +1F and +3F and a negative element of focal length between -1.2F and infinity, and of at least 2.8 times that of the positive component and which produces overcorrect spherical aberration, the focal length of the front part as a whole being between +1F and +6F and the negative element of the front part not being cemented to any other element and having a refractive index less than or equal to 0.13 greater than the refractive index of any positive element of the front part, a rear part comprising a positive singlet element with a focal length between +0.4F and +1.2F, and a field flattener behind the rear part and comprising a single negative element with a focal length between 0.4F and -1.1F.
Dependencies are inferred from the claim text.