Abstract: There is provided an endoscope that prevents occurrence of buckling of a flexible body built in an insertion part of the endoscope without damaging other built-in components, and is easy to manufacture without impairing the curving manipulability. The endoscope includes a curvable portion, and an elongated insertion part being inserted into a subject. The endoscope has an elongated flexible body built in the insertion part, and a flexible protective tube that covers an outer periphery of the flexible body. The protective tube has a first region that covers the range of the flexible body, and a second region that covers the range of the soft portion. The elastic constant of the first region is smaller than the elastic constant of the second region, and the external diameter of the protective tube in the first region is larger than the external diameter of the protective tube of the second region.

Abstract: There is provided an endoscope that prevents occurrence of buckling of a flexible body built in an insertion part of the endoscope without damaging other built-in components, and is easy to manufacture without impairing the curving manipulability. The endoscope includes a curvable portion, and an elongated insertion part being inserted into a subject. The endoscope has an elongated flexible body built in the insertion part, and a flexible protective tube that covers an outer periphery of the flexible body. The protective tube has a first region that covers the range of the flexible body, and a second region that covers the range of the soft portion. The elastic constant of the first region is smaller than the elastic constant of the second region, and the external diameter of the protective tube in the first region is larger than the external diameter of the protective tube of the second region.

Abstract: A flexible tube for an endoscope comprises: a spiral tube including a band-shaped plate which is spirally wound; a braid which covers an outer circumferential surface of the spiral tube; and an outer skin made of a resin, which covers an outer circumferential surface of the braid, wherein the braid includes metal fibers deposited with a release agent and heat-resistant resin fibers deposited with a bonding material, the metal fibers and the resin fibers are blended in a mesh pattern, and the braid is bonded to the outer skin by the bonding material.

Abstract: There is provided an endoscope that prevents occurrence of buckling of a flexible body built in an insertion part of the endoscope without damaging other built-in components, and is easy to manufacture without impairing the curving manipulability. The endoscope includes a curvable portion, and an elongated insertion part being inserted into a subject. The endoscope has an elongated flexible body built in the insertion part, and a flexible protective tube that covers an outer periphery of the flexible body. The protective tube has a first region that covers the range of the flexible body, and a second region that covers the range of the soft portion. The elastic constant of the first region is smaller than the elastic constant of the second region, and the external diameter of the protective tube in the first region is larger than the external diameter of the protective tube of the second region.

Abstract: An air/water channel is split into smaller-diameter branch channels before the air/water channel enters a bending portion so as to create a space within a joint ring constituting the bending portion. A forceps channel having the largest outer diameter among internal components of the joint rings is disposed at the center of the joint rings. In addition to the branch channels, optical fibers as a light guide, a signal line, and the like are arranged around the forceps channel within the joint rings. By eliminating the created space, a diameter of the joint rings is reduced and thus a diameter of an insertion section is reduced.

Abstract: An endoscope of a transnasal type includes an elongated tube for entry in a patient's body. A steering mechanism is provided in the elongated tube and on a proximal side from a distal end thereof, and bendable for changing a direction of the distal end. A forceps channel is formed through the elongated tube, for passing a treatment device to advance through the distal end. A constituent component is inserted in the elongated tube, disposed outside the forceps channel, and having an uneven thickness uneven within the steering mechanism in a direction transverse to an axial direction of the elongated tube, for extending in a tube lumen within the elongated tube. Specifically, the constituent component includes an air/water supply channel, or is an optical fiber bundle.

Abstract: A flexible tube for an endoscope comprises: a spiral tube including a band-shaped plate which is spirally wound; a braid which covers an outer circumferential surface of the spiral tube; and an outer skin made of a resin, which covers an outer circumferential surface of the braid, wherein the braid includes metal fibers deposited with a release agent and heat-resistant resin fibers deposited with a bonding material, the metal fibers and the resin fibers are blended in a mesh pattern, and the braid is bonded to the outer skin by the bonding material.

Abstract: An air/water channel is split into smaller-diameter branch channels before the air/water channel enters a bending portion so as to create a space within a joint ring constituting the bending portion. A forceps channel having the largest outer diameter among internal components of the joint rings is disposed at the center of the joint rings. In addition to the branch channels, optical fibers as a light guide, a signal line, and the like are arranged around the forceps channel within the joint rings. By eliminating the created space, a diameter of the joint rings is reduced and thus a diameter of an insertion section is reduced.