Canon Kabushiki Kaisha

Hiroshi Saruwatari

Takeshi Akiyama

Tsunefumi Tanaka

Norihiro Nanba

Kenichi Kimura

Keisuke Araki

Makoto Sekita

Nobuhiro Takeda

Toshikazu Yanai

Shigeo Ogura

Yoshihiro Uchino

Toshiya Kurihashi

Hiroyuki Hamano

Takashi Fujii

Sadahiko Tsuji

Hiroaki Hoshi

Yoshiro Udagawa

Taro Murakami

Toyokatsu Fujisaki

Yoshiyuki Mizoguchi

Kenichi Shinbori

Toshinobu Yamaguchi

Michiharu Aratani

Hiroyuyki Hamano

A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a rear lens group including a lens unit having negative refractive power arranged along an optical axis thereof. A focal length fw of the zoom lens at a wide-angle end, a focal length ft of the zoom lens at a telephoto end, an amount of movement Mof the first lens unit on the optical axis in zooming from the wide-angle end to the telephoto end, and a focal length frn of a lens unit Lrn that is a lens unit having a shortest focal length among lens units having negative refractive power included in the rear lens group are appropriately set based on predetermined mathematical conditions.

Zoom lens and image pickup apparatus including the same

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power. In the zoom lens, each lens unit moves to perform zooming. In addition, an amount of movement Mm of the fourth lens unit when zooming from a wide angle end to an intermediate zooming position, an amount of movement Mt of the fourth lens unit when zooming from the wide angle end to a telephoto end, a focal length fw of an entire system at the wide angle end, and focal lengths fand fof the respective third lens unit and fourth lens unit are properly set.

Zoom lens and image pickup apparatus including the zoom lens

A zoom lens includes, in order from an object side to an image side, a positive first lens unit, a negative second lens unit, a positive third lens unit, and a positive fourth lens unit. During zooming from a wide-angle end to a telephoto end, the first lens unit moves with a locus convex toward the image side, and the third lens unit moves toward the object side. The first lens unit includes, in order from the object side to the image side, a negative first lens, a positive second lens, and a positive third lens. A distance (d) between the first lens and the second lens, a focal length (fw) of the entire zoom lens at the wide-angle end, and a refractive index (Np) of a positive lens having the lowest refractive index among the refractive indices of materials of all positive lenses included in the first lens unit are appropriately set based on predetermined mathematical conditions.

Zoom lens and image pickup apparatus equipped with same

Provided is a zoom lens including, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power, all the lens units moving during zooming; and a secondary aperture having a constant aperture diameter disposed on the image side of the second lens unit, in which the second lens unit includes lens components having a positive refractive powers disposed at a position closest to the object side and a position closest to the image side, and a distance (dd) on an optical axis between a lens surface closest to the image side in the second lens unit and the secondary aperture, and a focal length (fw) of the entire zoom lens at a wide angle end are appropriately set.

Provided is a zoom lens having a high magnification and excellent optical performance over an entire zoom range between a wide-angle end and a telephoto end. The zoom lens includes, in order from object side to image side: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; and a fourth lens unit having positive refractive power, and performs zooming while the respective lens units move, in which: during zooming from wide-angle end to telephoto end, the first unit moves closer to object side at telephoto end than at wide-angle end and the fourth unit moves along a locus convex to object side; and a focal length of the second unit, a focal length of the zoom lens at wide-angle end, and an imaging magnification of the fourth unit at telephoto end are appropriately set.

A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a fourth lens unit having positive refractive power. The zoom lens performs zooming by moving each of the lens units. The first lens unit and the third lens unit are positioned closer to the object at a telephoto end than at a wide-angle end. The zoom lens satisfies the following conditions:0.3&#x3c;|1/2|&#x3c;1.50.3&#x3c;|3/2|&#x3c;0.8where m1, m2, and m3 are the amounts of movement of the first lens unit, the second lens unit, and the third lens unit, respectively, along an optical axis during zooming from the wide-angle end to the telephoto end.

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power and configured to move along an optical axis during zooming, a second lens unit having a negative refractive power and configured to move with a locus convex towards the image side during zooming, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power. The first lens unit is located closer to the object side at a telephoto end than at a wide-angle end and the second lens unit is located closer to the image side at the telephoto end than at the wide-angle end. A focal length of the second lens unit (f2), a focal length of the zoom lens at the wide-angle end (fw), and a focal length of the zoom lens at the telephoto end (ft) are appropriately set.

Zoom lens and image pickup apparatus having the zoom lens

A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, a third lens unit having positive refractive power, and a fourth lens unit having positive refractive power. The zoom lens performs zooming by moving each of the lens units. The first lens unit and the third lens unit are positioned closer to the object at a telephoto end than at a wide-angle end. The zoom lens satisfies the following conditions:0.3&#x3c;|m1/m2|&#x3c;1.50.3&#x3c;|m3/m2|&#x3c;0.8where mmand mare the amounts of movement of the first lens unit, the second lens unit, and the third lens unit, respectively, along an optical axis during zooming from the wide-angle end to the telephoto end.

A zoom lens system includes, in order from an object side to an image side, a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive optical power, and a fourth lens unit having positive optical power. Each lens unit moves during zooming. In particular, the first lens unit moves so as to be closer to an object at a telephoto end than at a wide-angle end during zooming, and the fourth lens unit moves in a locus convex toward the object side during zooming. The sharing of magnification variation between the third lens unit and the fourth lens unit is appropriately set.

Zoom lens system and camera having same

At least one exemplary embodiment is directed to a zoom lens system, which includes, in order from an object side to an image side, a first lens unit of positive optical power, a second lens unit of negative optical power, a third lens unit of positive optical power, and a fourth lens unit of positive optical power. During zooming, each of the lens units moves.

Zoom lens system and image pickup apparatus having the same

A zoom lens system comprises a 1st lens unit with positive optical power consisting of one lens element, a 2nd lens unit with negative optical power, a 3rd lens unit with positive optical power and a 4th lens unit with positive optical power, in order from the object side to the image side is disclosed. During zooming, the 1st lens unit and 3rd lens unit move so as to be located closer to the object side at the telephoto end than at the wide-angle end. Then, by appropriately setting the amount of movements of the 1st lens unit, 2nd lens unit and 3rd lens unit during zooming, the overall length of the zoom lens system is reduced and excellent optical performance is realized.

Zoom lens system and camera incorporating the same

At least one exemplary embodiment is directed to a zoom lens configured to correct chromatic aberration and having a high optical performance over the entire zoom range. The zoom lens includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, and a third lens unit of positive refractive power. During zooming, an interval between respective adjacent lens units varies. The third lens unit includes an optical element made of a solid material having an Abbe number (&#x3bd;d) and a relative partial dispersion (&#x3b8;gF) satisfying the following condition:&#x3b8;&#x2212;(&#x2212;1.665&#xd7;10+5.213&#xd7;10&#x2212;5.656&#xd7;10

Zoom lens and image pickup apparatus having the same

At least one exemplary embodiment is directed to a zoom lens system, which can have a diffractive optical element, achieves high optical performance over a wide zoom range. The zoom lens system includes a first lens unit having positive optical power, a second lens unit having negative optical power, and a rear lens component including at least one lens unit having positive optical power. The first lens unit, the second lens unit, and the rear lens component are arranged in that order from an object side towards an image side of the zoom lens system. The diffractive optical element is included in the first lens unit. The rear lens component is provided with a positive lens element having extraordinary dispersion characteristics.

Zoom lens system and image pickup apparatus with the system

A zoom lens system including, in order from an object side to an image side, a first lens unit of positive optical power, and a second lens unit of negative optical power, followed by a lens component having a lens unit, wherein at least one of the first lens unit and the second lens unit moves during zooming. One of the lens units of the zoom lens system includes a layer made of a material that satisfies the following conditions:11&#x3c;&#x3bd;IT&#x3c;270.2&#x3c;&#x3b8;IT&#x3c;0.4.Wherein &#x3bd;IT is an Abbe number of the layer, and &#x3b8;IT is a partial dispersion ratio for the g-spectral line and f-spectral line of the layer. The layer has an optical power of a sign opposite to that of the lens unit including the layer.

Zoom lens system

Disclosed is a zoom lens system including in an order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power, in which zooming is performed by changing each distance among the first, second, and third lens units. In this zoom lens system, partial charge of a changing magnification between the second and third lens units is suitably set to maintain excellent optical performance over the overall zoom area while a zoom ratio is large.

Growing community of inventors

Utsunomiya, Japan

Hiroshi Saruwatari