Patent US4168436A successfully refreshed from Google Patents.
Patent US3674343A successfully refreshed from Google Patents.
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US3674343A Expired / Lapsed US ⏱️ 0.0 years remaining

Lens barrel

Assignee: Canon Inc
•
Filing: 1970-09-15
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Granted: 1972-07-04
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Expires: 1990-09-15
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Abstract

Abstract A LENS BARREL WHICH HAS A FOCUSING RING, A MIDDLE CYLINDER, AN OUTER CYLINDER FIXED TO A CAMERA BODY, A FRONT LENS GROUP HOLDER, AND A REAR LENS GROUP HOLDER, WHEREIN THE MIDDLE CYLINDER AND THE OUTER CYLINDER ARE ROTATABLY SCREWED TO EACH OTHER, THE FOCUSING RING IS INTEGRALLY CONNECTED TO THE MIDDLE CYLINDER IN A ROTATABLE MANNER, THE MIDDLE CYLINDER HAS TWO SCREWED PARTS HAVING DIFFERENT LEADS, AND THE FRONT LENS GROUP HOLDER AND THE REAR LENS GROUP HOLDER ARE SCREWED TO EACH OF SAID SCREWED PARTS, THE FRONT LENS GROUP HOLDER BEING ENGAGED, WITH KEY GROOVE, TO THE REAR LENS GROUP HOLDER WHICH IS ENGAGED, WITH KEY GROOVE, TO THE OUTER CYLINDER, THUS AN ABERRATION IS COMPENSATED BY VARYING THE AIR SPACING BETWEEN THE FRONT LENS GROUP AND THE REAR LENS GROUP AT THE TIME OF FOCUSING WHEN THE FRONT LENS GROUP AND THE REAR LENS GROUP MAKE LINEAR MOVEMENTS WITH DIFFERENT AMOUNTS BY THE ROTATION OF THE FOCUSING RING.

Inventors

  • 👤 Goro Hasegawa
  • 👤 Masaharu Ito

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 03:28
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/02; G02B7/04

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-07-04 1976-01-03 1976-07-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-07-04 1980-01-03 1980-07-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-07-04 1984-01-03 1984-07-04 $7700.00 Window Closed / Lapsed

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