Patent ID: 6641530
Filing Date: 2003-11-04
Classification: A61B

Abstract:
An endoscope with an objective lens drive mechanism, comprising:an insertion instrument having an elongated flexible body with an angle section and a rigid tip end section successively connected to a fore end of said flexible body, said angle section being angularly bendable for turning said rigid tip end section at least in upward and downward directions; an image pickup assembly unit of an objective lens system mounted in an observation window opened in a casing of said rigid tip end section along with an illumination window and an exit opening of a biopsy channel, said optical objective lens system including at least a fixed lens mounted on a fixed lens frame and at least a movable lens mounted on a movable lens frame; and an objective lens drive mechanism including a lens drive shaft rotatably mounted within said casing of said rigid tip end section, a control cable having a flexible transmission coil shaft encased in a flexible sleeve and connected between said lens drive shaft and a rotational drive source, and an offset arm extended out from said movable lens frame and engaged with said lens drive shaft through a translating mechanism for converting forward and reverse rotations of said lens drive shaft into linear back and forth movements of said movable lens frame; interior of said casing of said rigid tip end section being divided into right and left subsections along a center line of upward and downward flexures of said angle section for the purpose of laying out internal components in a balanced state in terms of distribution of rigidity, said observation window being located across said flexural center line to occupy part of both of said right and left subsections, said exit opening of said biopsy channel being located in one of said right and left subsections, and said lens drive shaft of said objective lens drive mechanism being located in the other one of said right and left subsections away from said exit opening of said biopsy channel; said biopsy channel leading to said exit opening and said control cable are positioned on the opposite sides of said center line of upward and downward flexures within said angle section.