Olympus Corporation

Olympus Medical Systems Corporation

Nobuhiko Sone

Hideyasu Takato

Yuji Kamo

An objective optical system includes, in order from an object side: a first group having a negative refractive power; a second group having a positive refractive power; and a third group having a positive refractive power, in which the first group and the third group are fixed and the second group is movable, the first group includes at least two lenses having a negative refractive power, the third group includes, in order from the object side, a 3-1st group having a positive refractive power, a 3-2nd group having a negative refractive power, a 3-3rd group having a positive refractive power, and a 3-4th group having a positive refractive power, and the following conditional expression (1)′″ is satisfied:1.5≤3≤6  (1)′″.

Objective optical system, image pickup apparatus, endoscope and endoscope system

An objective optical system includes, in order from an object: a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power. The second lens group includes an aperture stop and moves at a time of changing magnification.

The endoscope includes an observing optical system having a magnified-observation function which enables a proximity observation by approximating an object, and at least three illuminating optical systems which are, a first illuminating optical system, a second illuminating optical system, and a third illuminating optical system. An amount of light of the first illuminating optical system which is at a distance nearest from the observing optical system, out of at least the three illuminating optical systems which are the first illuminating optical system, the second illuminating optical system, and the third illuminating optical system, is not more than half of an amount of light of the second illuminating optical system and the third illuminating optical system, and the endoscope satisfies the following conditional expressions (1'), (2&#x2032;), (3), (4), (6), and (7).0.5&#x3c;1/3&#x3c;0.75 &#x2003;&#x2003;(1&#x2032;)0.5&#x3c;1/2&#x3c;0.75 &#x2003;&#x2003;(2&#x2032;)0.3&#x3c;(21)/(12)&#x3c;1.2 &#x2003;&#x2003;(3)0.3&#x3c;(31)/(13)&#x3c;1.2 &#x2003;&#x2003;(4)1.05&#x3c;&#x3b8;1/&#x3b8;2&#x3c;1.45 &#x2003;&#x2003;(6)1.05&#x3c;&#x3b8;1/&#x3b8;3&#x3c;1.45 &#x2003;&#x2003;(7)

Endoscope

In order to perform a superior observation, in which halation is less likely to occur, by achieving uniform illumination from near sites to far sites and by ensuring a satisfactory light distribution and brightness, both when performing normal observation and when performing near-field observation, an endoscope apparatus includes an observation optical system that is provided at a distal end of an inserted portion of the endoscope apparatus to observe an observation subject and a plurality of illumination optical systems that are provided in the inserted portion and that illuminate the same viewing field by distributing illumination light emitted from a light source over the observation subject, wherein, of the plurality of the illumination optical systems, the distance from the observation optical system to the widest-angle illumination optical system is smaller than the distance from the observation optical system to the narrowest-angle illumination optical system.

Endoscope apparatus

An endoscope includes an observation optical system that allows a magnified observation close to a subject, and illumination optical systems. In a close observation, Iis a maximum brightness within an observation view field angle, and Iis a center brightness. In a normal observation Iis a center brightness, and Iis a brightness at a position of 80% of a maximum view angle. The following is satisfied:0.3&#x3c;&#x3c;0.450.15&#x3c;&#x3c;0.250.3&#x3c;/&#x3c6;&#x3c;0.6where fis a focal length of each of the entire illumination optical systems, fis a focal length of the entire observation optical system in a maximum magnification, &#x3c6;is an outer diameter of a lens that is farthest on an object side of each illumination optical system, and Iis a maximum image height of the observation optical system.

This endoscope has an observation optical system provided in a distal end of an inserted portion of the endoscope, for observation of an object, and plural illumination optical systems provided in the inserted portion, for illuminating a certain angle of view, wherein one illumination optical system having the widest light distribution is distant from the observation optical system relative to another illumination optical systems having the narrowest light distribution, and the following conditional expression is satisfied,0.6&#x2266;|&#x3c6;/&#x3c6;|&#x2266;1.0&#x2003;&#x2003;(1)

Endoscope provided with a plurality of illumination optical systems

Manufacturing errors are suppressed, a variable magnification function is provided, and good observation with aberrations appropriately corrected is performed. Provided is an endoscope objective lens including, in order from an object side, a positive first lens group, a negative second lens group, and a positive third lens group, in which the first lens group has a meniscus lens; and a normal observation state (wide angle end) and a magnifying observation state (telephoto end) can be switched between by moving the second lens group on the optical axis, and the following conditions are satisfied;&#x2212;9&#x3c;&#x3c;&#x2212;3.54.5&#x3c;||&#x3c;8.3where frepresents the focal distance of the meniscus lens, frepresents the entire focal distance for the normal observation, and frepresents the focal distance of the second lens group.

Endoscope objective lens

To provide excellent illumination over entire range from near view to distant view to achieve clear observation over entire range from near view to distant view. Provided is an endoscope including an imaging optical systemprovided in insertion portion at a distal end thereof and for observing an object to be observed, and a plurality of illumination optical systemsprovided in the insertion portionand for distributing the illuminating light emitted from a light source to the object to be observed, the illumination optical systems being directed in the same direction each other to illuminate the same field of view, wherein at least one of the plurality of illumination optical systems is a first illumination optical systemhaving a convex lens, and at least one of the others is a second illumination optical systemhaving a concave lens.

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Tokyo, Japan

Nobuhiko Sone