Minolta Camera Kabushiki Kaisha

Kyozo Uesugi

Hiroshi Ueda

Osamu Tanaka

Mitsuo Yasukuni

Tsuneyo Metabi

Yukio Okano

Yoshio Kuramoto

Masakazu Nakanishi

Nobuyuki Kita

Ryuzo Hachiken

A lens is provided with a first and second lens groups which can focus not only with their concurrent movement along the optical axis but also with the movement of either one of the two lens groups. The first and second lens groups are respectively carried by first and second movable barrels. First means is provided for shifting both of first and second movable barrels concurrently in accordance with manual focus control. Second means is provided for shifting the second movable barrel without causing any movement of the first movable barrel. Thus, members to be moved for focusing upon automatic focus control are less in number in comparison with the members upon manual focus control.

Automatic and manual focus control for objective lens assembly

A zoom lens barrel has incorporated therein two lens groups, the first of which is moved by a single operating ring for focusing and also for zooming. A cam member and an intermediate member are supported on a stationary cylinder. The first lens group is axially moved for focusing by the rotation of the operating ring. By way of the intermediate member, the stationary cylinder and the cam member, the operating ring, when axially moved, axially moves the first and second lens groups at the same time by different amounts for zooming. The barrel affords a high zooming ratio with ease, while the optical system can be designed compactly in a small size.

Compact zoom lens barrel with high zooming ratio

A zoom lens barrel is constructed such that the axial movement and rotation of a single operation ring relative to a stationary barrel causes zooming and focusing respectively and provides a device for providing constant magnification photography. This is accomplished by a plurality of cam grooves provided on one of the operation ring and the stationary barrel and a guide pin provided on the other of the operation ring and the stationary barrel and releasably engageable with each of the cam grooves. Each of the cam grooves forces the operation ring to rotate upon axial movement of the operation ring through the engagement with the guide pin such that magnification remains constant during focusing. The magnification that remains constant during focusing varies depending on which of the cam grooves the guide pin is engaged with.

Zoom lens barrel assembly for constant magnification

In a shifting device, wherein a shifting operation is effected by the engagement of a guide pin with a cam groove, which is delineated by a control face for guiding the guide pin, and a back-up face serving no guide pin guidance function. The guide pin is so constructed as to be normally maintained in engagement with the control face of the cam groove, so as to be shifted by engagement with the control face of the cam groove during the normal shifting operation. In the event that an undesired shock is imparted to the shifting device, the guide pin is adapted to impinge on the back-up face of the cam groove, rather than on the control face thereof, so that the engagement between the guide pin and the control face of the cam groove is maintained in an optimum condition, without being damaged due to such a shock, thus ensuring an accurate shifting operation of the shifting device.

Shock absorbent shifting device

A diaphragm control mechanism for a camera objective wherein the diaphragm aperture is maintained fully open before camera operation in order to facilitate framing and focusing of the objective system and is then stopped down in response to a camera release operation to a value manually preset or automatically determined. The fully open diaphragm aperture is adjusted in accordance with movement of a component or components of the objective for the sake of adjustment of the objective, for example, to change its focal length. The improvement according to the present invention lies in the construction of the fully open diaphragm aperture adjusting mechanism wherein a movable member which is included in the link system for the stopping down of the diaphragm bears against a periphery cam or cam edge of a fixed member fixedly mounted in the lens barrel of the objective independently of the link system so that the fully open diaphragm aperture is adjusted as a function of the contact point between the movable member and the cam, with the movable member being allowed to move away from the cam upon the diaphragm stopping down operation of the link system.

Diaphragm control mechanism for camera objectives

A zoom lens barrel capable of indicating adjusted distance and focal length is of compact construction having only those members essential for focusing and zooming. No special scale member is provided, although a focal length or zoom ratio scale extends circumferentially along the outer periphery of a cam ring which is rotated upon the zooming operation, while a distance scale extends circumferentially along an operating ring substantially at its rearward end. A stationary barrel on and in which the cam ring and the operating ring, respectively, are fitted has a window for the focal length or zoom ratio scale and an index at an external position adjacent the rearward end of the operating ring. Rotation of the ring causes helicoid threads to axially move a first lens group for focusing and the adjusted distance on the distance scale is indicated by the index. Axial movement of the operating ring axially moves the front lens group as well. This causes a pin-slot engagement to rotate the cam ring so that a second lens group is axially moved for zooming in a given spacial relationship with respect to the first lens group, and the adjusted focal length or zoom ratio on the focal length or zoom ratio scale seen through the window is indicated by the index.

Lens barrel capable of axial zooming operation and with barrel window

A zoom lens barrel has first and second manually operable members movable for effecting a zooming operation in different directions. The first operable member is axially movable for effecting movement of a first lens group and is threaded with an axially movable follower member such that the first operable member and the follower member are axially moved in response to axial movement of the other. A first pin-slot arrangement interconnects the follower member and a rotatable intermediate cam ring with one another such that the cam ring is rotated in response to axial movement of the follower member while the follower member is axially moved in response to rotation of the cam ring. A second pin-slot arrangement interconnects the cam ring with a lens frame supporting a second lens group such that the second lens group is moved for zooming in response to rotation of the cam ring with a given spatial relationship with respect to the first lens group. The second operable member is rotatable together with the cam ring. An adjusting device may adjust friction between a stationary barrel and the second operating member or the cam ring, thereby preventing accidental rotation of the cam ring.

Zoom lens barrel capable of different directional operations

An impact resistant zoom lens with a common focusing and zooming ring includes a camera mountable main barrel, front and rear axially movable lens carrying mounts, a control ring rotatably and slidably engaging the barrel and affixed to the front mount, an axial sleeve helicoid coupled to the first mount, a cylindrical cam rotatably supported by the barrel and longitudinally stationary therein and followers carried by the axial sleeve rearwardly thereof and by the rear mount and slidably engaging respective cam slots in the cam and guide tracks in the barrel. In order to prevent damage to the lens mechanism attendant to an impact on the front mount abutment members or faces are located on the front mount or sleeve and have large areas in stop engagement when the front mount is in its rearmost position with the follower movable therewith being shortly spaced from the rear end of the respective cam slot. Similarly related faces or members may be provided for limiting the forward movement of the front mount.

Shock resistant lens device

A lens barrel containing at least first and second movable lens groups and an operating member for shifting the movable lens groups along the optical axis includes a helicoid cylinder interposed between a first movable lens frame which supports the first movable lens group, and a fixed cylinder or a member whose movement relative to the fixed cylinder along the optical axis is prevented, whereby a shock externally imparted to the first movable lens frame is transmitted through the helicoid cylinder only to the fixed cylinder.

Shock resistant lens device with zoom and macrofocusing controls

An assembly includes a male member fitted in the bore of a female member in a rigid or slidable manner, with at least one of the confronting peripheral surfaces of both members being formed with a plurality of equally spaced projections which are positioned between the two members. These projections are of such a shape as to afford a low mechanical strength, such as for instance, triangular or trapezoidal in cross section, and contribute to eliminating any looseness in the fit between the assembled members. The projections may be cut or collapsed or otherwise altered under pressure by a face of the opposite member in which the projection carrying member is fitted during assembly thereby eliminating any clearance between the members with the resulting obviation of looseness.

Construction of parts providing fits

Lens barrel having plural lugs or similar article

A varifocal lens assembly of simplified construction which essentially comprises a lens mounting for focusing adjustment, a second lens mounting and a third lens mounting cooperative with the second lens mounting for adjustment of the focal length and for correction of optical aberrations resulting from the displacement of the second lens mounting and an operating barrel for operating the first and second lens mountings, either independently or simultaneously. The operating barrel effects, when rotated, the focusing operation and, when axially moved, the zooming operation.

Compact varifocal lens assembly

Each exchangeable lens in a series of exchangeable lenses for use in single lens reflex cameras comprises a lens barrel including at least one lens and a diaphragm, a fixed index on the outer surface of the lens barrel, a diaphragm setting ring including f-number graduations ranging from a maximum f-number to a minimum f-number of the exchangeable lens, with the ring rotatable to a plurality of positions to align any one of the f-number graduations to an index so as to be set to a desired f-number. A first projection on the ring is spaced a predetermined first distance, common to each exchangeable lens of the series, from the minimum f-number graduation in the rotational direction of the ring. Thus, the amount of rotation of the first projection with the ring set to a desired f-number corresponds to the step-difference between the minimum and the desired f-number. A second projection of the ring is spaced a predetermined second distance from the maximum f-number graduation in the rotational direction of the ring. The second distance is dependent on the value of the maximum f-number of each exchangeable lens of the series of lenses such that the second projection is at a position dependent on the value of the maximum f-number of the exchangeable lens with the ring set to the maximum f-number.

Exchangeable lenses for use in internal light measuring type single lens

A buffer or cushion made of a plastic material is interposed between an external device exposed to the exterior of a lens barrel and an internal mechanism within the barrel of a lens to absorb any impact applied to the external device and transmitted toward the internal mechanism and the lens unit. The external device may include an ornament ring and a barrel head sleeve and the internal mechanism may include sleeves for shifting the lens unit and members for holding the lens unit.

Cushioned objective lens

The present lens system is capable of providing not only a zooming function over a relatively wide range, but also macrophotography. The zoom lens system includes a first lens group capable of varying the focal length without a loss of focus and a second lens group forming a master lens group. The second lens group is spatially displaced on the image side of the first lens group and includes a lens component movably mounted on the optical axis of the system that is capable of varying the focal length of the second lens group. The movable lens component in the second lens group has two positions which will provide the same final image plane for the entire zoom lens system, for example, a forward and backward position does not introduce any image plane deviations and permits an extension of the zoom range of the total lens system. The intermediate position of the movable lens component of the second lens group can be utilized for focusing in a macrophotography range. Thus the movable lens component has the capability of providing an exaggerated image plane deviation between its forward and backward position to permit macrophotography with the lens system.

Growing community of inventors

Sakai, Japan

Kyozo Uesugi