Olympus Corporation

Olympus Medical Systems Corporation

Olympus Optical Company, Ltd.

Azusa Patent Office

Hideyasu Takato

Yuji Kamo

Nobuhiko Sone

Seiji Shimizu

Tsutomu Sasamoto

Shinichi Nakamura

Hiroshi Ishii

Yuji Miyauchi

Masataka Ide

Masahiro Katakura

Tsutomu Uzawa

Susumu Takahashi

Kazuhiro Gono

Nobuyuki Doguchi

Yasushi Namii

Seiji Iwasaki

Toshio Takahashi

Hironobu Ichimura

Masahiro Kawauchi

Azusa Noguchi

Hideaki Ishihara

Kiyoshi Miyake

Kazumi Ito

Yoshifumi Tsuji

An endoscope 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. Focusing from an object point at a long distance to an object point at a short distance is carried out by moving the second group from the object side to an image side. The first group includes a lens having a negative refractive power, the second group includes a lens which is a meniscus lens having a positive refractive power of which a convex surface is directed toward the image side, and the third group includes, in order from the object side, a lens having a positive refractive power, and a cemented lens composed of a lens having a positive refractive power and a lens having a negative refractive power.

Endoscope objective optical system and endoscope

An objective optical system includes, in order from an object side: a positive first group; a negative second group; a negative third group; and a positive fourth group, in which the second group and the third group move together toward an image side to perform focusing from an object point at a long distance to an object point at a close distance, and the following conditional expression (2) is satisfied: 0.2<(t34f−t34n)/F<2 (2), where t34f is a distance between the third group and the fourth group at a time of focusing to the object point at the long distance, t34n is a distance between the third group and the fourth group at a time of focusing to the object point at the close distance, and F is a focal length of the overall objective optical system at a time of focusing to the object point at the long distance.

Objective optical system and endoscope using the same

An objective optical system consists of in order from an object side to an image side, a first group having a positive refractive power, an aperture stop, a second group having negative refractive power, and a third group having a positive refractive power. Focusing is carried out by moving the second group. The objective optical system satisfies the following conditional expression (1').&#x2212;16.6&#x3c;2/FL&#x3c;&#x2212;11&#x2003;&#x2003;(1&#x2032;)

Objective optical system

An objective optical system consists of, in order from an object side, a first lens group having a negative refractive power, which is stationary all the time, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens group having a positive refractive power, which is stationary all the time. At a time of focusing from an object point at a long distance to an object point at a short distance, the second lens group moves toward the object side and the third lens group moves toward an image side. The following conditional expressions (1), (5), and (7) are satisfied:2&#x3c;2/&#x3c;8&#x2003;&#x2003;(1)0.2&#x3c;(3434)/&#x3c;0.5&#x2003;&#x2003;(5)&#x2212;8&#x3c;1/&#x3c;&#x2212;2&#x2003;&#x2003;(7).

Objective optical system, image pickup apparatus, and endoscope

The objective optical system includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. Focusing is carried out by moving the second lens group. The third lens group includes a positive lens and a cemented lens, and the cemented lens includes a positive lens and a negative lens. A first sub-unit includes a lens positioned on the object side of a predetermined air space and a second sub-lens group includes a lens positioned on an image side of the predetermined air space. The predetermined air space is the maximum air space among the air spaces in the third lens group.

An objective optical system for endoscope includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. At a time of focusing, the first lens group and the third lens group are fixed, and the second lens group moves. The third lens group consists of a front group having a positive refractive power and a rear group having a positive refractive power. The front group includes one cemented lens and the rear group includes one single lens, and the following conditional expressions are satisfied:1&#x2264;33&#x2264;5,0.1&#x2264;33&#x2264;1,&#x2212;8&#x2264;&#x2264;&#x2212;2, and&#x2212;7&#x2264;2/3&#x2264;&#x2212;2.

Objective optical system for endoscope

The objective optical system consists of order from an object side, a first group having a positive refractive power, a second group having a negative refractive power, and a third group having a positive refractive power, wherein focusing is carried out by moving the second group, and a lens nearest to image is a planoconvex positive lens having a convex surface directed toward the object side, and a flat surface of the planoconvex positive lens is either affixed directly to an image pickup surface or cemented to a cover glass formed on the image pickup surface, and the objective optical system satisfies the following conditional expression (1).5&#x3c;&#x3c;8&#x2003;&#x2003;(1)

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 objective optical system includes in order from an object side a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power, wherein focusing is carried out by moving the second lens group with respect to a change in an object-point distance, and the following conditional expressions (2) and (3) are satisfied:3&#x3c;|&#x3b2;|&#x2003;&#x2003;(2), and60&#xb0;&#x3c;&#x3c9;&#x2003;&#x2003;(3),

The objective optical system includes in order from an object side, a first unit having a positive refractive power, a second unit having a negative refractive power, and a third unit having a positive refractive power, and focusing is carried out by moving the second unit, the first unit and the third unit are fixed at the time of focusing, and the first unit Gincludes in order from the object side, a negative lens L, one of a positive lens and a cemented lens, and a positive lens, and the third unit includes a positive lens, and a cemented lens of a positive lens and a negative lens, and the objective optical system satisfies the following conditional expression (3)&#x2212;20&#x3c;&#x3c;&#x2212;5&#x2003;&#x2003;(3)

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.

Endoscope

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

An objective optical system consists of, from an object side to an image side: a first lens group having positive optical power; a second lens group having negative optical power; and a third lens group having positive optical power, wherein the first lens group includes, from the object side to the image side, a first lens having negative optical power and a second lens having positive optical power, and the second lens group is moved according to a change in an object distance to perform focusing, and the following conditional expressions are satisfied:&#x2212;19&#x3c;2/1&#x3c;&#x2212;3.50.5&#x3c;&#x3c;1.1

An endoscope tip part has impact resistance even when applied to a thin endoscope, and the light distribution characteristics thereof can be improved even at a wide angle of view. An endoscope tip part includes a tip part main body that is attached to the tip of an insertion section of an endoscope and a positive-power transparent-plastic tip lens that is integrated with the tip part main body through two-color molding. The tip lens is a lens that is located closest to an object, among optical elements constituting an illumination optical system of the endoscope, and the tip part main body is provided with an insertion hole into which two positive-power rear lenses that will be disposed behind the tip lens are inserted.

Endoscope tip part and endoscope

Provided is an endoscope objective optical system that is constituted of, in order from the object side, a positive first group, an aperture stop, and a positive second group, wherein the first group is constituted of a negative first lens whose surface on the object side is flat and a positive second lens; the second group is constituted of a combined lens formed of a positive third lens and a negative fourth lens; and Conditional Expressions (1) to (3) are satisfied. F, F, and f are the focal lengths of the third lens, the fourth lens, and the entire system, respectively; and Rand Rare the radii of curvature at the object-side surface and the image-side surface of the second lens, respectively. 1.2&#x3c;f/f&#x3c;1.55 . . . (1), &#x2212;2.8&#x3c;f/f&#x3c;&#x2212;1.98 . . . (2), and 0.38&#x3c;|R+R|/|R&#x2212;R|&#x3c;0.77 . . . (3).

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Hino, Japan

Hideyasu Takato