JP5175639B2 - Endoscope and its assembly method - Google Patents

Description

  The present invention relates to an endoscope in which a circuit board that receives observation light is fixed to a hard tip portion, and a signal line to which a conductor is soldered is derived from the circuit board, and an assembling method thereof.

  Endoscopes used for industrial use, medical use, etc., are guided to a light receiving part of a solid-state image sensor provided horizontally by bending the optical axis of an objective optical system provided at the distal end part of the endoscope. The solid-state imaging device is mounted on a circuit board on which electrical components are mounted, and signal lines for transmitting photoelectrically converted electrical signals are connected to the circuit board with solder and further fixed with an adhesive. However, when the signal line is bent along with the bending operation of the insertion portion that is repeatedly performed during the operation, stress such as tension, torsion, and compression is generated in the signal line. At this time, if the adhesion area of the outer sheath of the signal line is small, disconnection or contact failure may occur at the connection part (particularly the solder connection part) between the signal line and the circuit board.

  For example, Patent Document 1 discloses that the outer sheath of the signal cable bundle is provided at the front to reduce the stress generated at the connection portion between the circuit board and the signal line and prevent contact failure or disconnection at the connection portion. It extends to the solid-state imaging device side, and an adhesive is filled between the outer sheath and the shield frame, and the outer sheath is integrally bonded and fixed in the imaging unit. It is described that it is prevented from being pulled in the direction. In Patent Document 2, a signal cable covered with a cable protection member is connected to a circuit board, while a solid-state imaging device is fixed to a shield frame via an element frame, and the cable protection member is fixed to the shield frame with an adhesive. Thus, it is described that the stress generated in the connection portion between the circuit board and the signal cable is reduced, and contact failure and disconnection are prevented.

  Patent Document 3 describes that an electrically insulating thread material is inserted into a signal cable in the axial direction, and the tip end portion of the thread material is fixed to a substrate. In Patent Document 4, a connection portion for connecting each signal line of a signal cable is formed on the base end side of the circuit board, and an inner conductor of a coaxial line is connected to the surface side of the circuit board. On the back side, it is described that an outer conductor of a coaxial line is connected to enable reliable connection. Patent Document 5 describes that a light-shielding resin is filled between the imaging element, the light guide fiber, and the forceps channel to increase the strength against an external force.

Japanese Patent Laid-Open No. 11-225956 JP 2000-14635 A JP 2000-107124 A JP 2000-125161 A JP 2001-128930 A

However, since the technique disclosed in Patent Document 1 is filled with an adhesive and the outer sheath is integrally bonded and fixed in the imaging unit, the components in the imaging unit are particularly affected by the difference in thermal expansion coefficient at high temperatures. Stress may be applied to (particularly optical system parts), and as a result, the parts may be misaligned or damaged. The technique disclosed in Patent Document 2 requires a cable protection member, an element frame, and a shield frame, and these members are fixed to each other with an adhesive, so that the number of parts increases, the cost increases, and the structure becomes complicated. It was. The technology disclosed in Patent Document 3 uses a signal cable through which a thread material is inserted, and the tip portion of the thread material is fixed to the substrate, so that the stress in the pulling direction can be reduced, but stress such as torsion and compression is reduced. I couldn't. In the technique disclosed in Patent Document 4, the inner conductor of the coaxial line and the outer conductor of the coaxial line are connected to the front and back surfaces of the circuit board, so that the structure becomes complicated, the assembling work becomes complicated, and there is a through hole. Special circuit boards were needed. Since the technology disclosed in Patent Document 5 is filled with a light-shielding resin between the imaging element, the light guide fiber, and the forceps channel, all the parts must be removed when the parts are replaced. There is a disadvantage that it takes time for the separation, and there is a possibility that the parts may be damaged during the separation, resulting in poor maintenance.
The present invention has been made in view of the above situation, and its purpose is to avoid stress concentration on parts due to the difference in thermal expansion coefficient, and without providing a new signal line fixing member or fixing structure, it is simple and inexpensive. An object of the present invention is to provide an endoscope that can reliably support a stress acting on a signal line, and that can be well maintained, and an assembling method thereof.

The present invention has the following configuration.
(1) An internal circuit comprising: a circuit board mounted with an imaging device fixed to the hard tip portion and receiving observation light via an imaging optical system; and a forceps pipe fixed to the hard tip portion along the axis. A endoscope,
Soldered signal line conductors on the circuit board is fixed by adhesive to the forceps pipe,
The distal end hard portion is connected to a curved portion composed of a plurality of node rings connected to each other via a plurality of rotating shafts,
The endoscope characterized in that the adhesive reaches the first rotation shaft that is closest to the first hard shaft in the axial direction of the hard tip portion, and covers the first rotation shaft.

According to this endoscope, it is not necessary to fill the adhesive and integrally bond and fix the signal line in the imaging unit. New fixing members and fixing structures such as a cable protection member, an element frame, a shield frame, a signal cable through which a thread material is inserted, and a special circuit board having a through hole are not required. A complicated assembly operation such as connecting the inner conductor of the coaxial line and the outer conductor of the coaxial line to the front and back surfaces of the circuit board is not necessary. Further, since the support partner is only the forceps pipe, the circuit board can be easily detached with the forceps pipe.
In addition, the signal line is covered with an adhesive and supported by the forceps pipe until the first rotating shaft is bent, and the stress generated by the bending is supported by the forceps pipe via the adhesive. Thereby, stresses such as tension, torsion, and compression accompanying the bending operation of the insertion portion repeatedly performed during the operation are not transmitted to the connection portion (particularly, the solder connection portion) between the signal line and the circuit board.

(2) The endoscope according to (1),
The light guide is fixed along the axis to the hard tip,
An endoscope, wherein a gap is formed between the adhesive and the light guide.

  According to this endoscope, when maintenance of the imaging optical system is required, the imaging optical system and the circuit board can be detached together with the forceps pipe, and the light guide can be left without being detached. Even when it is necessary to remove the adhesive for maintenance, the bonding partner is a forceps pipe made of SUS or the like, so that the peeling operation is facilitated and the expensive light guide is not damaged.

( 3 ) The endoscope according to (1) or (2) ,
The imaging optical system and the circuit board are fixed to the hard tip portion by a fixing means that can be fixed and released,
The endoscope, wherein the forceps pipe is fixed to the hard distal end portion by fixing means that can be fixed and released.

  According to this endoscope, by fixing both the imaging optical system and the circuit board fixing means and the forceps pipe fixing means, the imaging optical system and the circuit board fixed by the adhesive, the forceps pipe, Is integrally removable from the distal end hard portion.

( 4 ) a circuit board on which an imaging element that is fixed to the distal end hard portion and receives observation light via an imaging optical system is mounted; and a forceps pipe that is fixed along the axis to the distal end hard portion; An endoscope assembling method in which the distal end hard portion is connected to a bending portion including a plurality of node rings connected to each other via a plurality of rotation axes ,
A step of fixing the forceps pipe to the hard tip portion;
A step of fixing the circuit board together with the imaging optical system to the hard tip portion;
After that, the signal wire soldered to the circuit board is fixed to the forceps pipe with an adhesive, and the adhesive is connected to the first rotating shaft closest to the distal end hard portion in the axial direction. And reaching the first rotating shaft ,
An assembly method for an endoscope, comprising:

  According to this endoscope assembling method, the forceps pipe, the imaging optical system, and the circuit board are fixed to the distal end hard portion, and after the relative positions of the two are determined, the signal line derived from the circuit board is replaced with the forceps. Since it is fixed to the pipe, it can be fixed as a detachable integral structure.

  According to the endoscope of the present invention, a circuit board on which an imaging element that is fixed to the distal end rigid portion and receives observation light via the imaging optical system is mounted, and forceps that are secured to the distal end rigid portion along the axis. In an endoscope equipped with a pipe, the signal wire soldered to the circuit board is fixed to the forceps pipe with an adhesive, so that the imaging optical system is not covered with the adhesive and the component due to the difference in thermal expansion coefficient The stress acting on the signal line can be supported easily, inexpensively and reliably without the concentration of stress on the surface and without providing a new signal line fixing member or fixing structure. Further, since the support partner is only the forceps pipe, the circuit board can be attached and detached together with the forceps pipe, and the maintenance can be performed well. As a result, it is possible to prevent signal line disconnection and contact failure at low cost by using only existing components.

  According to the endoscope assembling method of the present invention, the signal line is fixed to the forceps pipe after the relative positions of the forceps pipe, the imaging optical system, and the circuit board are determined. The structure can be fixed, and the forceps pipe, the imaging optical system, and the circuit board cannot be attached due to the positional deviation from the hard tip portion that occurs when the structure is bonded before fixing.

Hereinafter, preferred embodiments of an endoscope and an assembling method thereof will be described in detail with reference to the drawings.
FIG. 1 is a perspective view of the distal end portion of the endoscope, and FIG. 2 is a view taken along the line AA in FIG.
The endoscope 100 is roughly divided into an operation unit (not shown) and an insertion unit 11 that is inserted into a body cavity. The insertion portion 11 includes a distal end hard portion 13 disposed at the distal end, a bendable bending portion 15 provided continuously with the proximal end of the distal end hard portion 13, and a proximal end of the bending portion 15. It consists of the introduction part (not shown) which comprises a base end.

  The distal end of the distal end hard portion 13 is covered with a synthetic resin cap 17, and the distal end surface thereof has an observation window 21 of the imaging optical system 19, illumination windows 25 and 25 of the pair of illumination optical systems 23, and an air / water feed nozzle 27. A forceps port 29 is provided. An imaging element (CCD) 33 is disposed behind the imaging optical system 19 via a prism 31, and a signal line 37 is connected to a circuit board 35 that supports the CCD 33. The signal line 37 is led out to an electrical connector (not shown) via the insertion unit 11 and the universal cable of the operation unit, and is connected to the processor. Therefore, the observation image captured by the observation window 21 is formed on the light receiving surface of the CCD 33 and converted into an electric signal. This electric signal is output to the processor via the signal line 37 and converted into a video signal. As a result, the observation image is displayed on the monitor connected to the processor.

  An exit end of the light guide 39 is disposed behind the illumination optical system 23. The light guide 39 is inserted through the insertion portion 11, the operation portion, and the universal cable, and an incident end is disposed in the LG connector. Therefore, by connecting the LG connector to the light source device, the illumination light emitted from the light source device is transmitted to the illumination optical system 23 through the light guide 39, and forward of the optical path from the illumination windows 25, 25 of the illumination optical system 23. Irradiated.

  The air / water supply nozzle 27 communicates with a valve (not shown) of the operation unit, and this valve further communicates with an air / water supply connector provided on the LG connector. An air / water supply means is connected to the air / water connector to supply air and water.

  In the distal end rigid portion 13, the distal end of a forceps pipe 41 made of stainless steel or the like is inserted into the forceps opening 29, and a flexible forceps tube 43 is connected to the rear end of the forceps pipe 41. The rear end of the forceps tube 43 is connected to a forceps insertion portion (not shown) in the vicinity of the operation portion. That is, the treatment instrument inserted from the forceps insertion portion can be advanced and retracted from the forceps opening 29. The outer periphery of the rear portion of the distal end hard portion 13 is covered with an angle rubber 45 together with the curved portion 15.

FIG. 3 is an explanatory view of a bending portion, in which a longitudinal sectional view of a bending portion including a rotation shaft and a node ring is represented by (a) and a planar sectional view is represented by (b).
The bending portion 15 is configured by a node ring structure in which a plurality of node rings 47 formed in a ring shape are connected in an axial direction. Adjacent node rings 47 and 47 are connected to each other in a rotatable manner by inserting a caulking pin 49 as a rotation shaft after caulking the mutual connecting portions and caulking the outside of the caulking pin 49. Of the jointed node rings 47, the most distal node ring 47 is connected to the distal end rigid portion 13, and the most proximal node ring 47 is connected to the introduction portion near the operation portion.

  Inside the node ring 47, a plurality of operation wires 51 are arranged at predetermined intervals in the circumferential direction along the axial direction of the inner peripheral surface. The distal end of the operation wire 51 is fixed to the distal end hard portion 13, and the proximal end of the operation wire 51 is connected to a pulley (not shown) that is rotated by a bending operation knob (not shown) of the operation portion. Thereby, when the pulley is rotated by operating the bending operation knob, the operation wire 51 is pulled, and the bending portion 15 is bent in a desired direction.

  The signal line 37 with the conductor soldered to the circuit board 35 is guided backward from the rear end portion of the circuit board 35, passes through the bending portion 15, and passes through the insertion portion 11 and the universal cable of the operation portion. Derived to the connector. That is, the signal line 37 drawn from the circuit board 35 is disposed along the forceps pipe 41.

FIG. 4 is a plan view of FIG. 2 viewed from the upper side of FIG.
Here, the signal line 37 drawn out from the circuit board 35 is fixed integrally with the forceps pipe 41 by the adhesive 53 together with the rear end portion of the circuit board 35. The rear end portion of the circuit board 35 refers to a range that does not reach the prism 31. As shown in FIG. 4, a gap 55 is formed between the adhesive 53 and the light guide 39. For example, when the imaging optical system 19 needs to be maintained, the imaging optical system 19 and the circuit board 35 can be detached together with the forceps pipe 41, and the light guide 39 can be left without being detached. Even if it is necessary to remove the adhesive 53 for maintenance, since the bonding partner is the forceps pipe 41 made of SUS or the like, the peeling operation is facilitated and the expensive light guide 39 is not damaged.

  The imaging optical system 19 and the circuit board 35 are fixed to the distal end hard portion 13 by fixing means 57 that can be fixed and released. The forceps pipe 41 is fixed to the distal end hard portion 13 by fixing means 59 that can be fixed and released. As these fixing means 57 and 59, screws for pressing the imaging optical system 19 and the forceps pipe 41 from the outside in the radial direction can be used. The imaging optical system 19 and the circuit board 35 and the forceps pipe 41 fixed by the adhesive 53 are released by fixing both the fixing means 57 for the imaging optical system 19 and the circuit board 35 and the fixing means 59 for the forceps pipe 41. Can be integrally detached from the distal end hard portion 13.

  Further, the adhesive 53 reaches the position corresponding to the closest first caulking pin 49A in the axial direction of the distal end hard portion 13. The adhesive 53 may be positioned in proximity to the first caulking pin 49A, but preferably passes through the first caulking pin 49A and reaches the rear end side. According to this, the signal line 37 is covered with the adhesive 53 and supported by the forceps pipe 41 until the first caulking pin 49A that is bent first, and the stress caused by the bending is supported by the forceps pipe 41 via the adhesive 53. The Therefore, stress such as tension, torsion, and compression accompanying the bending operation of the bending portion 15 repeatedly performed during the operation of the endoscope is not transmitted to the connection portion (particularly, the solder connection portion) between the signal line 37 and the circuit board 35.

  In the endoscope 100, the above configuration eliminates the need for filling the adhesive 53 and integrally bonding and fixing the signal line 37 in the imaging unit. New fixing members and fixing structures such as a cable protection member, an element frame, a shield frame, a signal cable through which a thread material is inserted, and a special circuit board having a through hole are not required. A complicated assembly operation such as connecting the inner conductor of the coaxial line and the outer conductor of the coaxial line to the front and back surfaces of the circuit board 35 becomes unnecessary. Further, since the support partner is only the forceps pipe 41, the circuit board 35 can be easily detached with the forceps pipe 41.

  To assemble the endoscope 100, first, the forceps pipe 41 is fixed to the distal end hard portion 13 by the fixing means 59. Next, the circuit board 35 is fixed to the distal end hard portion 13 together with the imaging optical system 19 by the fixing means 57. These assembly orders may be changed. Thereafter, the signal wire 37 with the conductor soldered to the circuit board 35 is fixed to the forceps pipe 41 with the adhesive 53. In this way, after the forceps pipe 41, the imaging optical system 19 and the circuit board 35 are fixed to the distal end hard portion 13 and the relative positions of both are determined, the signal line 37 led out from the circuit board 35 is connected to the forceps pipe 41. Therefore, fixing as a detachable integral structure is possible.

  Therefore, according to the endoscope 100 described above, the circuit board 35 on which the CCD 33 fixed to the distal end hard portion 13 and receiving observation light via the imaging optical system 19 is mounted, and the distal end hard portion 13 along the axis. Since the signal line 37 having a fixed forceps pipe 41 and a conductor soldered to the circuit board 35 is fixed to the forceps pipe 41 with the adhesive 53, the imaging optical system 19 is not covered with the adhesive 53, Stress concentration on parts due to the difference in thermal expansion coefficient can be avoided, and stress acting on the signal line 37 can be supported easily, inexpensively and reliably without providing a new signal line fixing member or fixing structure. Further, since the support partner is only the forceps pipe 41, the circuit board 35 can be attached and detached together with the forceps pipe 41, and the maintenance can be performed well. As a result, it is possible to prevent disconnection and poor contact of the signal line 37 at low cost using only existing components.

  Also, according to the assembly method of the endoscope 100, the signal line 37 is fixed to the forceps pipe 41 after the relative positions of the forceps pipe 41, the imaging optical system 19 and the circuit board 35 are determined. The mounting as a unitary structure that can be mounted is possible, and the forceps pipe 41, the imaging optical system 19, and the circuit board 35 cannot be attached due to the positional deviation with respect to the hard tip portion 13 that occurs when bonded before fixing.

It is a perspective view of the front-end | tip part of an endoscope. It is an AA arrow line view of FIG. It is explanatory drawing of the curved part which represented the longitudinal cross-sectional view of the curved part which consists of a rotating shaft and a node ring with (a), and represented the cross-sectional view with (b). It is the top view which looked at FIG. 2 from the same figure upper part side.

Explanation of symbols

13 Hard tip portion 15 Bending portion 19 Imaging optical system 33 CCD (imaging device)
35 Circuit board 37 Signal line 39 Light guide 41 Forceps pipe 47 Node ring 49 Caulking pin (rotating shaft)
49A First rotating shaft 53 Adhesive 55 Gap 57, 59 Fixing means 100 Endoscope

Claims (4)

An endoscope comprising: a circuit board on which an imaging device fixed to a hard tip portion and receiving observation light via an imaging optical system is mounted; and a forceps pipe fixed along the axis to the hard tip portion. There,
Soldered signal line conductors on the circuit board is fixed by adhesive to the forceps pipe,
The distal end hard portion is connected to a curved portion composed of a plurality of node rings connected to each other via a plurality of rotating shafts,
The endoscope characterized in that the adhesive reaches the first rotation shaft that is closest to the first hard shaft in the axial direction of the hard tip portion, and covers the first rotation shaft . The endoscope according to claim 1, wherein
The light guide is fixed along the axis to the hard tip,
An endoscope, wherein a gap is formed between the adhesive and the light guide. The endoscope according to claim 1 or 2, wherein
The imaging optical system and the circuit board are fixed to the hard tip portion by a fixing means that can be fixed and released,
The endoscope, wherein the forceps pipe is fixed to the hard distal end portion by fixing means that can be fixed and released. A circuit board mounted with an imaging device that is fixed to the distal end rigid portion and receives observation light via an imaging optical system; and a forceps pipe that is secured to the distal end rigid portion along an axis, the distal end rigid portion The method of assembling an endoscope, wherein the portion is connected to a bending portion composed of a plurality of node rings connected to each other via a plurality of rotation axes,
A step of fixing the forceps pipe to the hard tip portion;
A step of fixing the circuit board together with the imaging optical system to the hard tip portion;
After that, the signal wire soldered to the circuit board is fixed to the forceps pipe with an adhesive, and the adhesive is connected to the first rotating shaft closest to the distal end hard portion in the axial direction. And reaching the first rotating shaft,
An assembly method for an endoscope, comprising:

Images