JP7480979B2 - Imaging Module and Visualization Probe - Google Patents

Description

This disclosure relates to an imaging module and a visualization probe.

For example, imaging modules housed at the tip of visualization probes are required to be smaller in size as well as thinner in diameter. For example, a wafer-level packaging (WLP) type imaging module disclosed in Patent Document 1 is produced by cutting a bonded wafer in which an imaging wafer containing multiple imaging elements and a glass wafer are bonded together into individual pieces. For this reason, the entire light receiving surface on which the light receiving parts of the imaging elements are formed is covered with a cover glass.

When creating an imaging module by integrating a lens barrel housing an optical system with the imaging element covered with this cover glass, it is effective to use a sensor holding member to connect the two components. Hereinafter, the imaging element may be referred to as the "imaging sensor." Even in this case, due to the demand for compact imaging modules, it is desirable for the imaging sensor to fit within the projection surface in the optical axis direction of the sensor holding member. In other words, imaging modules suitable for miniaturization are those in which the sensor holding member and the imaging sensor are roughly the same external size.

JP 2018-160763 A

However, in an imaging module, if the sensor holding member and the outer shape of the imaging sensor are rectangular and of roughly the same size, the imaging sensor is hidden by the sensor holding member when viewed from the objective side during alignment work during assembly, making it difficult to determine whether it is in the correct position. In addition, when bonding the sensor holding member and the imaging sensor, it is desirable to be able to apply adhesive either from a direction along the optical axis or from a side perpendicular to the optical axis. Furthermore, there is a demand to perform positioning adjustment work without having uncured adhesive between the sensor holding member and the imaging sensor (i.e., preventing adhesive from penetrating the effective optical surface).

The present disclosure has been devised in consideration of the above-described conventional circumstances, and aims to provide an imaging module and a visualization probe that are capable of precisely positioning a sensor holding member and an imaging sensor when assembling the sensor holding member and the imaging sensor .

The present disclosure provides an imaging sensor including a sensor front surface perpendicular to an optical axis of an optical system and having a rectangular outer shape, a first end face having a hole perpendicular to the optical axis, a second end face parallel to the first end face and disposed closer to the imaging sensor than the first end face, a space penetrating from the hole to the second end face, and an outer periphery perpendicular to the second end face and extending from the second end face to the first end face, the imaging sensor being disposed within a projection plane of the imaging sensor in a direction parallel to the optical axis and facing the imaging sensor at the second end face. Provided is an imaging module comprising: a sensor holding member; and a barrel that holds the optical system and is disposed in the space, wherein the sensor front surface has four corners, the sensor holding member has a shape that has more vertices than a rectangle when viewed in a viewing direction that is parallel to the optical axis and from the first end face to the second end face, one or more of the four corners are exposed from the sensor holding member , the outer periphery has a chamfered portion adjacent to the one or more corners, and a first adhesive is provided from the one or more corners to the chamfered portion .

The present disclosure also relates to a visualization probe including an imaging sensor having a sensor front surface orthogonal to an optical axis of an optical system and having a rectangular outer shape, a first end face having a hole and orthogonal to the optical axis, a second end face that is parallel to the first end face and is disposed closer to the imaging sensor than the first end face, a space portion penetrating from the hole to the second end face, and an outer periphery that is orthogonal to the second end face and extends from the second end face to the first end face, the visualization probe including a sensor holding member that is disposed within a projection plane of the imaging sensor in a direction parallel to the optical axis and faces the imaging sensor at the second end face, a lens barrel that holds the optical system and is disposed in the space portion, and a tip surface formed with an imaging window for introducing light into the optical system, the lens barrel, the imaging sensor, and the sensor holding member being covered by the visualization probe, a cylindrical tip portion disposed at a tip of a lobe; a light guide inserted into the tip portion and with its light-emitting tip disposed on the tip surface; a flexible substrate disposed within a projection surface of the imaging sensor in a direction parallel to the optical axis and electrically connected to the imaging sensor; and a cable inserted into the tip portion and electrically connected to the flexible substrate, wherein the sensor front surface has four corners, the sensor holding member has a shape having more vertices than a rectangle when viewed in a visual direction parallel to the optical axis from the first end surface to the second end surface, one or more of the four corners are exposed from the sensor holding member , the outer periphery has a chamfered portion adjacent to the one or more corners, and a first adhesive is provided from the one or more corners to the chamfered portion .

According to the present disclosure, it is possible to provide an imaging module and a visualization probe in which the sensor holding member and the imaging sensor can be accurately positioned when assembling the sensor holding member and the imaging sensor in the imaging module or visualization probe .

FIG. 2 is a perspective view of a main part showing the external appearance of the tip side of the visualization probe according to the first embodiment; FIG. 2 is a perspective view showing the tip of the visualization probe shown in FIG. 1 . FIG. 3 is a perspective view of the imaging module shown in FIG. FIG. 3 is a side view of the imaging module shown in FIG. A rear view of the imaging module shown in FIG. 4 as seen from the flexible substrate side. FIG. 1 is a perspective view showing an image sensor and a flexible substrate with a portion cut away; FIG. 1 is a front view of an imaging module according to a comparative example; FIG. 1 is a front view of an imaging module according to a first embodiment;

Below, with reference to the drawings as appropriate, an embodiment that specifically discloses the configuration and operation of the imaging module and visualization probe according to the present disclosure will be described in detail. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. Note that the attached drawings and the following explanation are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

Figure 1 is a perspective view of the main parts showing the external appearance of the tip side of a visualization probe 11 according to embodiment 1. The imaging module according to embodiment 1 is suitable for use in the visualization probe 11. The visualization probe 11 can be used, for example, as a medical endoscope or an industrial endoscope. The visualization probe 11 includes a scope 13 that is inserted into the object of observation, and a plug portion (not shown) to which the rear end portion of the scope 13 is connected. The scope 13 includes a relatively long flexible soft portion 15, and a rigid cylindrical tip portion 17 provided at the tip of the soft portion 15.

The visualization probe 11 has an imaging module 21 (see FIG. 2) behind the imaging window 19 in the tip portion 17. On the tip surface 23 of the tip portion 17, multiple irradiation windows 25 (three in the example in FIG. 1) that irradiate illumination light are arranged around the imaging window 19. The light-emitting tip of a light guide 27 inserted into the tip portion 17 is connected to each irradiation window 25. For example, a bundle fiber in which multiple optical fiber strands are bundled together is used for the light guide 27.

The visualization probe 11 has the above-mentioned plug portion (not shown) inserted into the socket portion of the video processor (not shown) to connect the visualization probe 11 to the video processor, enabling transmission and reception of power and various signals (e.g., video signals, control signals) between the visualization probe 11 and the video processor. These power and various signals are transmitted from the plug portion to the flexible portion via a transmission cable 29 (see FIG. 2) inserted inside the scope 13. In addition, an image signal output from an imaging sensor 31 (see FIG. 2) provided inside the tip portion 17 is transmitted to the video processor via the transmission cable 29 and the plug portion.

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

Figure 2 is a perspective view showing the tip 17 of the visualization probe 11 shown in Figure 1. The tip 17 of the visualization probe 11 contains the imaging module 21 according to embodiment 1, a light guide 27, a flexible substrate 33, and a transmission cable 29.

The imaging module 21 mainly comprises a lens barrel 35, an imaging sensor 31, and a sensor holding member 37.

The lens barrel 35 holds an optical system 39 inside. The optical system 39 is composed of, for example, an objective cover glass, a lens, an aperture, a spacer, a bandpass filter, etc.

In the first embodiment, the lens barrel 35 is made of metal (e.g., SUS) and is cylindrical. The lens barrel 35 is manufactured with a small outer diameter of, for example, about 2.4 mm.

Figure 3 is a perspective view of the imaging module 21 shown in Figure 2. The imaging sensor 31 is arranged such that the sensor front surface 43 (see Figure 6) is perpendicular to the optical axis 41 of the optical system 39. The imaging sensor 31 has a rectangular shape. The imaging sensor 31 is configured by attaching a sensor cover glass 47 to the light incident surface side of the imaging element 45. For example, a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) is used for the imaging element 45.

4 is a side view of the imaging module 21 shown in FIG. 2. The sensor holding member 37 has a pair of parallel end faces (end faces 42A and 42B) perpendicular to the optical axis 41, which are approximately the same size as the outer shape of the imaging sensor 31 (see FIG. 8), and has an outer periphery 42C extending from the end face 42B to the end face 42A. The end face 42A is an example of a first end face in this embodiment, and the end face 42B is an example of a second end face in this embodiment. The sensor holding member 37 is provided with a holding hole 49 penetrating the pair of end faces. The opening of the holding hole 49 arranged in the end face 42A is an example of a hole portion in this embodiment, and the holding hole 49 is an example of a space portion in this embodiment. The lens barrel 35 is fitted into the holding hole 49. The other end face of the sensor holding member 37 becomes a sensor abutment surface 51 that abuts against the sensor front surface 43.

The sensor holding member 37 has a chamfered portion 55 (see FIG. 8) in which at least one of the ridges 53 (see FIG. 7) perpendicular to the end face 42B has been removed. The chamfered portion 55 exposes one or more of the four corners 57 (see FIG. 8) of the sensor front face 43. FIG. 8 shows an imaging module 21 having a sensor holding member 37 with an end face 42A having four corners 57 exposed. The corners 57 of the sensor front face 43 exposed by the chamfered portion 55 can be viewed from a direction along the optical axis 41 in front of the lens barrel 35. That is, when viewed in a direction parallel to the optical axis 41 from the end face 42A toward the end face 42B (visual direction), the sensor holding member 37 exposes one or more of the four corners 57 of the sensor front face 43 from the sensor holding member 37 , and has a shape with more vertices than a rectangle (see FIG. 8). More specifically, the sensor holding member 37 is an octagon when viewed in the visual direction. Four corners 57 of the sensor front surface 43 are exposed from the sensor holding member 37. The shape of the sensor holding member 37 in the visual direction is the shape of the end faces 42A and 42B (see FIG. 4 ) when viewed in a direction parallel to the optical axis 41. Thus, the end faces 42A and 42B when viewed in a direction parallel to the optical axis 41 have a shape with more vertices than a rectangle (see FIG. 8 ), and one or more of the four corners 57 of the sensor front surface 43 are exposed from the sensor holding member 37.

In the first embodiment, the chamfered portions 55 are formed in four locations by removing all four ridges 53 perpendicular to the sensor contact surface 51 (see FIG. 8).

The imaging module 21 is fixed between the sensor holding member 37 and the imaging sensor 31 by a first adhesive 59 provided across the corner 57 of the sensor front surface 43 and the chamfered portion 55 of the sensor holding member 37.

Furthermore, in the imaging module 21, each side portion of the sensor contact surface 51 and the imaging sensor 31 are fixed by the second adhesive 61. That is, in the imaging module 21, the imaging sensor 31 and the sensor holding member 37 are fixed by the first adhesive 59 and the second adhesive 61 (see FIG. 4). Furthermore, the end surface 42B is fixed to the sensor front surface 43 by the first adhesive 59 (see FIG. 4).

In the imaging module 21, gripping grooves 65 perpendicular to the optical axis 41 are formed on a pair of side surfaces 63 parallel to the optical axis 41 of the sensor holding member 37. That is, the outer circumferential portion 42C of the sensor holding member 37 has the gripping grooves 65 perpendicular to the optical axis 41 (see FIG. 4).

The visualization probe 11 according to embodiment 1 also includes a flexible substrate 33 (see FIG. 2) that is contained within the projection plane in the optical axis direction of the imaging sensor 31 and is electrically connected to the imaging sensor 31, and a transmission cable 29 (see FIG. 2) that is electrically connected to the flexible substrate 33.

Figure 5 is a rear view of the imaging module 21 shown in Figure 4, seen from the flexible substrate side. The flexible substrate 33 is bent into a cylinder 69 having an axis in the same direction as the straight tip portion of the electric wire 67. The cylinder 69 can be, for example, a rectangular tube. As long as the outer shape of the cross section perpendicular to the axis of the rectangular tube is rectangular, a portion of the flexible substrate 33 may be bent inward.

The flexible substrate 33 is broadly divided into a substrate main body 71, an imaging element mounting peninsula 73, and an electronic component mounting peninsula 75, which are molded as a single unit. 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 cylinder 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 rectangular outer surface. The flexible substrate 33 is arranged such that the cylinder 69 is within the projection area range of the imaging element 45. The imaging element mounting peninsula 73 has multiple terminals provided on the back side of FIG. 5 that are connected to bumps 89 (see FIG. 4) of the imaging element 45.

6 is a perspective view of the imaging sensor 31 and the flexible substrate 33 with a portion cut away. The electronic component mounting peninsula 75 is formed in a rectangular shape, extends from the second surface 79 of the flexible substrate 33 through a constricted portion, and is bent to the opposite side of the imaging element 45 across the imaging element mounting peninsula 73. As a result, the electronic component mounting peninsula 75 is disposed within the projected area range of the imaging element 45. A plurality of electronic components 91 that are electrically connected to the circuit are mounted on the surface of the electronic component mounting peninsula 75 facing the imaging element mounting peninsula 73. The electronic component mounting peninsula 75 is formed to a size that does not contact the inner circumference of the cylindrical body 69. The electronic component mounting peninsula 75 is bent at a bending angle of 90 degrees or more so that it is reliably inserted inside the cylindrical body 69. This avoids interference with the imaging element mounting peninsula 73.

The electronic component 91 may be mounted on the surface of the electronic component mounting peninsula 75 opposite to that of the first embodiment. A plurality of electronic component mounting peninsulas 75 may be formed. In this case, the plurality of electronic component mounting peninsulas 75 are stacked on top of each other on the back side of the imaging element mounting peninsula 73, and are arranged facing each other in a layered configuration.

Each electric wire 67 is electrically connected to the circuit on the inner surface of the cylindrical body 69. All electric wires 67 are connected to the inner surface of the cylindrical body 69, and are not connected to the outer surface of the cylindrical body 69.

Next, we will explain the operation of the imaging module 21 according to embodiment 1.

The imaging module 21 according to the first embodiment includes a lens barrel 35 that holds an optical system 39, and an imaging sensor 31 that has a rectangular outer shape and a sensor front surface 43 that is arranged perpendicular to the optical axis 41 of the optical system 39. The imaging module 21 is formed as a substantially rectangular parallelepiped with a pair of parallel end surfaces perpendicular to the optical axis 41 that are substantially the same size as the outer shape of the imaging sensor 31, and a holding hole 49 is drilled through the pair of end surfaces, so that the lens barrel 35 is fitted into the holding hole 49 on one end surface, and the other end surface forms a sensor abutment surface 51 that abuts against the sensor front surface 43. The sensor holding member 37 has a chamfered portion 55 in which at least one of the ridges 53 perpendicular to the sensor abutment surface 51 has been removed, and the chamfered portion 55 exposes a corner 57 of the sensor front surface 43.

In the imaging module 21 according to the first embodiment, the sensor holding member 37 is formed as a substantially rectangular parallelepiped. The sensor holding member 37 has a pair of parallel end faces perpendicular to the optical axis 41 that are rectangular and have substantially the same size as the outer shape of the imaging sensor 31. The sensor holding member 37 has a holding hole 49 that penetrates the pair of end faces. The lens barrel 35 that holds the optical system 39 is fitted into one of the pair of end faces.

The other end face of the sensor holding member 37 becomes the sensor abutment surface 51 that abuts against the sensor front surface 43. Therefore, the rectangular sensor abutment surface 51 has a retaining hole 49 opening on the inside. The sensor abutment surface 51 becomes an annular frame surface (see FIG. 8) that is sandwiched between the outer shape of the sensor abutment surface 51 and the retaining hole 49 that opens into the sensor abutment surface 51. The area of the sensor front surface 43 that faces the retaining hole 49 that opens into this annular frame surface becomes the optically effective surface.

In this way, the sensor holding member 37 is formed as a substantially rectangular parallelepiped, and the other end face forms a sensor abutment surface 51 that abuts against the sensor front surface 43. Here, the sensor holding member 37 has a chamfered portion 55 in which at least one of the ridges 53 perpendicular to the sensor abutment surface 51 has been removed. Alternatively, the sensor holding member 37 may have any of two, three, or four ridges 53 removed. For example, when the sensor holding member 37 has a chamfered portion 55 in which four ridges 53 have been removed, the four corners of the sensor front surface 43 are exposed at each of the chamfered portions 55.

Figure 7 is a front view of an imaging module 93 according to a comparative example. In some imaging modules, the imaging sensor 31 is formed with an outer shape smaller than the standard outer shape due to dimensional tolerances when cutting out the imaging sensor 31. In this case, in a sensor holding member 95 of an imaging module 93 that does not have a chamfered portion 55, the outer shape of the imaging sensor 31 shown by the dashed line in Figure 7 is hidden behind the sensor holding member 37 and cannot be seen.

In contrast, the imaging module 21 has a chamfered portion 55 where the ridge portion 53 of the sensor holding member 37 has been removed, so that the corner portion 57 of the sensor front surface 43 can be visually observed from the front of the lens barrel 35 in the direction along the optical axis 41. As a result, even if the imaging sensor 31 is hidden by a sensor holding member 37 of the same size, the imaging module 21 can grasp the relative position of the sensor holding member 37 and the imaging sensor 31 from the shape and size of the visually recognized corner portion 57.

The more chamfered portions 55 there are, the easier it is to align the sensor holding member 37 with the image sensor 31, and the higher the positioning accuracy can be.

In addition, because the corners 57 of the sensor front surface 43 are exposed in a direction along the optical axis 41, adhesive can be applied to the corners 57 from the same direction. By applying adhesive to the corners 57 of the imaging module 21, adhesive can be applied to both the corners 57 and the chamfered portions 55. In other words, adhesive can be applied from either a direction along the optical axis 41 or from a side perpendicular to the optical axis 41.

Furthermore, since the adhesive applied to the corner 57 only needs to be applied mainly to the corner 57 and the chamfered portion 55, an adhesive with a relatively high viscosity can be used. This makes it possible to prevent the adhesive from penetrating deeply from the corner 57 between the sensor front surface 43 and the sensor contact surface 51 and reaching the optically effective surface.

Therefore, according to the imaging module 21 of the first embodiment, the sensor holding member 37 and the imaging sensor 31 can be easily aligned and bonded, and the infiltration of adhesive into the optically effective surface can be suppressed.

In addition, in the imaging module 21, the sensor holding member 37 and the imaging sensor 31 are fixed by a first adhesive 59 provided across the corner portion 57 and the sensor holding member 37.

In this imaging module 21, a first adhesive 59 is provided at a corner 57 of the sensor front surface 43. The first adhesive 59 provided at the corner 57 can be easily attached to both the corner 57 and the chamfered portion 55. As a result, in the imaging module 21, the sensor holding member 37 and the imaging sensor 31 are fixed by the first adhesive 59 at the corner 57.

For example, the sensor holding member 37, to which the lens barrel 35 has been fixed in advance, is moved in the XY directions shown in FIG. 3 perpendicular to the optical axis 41 relative to the sensor front surface 43 of the imaging sensor 31 to adjust the relative position. At this time, the first adhesive 59 is not applied to the corners 57. Once the relative positions of the sensor holding member 37 and the imaging sensor 31 have been determined, the first adhesive 59 is applied (dropped or applied) to the corners 57. When the first adhesive 59 applied to the corners 57 solidifies, the sensor holding member 37 and the imaging sensor 31 can be quickly fixed or temporarily fixed immediately after positioning is completed.

In addition, in the imaging module 21, each side of the sensor contact surface 51 and the imaging sensor 31 are fixed with a second adhesive 61.

In this imaging module 21, for example, if the first adhesive 59 provided at the corner 57 is used to temporarily fix the sensor holding member 37 and the imaging sensor 31, the second adhesive 61 permanently fixes the sensor holding member 37 and the imaging sensor 31. The second adhesive 61 is filled and applied by capillary action into the minute gap between the sensor contact surface 51 of the sensor holding member 37 and the sensor front surface 43 of the imaging sensor 31, which are in a nearly tight contact state. Therefore, it is preferable that the second adhesive 61 has a lower viscosity than the first adhesive 59.

The sensor holding member 37 and the image sensor 31 can be bonded to each other with high strength by temporarily fixing the corners 57 with the first adhesive 59 and by permanently fixing each side with the second adhesive 61.

The second adhesive 61 is also applied to each side of the sensor contact surface 51 of the sensor holding member 37. As a result, the periphery of the gap between the sensor holding member 37 and the imaging sensor 31 is completely sealed with the first adhesive 59 and the second adhesive 61. By sealing the periphery of the gap between the sensor holding member 37 and the imaging sensor 31, the imaging module 21 can prevent the filling resin material covering the periphery from penetrating into the optically effective surface, for example, when forming the tip 17 of the visualization probe 11.

In addition, in the imaging module 21, a pair of side surfaces 63 parallel to the optical axis 41 of the sensor holding member 37 are formed with gripping grooves 65 that are perpendicular to the optical axis 41.

In this imaging module 21, a pair of side surfaces 63 of the sensor holding member 37 parallel to the optical axis 41 are formed with gripping grooves 65 perpendicular to the optical axis 41. The sensor holding member 37 and the imaging sensor 31 are, for example, fixed to the imaging sensor 31, and the sensor holding member 37 is gripped by a gripping tool to position the sensor holding member 37 relative to the imaging sensor 31. At this time, the sensor holding member 37 is clamped by the gripping tool. The gripping tool has, for example, a pair of finger rods that fit into the pair of gripping grooves 65. The sensor holding member 37 is adjusted by being able to move in the XY plane parallel to the sensor front surface 43 by the pair of gripping grooves 65 being clamped by the finger rods. At this time, since the finger rods of the gripping tool are fitted into the gripping grooves 65, the gripping tool can hold the sensor holding member 37 without slipping while applying an appropriate pressing force in the Z direction shown in FIG. 3 (i.e., the direction along the optical axis 41) perpendicular to the XY plane. This allows the sensor holding member 37 to be aligned with greater precision while in close contact with the sensor front surface 43.

In addition, in the imaging module 21, the lens barrel 35 is cylindrical.

In this imaging module 21, the lens barrel 35 is formed as a cylinder. Since the lens barrel 35 is formed as a cylinder, the retaining hole 49 into which the lens barrel 35 fits is also a circular hole that penetrates the sensor holding member 37. The sensor abutment surface 51 of the sensor holding member 37 becomes an annular frame surface sandwiched between the outer shape and the retaining hole 49 by opening the retaining hole 49 inside the square. The sensor abutment surface 51 abuts this annular frame surface against the sensor front surface 43. The annular frame surface has approximately triangular corner triangular surfaces 97 (FIG. 8) with vertices at points far from the retaining hole 49 in four radial directions that are approximately orthogonal to each other. The corner triangular surfaces 97 have a base that is an arc of the retaining hole 49. Since the four corner triangular surfaces 97 are formed on the sensor abutment surface 51 of the sensor holding member 37, the removal of the chamfered portion 55 can be easily performed.

In addition, in the imaging module 21, chamfered portions 55 are formed at four locations where the four ridge portions 53 have been removed.

8 is a front view of the imaging module 21 according to the first embodiment. In this imaging module 21, the sensor holding member 37 is formed in a substantially rectangular parallelepiped shape, and four ridges 53 perpendicular to the end face 42B are removed to form four chamfered portions 55. The outer periphery 42C (see FIG. 4) of the sensor holding member 37 corresponds to a portion of the sensor holding member 37 that extends from the end face 42B to 42A and where the chamfered portions 55 are formed. As a result, the end faces 42A and 42B are substantially octagonal . The sensor holding member 37 has four chamfered portions 55 that allow four corners 57 on the sensor front face 43 to be visible, so that the positioning in the in-plane direction on the XY plane can be performed with higher accuracy.

The visualization probe 11 according to the first embodiment includes a lens barrel 35 that holds the optical system 39, and an imaging sensor 31 in which a sensor front surface 43 is arranged perpendicular to the optical axis 41 of the optical system 39 and has a rectangular outer shape. The visualization probe 11 is formed as a substantially rectangular parallelepiped with a pair of parallel end surfaces perpendicular to the optical axis 41 that are substantially the same size as the outer shape of the imaging sensor 31, a holding hole 49 is drilled 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 forms a sensor abutment surface 51 that abuts against the sensor front surface 43, and includes a chamfered portion 55 in which at least one of the ridges 53 perpendicular to the sensor abutment surface 51 is removed, and the chamfered portion 55 exposes a corner 57 of the sensor front surface 43. The visualization probe 11 has an imaging window 19 on the tip surface 23 that allows imaging light to enter the optical system 39, and is equipped with a cylindrical tip portion 17 that covers the lens barrel 35, imaging sensor 31, and sensor holding member 37, a light guide 27 that is inserted into the tip portion 17 and has a light emitting tip located on the tip surface 23, a flexible board 33 that is contained within the 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 into the tip portion 17 and is electrically connected to the flexible board 33.

The visualization probe 11 according to embodiment 1 is equipped with an imaging module 21, so that even if the imaging sensor 31 is hidden by a sensor holding member 37 of the same size, the above-mentioned action makes it easy to grasp the relative positions of the sensor holding member 37 and the imaging sensor 31 from the shape and size of the visible corner 57.

In addition, because the corners 57 of the sensor front surface 43 are exposed in a direction along the optical axis 41, adhesive can be applied to the corners 57 from the same direction. In other words, adhesive can be applied from either a direction along the optical axis 41 or from a side perpendicular to the optical axis 41.

Furthermore, the adhesive applied to the corner 57 only needs to be applied mainly to the corner 57 and the chamfered portion 55, so a relatively high viscosity adhesive can be used. Separately, by infiltrating a low viscosity adhesive from the corner 57 into the space between the sensor front surface 43 and the sensor contact surface 51, the space between the image sensor 31 and the optical system 39 can be completely isolated from the outside, and degradation of image quality due to the intrusion of moisture or dust can be prevented. Note that the above-mentioned low viscosity adhesive is allowed to penetrate deeply into the minute gap between the sensor front surface 43 and the sensor contact surface 51 without being pumped, and is allowed to harden in that state, preventing it from reaching the optically effective surface.

In addition, the visualization probe 11 has a cylindrical tip 17 that covers the lens barrel 35, the imaging sensor 31, and the sensor holding member 37. The tip 17 may have an outer shell formed from a hard cylinder, or may be formed by solidifying a filling resin material inside a flexible sheath that extends from the insertion portion of the visualization probe 11.

This allows the visualization probe 11 to be made smaller in diameter with fewer parts, while sealing the imaging module 21 airtight and watertight.

In addition, the visualization probe 11 has a light guide 27 arranged radially outside the imaging module 21, making it possible to observe the subject alone, even in dark areas, without the need for other illumination means.

Furthermore, the visualization probe 11 does not prevent the diameter from being reduced because the flexible substrate 33 fits within the projection surface of the imaging sensor 31 in the optical axis direction. This makes it possible for the visualization probe 11 to use a high-image-quality imaging sensor 31 that requires the connection of a transmission cable 29 made up of a large number of bundled electric wires 67.

With the visualization probe 11 according to the first embodiment, the sensor holding member 37 and the imaging sensor 31 can be easily aligned and bonded together, and the intrusion of adhesive into the optically effective surface can be suppressed, allowing the diameter of the tip 17 to be reduced.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, amendments, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components in the various embodiments described above may be combined in any manner as long as it does not deviate from the spirit of the invention.

The present disclosure is useful as an imaging module in which the sensor holding member and the imaging sensor can be easily aligned and bonded, and in which the infiltration of adhesive into the optically effective surface is suppressed, and as a visualization probe in which the sensor holding member and the imaging sensor can be easily aligned and bonded, and in which the infiltration of adhesive into the optically effective surface is suppressed, and in which the tip has a small diameter.

REFERENCE SIGNS LIST 11 Visualization probe 17 Tip portion 19 Imaging window 21 Imaging module 23 Tip surface 27 Light guide 29 Transmission cable 31 Imaging sensor 33 Flexible substrate 35 Lens barrel 37 Sensor holding member 39 Optical system 41 Optical axis 43 Sensor front surface 49 Holding hole 51 Sensor contact surface 53 Ridge portion 55 Chamfered portion 57 Corner portion 59 First adhesive 61 Second adhesive 63 Side surface 65 Gripping groove

Claims (6)

an image sensor having a sensor front surface perpendicular to an optical axis of the optical system and having a rectangular outer shape;
a sensor holding member including a first end face having a hole and perpendicular to the optical axis, a second end face parallel to the first end face and disposed closer to the image sensor than the first end face, a space penetrating from the hole to the second end face, and an outer circumferential portion perpendicular to the second end face and extending from the second end face to the first end face, the sensor holding member being disposed within a projection plane of the image sensor in a direction parallel to the optical axis and facing the image sensor at the second end face;
a lens barrel that holds the optical system and is disposed in the space,
The sensor front surface has four corners,
the sensor holding member has a shape with more vertices than a rectangle when viewed in a viewing direction parallel to the optical axis from the first end face to the second end face,
One or more of the four corners are exposed from the sensor holding member,
the outer periphery has a chamfer adjacent to the one or more corners;
A first adhesive is provided from the one or more corners to the chamfered portion.
Imaging module. The second end surface is
fixed to the front surface of the sensor via a second adhesive;
The imaging module according to claim 1 . the first adhesive and the second adhesive are continuous and seal an outer periphery of a gap between the sensor holding member and the image sensor;
The imaging module according to claim 2 . The lens barrel is a cylinder.
The imaging module according to any one of claims 1 to 3. The first end surface and the second end surface are
When viewed in the viewing direction, the shape is octagonal;
The four corners are exposed from the sensor holding member.
The imaging module according to any one of claims 1 to 4. A visualization probe, comprising:
an image sensor having a sensor front surface perpendicular to an optical axis of the optical system and having a rectangular outer shape;
a sensor holding member including a first end face having a hole and perpendicular to the optical axis, a second end face parallel to the first end face and disposed closer to the image sensor than the first end face, a space penetrating from the hole to the second end face, and an outer circumferential portion perpendicular to the second end face and extending from the second end face to the first end face, the sensor holding member being disposed within a projection plane of the image sensor in a direction parallel to the optical axis and facing the image sensor at the second end face;
a lens barrel that holds the optical system and is disposed in the space;
a cylindrical tip portion having a tip surface on which an imaging window for allowing light to enter the optical system is formed, the tip portion covering the lens barrel, the imaging sensor, and the sensor holding member, and being disposed at the tip of the visualization probe;
a light guide that is inserted through the tip portion and has a light emitting tip disposed on the tip surface;
a flexible substrate disposed within a projection plane of the image sensor in a direction parallel to the optical axis and electrically connected to the image sensor;
a cable that is inserted through the tip portion and electrically connected to the flexible substrate;
The sensor front surface has four corners,
the sensor holding member has a shape with more vertices than a rectangle when viewed in a viewing direction parallel to the optical axis from the first end face to the second end face,
One or more of the four corners are exposed from the sensor holding member,
the outer periphery has a chamfer adjacent to the one or more corners;
A first adhesive is provided from the one or more corners to the chamfered portion.
Visualization probe.

Images