Imaging Modules and Visualization Probes

Abstract

The imaging module includes: a lens barrel holding an optical system; an imaging sensor, a sensor front surface of which is vertically arranged on the optical axis of the optical system and has a quadrilateral shape; and a sensor holder, which is formed into a substantially rectangular parallelepiped shape having a pair of parallel end surfaces orthogonal to the optical axis and having substantially the same size as the imaging sensor, and in which a holding hole penetrating the pair of end surfaces is drilled, the lens barrel being assembled into the holding hole on one end surface, the other end surface being used as a sensor abutting surface abutting against the sensor front surface, a chamfered portion being provided from which at least one of the ridgeline portions perpendicular to the sensor abutting surface is removed, and the chamfered portion exposes a corner of the sensor front surface.

Description

Technical Field

[0001] The present disclosure relates to imaging modules and visualization probes. Background Art

[0002] For example, it is necessary to reduce the diameter and size of the imaging module housed at the front end of the visualization probe. For example, the wafer-level package (WLP) type imaging module disclosed in Patent Document 1 is manufactured by cutting and singulating a bonded wafer, wherein an imaging wafer including a plurality of imaging elements and a glass wafer are bonded to each other. Therefore, the entire surface of the light-receiving surface on which the light-receiving portion of the imaging element is formed is covered by a cover glass.

[0003] When an imaging module is formed by integrating a lens barrel that houses an optical system with an imaging element covered by a cover glass, it is effective to use a sensor holder to connect the two components. Hereinafter, the imaging element may be referred to as an "imaging sensor". In addition, in this case, in the imaging module, due to the demand for miniaturization, it is desirable that the imaging sensor is mounted within the projection plane of the sensor holder in the optical axis direction. That is, in the imaging module, it is preferred that the outer dimensions of the sensor holder and the imaging sensor are substantially the same, thereby achieving a small diameter.

[0004] Citation List

[0005] Patent Literature

[0006] [Patent Document 1] JP-2018-160763-A Summary of the invention

[0007] Technical issues

[0008] However, in the imaging module, there is a problem that when the outer shapes of the sensor holder and the imaging sensor are quadrilaterals having substantially the same size, in the alignment operation during the assembly process, when viewed from the object side, the imaging sensor is hidden by the sensor holder and it is difficult to recognize the normal position. In addition, when the sensor holder and the imaging sensor are joined to each other, it is desirable to be able to apply the adhesive from both the direction along the optical axis and the lateral direction orthogonal to the optical axis. Furthermore, it is also necessary to perform the position adjustment operation without inserting uncured adhesive between the sensor holder and the imaging sensor (i.e., preventing the adhesive from intruding into the optically effective surface).

[0009] The present disclosure is made in view of the above existing situation, and an object thereof is to provide an imaging module and a visualization probe, wherein a sensor holder and an imaging sensor can be easily aligned with each other, can be easily bonded, and adhesive is prevented from invading an optically effective surface.

[0010] Solution to the problem

[0011] The present disclosure provides an imaging module, comprising: a lens barrel holding an optical system; an imaging sensor having a quadrilateral shape and wherein a front surface of the sensor is arranged perpendicular to an optical axis of the optical system; and a sensor holder, wherein a pair of end surfaces parallel to each other and orthogonal to the optical axis are formed into a substantially rectangular parallelepiped shape having substantially the same size as the imaging sensor, a holding hole is drilled through the pair of end surfaces, the lens barrel is assembled into the holding hole of one end surface, and the other end surface is a sensor contact surface in contact with the front surface of the sensor, and the sensor holder has a chamfered portion in which at least a portion of an ridge portion perpendicular to the sensor contact surface is removed, and the chamfered portion exposes a corner portion of the front surface of the sensor.

[0012] In addition, the present disclosure provides a visualization probe, including: a lens barrel, which holds an optical system; an imaging sensor, which has a quadrilateral shape and in which the sensor front surface is arranged perpendicular to the optical axis of the optical system; a sensor holder, in which a pair of end faces parallel to each other and orthogonal to the optical axis are formed into a substantially rectangular parallelepiped shape having substantially the same size as the imaging sensor, a holding hole is drilled through the pair of end faces, the lens barrel is fitted into the holding hole of one end face, the other end face is a sensor contact face that contacts the sensor front surface, the sensor holder has a chamfered portion, in which at least a portion of an ridge portion perpendicular to the sensor contact face is removed, and the chamfered portion exposes a corner portion of the sensor front surface; a cylindrical front end portion having an imaging window on the front end face and covering the lens barrel, the imaging sensor and the sensor holder; a light guide, which is inserted through the front end portion and has a light-emitting front end arranged on the front end face; a flexible substrate, which is accommodated in a projection plane of the imaging sensor in the optical axis direction and is electrically connected to the imaging sensor; and a cable, which is inserted through the front end portion and is electrically connected to the flexible substrate.

[0013] Advantageous Effects of the Invention

[0014] According to the present disclosure, in an imaging module or a visualization probe, a sensor holder and an imaging sensor can be easily aligned with each other, can be easily bonded, and an adhesive can be prevented from intruding into an optically effective surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] [ Figure 1 ] Figure 1 : is a perspective view of a main part showing the appearance of the front end side of the visualization probe according to the first embodiment.

[0016] [ Figure 2 ] Figure 2 yes Figure 1 Shown is a transparent perspective view of the front end of the visualization probe.

[0017] [ Figure 3 ] Figure 3 yes Figure 2A perspective view of an imaging module is shown.

[0018] [ Figure 4 ] Figure 4 yes Figure 2 A side view of the imaging module is shown.

[0019] [ Figure 5 ] Figure 5 Viewed from the flexible substrate side Figure 4 A rear view of the imaging module is shown.

[0020] [ Figure 6 ] Figure 6 is a perspective view with a portion of the imaging sensor and flexible substrate cut away.

[0021] [ Figure 7 ] Figure 7 is a front view of an imaging module according to a comparative example.

[0022] [ Figure 8 ] Figure 8 is a front view of the imaging module according to the first embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments that specifically disclose the configuration and functions of the imaging module and visualization probe according to the present disclosure will be described in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, a detailed description of a well-known matter or a repeated description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate the understanding of those skilled in the art. It should be understood that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the scope of the claims.

[0024] Figure 1 1 is a perspective view of a main part showing the appearance of the front end side of the visualization probe 11 according to the first embodiment. The imaging module according to the first embodiment is suitable for use with the visualization probe 11. The visualization probe 11 can be used as, for example, a medical endoscope or an industrial endoscope. The visualization probe 11 includes an observer 13 to be inserted into an observation target and a plug portion (not shown) connected to the rear end portion of the observer 13. The observer 13 includes a flexible portion 15 having a long flexibility and a cylindrical front end portion 17 having rigidity provided at the front end of the flexible portion 15.

[0025] The visualization probe 11 includes an imaging module 21 located behind the imaging window 19 in the front end portion 17 (see Figure 2 On the front end face 23 of the front end portion 17, a plurality of ( Figure 1The irradiation windows 25 (three in the example) are arranged around the imaging window 19. The light emitting tip of the light guide 27 inserted through the tip portion 17 is connected to each irradiation window 25. For example, an optical fiber bundle formed by bundling a plurality of optical fiber strands is used as the light guide 27.

[0026] In the visualization probe 11, the above-mentioned plug portion (not shown) is inserted into the socket portion of the video processor (not shown), and the visualization probe 11 and the video processor are connected to each other. Therefore, power and various signals (for example, video signals and control signals) can be sent and received between the visualization probe 11 and the video processor. These power and various signals are transmitted through the transmission cable 29 (see FIG. 29 ) inserted into the viewer 13. Figure 2 ) is transmitted from the plug portion to the flexible portion side. In addition, from the imaging sensor 31 (see Figure 2 )The image signal output by the video processor is transmitted to the video processor via the transmission cable 29 and the plug part.

[0027] The video processor performs image processing on the image signal transmitted via the transmission cable 29, converts the image data after the image processing into a display signal, and outputs the display signal to a monitor (not shown).

[0028] Figure 2 yes Figure 1 A transparent perspective view of the front end portion 17 of the visualization probe 11 is shown. The imaging module 21, the light guide 27, the flexible substrate 33, and the transmission cable 29 according to the first embodiment are accommodated in the front end portion 17 of the visualization probe 11.

[0029] The imaging module 21 includes a lens barrel 35 , an imaging sensor 31 , and a sensor holder 37 as main components.

[0030] The lens barrel 35 holds therein an optical system 39. The optical system 39 includes, for example, an objective cover glass, lenses, an aperture, a spacer, a bandpass filter, and the like.

[0031] In the first embodiment, the lens barrel 35 is made of metal (eg, SUS) and formed into a cylindrical shape. The outer diameter of the lens barrel 35 is, for example, a small diameter of about 2.4 mm.

[0032] Figure 3 yes Figure 2 21. In the imaging sensor 31, the sensor front surface 43 (see Figure 6 ) is arranged perpendicular to the optical axis 41 of the optical system 39. The imaging sensor 31 has a quadrilateral shape. The imaging sensor 31 is formed by attaching a sensor cover glass 47 to the light incident surface side of the imaging element 45. For example, a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like is used as the imaging element 45.

[0033] Figure 4 yes Figure 2 4 is a side view of the imaging module 21 shown in FIG. In the sensor holder 37, a pair of end faces parallel to each other and orthogonal to the optical axis 41 are formed into a substantially rectangular parallelepiped shape, which is a quadrilateral shape having substantially the same size as the outer shape of the imaging sensor 31. A holding hole 49 is bored in the sensor holder 37 to penetrate the pair of end faces. The lens barrel 35 is fitted into the holding hole 49 in one end face of the sensor holder 37. In addition, the other end face of the sensor holder 37 serves as a sensor contact surface 51 that contacts the sensor front surface 43.

[0034] The sensor holder 37 has a chamfered portion 55 (see Figure 8 ), in the chamfered portion 55, the ridgeline portion 53 (see Figure 7 ) is removed. The chamfered portion 55 exposes a corner portion 57 (see Figure 8 ). The corner portion 57 of the sensor front surface 43 exposed by the chamfered portion 55 can be visually recognized from the front of the lens barrel 35 in the direction along the optical axis 41 .

[0035] In the first embodiment, by removing all four ridge portions 53 perpendicular to the sensor contact surface 51, chamfered portions 55 are formed at four portions (see Figure 8 ).

[0036] In the imaging module 21 , the sensor holder 37 and the imaging sensor 31 are fixed to each other by a first adhesive 59 provided across a corner portion 57 of the sensor front surface 43 and a chamfered portion 55 of the sensor holder 37 .

[0037] Furthermore, in the imaging module 21 , each side portion of the sensor contact surface 51 and the imaging sensor 31 are fixed to each other by the second adhesive 61 .

[0038] In the imaging module 21 , a clamping groove 65 orthogonal to the optical axis 41 is formed on a pair of side surfaces 63 of the sensor holder 37 which are parallel to the optical axis 41 .

[0039] Furthermore, the visualization probe 11 according to the first embodiment includes a flexible substrate 33 (see Figure 2 ) and a transmission cable 29 electrically connected to the flexible substrate 33 (see Figure 2 ), the flexible substrate 33 is accommodated in the projection plane of the imaging sensor 31 in the optical axis direction and is electrically connected to the imaging sensor 31.

[0040] Figure 5 Viewed from the flexible substrate side Figure 4The rear view of the imaging module 21 is shown. The flexible substrate 33 is bent into a column 69, the axis of which is in the same direction as the front straight portion of the wire 67. The column 69 can be, for example, a quadrangular prism. In the quadrangular prism, as long as the outer shape of the cross section orthogonal to the axis is a quadrilateral, a part of the flexible substrate 33 can be bent inward.

[0041] The flexible substrate 33 is roughly divided into a substrate main body 71, an imaging element mounting peninsula 73, and an electronic component mounting peninsula 75, and is integrally formed. The substrate main body 71 is further divided into a first surface 77, a second surface 79, a third surface 81, a fourth surface 83, a fifth surface 85, and a sixth surface 87. The first surface 77 of the column 69 is folded inward, and the second surface 79, the third surface 81, the fourth surface 83, the fifth surface 85, and the sixth surface 87 form a quadrilateral outer peripheral surface. In the flexible substrate 33, the column 69 is arranged within the projection area of ​​the imaging element 45. In the imaging element mounting peninsula 73, the column 69 is arranged within the projection area of ​​the imaging element 45. Figure 5 The plurality of terminals on the back side of the imaging element 45 are connected to the bump 89 (see Figure 4 )connect.

[0042] Figure 6 3 is a perspective view in which a portion of the imaging sensor 31 and the flexible substrate 33 are cut away. The electronic component mounting peninsula 75 is formed in a quadrilateral shape, extends from the second surface 79 of the flexible substrate 33 via the reduced diameter portion, and is bent toward the opposite side of the imaging element 45, wherein the imaging element mounting peninsula 73 is sandwiched between the imaging element 45 and the electronic component mounting peninsula 75. Therefore, the electronic component mounting peninsula 75 is disposed within the projection area of ​​the imaging element 45. A plurality of electronic components 91 that are conductive to the circuit are mounted on the surface of the electronic component mounting peninsula 75 that faces the imaging element mounting peninsula 73. The electronic component mounting peninsula 75 is formed to have a size that does not contact the inner circumference of the column 69. The electronic component mounting peninsula 75 is bent at a bending angle of 90 degrees or more so as to be reliably inserted into the column 69. Therefore, interference with the imaging element mounting peninsula 73 is avoided.

[0043] The electronic component 91 can be mounted on the surface of the electronic component mounting peninsula 75 opposite to the surface in the first embodiment. In addition, a plurality of electronic component mounting peninsulas 75 can be formed. In this case, a plurality of electronic component mounting peninsulas 75 are stacked on the back side of the imaging element mounting peninsula 73 and are arranged to face each other in a stacked state.

[0044] Each wire 67 is electrically connected to a circuit on the inner surface of the column 69. All wires 67 are connected to the inner surface of the column 69, but not to the outer surface of the column 69.

[0045] Next, the function of the imaging module 21 according to the first embodiment will be described.

[0046] The imaging module 21 according to the first embodiment includes a lens barrel 35 holding an optical system 39 and an imaging sensor 31 having a quadrangular outer shape, wherein a sensor front surface 43 is disposed perpendicular to an optical axis 41 of the optical system 39. The imaging module 21 includes a sensor holder 37 in which a pair of end surfaces parallel to each other and orthogonal to the optical axis 41 are formed into a substantially rectangular parallelepiped shape, which is a quadrangular shape having substantially the same size as the outer shape of the imaging sensor 31, a holding hole 49 is bored through the pair of end surfaces, the lens barrel 35 is fitted into the holding hole 49 of one end surface, and the other end surface is a sensor contact surface 51 in contact with the sensor front surface 43. The sensor holder 37 has a chamfered portion 55 in which at least a portion of a ridgeline portion 53 perpendicular to the sensor contact surface 51 is removed, and the chamfered portion 55 exposes a corner portion 57 of the sensor front surface 43.

[0047] In the imaging module 21 according to the first embodiment, the sensor holder 37 is formed in a substantially rectangular parallelepiped shape. In the sensor holder 37, a pair of end faces parallel to each other and orthogonal to the optical axis 41 have a quadrilateral shape having substantially the same size as the outer shape of the imaging sensor 31. A holding hole 49 is bored in the sensor holder 37 to penetrate the pair of end faces. The lens barrel 35 holding the optical system 39 is fitted into one of the pair of end faces.

[0048] The other end surface of the sensor holder 37 serves as a sensor contact surface 51 that contacts the sensor front surface 43. Therefore, the holding hole 49 is opened on the inner side of the quadrilateral sensor contact surface 51. The sensor contact surface 51 is an annular frame surface sandwiched between the outer shape of the sensor contact surface 51 and the holding hole 49 opened on the sensor contact surface 51 (see Figure 8 ). In the sensor front surface 43, the area facing the holding hole 49 opened in the annular frame surface serves as an optically effective surface.

[0049] Therefore, the sensor holder 37 is formed in a substantially rectangular parallelepiped shape, and the other end surface serves as a sensor contact surface 51 that contacts the sensor front surface 43. Here, the sensor holder 37 has a chamfered portion 55 in which at least a portion of the ridgeline portion 53 perpendicular to the sensor contact surface 51 is removed. In addition, in the sensor holder 37, any portion of the ridgeline portion 53, such as two portions, three portions, and four portions, may be removed. For example, when the sensor holder 37 has the chamfered portion 55 in which four ridgeline portions 53 are removed, four corner portions of the sensor front surface 43 are exposed at the respective chamfered portions 55.

[0050] Figure 7is a front view of an imaging module 93 according to a comparative example. In this imaging module, due to the dimensional tolerance when cutting the imaging sensor 31, the imaging sensor 31 may be formed to have an outer shape smaller than the standard outer shape. In this case, in the sensor holder 95 of the imaging module 93 without the chamfered portion 55, Figure 7 The outer shape of the imaging sensor 31 indicated by the dotted line in FIG. 8 is hidden behind the sensor holder 37 and is not visible.

[0051] On the other hand, in the imaging module 21, since the chamfered portion 55 is provided to remove the ridgeline portion 53 of the sensor holder 37, the corner portion 57 of the sensor front surface 43 can be observed from the front of the lens barrel 35 in the direction along the optical axis 41. Therefore, even when the imaging sensor 31 is hidden by the sensor holder 37 having the same size, the imaging module 21 can grasp the relative position between the sensor holder 37 and the imaging sensor 31 based on the shape and size of the corner portion 57 visually recognized.

[0052] The greater the number of chamfered portions 55 , the easier the alignment between the sensor holder 37 and the imaging sensor 31 is, and the higher the positioning accuracy is.

[0053] Furthermore, since the corner portion 57 of the sensor front surface 43 is exposed in the direction along the optical axis 41, it is possible to provide the adhesive on the corner portion 57 from the same direction. In the imaging module 21, since the adhesive is provided on the corner portion 57, the adhesive can adhere to both the corner portion 57 and the chamfered portion 55. That is, the adhesive can be applied from both the direction along the optical axis 41 and the lateral direction orthogonal to the optical axis 41.

[0054] In addition, since the adhesive provided on the corner portion 57 can mainly adhere to the corner portion 57 and the chamfered portion 55, an adhesive having a higher viscosity can be used. Therefore, it is possible to prevent the adhesive from deeply invading between the sensor front surface 43 and the sensor contact surface 51 from the corner portion 57 and reaching the optically effective surface.

[0055] Therefore, according to the imaging module 21 of the first embodiment, the sensor holder 37 and the imaging sensor 31 can be easily aligned with each other and can be easily bonded to each other, and further, the intrusion of the adhesive into the optically effective surface can be prevented.

[0056] Furthermore, in the imaging module 21 , the sensor holder 37 and the imaging sensor 31 are fixed to each other by the first adhesive 59 provided across the corner portion 57 and the sensor holder 37 .

[0057] In the imaging module 21, the first adhesive 59 is provided at the corner portion 57 of the sensor front surface 43. The first adhesive 59 provided on the corner portion 57 can be easily adhered to both the corner portion 57 and the chamfered portion 55. Therefore, in the imaging module 21, the sensor holder 37 and the imaging sensor 31 are fixed to each other by the first adhesive 59 at the corner portion 57.

[0058] For example, the sensor holder 37 to which the lens barrel 35 is fixed in advance is positioned at a position orthogonal to the optical axis 41 with respect to the sensor front surface 43 of the imaging sensor 31. Figure 3 The sensor holder 37 and the imaging sensor 31 are moved in the X and Y directions shown in the figure, and the relative position is adjusted. At this time, the first adhesive 59 is not applied to the corner portion 57. After the relative position between the sensor holder 37 and the imaging sensor 31 is positioned, the first adhesive 59 is set (dripped or applied) on the corner portion 57. By curing the first adhesive 59 set on the corner portion 57, the sensor holder 37 and the imaging sensor 31 can be quickly fixed or temporarily fixed immediately after the positioning is completed.

[0059] Furthermore, in the imaging module 21 , each side portion of the sensor contact surface 51 and the imaging sensor 31 are fixed to each other by the second adhesive 61 .

[0060] In the imaging module 21, for example, when the first adhesive 59 provided on the corner portion 57 is used to temporarily fix the sensor holder 37 and the imaging sensor 31, the sensor holder 37 and the imaging sensor 31 are finally fixed by the second adhesive 61. The second adhesive 61 is filled and applied to a minute gap between the sensor contact surface 51 of the sensor holder 37 and the sensor front surface 43 of the imaging sensor 31, which are in substantially close contact with each other, by using a capillary phenomenon. Therefore, it is preferable that the viscosity of the second adhesive 61 is lower than that of the first adhesive 59.

[0061] In the sensor holder 37 and the imaging sensor 31 , the corner portion 57 is temporarily fixed by the first adhesive 59 , and furthermore, each side portion is finally fixed by the second adhesive 61 , so that high bonding strength can be obtained.

[0062] Furthermore, the second adhesive 61 is applied to each edge of the sensor contact surface 51 of the sensor holder 37. Therefore, the entire periphery of the gap between the sensor holder 37 and the imaging sensor 31 is sealed by the first adhesive 59 and the second adhesive 61. In the imaging module 21, since the periphery of the gap between the sensor holder 37 and the imaging sensor 31 is sealed, for example, when the front end portion 17 of the visualization probe 11 is formed, it is possible to prevent the filling resin material covering the periphery from intruding into the optically effective surface.

[0063] Furthermore, in the imaging module 21 , a clamping groove 65 orthogonal to the optical axis 41 is formed on a pair of side surfaces 63 of the sensor holder 37 which are parallel to the optical axis 41 .

[0064] In the imaging module 21, a clamping groove 65 orthogonal to the optical axis 41 is formed on a pair of side surfaces 63 of the sensor holder 37 which are parallel to the optical axis 41. With respect to the sensor holder 37 and the imaging sensor 31, for example, the imaging sensor 31 is fixed, and the sensor holder 37 is clamped by a clamping tool so that the sensor holder 37 is positioned relative to the imaging sensor 31. At this time, the sensor holder 37 is held by the clamping tool. The clamping tool has, for example, a pair of finger rod portions assembled into the pair of clamping grooves 65. By clamping the pair of clamping grooves 65 by the finger rod portions, the sensor holder 37 is adjusted to be movable within an XY plane parallel to the sensor front surface 43. At this time, since the finger rod portions of the clamping tool are assembled into the clamping grooves 65, the sensor holder 37 can be held without sliding while being perpendicular to the XY plane. Figure 3 An appropriate pressure is applied in the Z direction (ie, the direction along the optical axis 41) as shown. Therefore, in a state where the sensor holder 37 is in close contact with the sensor front surface 43, the sensor holder 37 can be aligned with higher accuracy.

[0065] Furthermore, in the imaging module 21 , the lens barrel 35 is a cylinder.

[0066] In the imaging module 21, the lens barrel 35 is formed into a cylindrical shape. Since the lens barrel 35 is formed into a cylindrical shape, the holding hole 49 to which the lens barrel 35 is assembled also penetrates the sensor holder 37 as a circular hole. The sensor contact surface 51 of the sensor holder 37 is an annular frame surface sandwiched between the outer shape and the holding hole 49 by opening the holding hole 49 on the inner side of the quadrilateral. The sensor contact surface 51 contacts the annular frame surface against the sensor front surface 43. On the annular frame surface, there are formed approximately triangular corner triangular faces 97 ( Figure 8 ). The base of the corner triangular face 97 is the arc of the holding hole 49. In the sensor holder 37, since four corner triangular faces 97 are formed on the sensor contact surface 51, the chamfered portion 55 can be easily removed.

[0067] Furthermore, in the imaging module 21 , chamfered portions 55 are formed at four locations where the four ridge line portions 53 are removed.

[0068] Figure 8: is a front view of the imaging module 21 according to the first embodiment. In the imaging module 21, in the sensor holder 37 formed in a substantially rectangular parallelepiped shape, four ridgeline portions 53 perpendicular to the sensor contact surface 51 are removed to form four chamfered portions 55. Therefore, a pair of parallel end faces of the sensor holder 37 is substantially octagonal. In the sensor holder 37, since the four corner portions 57 in the sensor front surface 43 can be visually recognized by the four chamfered portions 55, positioning in the in-plane direction in the XY plane can be performed with higher accuracy.

[0069] Furthermore, the visualization probe 11 according to the first embodiment includes a lens barrel 35 holding an optical system 39, and an imaging sensor 31 in which a sensor front surface 43 is disposed perpendicular to the optical axis 41 of the optical system 39 and the outer shape of the imaging sensor 31 is formed in a quadrilateral shape. The visualization probe 11 includes a sensor holder 37 in which a pair of end faces parallel to each other and orthogonal to the optical axis 41 are formed in a substantially rectangular parallelepiped shape, which is a quadrilateral shape having substantially the same size as the outer shape of the imaging sensor 31, a holding hole 49 is bored through the pair of end faces, the lens barrel 35 is fitted into the holding hole 49 of one end face, and the other end face is a sensor contact face 51 in contact with the sensor front surface 43. The sensor holder 37 has a chamfered portion 55 in which at least a portion of a ridgeline portion 53 perpendicular to the sensor contact face 51 is removed, and the chamfered portion 55 exposes a corner portion 57 of the sensor front surface 43. The visualization probe 11 includes: a cylindrical front end portion 17 having an imaging window 19 on a front end face 23 that allows imaging light to be incident on an optical system 39 and covers a lens barrel 35, an imaging sensor 31, and a sensor holder 37; a light guide 27 that is inserted through the front end portion 17 and has a light-emitting front end disposed on the front end face 23; a flexible substrate 33 that is accommodated in a projection plane of the imaging sensor 31 in the optical axis direction and is electrically connected to the imaging sensor 31; and a cable that is inserted through the front end portion 17 and is electrically connected to the flexible substrate 33.

[0070] In the visualization probe 11 according to the first embodiment, since the imaging module 21 is provided, even when the imaging sensor 31 is hidden by the sensor holder 37 having the same size, the relative position between the sensor holder 37 and the imaging sensor 31 can be easily grasped based on the shape and size of the visually recognized corner portion 57 through the above-mentioned function.

[0071] Furthermore, since corners 57 of sensor front surface 43 are exposed in the direction along optical axis 41, adhesive can be provided on corners 57 from the same direction. That is, adhesive can be applied from both the direction along optical axis 41 and the lateral direction orthogonal to optical axis 41.

[0072] Furthermore, since the adhesive provided on the corner portion 57 can be mainly adhered to the corner portion 57 and the chamfered portion 55, an adhesive having a higher viscosity can be used. In addition, the adhesive having a low viscosity is made to penetrate from the corner portion 57 into between the sensor front surface 43 and the sensor contact surface 51, and therefore, the space between the imaging sensor 31 and the optical system 39 is completely isolated from the outside, and degradation of the image quality of the video due to the intrusion of moisture or dust can be prevented. The adhesive having a low viscosity deeply intrudes into the minute gap between the sensor front surface 43 and the sensor contact surface 51 without suction, and solidifies in this state, thereby being able to prevent the adhesive having a low viscosity from reaching the optical effective surface.

[0073] Furthermore, in the visualization probe 11, the lens barrel 35, the imaging sensor 31, and the sensor holder 37 are covered by the cylindrical front end portion 17. The front end portion 17 may have an outer shell formed of a hard cylinder, or may be formed by curing a filling resin material within a flexible sheath extending from the insertion portion of the visualization probe 11.

[0074] Therefore, the visualization probe 11 can hermetically and watertightly seal the imaging module 21 while reducing the diameter through a small number of components.

[0075] Furthermore, in the visualization probe 11 , since the light guide 27 is provided radially outside the imaging module 21 , the subject can be independently observed even in a dark place without requiring an additional lighting device.

[0076] In addition, in the visualization probe 11, since the flexible substrate 33 is accommodated in the projection plane of the imaging sensor 31 in the optical axis direction, the diameter reduction is not hindered. Therefore, the visualization probe 11 can use the imaging sensor 31 to obtain high image quality, which requires connecting the transmission cable 29 in which a large number of wires 67 are bundled.

[0077] According to the visualization probe 11 of the first embodiment, the sensor holder 37 and the imaging sensor 31 can be easily aligned with each other and can be easily engaged with each other, furthermore, the adhesive can be prevented from intruding into the optically effective surface, and the diameter of the front end portion 17 can be reduced.

[0078] Although various embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such examples. It is obvious to those skilled in the art that various changes, modifications, substitutions, additions, deletions and equivalents can be envisioned within the scope of the claims, and it should be understood that such changes also belong to the technical scope of the present disclosure. The components in the various embodiments described above can be arbitrarily combined within the scope of the spirit of the present invention.

[0079] This application is based on the Japanese patent application (Japanese Patent Application No. 2019-167407) filed on September 13, 2019, the contents of which are incorporated into this application by reference.

[0080] Industrial Applicability

[0081] The present disclosure can be used as an imaging module and a visualization probe, in which the sensor holder and the imaging sensor can be easily aligned with each other and can be easily engaged with each other to prevent the adhesive from invading the optically effective surface, and in the visualization probe, the sensor holder and the imaging sensor can be easily aligned with each other and can be easily engaged with each other to prevent the adhesive from invading the optically effective surface and can reduce the diameter of the front end portion.

[0082] Reference numerals list

[0083] 11. Visualization Probe

[0084] 17: Front end

[0085] 19: Imaging Window

[0086] 21: Imaging module

[0087] 23: Front face

[0088] 27: Light guide

[0089] 29: Transmission cable

[0090] 31: Imaging Sensor

[0091] 33: Flexible substrate

[0092] 35: Lens barrel

[0093] 37: Sensor holder

[0094] 39: Optical system

[0095] 41: Optical axis

[0096] 43: Sensor front surface

[0097] 49: Keep hole

[0098] 51: Sensor contact surface

[0099] 53: Ridge

[0100] 55: Chamfer

[0101] 57: Corner

[0102] 59: First Adhesive

[0103] 61: Second adhesive

[0104] 63: Side

[0105] 65: Clamping slot

Claims

1. An imaging module, comprising: The lens barrel holds the optical system; an imaging sensor having a quadrilateral shape and wherein a front surface of the sensor is disposed perpendicular to an optical axis of the optical system; as well as a sensor holder formed in a substantially rectangular parallelepiped shape and having a first end face and a second end face parallel to each other and orthogonal to the optical axis, the first end face and the second end face being formed to have substantially the same size as the sensor front surface of the imaging sensor, the sensor holder including a holding hole penetrating the first end face and the second end face and a peripheral portion surrounding the holding hole, the lens barrel being fitted into the holding hole on the first end face, the second end face being a sensor contact surface contacting the sensor front surface, wherein the sensor front surface has four corner portions, and the peripheral portion has a chamfered portion adjacent to one or more of the four corner portions and extending from the first end surface to the second end surface, so that the one or more corner portions are exposed from the sensor holder, and Wherein, the adhesive is provided from the one or more corner portions to the chamfered portion.

2. The imaging module according to claim 1, wherein The sensor holder and the imaging sensor are fixed to each other by a first adhesive provided on the one or more corner portions and the chamfered portion.

3. The imaging module according to claim 1 or 2, wherein Each edge of the sensor contact surface is fixed to the sensor front surface by a second adhesive.

4. The imaging module according to claim 1, wherein A clamping groove orthogonal to the optical axis is formed on a pair of side surfaces of the sensor holder parallel to the optical axis.

5. The imaging module according to claim 1, wherein The lens barrel is a cylinder.

6. The imaging module according to claim 1, wherein When viewed in a direction parallel to the optical axis, the first end surface and the second end surface have an octagonal shape, and the four corner portions are exposed from the sensor holder.

7. A visualization probe, comprising: The lens barrel holds the optical system; an imaging sensor having a quadrilateral shape and wherein a front surface of the sensor is disposed perpendicular to an optical axis of the optical system; a sensor holder formed in a substantially rectangular parallelepiped shape and having a first end face and a second end face parallel to each other and orthogonal to the optical axis, the first end face and the second end face being formed to have substantially the same size as the sensor front surface of the imaging sensor, the sensor holder comprising a holding hole penetrating the first end face and the second end face and a peripheral portion surrounding the holding hole, the lens barrel being fitted into the holding hole on the first end face, the second end face being a sensor contact surface contacting the sensor front surface, wherein the sensor front surface has four corner portions, and the peripheral portion has a chamfered portion adjacent to one or more of the four corner portions and extending from the first end face to the second end face so that the one or more corner portions are exposed from the sensor holder, and wherein an adhesive is provided from the one or more corner portions to the chamfered portion; a cylindrical front end portion having an imaging window on a front end surface and covering the lens barrel, the imaging sensor and the sensor holder; a light guide inserted through the cylindrical front end portion and having a light emitting front end disposed on the front end face; a flexible substrate accommodated in a projection plane of the imaging sensor in the optical axis direction and electrically connected to the imaging sensor; and A cable is inserted through the cylindrical front end portion and is electrically connected to the flexible substrate.

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