ENDOSCOPE TIP PART

Abstract

An endoscope tip part for an endoscope for visually inspecting inaccessible places, including a tip housing enclosing a sealed interior space and including a transparent portion; an image sensor viewing in an optical direction through the transparent portion of the tip housing; a light guide component having a light entry surface and a light exit surface; a first light source having a light-emitting surface and being configured to emit light from the light-emitting surface in a central illumination direction; and an electrical circuit in electrical communication with the image sensor and the first light source, wherein the first light source, the image sensor, and the electrical circuit are accommodated in the sealed interior space of the tip housing, wherein the first light source is attached to the light guide component.

Claims

1. An endoscope tip part for an endoscope, the endoscope tip part comprising: an exterior surface; a longitudinal axis; a housing at least partially enclosing an interior space, the housing including a first portion having a first part of the exterior surface and a transparent portion having an interior surface facing the interior space and an exterior surface forming a second part of the exterior surface, the interior surface disposed opposite the exterior surface of the second part; an imaging subassembly including an image sensor viewing in an optical direction through the transparent portion of the housing; a light guide component comprising a first light guide having a light entry surface and a light exit surface; a first light source attached to the light guide component and having a first light emitting surface adjacent the light entry surface of the first light guide, the light source positioned proximally relative to the image sensor; and an electrical circuit in electrical communication with the image sensor, wherein the first light source, the image sensor, and the electrical circuit are accommodated in the interior space of the housing.

2. The endoscope tip part of claim 1, wherein the light guide component comprises a crossmember and a second light guide, the crossmember positioned proximally of the image sensor and overlapping the image sensor in a longitudinal direction, the second light guide having a light entry surface and a light exit surface, and wherein the first and second light guides extend side-by-side on opposite sides of the imaging subassembly.

3. The endoscope tip part of claim 2, wherein the first and/or the second light source(s) at least partially overlap the imaging subassembly when viewed along the longitudinal direction.

4. The endoscope tip part of claim 1, wherein the first light emitting surface of the first light source is adhered by an adhesive to the light entry surface of the first light guide.

5. The endoscope tip part of claim 4, wherein the light exit surface of the first light guide is detached from the transparent portion.

6. The endoscope tip part of claim 1, further comprising cables connected to the electrical circuit, wherein the electrical circuit is entirely accommodated in the interior space of the tip housing, and wherein the cables extend proximally from the housing.

7. The endoscope tip part of claim 1, wherein the housing comprises a distal end face and a proximal opening providing access to the interior space, wherein the distal end face is positioned opposite the proximal opening, and wherein the distal end face comprises at least part of the exterior surface of the transparent portion.

8. The endoscope tip part of claim 1, wherein the light guide component comprises a second light guide having a light entry surface and a light exit surface, wherein the endoscope tip part comprises a second light source having a light-emitting surface adjacent the light entry surface of the second light guide, wherein the second light source is attached to the light guide component and positioned proximally relative to the image sensor, and wherein the first and second light guides extend side-by-side on opposite sides of the imaging subassembly.

9. The endoscope tip part of claim 8, wherein the light guide component is formed separately from the housing, and wherein the light exit surface of the first light guide and the light exit surface of the second light guide are oriented to emit light towards the interior surface of the transparent portion.

10. The endoscope tip part of claim 8, wherein the first and/or the second light source(s) is/are at least partially overlapping the imaging subassembly when viewed in a cross-section perpendicular to the longitudinal axis.

11. The endoscope tip part of claim 8, wherein the first and/or the second light guide consist(s) essentially of a transparent material with a first refractive index, and wherein the light-emitting surface of the first and/or the second light source(s) is/are adhered to the light entry surface of the first and/or the second light guide, respectively, by an adhesive.

12. The endoscope tip part of claim 1, wherein the light guide component further comprises: a second light guide spaced apart from the first light guide by a gap, the first and the second light guides extending along a respective longitudinal center line, wherein each of the first and the second light guide has a proximal end, a distal end, a light entry surface at the proximal end, a light exit surface at the distal end, and a circumferential surface extending from the light entry surface to the light exit surface around the respective longitudinal center line, and a crossmember extending transversely from the first light guide to the second light guide so as to form a unitary rigid light guide component, wherein the first and the second light guides are configured for propagating light received through the respective light entry surface out through the respective light exit surface.

13. A light guide component for an endoscope tip part, the light guide component comprising: a first and a second light guide spaced apart by a gap and extending along a respective longitudinal center line, wherein each of the first and the second light guide has a proximal end, a distal end, a light entry surface at the proximal end, a light exit surface at the distal end, and a circumferential surface extending from the light entry surface to the light exit surface around the respective longitudinal center line, and a crossmember extending transversely from the first light guide to the second light guide so as to form a unitary rigid light guide component, wherein the first and the second light guides are configured for propagating light received through the respective light entry surface out through the respective light exit surface.

14. The light guide component of claim 13, wherein the crossmember extends transversely from the proximal end of the first light guide to the proximal end of the second light guide.

15. The light guide component of claim 13, wherein the light guide component is formed monolithically.

16. The light guide component of claim 13, wherein the light entry surfaces of the first and the second light guides are planar, and/or wherein the light exit surfaces of the first and the second light guides are planar.

17. An endoscope comprising: a handle for gripping by an operator and comprising a control device; an endoscope tip part according to claim 1; an insertion tube extending from the handle to the endoscope tip part and comprising a bending section; one or more cables running through the insertion tube and electrically connecting the electrical circuit of the endoscope tip part with the handle; and at least one steering wire connecting the handle with a distal end of the bending section so that manipulation of the control device causes bending of the bending section.

18. An endoscope system for visually inspecting inaccessible places, the endoscope system comprising: a monitor; and an endoscope according to claim 17, wherein the endoscope is connectable to the monitor to display an image captured by the image sensor of the endoscope tip part.

19. A method for assembling an endoscope tip part, the endoscope tip part extending along a longitudinal axis and having a an exterior surface, the method comprising: providing a housing extending along the longitudinal axis and at least partially enclosing an interior space, the housing including: a first portion having a first part of the exterior surface and a transparent portion having an interior surface facing the interior space and an exterior surface forming a second part of the exterior surface, the interior surface disposed opposite the exterior surface of the second part; providing an imaging subassembly including an image sensor viewing in an optical direction through the transparent portion of the housing after assembly, providing a light guide component comprising a first light guide having a light entry surface and a light exit surface, providing a first light source having a first light emitting surface and being configured to emit light from the light emitting surface in a central illumination direction, and providing an electrical circuit; attaching the first light source to the light guide component, so that light emitted by the first light source is received by the light entry surface of the first light guide, and so that the imaging subassembly, the light guide component, and the electrical circuit form a main subassembly; inserting the main subassembly through the proximal opening of the housing into the interior space so that the optical direction of the image sensor extends through the transparent portion, and so that a surface normal of the light exit surface of the first light guide is at least partially oriented towards the interior surface of the transparent portion; fixing the main subassembly to the housing; and sealing the proximal opening to seal the interior space.

20. The method of claim 19, wherein the light guide component comprises a crossmember and a second light guide, the crossmember positioned proximally of the image sensor and overlapping the image sensor in a longitudinal direction, the second light guide having a light entry surface and a light exit surface, and wherein the first and second light guides are sized and shaped to extend side-by-side on opposite sides of the imaging subassembly.

21. The method of claim 19, further comprising: arranging the main subassembly in a jig, adjusting the light guide component relative to the imaging subassembly to a predetermined relative position along the longitudinal direction via flexing of the electrical circuit, and subsequently fixing the light guide component relative to the imaging subassembly, wherein inserting the main subassembly comprises inserting the main subassembly along the longitudinal direction until a distal end of the imaging subassembly abuts an interior distal portion of the tip housing, and until a distal end of the light guide component abuts an interior distal portion of the housing.

22. The method of claim 19, further comprising: arranging the main subassembly in a jig, adjusting the light guide component relative to the imaging subassembly to a predetermined relative position along the longitudinal direction via flexing of the electrical circuit, and subsequently fixing the light guide component relative to the imaging subassembly, wherein inserting the main subassembly comprises inserting the main subassembly along the longitudinal direction until the light exit surface abuts the interior surface of the transparent portion of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Embodiments of this disclosure will be described in more detail in the following detailed description with regard to the accompanying figures. The figures show one or more ways of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

[0106] FIG. 1 is a schematic perspective illustration of an endoscope according to this disclosure,

[0107] FIG. 2 is a schematic perspective illustration of a distal tip and a bending section of the endoscope shown in FIG. 1,

[0108] FIG. 3 is a schematic perspective illustration of the distal tip of FIG. 2 without the bending section,

[0109] FIG. 4a is a schematic perspective cross-sectional illustration of the distal tip along the A-A line of FIG. 3,

[0110] FIG. 4b is a schematic side cross-sectional illustration of the distal tip along the A-A line of FIG. 3 and illustrates detail view A,

[0111] FIG. 5 is a schematic side cross-sectional illustration of the distal tip along the B-B line of FIG. 3,

[0112] FIGS. 6a-6b are schematic illustrations of the distal tip of FIG. 3 without the tip housing in a perspective and side view, respectively,

[0113] FIGS. 7a-7b are schematic illustrations of a second embodiment of a distal tip without the tip housing in a distal and proximal perspective view, respectively,

[0114] FIG. 8 is a schematic top view of a third embodiment of a distal tip without the tip housing, and

[0115] FIG. 9 is a schematic perspective illustration of a monitor connectable to the endoscope of FIG. 1.

[0116] FIG. 10a is a schematic perspective illustration of the light guide component alone.

[0117] FIG. 10b is a schematic cross-sectional illustration of the light guide component in a plane perpendicular to the longitudinal axis of the distal tip part.

[0118] FIG. 11 is an enlarged view of detail view A as shown in FIG. 4b and illustrates transition portion of the light guide defining the taper angle α.

DETAILED DESCRIPTION

[0119] FIG. 1 illustrates an endoscope 1, which is disposable and not intended to be cleaned and reused. The endoscope 1 comprises an endoscope tip part 50, a handle 20 with a handle housing 22 for gripping and a control lever 21, and an insertion tube 30 for insertion into a patient and extending between the handle 20 and a proximal end 41 of a bending section 40. The insertion tube 30 has an exterior tubular surface 31 providing a barrier against the surroundings of the endoscope 1. The bending section 40 comprises articulated segments 43, hinges 44 connecting the segments 43 as best seen in FIG. 2, and a thin outer sleeve 42. The endoscope 1 further comprises two steering wires (24a, 24b) extending inside the insertion tube 30 from the control lever 21 of the handle 20 to the distal tip part 50 and arranged in a Bowden cable configuration so that an operator can, upon manipulation of the control lever 21, articulate the segments 43 of the bending section about their respective hinges 44 to cause bending of the bending section 40. The thin outer sleeve 42 covers the segments 43, the hinges 44, and the gaps between the segments 43, thereby providing a smooth outer surface for the bending section 40 in order to improve the comfort of a patient undergoing endoscopy, especially when the operator articulates the bending section 40. The thin outer sleeve 42 further provides an additional layer of sealing for the connection between the endoscope tip part 50 and the bending section 40. Furthermore, a working channel (not shown) runs along the inside of the insertion tube from the handle 20 to a working channel opening (not shown) of the endoscope tip part 50, e.g. allowing liquid to be removed from the body cavity or allowing the insertion of medical tools or surgical instruments into the body cavity.

[0120] Turning to FIGS. 3 and 4a-4b, the endoscope tip part 50 can be seen in greater detail without the bending section 40. FIG. 3 also shows lines A-A and B-B identifying cross-sections illustrated in FIGS. 4a, 4b, and 5. The tip part 50 comprises an exterior surface 51 facing the exterior of the tip part 50, and a tip housing 60 having an exterior surface 64, the tip housing 60 comprising a cylindrical-shell shaped circumferential wall 68 extending circumferentially around a longitudinal axis 52 and surrounding an interior space 62 as best seen in FIGS. 4a-4b. The circumferential wall 68 is closed at a distal end of the tip housing 60 by a distal end wall 69 and has a proximal opening 63, which provides the only access to the interior space 62, at the opposite end of the tip housing 60. The circumferential wall 68 has an interior surface 68a. As described below, in some embodiments a guide light component is sized and shaped to fit closely with the interior surface 68a defining a narrow gap which limits the possibiliy of adhesive flowing from a proximal to a distal compartment. The tip housing 60 comprises an opaque, or first, portion and a transparent, or second, portion including a window 65 arranged in or adjacent the distal end wall 69. Optionally, a couple of parallel, opaque, internally extending walls extend toward the window, which in a two-step molding process is molded around their distal ends. The parallel walls provide a light shield for the imaging subassembly 70. The window 65 has an interior surface 66 facing the sealed interior space 62 and an exterior surface 67 forming part of the exterior surface 51 of the tip housing 60. The exterior surface 67 of the window 65 and the distal ends of the parallel walls form a distal end face 61 (shown in FIG. 2). The tip housing may be manufactured by two-shot injection moulding processes so that the transparent portion 65 is formed by a transparent polymer material shot of the two shot injection moulding process and the opaque portion is formed by an opaque polymer material shot of the two shot injection moulding process so that the tip housing 60 is formed as a monolithic polymer piece. The tip part 50 further comprises a separately formed plug or proximal wall (not shown) arranged in and sealing the proximal opening 63 via an adhesive, thereby fully liquid- and gas-sealing the air-filled interior space 62. The tip housing may be manufactured by adhering the transparent portion 65 to the opaque portion.

[0121] As best seen in FIGS. 4a-4b, the tip part 50 comprises an imaging subassembly 70, a first embodiment of a guide light component 80, a first and a second light source 90, 91, and an electrical circuit 94 mounted on a frame part (not shown). An enlarged view of detail view A of FIG. 4b is shown in FIG. 11.

[0122] The imaging subassembly 70 includes a lens barrel 73 and an image sensor 71 viewing in an optical direction 72 (shown in FIG. 6a) through the lens barrel 73 and out through the window 65 of the tip housing 60. The lens barrel 73 comprises several lenses enclosed in a barrel. The lenses optimise the view of the image sensor 71 and the barrel forms an optical barrier preventing stray light from entering the image sensor 71.

[0123] The first embodiment of the light guide component 80 includes a first and a second light guide 81, 82 spaced apart by a gap and extending in parallel along a respective straight longitudinal central center line. Each light guide has a proximal end, a distal end opposite of the proximal end, a light entry surface 83 at the proximal end, a light exit surface 84 at the distal end, and a circumferential surface 85 extending from the light entry surface 83 to the light exit surface 84 around the respective longitudinal central center line. The light entry surfaces 83 of the first and second light guides 80, 81 are planar and parallel, and the light exit surfaces 84 of the first and second light guides 80, 81 are planar and parallel. The circumferential surface 85 defines a polymer-air interface between the light guide component 80 and the interior space 62. The light guide component 80 further includes a crossmember 86 extending transversely from the proximal end of the first light guide 81 to the proximal end of the second light guide 82 over the gap between the light guides 81, 82. The light guide component 80 is monolithically formed of a rigid and transparent polymer material with a refractive index that is higher than the refractive index of air. This ensures that the critical angle for total internal reflection of light incident on the circumferential surface 85 of each light guide 81, 82 is also increased and thus increases the ability of the light guides 81, 82 to propagate light from the respective light entry surface 83 to the respective light exit surface 84 and thereby minimising light loss through the circumferential surfaces 85.

[0124] The tip part 50 further comprises a first and a second light source 90, 91 each formed of a single phosphor-based light-emitting diode for emitting substantially white light. Each light source 90, 91 comprises a single semiconductor die (not shown) for emitting light surrounded by an epoxy-based cover with an exterior surface forming a light-emitting surface 92. The light-emitting surface 92 of each light source 90, 91 is adhered to the light entry surface 83 of the respective light guide 80, 81 by an adhesive so that light emitted by each light source 90, 91 is propagated by the respective light guide 80, 81 out through the window 65 to provide illumination for the image sensor 71. Alternatively, the light source could be the distal end of an optical fibre transporting light from an LED arranged in the handle of the endoscope.

[0125] As best seen in FIG. 5, in their intended position the first and the second light sources 90, 91 are partially overlapping the imaging subassembly 70, in particular the lens barrel 73, when viewed in a cross-section normal to the longitudinal axis 52. When accounting for manufacturing and assembly variance, the overlap of the light sources 90, 91 with the imaging subassembly 70 is significant in a large proportion of tip parts. An overlap gap Go is shown and described in FIG. 8. The allowance for overlap enables use of larger light emitting diodes (LEDs) and also use of LEDs with different shapes chosen to maximize lighting and minimize the size of tip part. A transverse wall 54 is molded along cross-section B-B within the housing circumpherential wall. The transverse wall 54 has an opening through which the imaging subassembly 70 is introduced in the the distal compartment.

[0126] The light guide component crossmember is positioned proximally of the image sensor and overlapping the image sensor in a longitudinal direction. In this instance, “overlapping” denotes that the crossmember traverses a longitudinal projection of the image sensor, e.g. it falls within a “shadow” cast by the image sensor in the longitudinal direction.

[0127] The light guides 81, 82 have mutual reflection symmetry in a first plane 80a extending equidistantly between the light guides 81, 82 and does not intersect the light guides 81, 82. The first plane 80a comprises the longitudinal direction 52 of the tip part 50. Each light guide 81, 82 has individual reflection symmetry in a second plane 80b comprising the longitudinal central center line of each light guide 81, 82 and being perpendicular to the first plane 80a. Each light guide is asymmetric in a respective third plane 80c. The third plane 80c is perpendicular to the second plane 80b and parallel to the first plane 80a and comprises the longitudinal central center line of the respective light guide 81, 82. This allows more compact packing of the elements of the tip housing.

[0128] Turning to FIGS. 6A-6B showing the tip part 50 without the tip housing 60, the tip part 50 further comprises an electrical circuit 94 provided on a flexible circuit board (FPC). The electrical circuit 94 comprises a folded main circuit portion 98, a first circuit portion 95 in electrical communication with the image sensor 71 and the main circuit portion 98, and a second circuit portion 96 in electrical communication with the first and second light source 90, 91 and the main circuit portion 98. The electrical circuit 94 is configured for transmitting an image signal generated by the image sensor 71 indicative of the view in the optical direction 72 to a circuit (not shown) of the handle 20 of the endoscope 1 via several cables 97 connected to the main circuit portion 98 as best seen in FIG. 6a. It should be understood that as used herein the term “cable” denotes an insulated wire and the word “cables” denotes a plurality of insulated wires, which may or may not be enclosed in a sheath. The first and the second circuit portions 95, 96 are flexible circuit structures and comprise a slight bend which allow, prior to fixing in the tip housing 60, the imaging subassembly 70 and light sources 90, 91 to move along the longitudinal direction 52, which in this case coincides with the optical direction 72, relative to each other via the flexing of first and second circuit portions 95, 96. The electrical circuit 94 is positioned distally relative to the plug (not shown) and is accommodated in the sealed interior space of the tip housing 60.

[0129] A surface normal 93 of each light-emitting surface 92 is preferably oriented in parallel to the optical direction 72 of the image sensor 71 so that light is emitted from the light sources 90, 91 in the same direction as the view of the image sensor 71. The light guide component 80 is arranged so that the imaging subassembly 70 occupies the gap between the light guides 81, 82 and so that the light sources 90, 91 are positioned proximally, i.e. behind, relative to the image sensor 71. This allows a more compact configuration of the imaging subassembly 70 and the light sources 90, 91.

[0130] Turning to FIG. 7a-7b, a tip part 50 with a second embodiment of a light guide component 80 is shown without a tip housing and without cables. This second embodiment differs from the previously shown light guide component in that the light guide component comprises at least one rail 89 at each light entry surface 83, in that the crossmember 86 is plate shaped, and in that each light guide 81, 82 is not asymmetric in a corresponding third plane 80c. As best seen in FIG. 7b, the rails 89 partially surround the respective light entry surface 83 and are configured to retain and define a seat for the respective light source 90, 91 adhered to the respective light entry surface. Two or more rails may be provided to create a frame around the seat, such that during assembly the light source can easily and quickly be adhered to the light guide component 80. The plate-shaped crossmember 86 provides a barrier with only a narrow gap between the crossmember 86 and the interior surface 68a of the tip housing. Thus, the crossmember 86 prevents sealing adhesive applied proximal to the crossmember 86 from passing the crossmember 86, which could negatively affect the function of the light guides 81, 82. The internal space proximal of the crossmember 86 can be referred to as a proximal compartment and the distal space can be referred to as the distal compartment. The light guides 81, 82 are in the distal compartment. The narrow gap, shown as gap Ga (e.g. adhesive gap) in FIG. 8, extends along lateral arcuate peripheries of the plate-shaped crossmember 86, best seen in FIG. 7a. By plate-shaped is meant that the transverse surface of crossmember 86 extends beyond the surface area of the light receiving surfaces of the light guides, the additional surface providing an adhesive barrier by the defining, together with surface 68a, the narrow gap Ga, and also providing a support on which to place the rails. What constitutes a “narrow” gap depends on the viscosity of the adhesive. Denser adhesives permit wider gaps and vice versa. The gap size can be determined experimentally by placing sealing adhesive in the proximal compartment and observing whether the sealing adhesive passes through the gap to affect the function of the light guides. Sealing adhesive can be used after assembly to secure the circuit board and imaging subassembly 70 in place.

[0131] Turning to FIG. 8, a tip part 50 with a third embodiment of a light guide component 80 is shown without a tip housing and without cables. This third embodiment differs from the second embodiment in that the longitudinal central center line is not straight but rather follows an angled course and comprises an initial outwardly angled part 82a at the light entry surface and a final straight part 82b. An overlap gap Go is shown. Similar overlap gaps Go can be present in the first and second embodiments. A pair of dashed lines P.sub.LD represent the longitudinal projections of the surfaces of the imaging subassembly 70 and these dashed lines pass through the light sources 90, 91, the gaps Go representing the amount of overlap. The inner-most aspect of the light sources 90, 91, also represented by dashed lines, may be beneath the circuit 94 board and thus not visible in FIG. 8. The allowance for overlap enables use of larger light emitting diodes (LEDs) and also use of LEDs with different shapes chosen to maximize lighting and minimize the size of tip part. The narrow gap Ga is shown between the lateral arcuate periphery(ies) of the plate-shaped crossmember 86, best seen in FIG. 7a, and the internal surface 68a of circumpherential wall 68.

[0132] Assembly of the tip part 50 is performed as follows. The tip housing 60, the plug (not shown), the light guide component 80, and the electrical circuit 94 are provided as separately manufactured parts. The tip housing 60, the plug and the light guide component 80 are injection-moulded polymer parts. The electrical circuit 94 are mounted on a frame part (not shown) and has the imaging subassembly 70 and the light sources 90, 91 pre-mounted on the respective circuit portions 95, 96. The light guide component 80 can be any one of the three described embodiments.

[0133] The light-emitting surface 92 of first light source 90 is then adhered directly to the light entry surface 83 of the first light guide 81 and the light-emitting surface 92 of the second light source 91 is adhered directly to the light entry surface 83 of the second light guide 82. This ensures that light emitted from the light sources is received by the respective light guide and transmitted out via the respective light exit surface 84, and that the electrical circuit 94, imaging subassembly 70, the light sources 90, 91, and the light guide component 80 can be handled as a main subassembly, e.g. as shown in FIGS. 4a-4b, FIGS. 6a-6b, or FIG. 8.

[0134] The main subassembly is then positioned in a jig (not shown) that allows only relative translational adjustment of the light guide component 80 relative to the imaging subassembly 70. The distal end 74 of the lens barrel 73 is then adjusted to a predetermined position relative to the light exit surfaces 84 of the light guide component 80 via flexing of the first and second circuit portions 95, 96. This predetermined position corresponds to the desired position of these components in the tip housing 60 and is in this case that the distal end 74 of the lens barrel 73 is positioned in the same plane as the light exit surfaces 84, as can best be seen in FIGS. 6b and 8. The light guide component 80 and the imaging subassembly 70 are then fixed to the frame part to fix their relative position.

[0135] This main subassembly is then inserted through the proximal opening 63 of the tip housing 60 into the interior space 62 so that the optical direction 72 of the image sensor 71 extends through the window 65, and so that the light exit surface 84 of the first and second light guides 81, 82 is oriented towards the interior surface 66 of the window 65. The main subassembly is pushed into the interior space 62 until the light exit surfaces 84 and the distal end 74 of the lens barrel 73 abut the interior surface 66 of the window 65 simultaneously due to the prior relative adjustment. The main subassembly is then adhered to the interior surface of the tip housing 60.

[0136] The plug (not shown) is then inserted into and closes off the proximal opening 63 while allowing the cables 97 to pass therethrough to the handle 20. An adhesive is applied between the plug and an interior housing surface to fluid and gas seal the interior space 62. The tip part 50 can then be assembled with the bending section 40, the insertion tube 30, and the handle 20, to form the endoscope shown in FIG. 1.

[0137] In FIG. 9, a monitor 11 is shown. The monitor 11 comprises a cable socket 12 to which a monitor cable 13 of the endoscope 1 shown in FIG. 1 can be connected to establish signal communication between the image sensor of the endoscope 1 and the monitor 11 via a circuit of the handle 20 connected to the electrical circuit 94 of the housing 60 of the tip part 50 via the cables 97. The monitor 11 display images and/or video captured by the image sensor of the endoscope 1, thus allowing an operator to see through the image sensor of the endoscope 1.

[0138] As best seen in FIGS. 10a-10b, each light guide 81, 82 comprises a tapering transition portion 87 including the respective light entry surface 83 and a straight portion 88 directly extending from the transition portion 87 to the respective light exit surface 84. As shown in FIG. 10b, the straight portion 88 of each light guide 81, 82 has a width w and a height h. Further, the light guides 81, 82 are spaced apart transversely to the longitudinal axis 52 by a distance d. The width w is in the range of 0.35-0.55 mm, preferably in the range of 0.4-0.5 mm. The height h is in the range of 0.6-0.8 mm, preferably in the range of 0.65-0.75 mm. The distance d is in the range of 1.3-1.8 mm, preferably in the range of 1.4-1.7.

[0139] FIG. 11 is an enlarged view of detail view A of FIG. 4b. As can be seen on FIG. 11, the transition portion 87 of each light guide 81, 82 tapers from the respective light entry surface 83 to the respective straight portion 88 with a taper angle α with respect to the longitudinal axis 52. The taper angle α is in the range 1-12 degrees, preferably 5-10 degrees, more preferably 7-10 degrees.

[0140] The following items are examples of various embodiments disclosed above:

[0141] Item 1. An endoscope tip part for an endoscope for visually inspecting inaccessible places, such as human body cavities, the endoscope tip part having an exterior surface and extending along a longitudinal axis and comprising: [0142] a tip housing extending along the longitudinal axis and at least partially enclosing a sealed interior space, the tip housing including: [0143] an exterior housing surface for forming a first part of the exterior surface of the endoscope tip part, and [0144] a transparent portion, such as a window or a front lens, having an interior surface facing the sealed interior space of the endoscope tip part and an exterior surface forming a second part of the exterior surface of the endoscope tip part; [0145] an imaging subassembly including an image sensor viewing in an optical direction through the transparent portion of the tip housing; [0146] a light guide component comprising a first light guide having a light entry surface and a light exit surface, the first light guide being configured for propagating light received through the light entry surface out through the light exit surface and the transparent portion of the tip housing; [0147] a first light source being configured to emit light in a central illumination direction to be received by the light entry surface of the first light guide; and [0148] an electrical circuit comprising a first circuit portion in electrical communication with the image sensor, the electrical circuit being configured for transmitting an image signal generated by the image sensor indicative of the view in the optical direction; [0149] wherein the first light source, the image sensor, and the electrical circuit are accommodated in the sealed interior space of the tip housing, wherein the first light source is attached to the light guide component and preferably positioned proximally relative to the image sensor.

[0150] Item 2. An endoscope tip part according to item 1, wherein the light guide component comprises a second light guide having a light entry surface and a light exit surface, the second light guide being configured for propagating light received through the light entry surface out through the light exit surface and the transparent portion of the tip housing, wherein the endoscope tip part comprises a second light source having a light-emitting surface and being configured to emit light from the light-emitting surface in a central illumination direction to be received by the light entry surface of the second light guide, wherein the second light source is attached to the light guide component and preferably positioned proximally relative to the image sensor, and wherein the first and second light guides extend side-by-side on opposite sides of the imaging subassembly.

[0151] Item 3. An endoscope tip part according to any one of the previous items, wherein the light guide component is formed separately from the tip housing, and wherein the first light guide exit and/or the second light guide exit is/are oriented towards the interior surface of the transparent portion.

[0152] Item 4. An endoscope tip part according to any one of the previous items, wherein the tip housing comprises a distal end face and a proximal opening providing access to the sealed interior space, wherein the distal end face is positioned opposite the proximal opening, and wherein the distal end face comprises at least part of the exterior surface of the transparent portion.

[0153] Item 5. An endoscope tip part according to any one of the previous items, wherein the first and/or the second light source(s) is/are at least partially overlapping the imaging subassembly when viewed in a cross-section perpendicular to the longitudinal axis.

[0154] Item 6. An endoscope tip part according to any one of the previous items, wherein the first and/or the second circuit portion(s) is/are flexible circuit structures.

[0155] Item 7. An endoscope tip part according to any one of the previous items, wherein the first and/or the second light guide consist(s) essentially of a transparent material with a first refractive index, and wherein the light-emitting surface of the light source(s) is/are adhered to the light entry surface of the respective light guide by an adhesive.

[0156] Item 8. A light guide component for an endoscope tip part, the light guide component comprising: [0157] a first and a second light guide being spaced apart by a gap and extending along a respective longitudinal centre line, wherein each light guide has a proximal end, a distal end, a light entry surface at the proximal end, a light exit surface at the distal end, and a circumferential surface extending from the light entry surface to the light exit surface around the respective longitudinal centre line, and [0158] a crossmember extending transversely from the first light guide to the second light guide so as to form a unitary rigid light guide component, [0159] wherein the light guides are configured for propagating light received through the respective light entry surface out through the respective light exit surface.

[0160] Item 9. A light guide component according to item 8, wherein the crossmember extends transversely from the proximal end of the first light guide to the proximal end of the second light guide.

[0161] Item 10. A light guide component according to any one of the items 8-9, wherein the light guide component is formed monolithically.

[0162] Item 11. A light guide component according to any one of the items 8-10, wherein the light entry surfaces of the first and second light guides are planar, and/or wherein light exit surfaces of the first and second light guides are planar.

[0163] Item 12. An endoscope tip part according to any one of the items 1-7, wherein the light guide component is a light guide component according to any one of items 8-11.

[0164] Item 13. An endoscope for visually inspecting inaccessible places such as human body cavities, comprising: [0165] a handle for gripping by an operator and comprising a control device; [0166] an endoscope tip part according to any one of the items 1-7 or item 12; [0167] an insertion tube for insertion into a patient, the insertion tube extending from the handle to the endoscope tip part and comprising a bending section; [0168] one or more cables running through the insertion tube and electrically connecting the electrical circuit of the endoscope tip part with the handle; and [0169] at least one steering wire connecting the handle with a distal end of the bending section so that manipulation of the control device causes bending of the bending section.

[0170] Item 14. An endoscope system for visually inspecting inaccessible places, such as human body cavities, the endoscope system comprising a monitor, and an endoscope according to item 13 or an endoscope comprising an endoscope tip part according to any one of items 1-7 or 12, wherein the endoscope is connectable to the monitor, and the monitor is configured for displaying an image captured by the image sensor of the endoscope tip part.

[0171] Item 15. A method for assembling an endoscope tip part, the endoscope tip part extending along a longitudinal axis, the method comprising the steps of: [0172] providing: [0173] a housing extending along the longitudinal axis and at least partially enclosing an interior space, the tip housing including: [0174] a proximal opening providing access to the interior space, [0175] an exterior housing surface for forming an exterior surface of the endoscope tip part, and [0176] a transparent portion, such as a window or a front lens, having an interior surface and an exterior surface, the interior surface facing the interior space of the endoscope tip part and the exterior surface facing the exterior of the endoscope tip part, [0177] an imaging subassembly including an image sensor viewing in an optical direction, [0178] a light guide component comprising a first light guide including a proximal end, a distal end, a light entry surface at the proximal end, a light exit surface at the distal end, and a circumferential surface extending from the light entry surface to the light exit surface around the respective longitudinal centre line, the first light guide being configured for propagating light received through the light entry surface out through the light exit surface, [0179] a first light source having a light-emitting surface and being configured to emit light from the light-emitting surface in a central illumination direction, and [0180] an electrical circuit comprising a first circuit portion in electrical communication with the image sensor and a second circuit portion in electrical communication with the light source(s), the electrical circuit being configured for transmitting an image signal generated by image sensor indicative of the view in the optical direction, wherein at least one of the first and second circuit portions is flexible so the image sensor and light source(s) are movable relative to each other; [0181] attaching the first light source to the light guide component, so that light emitted by the first light source is received by the light entry surface of the first light guide, and so that the imaging subassembly, the light guide component, and the electrical circuit form a main subassembly; [0182] inserting the main subassembly through the proximal opening of the tip housing into the interior space so that the optical direction of the image sensor extends through the transparent portion, and so that a surface normal of the light exit surface of the first light guide is at least partially oriented towards the interior surface of the transparent portion; [0183] fixing the main subassembly to the tip housing and sealing the proximal opening to seal the interior space.

[0184] Item 16. A method according to item 15, wherein the light guide component is provided according to any one of items 8-11.

[0185] Item 17. A method according to any one of items 15-16, further comprising a step of: [0186] arranging the main subassembly in a jig, adjusting the light guide component relative to the imaging subassembly to a predetermined relative position along the longitudinal direction via flexing of the first and/or second circuit portion, and subsequently fixing the light guide component relative to the imaging subassembly, [0187] wherein the step of inserting the main subassembly comprises inserting the main subassembly along the longitudinal direction until a distal end of the imaging subassembly abuts an interior distal portion of the tip housing, and until a distal end of the light guide component abuts an interior distal portion of the tip housing.

LIST OF REFERENCES

[0188] The following is a list of reference numerals used throughout this disclosure. In case of any doubt, the reference numerals of the following list apply. [0189] 1 endoscope [0190] 11 monitor [0191] 12 cable socket [0192] 13 monitor cable [0193] 20 handle [0194] 21 control lever [0195] 22 handle housing [0196] 24a steering wire [0197] 24b steering wire [0198] 30 insertion tube [0199] 31 exterior tubular surface [0200] 32 working channel [0201] 40 bending section [0202] 41 proximal end [0203] 42 sleeve [0204] 43 segment [0205] 44 hinge [0206] 50 tip part [0207] 51 exterior surface [0208] 52 longitudinal axis [0209] 54 wall [0210] 60 housing [0211] 61 distal end face [0212] 62 interior space [0213] 63 proximal opening [0214] 64 exterior housing surface [0215] 65 window [0216] 66 interior window surface [0217] 67 exterior window surface [0218] 68 circumferential wall [0219] 68a circumferential wall internal surface [0220] 69 distal end wall [0221] 70 imaging subassembly [0222] 71 image sensor [0223] 72 optical direction [0224] 73 lens barrel [0225] 74 distal end [0226] 80 light guide component [0227] 80a first plane [0228] 80b second plane [0229] 80c third plane 81 first light guide [0230] 82 second light guide [0231] 83 light entry surface [0232] 84 light exit surface [0233] 85 circumferential surface [0234] 86 crossmember [0235] 87 transition portion [0236] 88 straight portion [0237] 89 rail [0238] α taper angle [0239] 90 first light source [0240] 91 second light source [0241] 92 light-emitting surface [0242] 93 central illumination direction [0243] 94 electrical circuit [0244] 95 first circuit portion [0245] 96 second circuit portion [0246] 97 cable [0247] 98 main circuit portion