Linear transmission member driving unit for endoscope

• US 6,422,995 B2
• Filed: 11/30/2000
• Issued: 07/23/2002
• Est. Priority Date: 12/03/1999
• Status: Expired due to Term

• Current Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Inventors: Akiba, Haruo
• Primary Examiner(s): Esquivel, Denise L.
• Assistant Examiner(s): NORMAN, MARC E
• Application Number:
  US09/725,749
• Publication Number:
  US 20010018552A1
• Time in Patent Office: 600 Days
• Field of Search: 600/167, 600/168, 600/160
• US Class Current: 600/167
• CPC Class Codes: A61B 1/00188 with focusing or zooming features
• CPC Class Codes: F16C 1/02 for conveying rotary movements

Abstract

In the endoscope configured so as to drive a tip end portion movable lens for making the observation distance variable by the linear transmission member and to rotate this linear transmission member by a motor, a shaft of the motor is connected to a shaft connecting member, and a sliding guide hole having a predetermined length is formed on a cylindrical member wall of this shaft connecting member. And, within this shaft connecting member, a distal member of the linear transmission member is movably disposed, and this distal member is provided with a pin engaging with the sliding guide hole. This apparatus advances and retreats the linear transmission member in the rotating shaft direction during the bending operation, and provides a constant load to a motor rotating shaft, making it possible to obtain a stable magnification changing operation even though there may be a change in posture of an endoscope insertion unit. In addition, an outside diameter of the linear transmission member is formed to be smaller than a soft portion within an angle portion to reduce a frictional resistance during rotation.

Claims

1. A linear transmission member driving unit for an endoscope, comprising:

a linear transmission member which performs a rotary motion in order to drive an object;

a protective tube which rotationally envelops said linear transmission member;

a motor, to which said linear transmission member is shaft-connected;

a chassis to which said motor is fixed; and

a mobile type linear transmission member shaft coupling mechanism, which couples a shaft of said motor fixed to said chassis to an end portion of said linear transmission member, and to which said linear transmission member is mounted so as to be able to move in a direction of a rotating shaft of said motor.

2. The linear transmission member driving unit for an endoscope according to claim 1, wherein said mobile type linear transmission member shaft coupling mechanism is configured by a cylindrical member coupled and fixed to said motor shaft, and comprises:

a shaft connecting member in which a sliding guide hole having a predetermined length in the direction of said rotating shaft is formed; and

a distal member of said linear transmission member, which is disposed so as to move within a cylinder of said shaft connecting member, and, in which there is provided a pin for engaging with said sliding guide hole to slide,

wherein a pin of said distal member is caused to be engaged with said sliding guide hole, whereby it is made possible to transmit rotation of said motor to said linear transmission member and to move said linear transmission member concerned in the direction of said rotating shaft by a predetermined amount.

3. The linear transmission member driving unit for an endoscope according to claim 1, wherein said motor and said mobile type linear transmission member shaft coupling mechanism are disposed in space on a side of an angle operating knob mechanism being mounted, partitioned by said chassis within an operating unit, and said motor and said protective tube are caused to be mounted to said chassis concerned by the use of an integrally formed holding member.

4. The linear transmission member driving unit for an endoscope according to claim 1, wherein as said chassis, a plurality of sheets of plates are superposedly disposed, and the rotating shaft for said angle operating knob and said holding member are caused to be mounted onto different plates respectively.

5. The linear transmission member driving unit for an endoscope according to claim 1, wherein lubricating coat is applied to a sliding member of said mobile type shaft coupling mechanism.

6. The linear transmission member driving unit for an endoscope according to claim 2, wherein on an outer periphery of said distal member, there are formed protruding portions in contact with an inner wall of said shaft connecting member at two places where said pin is sandwiched therebetween such that said linear transmission member is caused to move by sliding of said protruding portions within said shaft connecting member concerned.

7. A linear transmission member driving unit for an endoscope, comprising:

a movable member disposed on the side of the tip end of an insertion unit having an angle portion and a soft portion;

a transmission coil, which is a linear transmission member for transmitting the rotary driving force of said motor to said movable member, comprising wire spirally wound; and

a flexible protective tube which rotationally envelops said transmission coil,

wherein said transmission coil, whose wire diameters are actually the same, comprises two coil portions having different outside diameters, has a small-diameter coil portion having smaller outside diameter within said angle portion, and a large-diameter coil portion having a larger outside diameter within said soft portion, these both coil portions being coupled by a coupling member so as to be able to integrally rotate at a connecting position between said angle portion and said soft portion or in the vicinity thereof.

8. The linear transmission member driving unit for an endoscope according to claim 7, wherein an outside diameter of said small-diameter coil portion is set so as to be smaller than a size in a direction of an end shaft when said angle portion goes into a maximum curved state and said protective tube becomes deformed so as to be flattened.

9. The linear transmission member driving unit for an endoscope according to claim 7, wherein said movable member is a movable lens among an object lens group provided at said tip hard portion.

10. The linear transmission member driving unit for an endoscope according to claim 7, wherein said transmission coil comprises bonded coil, and said bonded coil is configured by a double coil comprising coils wound in opposite directions to each other.