To achieve optimum hardness distribution for insertion by reducing the variation in hardness of an insertion unit so as to prevent sudden bending thereof.
An endoscope is characterized in that an endoscope flexible portion includes: a flexible hardness varying portion which is located in a predetermined region extending from a distal end of the flexible portion, and has hardness varying from the lowest hardness in the flexible portion to a predetermined hardness higher than the lowest hardness, the hardness being the lowest hardness at the distal end of the flexible portion, the hardness being the predetermined hardness at a proximal end of the flexible portion; a hard portion which is located in a predetermined region extending from a proximal end of the flexible portion, and has the highest hardness in the flexible portion; and an intermediate-hardness varying portion which is located between the flexible hardness varying portion and the hard portion, and has hardness gradually varying in a region extending from the proximal end of the flexible hardness varying portion to a distal end of the hard portion.
SAITO MAKI
ISHIHARA ATSUHIKO
IYAMA KATSUZO
| JPS55112505U | 1980-08-07 | |||
| JP3869060B2 | 2007-01-17 | |||
| JPH10192223A | 1998-07-28 |