摘要:
A diaphragm device in which a plurality of diaphragm blades are arranged in partly overlapping relation to one another. This diaphragm device provides a diaphragm aperture of a substantially elongated circle having its length extending in a specific direction, when stopped down beyond a given diaphragm aperture. More particularly, the diaphragm aperture is defined by a pair of arcs which oppose each other in a direction perpendicular to the specific direction passing through the center of the aperture and another pair of arcs which are disposed on the opposite sides in the aforesaid specific direction, while the distance of either one of the pair of arcs to the center of the aperture is shorter than the distance of either of the other pair of arcs to the center of the aperture. These pairs of arcs define portions of the inner peripheral edges of the diaphragm blades.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.