Patent US4063801A successfully refreshed from Google Patents.
US4063801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephoto type objective
Assignee: Canon Inc
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Filing: 1976-07-26
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Granted: 1977-12-20
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Expires: 1996-07-26
Abstract
Abstract A telephoto type objective comprising a front lens group and a rear lens group axially spaced apart from each other. The front lens group has a positive refracting power and which remains stationary during focusing. The rear lens group has a negative refracting power and is comprised of two movable lens members for focusing. When the two movable lens members are moved along the optical axis toward an image plane, the telephoto type objective is caused to focus an object at a near distance from its focusing on an object at a far distance with the resulting amount of movement of the rear lens member being larger than that of movement of the front movable lens group.
Inventors
- 👤 Hideo Yokota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:14
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/02
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
127 words
A telephoto type objective comprising: a front lens group having a positive refracting power and which remains stationary during focusing, said front lens group being comprised of a plurality of lens members, and a rear lens group having a negative refracting power and positioned on the image side of said front lens group in axial alignment therewith, said rear lens group including at least two movable lens members arranged to be moved in the same direction along the common optical axis toward the image plane when the object distance is changed in focusing from infinitely distant object to close object with the resulting speed of movement of the front one of said two movable lens members being different from that speed of movement of the rear one.
Claim 2
Dependent Claim
127 words
A telephoto type objective comprising: a front lens group having a positive refracting power and which remains stationary during focusing, said front lens group being comprised of a plurality of lens members, and a rear lens group having a negative refracting power and positioned on the image side of said front lens group in axial alignment therewith, said rear lens group including at least two movable lens members arranged to be moved in the same direction along the common optical axis toward the image plane when the object distance is changed in focusing from infinitely distant object to close object with the resulting speed of movement of the front one of said two movable lens members being different from that speed of movement of the rear one.
Claim 3
Dependent Claim
28 words
A telephoto type objective according to claim 1, wherein said front lens member of said rear lens group moves at a slower speed than said rear lens member.
Claim 4
Dependent Claim
28 words
A telephoto type objective according to claim 2, wherein said rear movable lens member has at least one positive lens element and at least one negative lens element.
Claim 5
Dependent Claim
23 words
A telephoto type objective according to claim 2, wherein said front movable lens member has a front lens surface convex toward the front.
Claim 6
Dependent Claim
35 words
A telephoto type objective according to claim 1, wherein said front movable lens member of said rear lens group has a positive refracting power, and said rear movable lens member has a negative refracting power.
Claim 7
Dependent Claim
78 words
A telephoto type objective according to claim 5, wherein said front movable lens member has a plurality of surfaces including a strongest converging surface convex toward the front, and said rear movable lens member has a plurality of surfaces including a strongest diverging surface concave toward the rear, and wherein the focusing is effected with the resulting speed of movement of said front movable lens member being slower than that of movement of said rear movable lens member.
Claim 8
Dependent Claim
43 words
A telephoto type objective according to claim 6, wherein the mean value of the Abbe numbers of the positive lens elements in said rear movable lens member is larger than the mean value of the Abbe numbers of the negative lens elements therein.
Claim 9
Dependent Claim
30 words
A telephoto type objective according to claim 1, wherein said front lens group is comprised of a positive lens, a negative lens and a positive lens arranged in this order.
Claim 10
Dependent Claim
78 words
A telephoto type objective comprising: a primary lens group having a positive refracting power and which remains stationary during focusing, said primary lens group being comprised of a plurality of lens member, and two movable sub-groups positioned on the image side of said primary lens group in axial alignment therewith to be movable for focusing in such a manner that the image side one of said two sub-groups moves at a faster speed than the object side sub-group.
Claim 11
Dependent Claim
78 words
A telephoto type objective comprising: a primary lens group having a positive refracting power and which remains stationary during focusing, said primary lens group being comprised of a plurality of lens member, and two movable sub-groups positioned on the image side of said primary lens group in axial alignment therewith to be movable for focusing in such a manner that the image side one of said two sub-groups moves at a faster speed than the object side sub-group.
Claim 12
Dependent Claim
28 words
A telephoto type objective according to claim 9, wherein said image side sub-group has a negative refracting power, and said object side sub-group has a positive refracting power.
Claim 13
Dependent Claim
31 words
A telephoto type objective according to claim 9, wherein said image side sub-group has at least one positive and at least one negative lenses, and said object side sub-group is meniscus-shaped.
Claim 14
Dependent Claim
30 words
A telephoto type objective according to claim 9, wherein the axial separation between said primary lens group and said object side sub-group is larger than that between said two sub-groups.
Claim 15
Dependent Claim
30 words
A telephoto type objective according to claim 9, wherein said primary lens group is comprised of a positive lens, a negative lens and a positive lens arranged in this order.
References Cited (Backward Citations)
US2503789A
Cited
US3854797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |