Forum Übersicht - A-Bajonett-Objektive » Patent für Konica Minolta / Nikon AF 1,4/24mm FX

Durch den Hinweis eines Lesers auf SAR bin ich darauf aufmerksam geworden, daß Konica Minolta und Nikon am 2009-09-09 gemeinsam das japanische Patent 2011-59290 für ein 1,4/24mm Autofokus-Weitwinkelobjektiv eingereicht haben, welches das Kleinbildvollformat ausleuchtet. Das Patent wurde am 2011-03-24 erteilt:

http://www19.ipdl.inpit.go.jp/PA1/cgi-bin/PA1INIT
http://www19.ipdl.inpit.go.jp/PA1/cgi-bin/PA1INDEX
ZITATPATENT ABSTRACTS OF JAPAN

(11) Publication number:
2011-059290

(43) Date of publication of application:
24.03.2011

(51) Int.Cl.

G02B 13/04 (2006.01)
G02B 13/18 (2006.01)

(21) Application number:
2009-207811

(71) Applicant:
KONICA MINOLTA OPTO INC
NIKON CORP

(22) Date of filing:
09.09.2009

(72) Inventor:
YAMAMOTO YASUSHI
HARADA MASAKI

(54) WIDE ANGLE LENS, IMAGING OPTICAL DEVICE AND DIGITAL EQUIPMENT

(57) Abstract:

PROBLEM TO BE SOLVED: To provide a wide angle lens high in performance that suppresses aberration fluctuation during focusing despite a large aperture, and to provide an imaging optical device that has the wide angle lens, and digital equipment.

SOLUTION: The wide angle lens LN comprises, in an order from an object side, a first group Gr1 of positive power and a second group Gr2 of positive power. The wide angle lens LN focuses on a close distance object by moving a second group Gr2 toward the object side while a position of the first group Gr1 is fixed. The wide angle lens LN satisfies a conditional expression: 10<f1/fL<150 (f1 represents the focal distance of the first group Gr1 and fL represents the focal distance of the entire system).
[attachment=11185:2011_59290_fig02.png][/quote]
und
http://www4.ipdl.inpit.go.jp/Tokujitu/PAJd...001=2011-059290

http://www.google.de/patents/US20110090574
ZITATWIDE-ANGLE LENS, IMAGING OPTICAL APPARATUS AND DIGITAL EQUIPMENT

Hiroki Harada et al

Application number: 12/878,292
Publication number: US 2011/0090574 A1
Filing date: 9 Sep 2010

Abstract

A wide-angle lens LN consists of, in order from an object side: a first lens group Gr1 having positive refractive power; and a second lens group Gr2 having positive refractive power; the second lens group Gr2 is movable toward the object side with fixing the first lens group Gr1, thereby carrying out focusing on a close object, and a given conditional expression is satisfied. Therefore, a wide-angle lens having high optical performance with suppressing variation in aberrations upon focusing in spite of being a large aperture, an imaging optical apparatus equipped therewith, and a digital equipment are provided.

Inventors: Hiroki Harada, Yasushi Yamamoto
Current U.S. Classification: 359/717; 359/753; 359/794

Claims

1. A wide-angle lens consisting of, in order from an object side:

a first lens group having positive refractive power; and

a second lens group having positive refractive power;

the second lens group being movable toward the object side with fixing the first lens group, thereby carrying out focusing on a close object, and

the following conditional expression being satisfied:

10 < f1 / fL < 150

where f1 denotes a focal length of the first lens group, and fL denotes a focal length of the wide-angle lens.

2. The wide-angle lens according to claim 1, wherein the first lens group includes, in order from the object side, a first lens having negative refractive power with a concave surface facing an image side, a second lens having negative refractive power with a concave surface facing the image side, and at least one lens component having positive refractive power with a convex surface facing the object side disposed to the image side of the second lens, and one lens component having shorter focal length among said at least one lens component satisfies the following conditional expression:

0.6 < T / fL < 1.25

where T denotes a distance from a vertex of an image side surface of the second lens to a vertex of an object side surface of the lens component having positive refractive power with a convex surface facing the object side.

3. The wide-angle lens according to claim 1, wherein the first lens group includes at least one negative lens, and the negative lens in the first lens group includes at least one aspherical surface.

4. The wide-angle lens according to claim 3, wherein the first lens group includes, in order from the object side, a first lens having negative refractive power with a concave surface facing an image side, and a second lens having negative refractive power with a concave surface facing an image side, and the aspherical surface is formed on the image side surface of the second lens.

5. The wide-angle lens according to claim 1, wherein the second lens group consists of, in order from the object side, a front lens group having positive refractive power, an aperture stop, and a rear lens group having positive refractive power, and the most object side lens in the front lens group is a negative lens.

6. The wide-angle lens according to claim 5, wherein the most object side lens in the front lens group satisfies the following conditional expression:

-4 < f21 / fL < -2.5

where f21 denotes a focal length of the most object side lens in the front lens group.

7. The wide-angle lens according to claim 5, wherein the rear lens group consists of three lens blocks which are, in order from the object side, a first lens block having negative refractive power, a second lens block having positive refractive power, and a third lens block having positive refractive power, and the second lens block satisfies the following conditional expression:

65 < vd2

where vd2 denotes an Abbe number of the second lens block or an Abbe number of a positive lens composing the second lens block when the second lens block is a cemented lens.

8. The wide-angle lens according to claim 5, wherein the rear lens group consists of three lens blocks which are, in order from the object side, a first lens block having negative refractive power, a second lens block having positive refractive power, and a third lens block having positive refractive power, and at least one aspherical surface is formed on the image side surface of the first lens block.

9. The wide-angle lens according to claim 1, wherein the first lens group consists of, in order from the object side, a first lens having negative refractive power, a second lens group having negative refractive power, a third lens having a concave surface facing the object side, and a fourth lens having positive refractive power, and the following conditional expression is satisfied:

0.1 < T13 / fL < 0.25

where T13 denotes a thickness of the third lens in the first lens group.

10. The wide-angle lens according to claim 9, wherein the following conditional expression is satisfied:

-0.03 < fL / f13 < 0.02

where f13 denotes a focal length of the third lens in the first lens group.

11. The wide-angle lens according to claim 1, wherein the following conditional expression is satisfied:

0.5 < fL / f2 < 0.65

where f2 denotes a focal length of the second lens group.

12. The wide-angle lens according to claim 1, wherein an f-number of the wide-angle lens is 1.9 or less.

13. An imaging optical apparatus comprising:

the wide-angle lens according to claim 1; and

an imaging device for converting an optical image formed on a detecting surface into an electrical signal;

the wide-angle lens being disposed in such a manner that an optical image of an object is formed on the detecting surface of the imaging device.

14. A digital equipment added at least one function among taking a still picture and shooting movie of an object by installing the imaging optical apparatus according to claim 13.[/quote]

Siehe auch:

http://egami.blog.so-net.ne.jp/2011-03-27#english

Das Nikon AF-S Nikkor 24mm f/1.4G ED kommt dem in diesem Patent beschriebenen Objektiv sehr ähnlich.
[attachment=11195:afs_nikk...4_14g_ed.gif]
Viele Grüße,

Matthias

ZITAt (matthiaspaul @ 2012-05-29, 22:05) Durch den Hinweis eines Lesers auf SAR bin ich darauf aufmerksam geworden, daß Konica Minolta und Nikon am 2009-09-09 gemeinsam das japanische Patent 2011-59290 für ein 1,4/24mm Autofokus-Weitwinkelobjektiv eingereicht haben, welches das Kleinbildvollformat ausleuchtet. Das Patent wurde am 2011-03-24 erteilt:
...
Das Nikon AF-S Nikkor 24mm f/1.4G ED kommt dem in diesem Patent beschriebenen Objektiv sehr ähnlich.

Viele Grüße,

Matthias[/quote]

Hochinteressant - das wusste ich nicht! Auch hier zeigt sich die klassische Minolta-Strategie für lichtstarke Weitwinkel, die sich erstmals im 1.4/35mm von 1987 fand: ein siebenlinsiger Doppelgauss als Grund-Objektiv mit davorgeschaltetem Weitwinkelkonverter. Dieselbe Auslegung finden wir beim ZA 2/24mm, bei den Sony-Patenten für die (gerüchteweise "Zeiss" herumgeisternden) neuen 1.4/50mm und 1.2/50mm, sowie - wie wir nun sehen - beim KoMiNikon 1.4/24mm.

Damit unterscheidet sich Minolta/Sony/"Zeiss"/Nikon deutlich von den wirklichen Zeiss-Distagonen, die von der optischen Konstruktion her viel "ganzheitlicher" scheinen - jedenfallls kann der Laie dort nicht auf Anhieb noch den klassischen "erweiterten Doppelgauss" erkennen...

Das bestätigt meine Eindrücke, die ich aus Gesprächen und aus der Analyse der Objektivquerschnitte habe - fast jeder arbeitet mit fast jedem zusammen. "Japan Inc." eben

Gr Steve

Interessant finde ich, daß in dem Patent mehrfach auf eine Art "Daumenregel" abgehoben wird, derzufolge die Lichtstärke 1:1,9 bei Designs für Weitwinkelobjektive mit einem Bildwinkel von 80-90° (also ca. 24mm bezogen auf das Kleinbildformat) offenbar soetwas wie eine "natürliche Grenze" darstellt, ab der der Konstruktionsaufwand (u.a. Anzahl der Linsen) zur Eindämmung insbesondere der sagittalen Koma durch die stark gewölbten Linsenoberflächen deutlich ansteigt.

Das dürfte der Grund sein, warum es nur ganz wenige vollformattaugliche Superweitwinkelobjektive mit größeren Lichtstärken gibt. Sigma hat sich schon vor Jahren mit den 1,8/20mm, 1,8/24mm und 1,8/28mm Weitwinkeln immerhin bis 1:1,8 vorgetraut, Sony/Zeiss mit dem Distagon T* 2/24mm ZA SSM (SAL-24F20Z) nicht ganz so weit. (Das Sony/Zeiss E Sonnar T* 1,8/24mm ZA (SEL-24F18Z) zählt hier nicht, da es nur das APS-C-Format ausleuchtet, also einen viel kleineren Bildwinkel hat.)

Viele Grüße,

Matthias