Title:
VARIABLE MAGNIFICATION OPTICAL SYSTEM, IMAGE PICKING-UP DEVICE AND DIGITAL EQUIPMENT
Document Type and Number:
WIPO Patent Application WO/2008/075539
Kind Code:
A1
Abstract:
The present invention sufficiently corrects various aberrations of color, astigmatism,
and the like while achieving a super compact structure device. For that purpose,
a variable magnification optical system includes a first lens group provided
with negative optical power, a second lens group provided with positive optical
power, a third lens group provided with negative optical power and a fourth lens
group provided with positive optical power in turn from an object side, wherein
a distance between the first lens group and the second lens group becomes narrow
at the magnification from a wide terminal to a telescopic terminal. In the case
where T1 is a thickness on the optical axis measured from the most front surface
of the fist lens group to the last surface of the fist lens group, fw and ft are resultant
focus distances of the total optical system at the wide angle terminal and the
telescopic terminal, respectively, ΔN2 is a difference in average refractive
index between the positive lenses and the negative lenses in the second lens group,
Δν2 is a difference in average Abbe number between the positive
lenses and the negative lenses in the second lens group, and N1 is the maximum refractive
index in a lens of the first lens group, the variable magnification optical system
satisfies the following: 0.20.15,
Δν2>20 and N1≥1.8.
More Like This:
| JP61286812 | ZOOM LENS |
| JP2011197471 | ZOOM LENS SYSTEM, INTERCHANGEABLE LENS DEVICE, AND CAMERA SYSTEM |
| WO/2012/077338 | ZOOM LENS AND IMAGING DEVICE |
Inventors:
MATSUSAKA, Keiji (Inc. 2970 Ishikawa-machi, Hachioji-sh, Tokyo 05, 1928505, JP)
松坂 慶二 (〒05 東京都八王子市石川町２９７０番地コニカミノルタオプト株式会社内 Tokyo, 1928505, JP)
FUKUTA, Yasunari (Inc. 2970 Ishikawa-machi, Hachioji-sh, Tokyo 05, 1928505, JP)
松坂 慶二 (〒05 東京都八王子市石川町２９７０番地コニカミノルタオプト株式会社内 Tokyo, 1928505, JP)
FUKUTA, Yasunari (Inc. 2970 Ishikawa-machi, Hachioji-sh, Tokyo 05, 1928505, JP)
Application Number:
JP2007/072824
Publication Date:
June 26, 2008
Filing Date:
November 27, 2007
Export Citation:
Assignee:
Konica Minolta Opto, Inc. (2970, Ishikawa-machi Hachioji-sh, Tokyo 05, 1928505, JP)
コニカミノルタオプト株式会社 (〒05 東京都八王子市石川町２９７０番地 Tokyo, 1928505, JP)
MATSUSAKA, Keiji (Inc. 2970 Ishikawa-machi, Hachioji-sh, Tokyo 05, 1928505, JP)
松坂 慶二 (〒05 東京都八王子市石川町２９７０番地コニカミノルタオプト株式会社内 Tokyo, 1928505, JP)
コニカミノルタオプト株式会社 (〒05 東京都八王子市石川町２９７０番地 Tokyo, 1928505, JP)
MATSUSAKA, Keiji (Inc. 2970 Ishikawa-machi, Hachioji-sh, Tokyo 05, 1928505, JP)
松坂 慶二 (〒05 東京都八王子市石川町２９７０番地コニカミノルタオプト株式会社内 Tokyo, 1928505, JP)
International Classes:
G02B15/20; G02B13/18; G02B15/167
Download PDF: