Shifting device for compensating image performance of photographic camera lens in close-up photographing

Claim 2

A photographic lens for a camera comprising: a photographic optical lens system consisting of a front lens group and a rear lens group and an air space variable by displacement between said front lens group and said rear lens group, an outer tube including means for securing said photographic lens to a camera body, a focusing ring rotatably and axially shiftably engaging said outer tube for focusing and shifting means including a pair of matingly engaging helicoid screws formed in the inner periphery of said outer tube and the confronting face of the focusing ring, said ring fixedly holding the front lens group of said photographic optical lens system, an inner tube engaged with said focusing ring through a compensational shifting means including a cam groove formed in the inner periphery of said focusing ring and a pin projecting from said inner tube and engaging cam groove and means for restricting said inner tube to axial movement relative to said outer tube and said inner tube being adapted to be displaced by said focusing operation, said inner tube fixedly holding the rear lens group of the photographic optical lens system and being fitted slidably and rotatably in said focusing ring through a sleeve fit.

Claim 3

A camera photographic objective lens comprising a rear barrel section (10) having a rear coupling portion (11) for mounting the objective lens, a front barrel section (12) coaxial with and forward of said rear barrel section said front and rear barrel sections having mating helicoidal threads (13) coaxial with said barrel whereby relative rotation of said front and rear barrel sections effects relative axial movement between said barrel sections, a front lens group (A) mounted in and movable with said front barrel section, and inner barrel section (14) at least partially telescoping said front barrel section, said front and inner barrel sections having relatively rotatably and axially engaging coaxial cylindrical faces (15), a rear lens group mounted in said inner barrel and separated from said front lens group by a floating space (C), said front barrel section having formed in the inner face thereof a peripherally and axially extending cam groove (16), a follower (17) mounted on said inner barrel section and slidably engaging said cam groove and means (18, 19) relatively movably intercoupling said rear and inner barrel sections for restricting the rotation of said inner barrel section relative to said rear barrel section and permitting relative axial movement therebetween.

Claim 4

A camera photographic objective lens comprising a rear barrel section (10) having a rear coupling portion (11) for mounting the objective lens, a front barrel section (12) coaxial with and forward of said rear barrel section said front and rear barrel sections having mating helicoidal threads (13) coaxial with said barrel whereby relative rotation of said front and rear barrel sections effects relative axial movement between said barrel sections, a front lens group (A) mounted in and movable with said front barrel section, and inner barrel section (14) at least partially telescoping said front barrel section, said front and inner barrel sections having relatively rotatably and axially engaging coaxial cylindrical faces (15), a rear lens group mounted in said inner barrel and separated from said front lens group by a floating space (C), said front barrel section having formed in the inner face thereof a peripherally and axially extending cam groove (16), a follower (17) mounted on said inner barrel section and slidably engaging said cam groove and means (18, 19) relatively movably intercoupling said rear and inner barrel sections for restricting the rotation of said inner barrel section relative to said rear barrel section and permitting relative axial movement therebetween.

Claim 5

The lens of claim 2 wherein said coupling means includes a key member (19) fixed to said inner barrel section slidably engaging a longitudinally extending keyway (18) formed in said rear barrel section.

Claim 6

The lens of claim 3 wherein said follower includes a cylindrical member projecting radially outwardly from said inner barrel section into registry with said cam groove.

Claim 7

The lens of claim 4 wherein said helicoidal threads are formed on an inside peripheral face of said rear barrel section and an outwardly facing surface of said front barrel section.