Canon Kabushiki Kaisha

Akihisa Horiuchi

Hiroki Nakayama

Hitoshi Mukaiya

Shigeyuki Suda

Hiroyuki Hamano

Nozomu Kitagishi

Jun Hattori

Yasunori Murata

Fumihito Wachi

Koji Takahashi

Nobuyoshi Suzuki

Akihiro Nishio

Muneharu Sugiura

Kenji Shinohara

Hideo Tamamura

Jun Makino

Nobuyuki Miyazawa

Tadanori Okada

Yuji Yamamoto

Masaki Higashihara

Hidetoshi Matsuoka

Nobuyuki Tochigi

Tomonori Kimura

Youichi Iwasaki

Motoo Kumagai

Hidemi Takayama

Etsuro Suzuki

Hiroyuki Asada

Hiroyuki Kasuga

Kazuhiko Hatano

A zoom lens includes 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 first to fourth lens units move during zooming. The first lens unit includes a cemented lens obtained by cementing negative and positive lenses, the second lens unit includes negative, negative, and positive lenses, the third lens unit includes positive and negative lenses, and the fourth lens unit includes a positive lens. Movement amounts Mand Mof the first and third lens units, respectively, during zooming from the wide-angle end to the telephoto end and focal lengths fand fof the first and third lens units, respectively, are appropriately set based on predetermined mathematical conditions.

Zoom lens and image pickup apparatus equipped with zoom lens

A zoom lens including first to fifth lens units in order from an object side toward an image. The refractive powers of the first to the fifth lens units are positive, negative, positive, negative and positive, respectively. The distance between the first and the second lens units is increased at the time of zooming from the wide angle end to the telephoto end, and the distance between the second and the third lens unit is decreased at the time of zooming from the wide angle end to the telephoto end. The first lens unit and the fourth lens unit are fixed for the zooming. When M2 and M3 are the amounts of movement of the second lens unit and the third lens unit at the time of zooming from the wide angle end to the telephoto end, respectively, the conditional expression; 0.2&#x3c;|M2/M3|&#x3c;5.0 is satisfied.

A zoom lens includes first and second lens units having positive and negative refractive powers, an aperture stop, and third and fourth lens units having positive and negative refractive powers in order from an object side to an image side. During zooming from a wide angle end to a telephoto end, the first lens unit remains fixed, and the second and fourth lens units move. The first lens unit includes negative, positive, negative, positive, and positive lenses in order from the object side to the image side, the third and fourth lens units include two or more lenses. Focal lengths of the first and third lens units and of the entire system at the wide angle end, the thickness of the first lens unit on an optical axis, and the distance between principal points between the first and the second lens units at a wide angle end are appropriately set.

A zoom lens comprising, in order from an object side to an image side, a first lens unit of a positive refractive power, a second lens unit of a negative refractive power, a third lens unit of a positive refractive power, and a fourth lens unit of a positive refractive power. In zooming, the first lens unit is configured fixed and the second, third, and fourth lens units are configured movable. The following conditions are satisfied where f3st is a movement amount of the third lens unit associated with zooming from a wide angle end to a telephoto end, f3 is a focal length of the third lens unit, &#x3b2;2w is a lateral magnification of the second lens unit at the wide angle end, and z is a zoom ratio, 0.010&#x3c;(|f3st|/f3)/z&#x3c;0.045, and &#x2212;0.33&#x3c;&#x3b2;2w&#x3c;&#x2212;0.20.

Zoom lens and image pickup apparatus having the same

A zoom lens includes positive, negative, positive, and positive lens units, and the second lens unit includes negative, negative, negative and positive lenses. The first and third lens units are fixed and the second and fourth lens units are moved in zooming. 0.01&#x3c;|f2/&#x221a;(fw*ft)|&#x3c;0.35 and 0.070&#x3c;D2/TL&#x3c;0.105 are satisfied. fw and ft are focal lengths of an overall system at wide angle and telephoto ends, f2 is a focal length of the second lens unit, TL is a distance on an optical axis from a lens surface closest to an object plane to an image plane when a distance from a lens surface closest to the image plane to the image plane is aerially converted, and D2 is a distance on the optical axis from a lens surface closest to the object plane in the second lens unit to the lens surface closest to the image plane in the second lens unit.

In an image sensing system having an image sensing optical system, and an image sensing element for photoelectrically converting incoming light from the image sensing optical system, a predetermined pattern image for adjustment, which is specified in advance, is read by the image sensing element, and the image sensing element is driven to adjust its position on the basis of an output from said image sensing element, thereby adjusting the relative position of the image sensing element with respect to the image sensing optical system prior to an image sensing operation.

Image sensing system and its control method

A zoom lens comprises, in the following order from the object side to the image side, a positive first lens unit, a negative second lens unit, which moves during zooming, a positive third lens unit, and a positive fourth lens unit, which moves during zooming. The first lens unit includes a negative lens subunit and a positive lens subunit. The negative lens subunit includes at least two negative lenses each having a concave surface facing the image side and at least one positive lens arranged from the object side. The positive lens subunit includes at least one biconvex positive lens, a negative lens and at least two positive lenses arranged from the object side, or at least one biconvex positive lens, a cemented lens composed of a negative lens and a positive lens and at least one positive lens arranged from the object side.

Zoom lens and image pickup apparatus equipped with same

Disclosed is a zoom lens system, in order from an object side to an image side, including: a first lens unit having a positive optical power; a second lens unit having a negative optical power; a third lens unit having a positive optical power; and a fourth lens unit having a positive optical power, in which during zooming, intervals of the lens units are changed. In such a zoom lens system, a material having a large refractive index is adopted for a material constituting a negative lens element disposed on the most object side in the second lens unit, whereby high optical performance is realized while the whole lens system is miniaturized.

Zoom lens system and image pickup apparatus having the same

A zoom lens 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 an aperture stop; a fourth lens unit having negative optical power; and a fifth lens unit having positive optical power, in which, during zooming from a wide-angle end to a telephoto end, the first lens unit stays, the second lens unit moves toward the image side, and the third lens unit moves together with the aperture stop.

Zoom lens and image pick up apparatus including the same

A zoom lens system is disclosed, comprising, 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, wherein the second and fourth lens units are moved during zooming. The third lens unit consists of a first lens subunit of positive optical power, an aperture stop, and a second lens subunit having one or more negative lens elements and one or more positive lens elements, in order from the object to the image sides. Optical parameters including the focal length of each lens unit, lens shapes, the lens structure of each lens unit are specified to realize a zoom lens system with a smaller size of the entire lens system and higher optical performance.

Zoom lens system

An optical apparatus is disclosed which comprises an optical system provided with a zoom lens for performing zooming by moving along the optical axis and a focus lens for performing correction and focusing at the time of zooming, an imaging device for imaging an optical image supplied from the optical system, a zoom actuator for driving the zoom lens, a focus actuator for driving the focus lens, a zoom position detecting device for detecting the position of the zoom lens, a focus position detecting device for detecting the position of the focus lens, an aperture stop member whose opening diameter changes so as to adjust the luminous energy passing through the optical system a filter member to be freely inserted into or extracted from the optical path of the optical system, an aperture stop state detecting device for detecting the opening state of the aperture stop member, a filter state detecting device for detecting the insertion state of the filter member, a memory storing the movement information on the relation between the position of the zoom lens for keeping a focused state and the position of the focus lens, and a control device for correcting the movement information in accordance with an output of the aperture stop state detecting device and an output of the filer state detecting device and controlling driving of the focus lens.

Optical apparatus

This specification discloses a zoom lens of novel construction in which ghost or flare caused by the reflection between a filter member and an image pickup surface suppressed. This zoom lens is provided, in succession from the front to the rear, with a first lens unit of positive power, a second lens unit of negative power moved during zooming, a stop unit, a third lens unit of positive power, and a fourth lens unit of positive power moved during zooming. The stop unit has a stop blade forming an aperture, and a filter member for attenuating the quantity of light passing through the aperture. The filter member is so disposed as to be inclined with respect to the optical axis of the zoom lens.

Zoom lens and image taking apparatus having the same

A 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, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power, zooming from a wide-angle end to a telephoto end being effected by moving the second lens unit toward the image side, and shifting of an image plane due to zooming being compensated for by moving the fourth lens unit, wherein the second lens unit consists of four separate single lenses including three negative lenses and one positive lens, and the third lens unit has at least one positive lens both surfaces of which are aspherical.

Growing community of inventors

Tokyo, Japan

Akihisa Horiuchi