Canon Kabushiki Kaisha

Sadatoshi Takahashi

Nozomu Kitagishi

Tsunefumi Tanaka

Keiji Ikemori

Sadahiko Tsuji

Kikuo Momiyama

Hiroshi Endo

Takashi Matsushita

Toshiaki Asano

Takeshi Koyama

Masatake Kato

Kazuo Fujibayashi

Kouji Oizumi

Hideki Ogawa

Setsuo Minami

Masamichi Tateoka

Akira Tajima

Koutaro Yano

A small-sized camera in which while the light emerging from a photographic lens having an optical axis parallel with a photosensitive plane is conducted by first and second mirrors to the photosensitive plane to form a photographic system, the first or second mirror is turned around a predetermined axis to conduct the light to an eyepiece lens to form a finder system. And, a structure of construction for efficiently removing the stray light of this camera is disclosed.

Small-sized camera

A zoom lens is disclosed comprising, from front to rear, a first lens groups of positive power, a second lens group of negative power, a third lens group of positive power, and a fourth lens group, at least two of these four lens groups being moved to effect zooming and the second lens group being moved to effect focusing, and satisfying the following condition:

Zoom lens

A zoom lens includes a first lens group having a negative refractive power and having an object-side sub-group stationary during focusing and an image-side sub-group arranged to move for focusing purposes, and a second lens group having a positive refractive power and arranged on the image side of the first lens group, wherein the first lens group and the second lens group move axially at the same time and in differential relation for zooming purposes.

Wide-angle type zoom lens having inner-focus lens

A camera having a photographic lens and an eyepiece lens for observing an image formed by the photographic lens, wherein when this camera is used as a telescope, the interval between the image and the eyepiece lens is shortened, while simultaneously changing the focal length of the eyepiece lens, so that the magnification of the finder is increased.

Camera having telescopic capability

A zoom lens is composed of, as counted from the object side of the lens, a first lens unit or group having a positive refractive power, a second lens unit or group having a negative refractive power, a third lens unit or group having a positive refractive power, a fourth lens unit or group having a negative refractive power and a fifth lens unit or group having a positive refractive power. Assuming that, when varying the magnifying power of the lens from a wide angle end to a telephoto end, an air space between an i-th lens unit and an i+l-th lens unit varies to a degree .DELTA.Di, the i-th lens unit has a focal length fi, the focal length of the whole lens system as obtained at the telephoto end is FT, and a space between the first and second lens units varies to a degree .DELTA.E1 between the wide angle end and the telephoto end, the zoom lens is arranged to satisfy the following conditions:

Zoom lens of high power varying ratio

A zoom lens including, from front to rear, a first lens unit of positive power, a second lens unit of negative power and a third lens unit of positive power, wherein for a standard focal length range at least the first and second lens units move simultaneously and independently of each other, and to obtain a focal length beyond the standard range, at least the second lens unit moves, whereby the locus of movement of the first lens unit bends at an end of the standard range, and as the standard range is exceeded, the first lens unit either remains stationary or moves forward.

Zoom lens capable of selecting a focal length beyond a standard focal

A telephoto lens comprising, from front to rear, a first lens unit including a lens of negative power with its rear surface concave toward the rear and whose overall power is positive, a second lens unit of negative power axially movable for focusing, and a third lens unit of positive overall refractive power having a negative lens whose front-most lens surface is concave toward the front and at least two positive lenses.

Telephoto lens of large aperture ratio

A zoom lens comprising, from front to rear, a first zoom section and a second zoom section, the first zoom section having a plurality of movable lens units which simultaneously move to effect zooming, and the second zoom section having a plurality of axially movable lens units, the light beam exiting from the rearmost unit in the first section enters directly the frontmost unit in the second section, and the refractive powers of the front and rear lens units are made positive and negative respectively, whereby the front and rear lens units are simultaneously moved in such a way that the magnifying power of the rear lens unit remains positive when the focal length of the entire system varies.

Zoom lens capable of obtaining focal lengths beyond a variable focal

A zoom lens comprising, from front to rear, a first lens unit of negative power, a second lens unit of positive power and a third lens unit, the first and second lens units being axially movable for zooming, and the zoom lens satisfying the following conditions:

A zoom lens having a plurality of lens units with the air separations, at least one of which is varied to effect zooming, the rearmost lens surface of successive two of the lens units and the frontmost lens surface of the rear one being both formed to convex shapes toward the front, whereby when these two lens units axially move at different speeds from each other, a soft-focus effect of varying magnitude is produced on the image.

Zoom lens having a capability of introducing special features into image

A zoom lens including, from front to rear, a first lens group of positive power, a second lens group of negative power, a third lens group of positive power, a fourth lens group of negative power, and a fifth lens group of positive power. For zooming from the shortest focal length to the longest focal length, the first lens group is moved forward, the air space between the first and second lens groups is increased, the air space between the second and the third lens groups is decreased, the air space between the third and fourth lens groups is increased, and the air space between the fourth and fifth lens groups is decreased. The fifth lens group remains stationary during zooming. This construction and arrangement results in a zoom lens of compact form with a large aperture while still permitting good stability of aberration correction throughout a greatly extended zooming range.

Compact zoom lens having a large aperture and good aberation correction

The disclosed zoom lens has at least four lens groups with proper refractive powers operating such that while the third lens group counting from front is held stationary, the first and second lens groups and at least one of the fourth lens group and those that follow are moved axially in differential relation to effect zooming. A given range of variation with zooming of the image magnification of the second lens group and a given differential relation for the zooming movement of the first and second lens groups achieve good stability of aberration correction over an extended zooming range.

High magnification range zoom lens

A high relative aperture Gauss type lens comprising, from front to rear, a first lens unit including at least one positive lens, a negative meniscus-shaped second lens convex toward the front, a positive third lens with its front surface of strong convex curvature toward the front, a negative fourth lens with its rear surface of strong concave curvature toward the rear, a negative fifth lens with its front surface of strong concave curvature toward the front, a positive sixth lens with its rear surface of strong convex curvature toward the rear, a negative meniscus-shaped seventh lens convex toward the rear, a positive meniscus-shaped eighth lens convex toward the rear, a positive ninth lens, and a positive meniscus-shaped tenth lens convex toward the front.

High relative aperture Gauss type lens

A zoom lens including, from front to rear, a first lens unit of negative power and a second lens unit of positive power with the separation therebetween being varied to effect zooming. The first lens unit is moved to effect focusing, wherein with the first lens unit focusing a finite object distance on the wide angle side, the second lens unit moves rearward to obtain focal lengths beyond the zooming range.

Zoom lens able to obtain focal lengths beyond the zooming range

A zoom lens having at least four components of which the 1st counting from the object side is of positive power, the 2nd is of negative power and the 3rd and 4th are of positive or negative power, wherein the 2nd component is made fixed, and the 1st component and at least one of those that follow the 2nd component are made movable for zooming, whereby the bulk and size of the lens system is minimized, while still permitting good correction of aberrations.

Growing community of inventors

Tokyo, Japan

Sadatoshi Takahashi