US 6,117,071 AGranted

Endoscope with movable imaging unit for zooming or focusing

AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha

InventorsKeiji Ito, Ryuichi Hoshino, Shizuharu Miura

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Abstract

An electronic endoscope includes a charge coupled device and provides macro-zooming function. The endoscope comprises an imaging unit including a plurality of optical elements forming an optical system and a support and guide mechanism for supporting and/or guiding the optical elements. The optical elements include a fixed lens, movable lenses, and a CCD. The support and guide mechanism comprises a casing including inner and outer cylinders. The axis of the inner cylinder defines a reference axis. A cam cylinder is fitted over the inner cylinder and is guided for rotational movement with no axial movement. An axial slider is fitted over the cam cylinder and guided for axial movement with no rotational movement. The axial slider is driven for axial movement through a manipulating lever provided on a handpiece. First and second carriages are fitted in the inner cylinder and guided for axial movement with no rotational movement. The fixed lens is secured to the casing, the movable lens are carried on the first carriage, and the CCD is carried on the second carriage. A first cam mechanism is provided to producing rotational movement of the cam cylinder in response to axial movement of the axial slider. A second cam mechanism is provided for producing respective axial movements of the carriages in response to rotational movement of the cam cylinder.

An endoscope comprising:

a handpiece including a manipulating member mounted thereon;
a tip unit having front and rear ends and including i) a housing and ii) an imaging unit housed in said housing for obtaining an image as viewed in a view field in front of said tip unit, said housing having front and rear ends;
an insertion tube extending between and interconnecting said handpiece and said tip unit, said insertion tube having a proximal end connected to said handpiece and a distal end connected to said rear end of said housing of said tip unit;
a manipulation cable assembly received in said insertion tube and having a proximal end operatively connected to said manipulating member and a distal end operatively connected to said imaging unit so as to allow a user to manipulate said imaging unit through said manipulating member;
said imaging unit comprising i) a plurality of optical elements forming an optical system and ii) a support and guide mechanism for supporting and/or guiding said plurality of optical elements;
and
said plurality of optical elements including i) a device having an image-bearing surface on which an image is to be formed and ii) a plurality of lenses arranged in line along a common optical axis for forming an image on said image-bearing surface of said device;
wherein said support and guide mechanism of said imaging unit comprises:
i) a first member fixedly mounted in said housing and including a hollow cylindrical portion having an axis and front and rear ends, said axis of said hollow cylindrical portion being a reference axis and defining an axial direction;
ii) a second member of a hollow cylindrical shape and having a cylindrical surface, said second member being fitted over said hollow cylindrical portion of said first member and being supported and guided for rotational movement about said reference axis with substantially no axial movement relative to said first member;
iii) a third member supported and guided for axial movement relative to said first and second members with substantially no rotational movement about said reference axis, said third member being operatively connected to said distal end of said manipulation cable assembly;
iv) at least one carriage carrying thereon one or more of said optical elements, said at least one carriage being supported and guided for axial movement relative to said first and second members with substantially no rotational movement about said reference axis;
v) a first cam mechanism provided between said second and third members for producing rotational movement of said second member in response to axial movement of said third member;
and
vi) a second cam mechanism provided between said second member and said at least one carriage for producing axial movement of said at least one carriage in response to rotational movement of said second member.

12 more elements

Abstract

Claims55