Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
243 words
A zoom lens comprising: a first lens component having a positive refractive power for focusing the lens; a second lens component on the image side of said first lens component and having a negative refractive power for varying the magnification power of the lens, said second lens component including, from front to rear, a negative meniscus-shaped lens having a strong refracting rear surface, and another negative meniscus-shaped lens having a strong refracting front surface and a cemented surface of forward convexity; a third lens component on the image side of said second lens component and having a negative refractive power for compensating for the image shift resulting from the change of the magnification power; and a fourth lens component on the image side of said third lens component and having a positive refractive power for forming an image of an object, a front group of said fourth lens component including, from front to rear, a bi-convex lens having a rear surface of strong curvature, another bi-convex lens having a front surface of strong curvature, a lens of negative power having a front surface of strong curvature and a lens of positive power having a front surface of strong curvature, and a second group of said fourth lens component including, from front to rear, a bi-concave lens having a surface of strong curvature, a bi-convex lens with a rear surface of strong curvature, and another bi-convex lens having a front surface of strong curvature.
Claim 2
Dependent Claim
243 words
A zoom lens comprising: a first lens component having a positive refractive power for focusing the lens; a second lens component on the image side of said first lens component and having a negative refractive power for varying the magnification power of the lens, said second lens component including, from front to rear, a negative meniscus-shaped lens having a strong refracting rear surface, and another negative meniscus-shaped lens having a strong refracting front surface and a cemented surface of forward convexity; a third lens component on the image side of said second lens component and having a negative refractive power for compensating for the image shift resulting from the change of the magnification power; and a fourth lens component on the image side of said third lens component and having a positive refractive power for forming an image of an object, a front group of said fourth lens component including, from front to rear, a bi-convex lens having a rear surface of strong curvature, another bi-convex lens having a front surface of strong curvature, a lens of negative power having a front surface of strong curvature and a lens of positive power having a front surface of strong curvature, and a second group of said fourth lens component including, from front to rear, a bi-concave lens having a surface of strong curvature, a bi-convex lens with a rear surface of strong curvature, and another bi-convex lens having a front surface of strong curvature.
Claim 3
Dependent Claim
99 words
A zoom lens according to claim 1, wherein in the said second lens component, RIIi denotes the radius of curvature of the i-th lens surface counting from front, fII the focal length of said second lens component, in said fourth lens component, RIVi denotes the radius of curvature of the i-th lens surface counting from the front and DIVi the i-th lens thickness or air space, and fW and fT the shortest and longest focal lengths respectively of the entire system, and said zoom lens satisfies the following conditions: 5.7<|ft/fll|<6.1 0.18<RII2/fT<0.22 1.40<|RIV3/RIV5|<1.95 (RIV3>0, RIV5<0) 1.5<RIV7/fW<1.9 1.15<RIV10/fW<1.3 0.07<DIV4/fW<0.25 0.95<DIV8/fW<1.35 0.12<DIV10/fW<0.18
Claim 4
Dependent Claim
28 words
A zoom lens as in claim 1, wherein a separation exists between the bi-concave lens and the bi-convex lens in the second group of said fourth lens component.
Claim 5
Dependent Claim
28 words
A zoom lens as in claim 2, wherein a separation exists between the bi-concave lens and the bi-convex lens in the second group of said fourth lens component.