Zoom lens and camera with zoom lens
AssigneeCasio Computer Co., Ltd.
InventorsTetsuro Narikawa, Etsuro Kawakami
Life of this patent
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AssigneeCasio Computer Co., Ltd.
InventorsTetsuro Narikawa, Etsuro Kawakami
Estimating the term…
There is provided a zoom lens of variable power ratio of the order of 3 in which the whole of the zoom lens is made up of three lens elements groups and the power configuration of each of the groups has an arrangement of negative, positive and negative, whereby the reduction in overall length of its optical system is enabled, so that a compact zoom lens and a camera with it can be provided. The zoom lens comprising, sequentially from an object side thereof, a first lens elements group has a negative refraction power as a whole, a second lens elements group has a positive refraction power as a whole and the third lens element group has a negative refraction power as a whole, and a variable power is realized by shifting the positions of the first and second lens elements group in the direction of an optical axis thereof.
A zoom lens comprising, sequentially from an object side thereof, a first lens elements group, a second lens elements group and a third lens element group, wherein the first lens elements group having a negative refraction power as a whole and being made up by disposing a first lens element which is a lens having a negative refraction power (hereinafter, referred to as a negative lens) and a second lens element which is a lens having a positive refraction power (hereinafter, referred to as a positive lens) and which constitutes a meniscus lens which is convex on an object side surface thereof, the second lens elements group having a positive refraction power as a whole and being made up by disposing a third lens element which is a positive lens, a fourth lens element which is a positive lens, a fifth lens element which is a negative lens and which constitutes a meniscus lens which is convex on an object side surface thereof and a sixth lens element which is a positive lens, and the third lens element group having a negative refraction power as a whole and being made up by disposing a seventh lens element which is a negative lens and which constitutes a meniscus lens which is convex on an image side surface thereof, wherein a variable power is realized by shifting the positions of the first lens elements group and the second lens elements group in a direction of an optical axis thereof, or so shifting, in addition to the first lens elements group and the second lens elements group, the position of the third lens element group, and wherein the zoom lens satisfies the following conditional expression (1) with respect to the power that the first lens elements group possesses, the following conditional expression (2) with respect to the power that the third lens element group possesses, and the following conditional expression (3) with respect to the size of a whole lens system
A zoom lens comprising, sequentially from an object side thereof, a first lens elements group, a second lens elements group and a third lens element group, wherein the first lens elements group having a negative refraction power as a whole and being made up by disposing a first lens element which is a lens having a negative refraction power (hereinafter, referred to as a negative lens) and a second lens element which is a lens having a positive refraction power (hereinafter, referred to as a positive lens) and which constitutes a meniscus lens which is convex on an object side surface thereof, the second lens elements group having a positive refraction power as a whole and being made up by disposing a third lens element which is a positive lens, a fourth lens element which is a negative lens and a fifth lens element which is a positive lens, and the third lens element group having a negative refraction power as a whole and being made up by disposing a sixth lens element which is a negative lens, and wherein a variable power is realized by shifting the positions of the first lens elements group and the second lens elements group in a direction of an optical axis thereof, or so shifting, in addition to the first lens elements group and the second lens elements group, the position of the third lens element group, and the zoom lens satisfies the following conditional expression (13) with respect to the power that the first lens elements group possesses, the following conditional expression (14) with respect to the power that the third lens element group possesses, and the following conditional expression (15) with respect to the size of a whole lens system
Dependencies are inferred from the claim text.