JPS5729024A - Zoom lens system having lens group for focusing behind the system - Google Patents

Zoom lens system having lens group for focusing behind the system

Info

Publication number
JPS5729024A
JPS5729024A JP10418680A JP10418680A JPS5729024A JP S5729024 A JPS5729024 A JP S5729024A JP 10418680 A JP10418680 A JP 10418680A JP 10418680 A JP10418680 A JP 10418680A JP S5729024 A JPS5729024 A JP S5729024A
Authority
JP
Japan
Prior art keywords
lens
group
focusing
positive
zoom lens
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10418680A
Other languages
Japanese (ja)
Inventor
Hisayuki Masumoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Minolta Co Ltd
Original Assignee
Minolta Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Minolta Co Ltd filed Critical Minolta Co Ltd
Priority to JP10418680A priority Critical patent/JPS5729024A/en
Priority to US06/270,150 priority patent/US4634236A/en
Publication of JPS5729024A publication Critical patent/JPS5729024A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/02—Optical objectives with means for varying the magnification by changing, adding, or subtracting a part of the objective, e.g. convertible objective
    • G02B15/04—Optical objectives with means for varying the magnification by changing, adding, or subtracting a part of the objective, e.g. convertible objective by changing a part
    • G02B15/08—Optical objectives with means for varying the magnification by changing, adding, or subtracting a part of the objective, e.g. convertible objective by changing a part by changing the rear part
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00—Optical objectives with means for varying the magnification
    • G02B15/14—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/143—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only
    • G02B15/1431—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being positive
    • G02B15/143105—Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective having three groups only the first group being positive arranged +-+

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

PURPOSE:To provide a compact zoom lens system of high variable magnification ratios by adding a lens group for focusing of simple constitution of the image side of the zoom lens consisting of 3 groups, and satisfying specific conditions. CONSTITUTION:The 1st group I on the object side consists of a positive lens and a negative lens, the 2nd group II of two negative lenses and a positive lens, and the 3rd group III of two positive lenses and each one of negative and positive lenses. The lens group for focusing on the image side is constituted of at least one piece of positive lens, and these are so constituted as to satisfy conditional formulas 1, 2, 3 where the focal lengths of the above-mentioned 3 groups are defined as f1, f2, f3, and the focal length of the entire system at the long focal length end is defined as fL. Thereby, zooming is accomplished with the positive refracting power group of a relatively small diameter as the 1st group, and focusing is accomplished with the focusing lens on the image side, whereby the compact zoom lens system of high variable magnification ratio is obtained.
JP10418680A 1980-06-12 1980-07-28 Zoom lens system having lens group for focusing behind the system Pending JPS5729024A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP10418680A JPS5729024A (en) 1980-07-28 1980-07-28 Zoom lens system having lens group for focusing behind the system
US06/270,150 US4634236A (en) 1980-06-12 1981-06-02 Compact zoom lens system of a relatively high zoom ratio capable of providing a wide field angle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10418680A JPS5729024A (en) 1980-07-28 1980-07-28 Zoom lens system having lens group for focusing behind the system

Publications (1)

Publication Number Publication Date
JPS5729024A true JPS5729024A (en) 1982-02-16

Family

ID=14373955

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10418680A Pending JPS5729024A (en) 1980-06-12 1980-07-28 Zoom lens system having lens group for focusing behind the system

Country Status (1)

Country Link
JP (1) JPS5729024A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58143312A (en) * 1982-02-19 1983-08-25 Minolta Camera Co Ltd Zoom lens system
JPS58150926A (en) * 1982-03-04 1983-09-07 Canon Inc Zoom lens
JPS58179810A (en) * 1982-04-15 1983-10-21 Olympus Optical Co Ltd Focusing system of zoom lens
JPS58202416A (en) * 1982-05-19 1983-11-25 Minolta Camera Co Ltd Zoom lens system of high variable magnification ratio containing wide angle area
JPS6021018A (en) * 1983-07-14 1985-02-02 Canon Inc Zoom lens system
US5859729A (en) * 1996-01-06 1999-01-12 Canon Kabushiki Kaisha Zoom lens device with four lens unit
JP2005055592A (en) * 2003-08-01 2005-03-03 Canon Inc Zoom lens and imaging device having the same

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5366226A (en) * 1976-11-25 1978-06-13 Bell & Howell Japan Focusing system for zoom lens
JPS5430855A (en) * 1977-07-30 1979-03-07 Asahi Optical Co Ltd Wide angle zoom lens system having high variable magnification

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5366226A (en) * 1976-11-25 1978-06-13 Bell & Howell Japan Focusing system for zoom lens
JPS5430855A (en) * 1977-07-30 1979-03-07 Asahi Optical Co Ltd Wide angle zoom lens system having high variable magnification

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58143312A (en) * 1982-02-19 1983-08-25 Minolta Camera Co Ltd Zoom lens system
JPH0477291B2 (en) * 1982-02-19 1992-12-08 Minolta Camera Kk
JPS58150926A (en) * 1982-03-04 1983-09-07 Canon Inc Zoom lens
JPS6155653B2 (en) * 1982-03-04 1986-11-28 Canon Kk
JPS58179810A (en) * 1982-04-15 1983-10-21 Olympus Optical Co Ltd Focusing system of zoom lens
JPH0529886B2 (en) * 1982-04-15 1993-05-06 Olympus Optical Co
JPS58202416A (en) * 1982-05-19 1983-11-25 Minolta Camera Co Ltd Zoom lens system of high variable magnification ratio containing wide angle area
JPH0529885B2 (en) * 1982-05-19 1993-05-06 Minolta Camera Kk
JPS6021018A (en) * 1983-07-14 1985-02-02 Canon Inc Zoom lens system
US5859729A (en) * 1996-01-06 1999-01-12 Canon Kabushiki Kaisha Zoom lens device with four lens unit
JP2005055592A (en) * 2003-08-01 2005-03-03 Canon Inc Zoom lens and imaging device having the same
JP4612790B2 (en) * 2003-08-01 2011-01-12 キヤノン株式会社 Zoom lens and imaging apparatus having the same

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