JP2014036799A - Optical unit and endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical unit formed by reliably integrally fixing an optical member provided with a shading mask and an optical member integrally fixed to the optical member with a photo-curing adhesive and an endoscope including the optical unit.SOLUTION: In an optical unit, an imaging unit 62 includes a cover glass 65 having light transmissivity and a centering glass 66, incident light from a subject is guided to transmit through the centering glass 66 and the cover glass 65 in order, and an outgoing surface of the incident light of the centering glass 66 and an incident surface of incident light of the cover glass 65 are integrally fixed by an adhesive having transmissivity to be hardened by curing light. One of the incident surface of the cover glass 65, and an incident surface and the outgoing surface of the centering glass 66 is provided with a mask part 67. An index of refraction N of the adhesive in curing light is equal to or more than an index of refraction N1 of the cover glass 65 in curing light or equal to or more than an index of refraction N2 of the centering glass 66 in curing light.

Description

  The present invention relates to an optical unit in which a first optical member having translucency and a second optical member having translucency are integrally fixed using an adhesive that is cured by curing light, and the optical unit is inserted into the optical unit. It relates to the endoscope mounted on.

  In an electronic endoscope in which an imaging device is built in the distal end of an elongated insertion portion, an optical image of an observation site (subject) captured in an observation field can be displayed on a monitor screen for inspection. In electronic endoscopes used in the medical field, the diameter of an insertion portion is required to be reduced in order to reduce pain given to a patient. For this reason, downsizing of the imaging device built in the tip portion is achieved, and the optical member and the imaging element constituting these imaging devices are also downsized.

  In an imaging apparatus, it is known that a light shielding mask that shields unnecessary ambient light incident from outside the observation visual field range is disposed in the vicinity of the imaging element. However, with the miniaturization of the image pickup apparatus, a high accuracy is required for position adjustment between the light shielding mask and the light receiving surface of the image pickup element, and there is a problem that it takes time to assemble.

  For the purpose of solving this problem, Patent Document 1 discloses an imaging apparatus that can prevent unnecessary ambient light from entering an image output area without using a light shielding mask. In this imaging apparatus, the refractive index of the optical member and the cover glass is set to 1.6 or less, the refractive index of the adhesive for joining the optical member and the cover glass is set to the same level, and the adhesive is made of ultraviolet light. It is shown to be a type that hardens. FIG. 6 of Patent Document 1 shows an optical unit in which a cover glass and an optical member are fixed with an adhesive that is cured by ultraviolet rays, and a light shielding mask is not required.

  Further, for the purpose of solving the above-described problems, a light-shielding mask that is a non-light-transmitting film on the exit surface in advance with respect to the cover glass 3 provided so as to cover the light-receiving surface 2a of the image sensor 2 as shown in FIG. The imaging unit 1 configured to prevent unnecessary ambient light from entering the light receiving surface can be realized by positioning and fixing the optical member 5 (a centering lens described later in the present invention) 5 provided with 4.

JP 2000-299806 A

  However, in the imaging unit 1 shown in FIG. 1, curing light is incident from the front surface of the optical member 5 in order to bond and fix the optical member 5 provided with the light-shielding mask 4 and the cover glass 3 with the photo-curing adhesive 6. Doing so causes the following problems. When the curing light is directed to the light shielding mask 4 as indicated by an arrow Y1a, the light shielding mask 4 blocks the incidence of the curing light on the adhesive 6. As a result, there is a possibility that the bonding strength may be reduced due to uneven curing where the portion indicated by the broken line, which is the back side portion of the light-shielding mask 4, is not sufficiently cured. On the other hand, when it goes to the light receiving surface 2a of the image pickup device 2 as indicated by the arrow Y1b, the adhesive 6 is cured by the curing light, but thereafter the curing light may enter the light receiving surface 2a and damage the image pickup device 2. There is.

  The present invention has been made in view of the above circumstances, and is an optical device in which an optical member provided with a light-shielding mask and an optical member that is integrally fixed to the optical member are securely fixed integrally with a photocurable adhesive. An object is to provide a unit and an endoscope including the optical unit.

  An optical unit according to one embodiment of the present invention includes a first optical member having a light-transmitting property and a second optical member having a light-transmitting property, and receives incident light from a subject as the second optical member. The first optical member is transmitted and guided in order, and the incident light exit surface of the second optical member and the incident light entrance surface of the first optical member are cured by light. An optical unit that is integrally fixed by a light-transmitting adhesive that cures, the incident surface of the first optical member, the incident surface of the incident light of the second optical member, or the second optical member In the configuration in which the mask portion is provided on any one of the emission surfaces, the refractive index of the adhesive in the curing light is equal to or higher than the refractive index of the first optical member in the curing light, or the first in the curing light. It is more than the refractive index of 2 optical members.

  According to the present invention, an optical unit in which an optical member provided with a light-shielding mask and an optical member that is integrally fixed to the optical member are securely fixed integrally with a photocurable adhesive, and an optical unit that includes the optical unit are provided. A scope can be realized.

The figure explaining the malfunction at the time of hardening an adhesive agent with hardening light and fixing integrally with the cover glass and optical member which comprise an imaging unit. 2 to 9 relate to an embodiment of the present invention, and FIG. 2 is a diagram illustrating an example of the configuration of an endoscope. The figure explaining the example of 1 structure of an observation optical system FIG. 4 is a diagram of an imaging unit that is one of the optical units constituting the observation optical system as seen from the Y4 direction in FIG. 3, and is a front view of the imaging unit. FIG. 4 is a diagram of the imaging unit viewed from the Y5 direction in FIG. 3, and a top view of the imaging unit The figure explaining the penetration | invasion route to the adhesive agent of hardening light (A) is a figure explaining the malfunction when the side surface of a cover glass is a surface with a rough surface roughness, (B) is a figure explaining the effect | action of the anti-reflective film provided in the rough surface of the side surface of a cover glass. The figure explaining the lens unit which is one of the optical units which comprise an observation optical system. The figure explaining the structural example which fixes an imaging frame and an imaging unit integrally. The figure explaining the structure of the imaging unit which provided the mask part in the entrance plane of the centering lens The figure explaining the structure of the imaging unit which the incident surface of the centering lens is a convex curved surface, and provided the mask part in the incident surface of the cover lens Side view of an imaging unit in which the cover lens of the imaging unit is configured with a prism 12 is a top view of the imaging unit in FIG. The figure explaining the imaging unit of the structure which set the mask part outer peripheral surface smaller than the outer peripheral surface of a centering lens The figure explaining the chamfered part provided in the edge shape part near the mask opening of a mask part The figure explaining the other structural example which fixes an imaging frame and an imaging unit integrally. The figure explaining another structural example which fixes an imaging frame and an imaging unit integrally. The figure explaining the other structural example which fixes an imaging frame and an imaging unit integrally. The figure explaining another structural example which fixes an imaging frame and an imaging unit integrally. The figure explaining another structural example which fixes a cover glass and centering glass integrally.

Embodiments of the present invention will be described below with reference to the drawings.
An embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 2, the endoscope 10 includes an insertion unit 11, an operation unit 12, and a universal cable 13.
In the optical member shown below, the incident surface is incident light from the subject and indicates the surface on which the optical image of the observation site is incident, and the exit surface is from the subject incident on the optical member through the incident surface. A surface from which an optical image, which is incident light, is emitted is shown, and a side surface is a surface located around the optical axis of incident light from a subject.

The insertion portion 11 is an elongated and long member that is inserted into the site to be observed. The insertion portion 11 is configured by connecting a distal end portion 14, a bending portion 15, and a flexible tube portion 16 in order from the distal end side. The distal end portion 14 incorporates, for example, an illumination optical system including a light guide (not shown), an observation optical system including an image sensor described later, and the like. The bending portion 15 is configured to be freely bent in, for example, four directions, up, down, left, and right. The flexible tube portion 16 is a long and flexible tubular member.
In the present embodiment, the insertion portion 11 is a so-called flexible endoscope having a distal end portion 14, a bending portion 15, and a flexible tube portion 16. However, the endoscope is not limited to this, and the distal end portion and the bending portion are curved. An endoscope having a rigid tube portion made of a rigid tubular member instead of a flexible tube portion, or a so-called rigid inner portion having a rigid tube portion made of a rigid tubular member without a curved portion. It may be an endoscope.

The operation unit 12 is provided with a bending operation unit 17, various switches 18, an air / water supply button 19, a suction button 20, and the like. The various switches 18 are, for example, a release switch, a freeze switch, and an observation mode switching switch for switching between normal observation and fluorescence observation. Reference numeral 21 denotes a treatment instrument insertion port.
The universal cable 13 extends from the side of the operation unit 12. An endoscope connector (not shown) is provided at the end of the universal cable 13.

As shown in FIG. 3, the observation optical system 30 includes an objective lens unit 40 and an imaging device 60.
The objective lens unit 40 includes a lens frame 41, an observation window 42, a first aperture member 43, a lens unit 44, and a spacer block 45. In the present embodiment, the observation window 42 and the first diaphragm member 43 are fixed in the distal end side recess 41 a of the lens frame 41. On the other hand, the spacer block 45 and the lens unit 44 are fixedly installed in an axial through hole 41b that communicates the tip side concave portion of the lens frame 41 with the outside.

  The lens unit 44 is one of optical units, and includes a proximal lens 47 that is a first optical member and a distal lens 46 that is a second optical member. A mask portion 48 is provided integrally. The exit surface of the distal lens 46 and the incident surface of the proximal lens 47 are integrally fixed by a translucent adhesive that constitutes a predetermined light transmissive adhesive portion 49. The lens unit 44 includes incident light from a subject (hereinafter simply referred to as “incident light”) of a distal end side lens 46, an adhesive 49, and a first optical member proximal end lens 47, which are second optical members. The light is sequentially transmitted and guided to the imaging device 60.

The spacer block 45 is an annular member, and defines the distance between the observation window 42 and the front end side lens 46 of the lens unit 44 in a predetermined positional relationship.
Note that the observation window 42 is also an optical member. For example, the entrance surface and the exit surface are flat, and a spherical recess is provided at the center of the exit surface.

On the other hand, the imaging device 60 includes an imaging frame 61, an imaging unit 62, and an imaging unit exterior frame 63.
The imaging unit 62 is one of optical units, and includes an imaging element 64, a cover glass 65 that is a first optical member, and a centering glass 66 that is a second optical member. A mask portion 67 is integrally provided on the emission surface. The centering glass 66 and the cover glass 65 are integrally fixed by a light-transmitting adhesive that constitutes a predetermined light-transmitting adhesive portion 68.
The exit surface of the cover glass 65 is fixed in advance to the image sensor 64 so as to cover the light receiving surface 64p of the image sensor 64.

  Reference numeral 69 denotes a unit bonding portion, which is configured by curing a unit fixing adhesive that integrally fixes the imaging unit 62 to the imaging frame 61. Reference numeral 70 denotes a sealing resin. In the present embodiment, a circuit board (not shown) on which electronic components (not shown) are mounted is connected to the image sensor 64, and a plurality of signal cables (not shown) are connected to the board. The sealing resin 70 is filled in the imaging unit exterior frame 63 and seals and fixes a circuit board, a signal cable, and the like disposed in the exterior frame 63.

Here, the lens unit 44 and the imaging unit 62 which are optical units will be described.
First, the imaging unit 62 will be described with reference to FIGS.
As shown in FIGS. 4 and 5, in this embodiment, the outer diameter of the cover glass 65 is larger than the outer diameter of the centering glass 66 by a predetermined dimension.
In the present embodiment, as shown in FIG. 4, the centering glass 66 and the cover glass 65 are cylindrical, but the present invention is not limited to this, and the centering glass and / or the cover glass is, for example, a square note or an octagon. It may be a prismatic shape as shown in the note.
The centering glass 66 is positioned and fixed to the image sensor 64 by adhesion. Specifically, the positional relationship between the mask opening 67m of the mask portion 67 provided on the exit surface of the centering glass 66 and the light receiving surface 64p of the image sensor 64 is adjusted and fixed in a predetermined state.

  The mask portion 67 is a non-light-transmitting film provided by vapor deposition on the exit surface of the centering glass 66 or a thin plate member that is bonded and fixed to the exit surface. The mask portion 67 is provided with a mask opening 67m.

  The adhesive that adheres and fixes the cover glass 65 and the centering glass 66 is a photo-curing transparent adhesive, for example, a UV adhesive that is cured by irradiating ultraviolet rays that are curing light. The refractive index of the adhesive in the curing light is N.

On the other hand, the cover glass 65 has a flat entrance surface and an exit surface, and the refractive index in the curing light is N1. On the other hand, the centering glass 66 has a flat entrance surface and an exit surface, and the refractive index in the curing light is N2.
In the present embodiment, a relationship of N ≧ N1 is set between the refractive index N and the refractive index N1. That is, the refractive index N of the adhesive is a cover glass that is an optical member that is not provided with the mask portion 67 out of the cover glass 65 that is the first optical member and the centering glass 66 that is the second optical member. A refractive index N1 of 65 or higher.

When the above-described centering glass 66 having a refractive index N2 and the cover glass 65 having a refractive index N1 are integrally fixed with an adhesive having a refractive index N, ultraviolet rays are incident on the optical axis La of incident light as indicated by arrows in FIG. Then, the light is incident from the side surface of the cover glass 65 toward the adhesive with a predetermined inclination θ. In other words, ultraviolet rays are irradiated obliquely from the base end side of the image sensor 64 to the side surface of the cover glass 65. That is, the ultraviolet light that is the curing light has an inclination with respect to the incident surface of the cover glass 65 that is the first optical member, and is irradiated toward the adhesive from the side surface excluding the incident surface and the output surface of the cover glass 65. Is done.
At this time, when the refractive index N of the adhesive and the refractive index N1 of the cover glass 65 are in a relationship of N <N1, ultraviolet rays are present at the boundary between the cover glass 65 and the adhesive as indicated by the broken arrow in FIG. UV rays do not reach the adhesive between the mask portion 67 and the cover glass 65, in particular, the adhesive provided on the incident surface near the outer periphery of the cover glass 65. The adhesive may not be cured. On the other hand, when the refractive index N of the adhesive and the refractive index N1 of the cover glass 65 described in the present embodiment have a relationship of N ≧ N1, ultraviolet rays are covered as indicated by the solid line arrows in FIG. Without being reflected at the boundary surface between the glass 65 and the adhesive or being refracted out of a desired direction, the adhesive is efficiently incident on the adhesive between the mask portion 67 and the cover glass 65 to cure the adhesive, and the adhesive portion 68. Configure.

  If the difference between the refractive index N and the refractive index N1 can be set larger, when the side surface of the cover glass 65 is irradiated at an inclination θ1 as shown by the solid line arrow in FIG. Is refracted at an angle β1 smaller than the angle α1 and enters the adhesive. In addition, when the side surface of the cover glass 65 is irradiated at an inclination θ2 as indicated by the broken arrow, the ultraviolet rays reach the boundary surface at an angle α2, refracted at an angle β2 smaller than the angle α2, and enter the adhesive. To do. That is, by taking a large difference between the refractive index N and the refractive index N1, the range of Δα can be expanded and the inclination θ of the curing light can be easily set to a desired angle.

  In this way, the refractive index of the cover glass 65 and the refractive index of the adhesive are set to a predetermined relationship. In addition, in order to bond and fix the cover glass 65 and the centering glass 66 while preventing damage to the light receiving surface of the image sensor due to the curing light, the imaging unit 62 that is the back side of the light receiving surface 64p of the image sensor 64 is used. From the base end side toward the side surface of the cover glass 65, irradiation is performed obliquely with respect to the optical axis La of incident light. As a result, it is eliminated that the curing light incident on the cover glass 65 is reflected at the boundary surface between the cover glass 65 and the adhesive or lost from a desired direction, and the curing light is effectively incident on the entire adhesive. Can be made. Therefore, the photo-curing type transparent adhesive is changed to the completely cured adhesive portion 68, and the cover glass 65 and the centering glass 66 can be bonded and fixed with a predetermined fixing strength. Further, when the cover glass 65 and the centering glass 66 are bonded and fixed, the light receiving surface 64p of the image sensor 64 can be prevented from being damaged by the curing light.

In addition, as shown to (A) of FIG. 7, the side surface of the cover glass 65 is a surface with a rough surface roughness compared with the incident surface and the output surface. For this reason, a part of the curing light irradiated obliquely with respect to the optical axis La of the incident light may be reflected as shown in the figure. Therefore, an antireflection film 71 is provided as an antireflection member on the side surface of the cover glass 65 as shown in FIG. As a result, the curing light can be efficiently incident on the cover glass 65.
The antireflection member is not limited to the antireflection film 71, and may be a transparent adhesive, a transparent tape, or the like. Also, a detachable transparent tape is used as the antireflection film, and the transparent tape is applied to the side surface of the cover glass 65 only when the adhesive constituting the adhesive portion 68 is cured by curing light, and in other cases, the transparent tape is peeled off. Also good.

Next, the lens unit 44 will be described with reference to FIG.
As shown in FIG. 8, the distal end side lens 46 and the proximal end side lens 47 are integrally fixed by an adhesive portion 49. The mask portion 48 provided on the exit surface of the front end side lens 46 is a thin plate member having a non-translucent film deposited on the exit surface of the front end side lens 46 or a mask opening 48m bonded and fixed to the exit surface.

  An adhesive portion 49 for adhering and fixing the distal end side lens 46 and the proximal end side lens 47 is a photocurable transparent adhesive similar to the adhesive constituting the adhesive portion 68 described above, and irradiates ultraviolet rays that are curing light. It is a UV adhesive that cures by. The refractive index of the adhesive is N.

The proximal lens 47 is an optical lens having a convex curved surface at least on its exit surface, such as a meniscus lens, a single convex lens, or a biconvex lens, and has a refractive index of N1. On the other hand, the front end side lens 46 is an optical lens having a curved surface, such as a meniscus lens, a biconvex lens, a single convex single plane lens, and a double concave single plane concave lens, and has a refractive index of N2.
Also in the present embodiment, a relationship of N ≧ N1 is set between the refractive index N and the refractive index N1. In other words, the refractive index N of the adhesive is an optical member that is not provided with the mask portion 48 out of the base end side lens 47 that is the first optical member and the front end side lens 46 that is the second optical member. The refractive index N1 or more of the proximal lens 47 is higher.

  When the above-described distal end lens 46 having a refractive index N2 and the proximal end lens 47 having a refractive index N1 are integrally fixed with an adhesive having a refractive index N, ultraviolet rays are incident on the optical axis of the incident light as indicated by solid line arrows in FIG. The light is incident on a so-called edge surface, which is a side surface of the proximal lens 47, with a predetermined inclination with respect to La, and is predetermined with respect to the optical axis La of incident light as indicated by a broken line arrow in the figure. The light is incident from the exit surface of the proximal lens 47 with an inclination. In other words, the ultraviolet light as the curing light is irradiated toward the adhesive from the emission surface and the side surface of the proximal lens 47 with an inclination with respect to the incident surface of the proximal lens 47 as the first optical member. Is done. Then, the curing light incident on the base end side lens 47 is efficiently incident on the adhesive without being reflected or refracted from a desired direction without being reflected at the boundary surface between the base end side lens 47 and the adhesive. The adhesive agent 49 is configured by curing the agent.

  Thus, the refractive index of the base end side lens having the convex curved surface portion and the refractive index of the adhesive are set in a predetermined relationship. In addition, in order to bond and fix the distal lens and the proximal lens, the curing light is irradiated obliquely with respect to the optical axis of the incident light from the rear surface to the side surface of the proximal lens from the exit surface of the proximal lens. To do. Accordingly, the curing light enters the lens from the edge surface and the exit surface of the proximal lens. The curing light that has entered the proximal lens is not concentrated at the central portion by the convex curved surface portion, and is reflected at the boundary surface between the proximal lens and the adhesive or deviates from a desired direction. It is effectively incident on the entire adhesive without being refracted and lost. As a result, the photo-curing type transparent adhesive is changed to the completely cured adhesive portion 49, and the distal end side lens 46 and the proximal end side lens 47 can be bonded and fixed with a predetermined fixing strength.

  As described above, the assembling workability can be improved by forming the lens unit by integrating the mask portion and the plurality of optical members.

  In addition, as an adhesive agent which comprises the adhesion parts 49 and 68 mentioned above, what the refractive index before hardening and the refractive index after hardening does not change is suitable. And when the refractive index before hardening and the refractive index after hardening change, what changes in the direction where the refractive index after hardening rises from the refractive index before hardening is preferable.

  In the imaging unit 62 described above, a centering glass 66 is disposed in the axial through hole 61a of the imaging frame 61 as shown in FIG. Then, a unit bonding portion 69 is provided at a contact portion between the front end surface (the end surface of the incident surface) of the cover glass 65 of the imaging unit 62 and the base end surface of the imaging frame 61, and the imaging unit 62 is integrally fixed to the imaging frame 61. .

  In this configuration, the outer diameter of the centering glass 66 and the axial through hole 61a are set to a predetermined fit. In other words, the centering glass 66 is in a state of being engaged and disposed in the axial through hole 61a, and the unit is fixed between the outer peripheral surface of the centering glass 66 and the inner peripheral surface of the axial through hole 61a. This is a configuration in which no adhesive is present.

  As described above, after the centering glass 66 is engaged and arranged in the axial through hole 61a with a predetermined fit, the image pickup unit 62 and the image pickup frame 61 are integrally fixed by providing the unit bonding portion 69. The unit fixing adhesive is not present in the gap between the centering glass 66 and the axial through hole 61a. As a result, the unit bonded portion provided in the gap between the centering glass 66 and the axial through hole 61a and the bonded portion due to the stress generated conventionally when the imaging frame 61 repeatedly expands or contracts is applied to the bonded portion 68. 68 can be reliably prevented from being destroyed.

  Therefore, the occurrence of a crack due to the destruction of the bonding portion 68 is solved, and the problem that the generated crack or the like is reflected in the endoscope image is solved.

  In the imaging unit 62 described above, the incident surface of the centering glass 66 is a flat surface. However, the imaging unit 62 may be configured by making the incident surface of the centering glass 66 a curved surface.

  In the imaging unit 62 described above, the mask portion 67 is provided on the exit surface of the centering glass 66. However, as shown in the imaging unit 62 </ b> A of FIG. 10, the mask portion 67 may be provided on the incident surface of the centering glass 66. In this configuration, the refractive index N1 of the cover glass 65 that is the first optical member and the refractive index N of the adhesive are set to the above-described relationship.

  According to this configuration, the curing light is irradiated obliquely with respect to the optical axis La of the incident light from the back side of the light receiving surface 64p of the image pickup device 64 to the side surface of the cover glass 65, and the optical axis La of the incident light as necessary. Irradiate at a right angle to. As a result, the curing light irradiated obliquely is eliminated from being reflected by the boundary surface between the cover glass and the adhesive or being refracted and refracted from a desired direction, and is incident on the adhesive. Further, the curing light irradiated at a right angle to the optical axis La of the incident light is directly incident on the adhesive. As a result, the same operation and effect as the above-described embodiment can be obtained.

In addition, as shown in FIG. 11, the incident surface of the centering glass 66 may be a convex curved surface, and the mask portion 67 may be provided on the incident surface of the cover glass 65. In the imaging unit 62B of the present embodiment, the relationship between the refractive index N2 of the centering glass 66 and the refractive index N of the adhesive is set to a relationship of N ≧ N2.
That is, the refractive index N of the adhesive is the centering that is an optical member that is not provided with the mask portion 67 out of the cover glass 65 that is the first optical member and the centering glass 66 that is the second optical member. The refractive index of the glass 66 is not less than N2.

  When the above-described centering glass 66 having a refractive index N2 and the cover glass 65 having a refractive index N1 are integrally fixed with an adhesive having a refractive index N, ultraviolet light, which is curing light, is incident on the incident light as indicated by a solid line arrow in FIG. The light is incident from the side surface of the centering glass 66 with a predetermined inclination with respect to the optical axis La. That is, the ultraviolet light that is the curing light is irradiated toward the adhesive from the incident surface and the side surface of the centering glass 66 with an inclination with respect to the exit surface of the centering glass 66 that is the second optical member. . Then, the curing light incident on the centering glass 66 is efficiently incident on the adhesive without being reflected at the interface between the centering glass 66 and the adhesive or being refracted out of a desired direction. The adhesive portion 68 is configured by curing.

  In addition, the ultraviolet light incident from the incident surface of the centering glass 66 with a predetermined inclination with respect to the optical axis La of the incident light is incident on the centering glass 66 as indicated by a broken line arrow in the figure. After that, without being reflected at the boundary surface between the centering glass 66 and the adhesive or being refracted out of a desired direction, it is efficiently incident on the adhesive and the adhesive is cured to form the adhesive portion 68. . Thereafter, the ultraviolet rays are refracted when passing through the adhesive and entering the cover glass 65. As a result, ultraviolet rays are prevented from entering the light receiving surface 64p.

  Thus, in the configuration in which the centering glass has a convex curved surface on the incident surface, the refractive index of the centering glass and the refractive index of the adhesive are set to a predetermined relationship and the incident light is cured with respect to the optical axis La. By setting the inclination of the light irradiation angle to a predetermined value, the imaging unit 62B having the mask portion 67 on the incident surface of the cover glass 65 can be configured. Other operations and effects are the same as those of the above-described embodiment.

Moreover, in the imaging units 62, 62A, and 62B described above, the incident surface and the exit surface of the cover glass 65 are in a positional relationship. That is, the optical image incident on the cover glass 65 is linearly formed on the light receiving surface 64p of the image sensor 64.
However, as shown in FIGS. 12 and 13, the cover glass 65C of the imaging unit 62C may be a so-called prism that bends the optical axis of the incident light to a desired angle by the reflecting surface 65r. The optical image incident on the cover glass 65C is bent by the reflecting surface 65r and formed on the light receiving surface 64p of the image sensor 64. In this configuration, the refractive index N1 of the cover glass 65C and the refractive index N of the adhesive are set to the above-described relationship.

  According to this configuration, as shown in FIG. 13, ultraviolet rays for curing the adhesive are irradiated obliquely with respect to the optical axis La of incident light from the rear side of the reflection surface 65r of the cover glass 65C to the side surface of the cover glass 65C. That is, the ultraviolet light that is the curing light is irradiated toward the adhesive from the side surface of the cover glass 65C with an inclination with respect to the incident surface of the cover glass 65C that is the first optical member.

  As a result, the curing light irradiated obliquely enters the adhesive without being reflected by the boundary surface between the cover glass 65C and the adhesive or being refracted and refracted from a desired direction. As a result, the same operation and effect as the above-described embodiment can be obtained.

  Further, the imaging units 62, 62A, 62B, and 62C described above have a configuration in which the outer surface of the mask portion 67 and the outer surface of the centering glass 66 coincide with each other. However, as shown in FIGS. 14A and 14B, the outer peripheral surface of the mask portion 67D is set to be uniformly smaller than the outer peripheral surface of the centering glass 66, and the adhesive portion 68 is provided on the outer surface side of the mask portion 67D. It may be configured.

  According to this configuration, the centering glass 66 and the cover glass 65 can be more firmly bonded and fixed as the bonding portion 68 increases. Moreover, the ultraviolet rays irradiated obliquely on the adhesive provided on the outer surface side of the mask portion 67D can be directly incident and cured quickly.

  Here, the shape of the mask portion is not limited to the mask portion 67D configured by setting the outer peripheral surface to be uniformly smaller than the outer surface of the centering glass 66. For example, as shown in FIG. 14C, a plurality of (four) cutout portions 67c may be provided to form the mask portion 67D1. The number of the notches 67c is not limited to four, and may be more or less.

  Further, as shown in FIG. 14D, the centering glass 66S and the cover glass 65S are formed in a quadrangular shape, and the mask portion in which the exit surface of the centering glass 66S is set to be uniformly smaller than the outer surface of the centering glass 66S. 67DS may be provided.

  Further, if the vicinity of the mask opening 67m of the mask portion 67 indicated by the arrow Y15BC in FIG. 15A is an edge shape (pointed shape), the bonding portion 68 may be destroyed due to stress concentration. For this reason, as shown in FIG. 15B, a chamfered portion 67c having a so-called C surface formed by a side in an edge shape portion 67e indicated by a broken line of the mask opening 67m, or an edge shape as shown in FIG. A chamfered portion 67r with a so-called R surface formed by a curved surface is provided in the portion 67e.

  As a result, it is possible to eliminate the edge shape portion from the mask opening 67m, and to solve the problem that the adhesive portion 68 is broken due to the stress concentration and a crack or the like occurs.

  In FIG. 9 described above, the unit bonding portion 69 is provided at a predetermined position in a state where the centering glass 66 is engaged and arranged in the axial through hole 61a, and the imaging unit 62 and the imaging frame 61 are connected. The unit fixing adhesive is not provided between the outer peripheral surface of the centering glass 66 and the inner peripheral surface of the axial through hole 61a.

However, the imaging unit 62 and the imaging frame 61 may be integrally fixed as shown in FIGS.
In FIG. 16, the imaging frame 61 has a large diameter portion 61b or a tapered surface 61c on the inner peripheral surface. The large diameter portion 61b and the tapered surface 61c are set to a predetermined length dimension in the axial direction from the base end surface of the imaging frame 61. As a result, the large diameter portion 61b and the tapered surface 61c are provided with a part on the emission surface side of the bonding portion 68 and the centering glass 66.
The other configuration is the same as the configuration shown in FIG. 9, and the same members are denoted by the same reference numerals and the description thereof is omitted.

  As described above, according to the configuration in which the large-diameter portion 61b is formed on the inner peripheral surface of the imaging frame 61, the centering glass 66 is positioned in the large-diameter portion 61b during the assembly work for assembling the imaging unit 62 to the imaging frame 61. While the cover glass 65 is tilted, the adhesive portion 68 can be prevented from being broken due to a load applied even when the cover glass 65 is tilted. As a result, the assemblability can be improved.

  On the other hand, according to the configuration in which the tapered surface 61c is formed on the inner peripheral surface of the imaging frame 61, during the assembling work for assembling the imaging unit 62 to the imaging frame 61, the centering glass 66 is positioned in the tapered surface 61c as described above. In the meantime, the adhesive portion 68 can be prevented from being broken due to a load, and the centering glass 66 can be smoothly guided into the axial through hole 61a by using the tapered surface 61c as a guide. As a result, the assembly can be further improved.

  In addition, in the structure which provides the large diameter part 61b in the inner peripheral surface of the imaging frame 61, the level | step difference 61d comprised by the large diameter part 61b and the axial direction through-hole 61a is made into a C surface or a taper surface, and it is centering glass. 66 can be introduced more smoothly into the axial through hole 61a.

In FIG. 17, an adhesive inflow prevention member 72 is provided to prevent the unit fixing adhesive that integrally fixes the imaging unit 62 and the imaging frame 61 from flowing into the axial through hole 61a. The adhesive inflow prevention member 72 is a polyimide tape or a sponge, and is disposed between the base end surface of the imaging frame 61 and the incident surface of the cover glass 65. The unit fixing adhesive is applied between the base end surface of the imaging frame 61 on the outer peripheral surface side of the adhesive inflow prevention member 72 and the incident surface of the cover glass 65.
The other configuration is the same as the configuration shown in FIG. 9, and the same members are denoted by the same reference numerals and the description thereof is omitted.

  In this way, a polyimide tape or a sponge is disposed between the base end surface of the imaging frame 61 and the incident surface of the cover glass 65, and then the unit fixing adhesive is placed on the outer peripheral surface side of the adhesive inflow prevention member 72. By applying to the surface, when the imaging unit 62 and the imaging frame 61 are fixed with the unit fixing adhesive, it is possible to reliably prevent the adhesive from flowing into the axial through hole 61a.

In FIG. 18, an adhesive reservoir 61 e that prevents the unit fixing adhesive that integrally fixes the imaging unit 62 and the imaging frame 61 from flowing into the axial through hole 61 a is provided on the base end surface of the imaging frame 61. ing. The adhesive reservoir 61e is a circular groove in which the width dimension and the depth dimension formed on the base end face of the imaging frame 61 are set to predetermined dimensions, and the incident end of the cover glass 65 is disposed within the groove width.
The other configuration is the same as the configuration shown in FIG. 9, and the same members are denoted by the same reference numerals and the description thereof is omitted.

  Thus, a circular groove is formed as an adhesive reservoir 61e on the base end surface of the imaging frame 61. As a result, when the imaging frame 61 and the imaging unit 62 are fixed with the unit fixing adhesive, it is possible to reliably prevent excess adhesive from accumulating in the circular groove and flowing into the axial through hole 61a. can do.

  In FIG. 19, a C surface 66c is provided at the end of the exit surface of the centering glass 66, and between the inner peripheral surface of the axial through hole 61a and the outer peripheral surface of the mask portion 67, and within the axial through hole 61a. A gap 61 f having a size corresponding to the cut height of the C surface 66 c is provided between the peripheral surface and the outer peripheral surface of the bonding portion 68. The gap 61f is an adhesive reservoir and prevents the unit fixing adhesive from flowing into the gap between the inner peripheral surface of the axial through hole 61a and the outer peripheral surface of the centering glass 66.

  The other configuration is the same as the configuration shown in FIG. 9, and the same members are denoted by the same reference numerals and the description thereof is omitted.

 As described above, the C surface 66c is provided at the peripheral end portion of the centering glass 66, while the inner periphery of the axial through hole 61a and the outer peripheral surface of the mask portion 67 and the inner periphery of the axial through hole 61a. A gap 61 f is provided between the surface and the outer peripheral surface of the bonding portion 68. As a result, when the imaging frame 61 and the imaging unit 62 are fixed with the unit fixing adhesive, if the excess adhesive flows into the axial through hole 61a, the unit fixing adhesive is accumulated in the gap 61f. The adhesive can be reliably prevented from flowing into the gap between the inner peripheral surface of the axial through hole 61a and the outer peripheral surface of the centering glass 66.

In FIG. 20, the mask portion 67 is fixed to the exit surface of the centering glass 66, and the mask portion 67 is fixed to the entrance surface of the cover glass 65, so that the mask opening 67 m of the mask portion 67 is sealed in the sealed space 73. It is said. The mask portion 67 is integrally fixed by providing a mask portion fixing adhesive portion 74 in the axial direction through hole 61 a of the imaging frame 61.
The other configuration is the same as the configuration shown in FIG. 19, and the same members are denoted by the same reference numerals and description thereof is omitted.

  Thus, the centering glass 66 and the cover glass 65 are integrally fixed via the mask portion 67 having the mask opening 67m for constituting the sealed space 73. As a result, the adhesive is not interposed between the centering glass 66 and the cover glass 65, and the occurrence of a problem due to the adhesive can be eliminated.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Imaging unit 2 ... Image sensor 2a ... Light-receiving surface 3 ... Cover glass 4 ... Light shielding mask 5 ... Optical member 6 ... Photocurable adhesive 10 ... Endoscope 11 ... Insertion part 12 ... Operation part 13 ... Universal cable 14 ... Tip portion 15 ... Bending portion 16 ... Flexible tube portion 17 ... Bending operation portion 18 ... Various switches 19 ... Air / water feeding button 20 ... Suction button 21 ... Treatment instrument insertion port 30 ... Observation optical system 40 ... Objective lens unit 41 ... Lens Frame 41a ... distal end side recess 41b ... axial through hole 42 ... observation window 43 ... first aperture member 44 ... lens unit 45 ... spacer block 46 ... distal end side lens 47 ... proximal end side lens 48 ... mask part 48m ... mask opening 49 ... Adhesion part 60 ... Imaging device 61 ... Imaging frame 61a ... Axial through-hole 61b ... Large diameter part
61c ... Tapered surface 61d ... Step 61e ... Adhesive reservoir 61f ... Gap
62, 62A, 62B, 62C ... Imaging unit 63 ... Imaging unit exterior frame
64 ... Image sensor 64p ... Light receiving surface 65, 65C, 65S ... Cover glass
65r ... reflective surface 66, 66S ... centering glass 66c ... C surface
67, 67D, 67D1, 67DS ... Mask portion 67c ... Chamfered portion 67e ... Edge-shaped portion 67m ... Mask opening 67r ... Chamfered portion 68 ... Adhesive portion 69 ... Unit adhesive portion 70 ... Sealing resin 71 ... Antireflection film 72 ... Adhesive Inflow prevention member 73 ... Sealed space 74 ... Mask portion fixing adhesive portion

Claims (11)

A first optical member having translucency, and a second optical member having translucency, and transmitting incident light from a subject in the order of the second optical member and the first optical member. And a light-transmitting adhesive that hardens the incident light exit surface of the second optical member and the incident light incident surface of the first optical member with curing light. An optical unit that is integrally fixed,
In a configuration in which a mask portion is provided on any one of the incident surface of the first optical member, the incident light incident surface of the second optical member, or the exit surface of the second optical member,
An optical system characterized in that a refractive index of the adhesive in the curing light is equal to or higher than a refractive index of the first optical member in the curing light or a refractive index of the second optical member in the curing light. unit.   The refractive index of the adhesive is greater than or equal to the refractive index of any one of the optical members not provided with the mask portion of the first optical member and the second optical member. Item 2. The optical unit according to Item 1. The mask portion is provided on the incident surface or the exit surface of the second optical member, and the incident light exit surface of the first optical member is used to guide the incident light to the light receiving surface of the image sensor. In the optical unit in which the light receiving surface of the imaging element is disposed,
The refractive index of the adhesive is not less than the refractive index of the first optical member,
The curing light is irradiated toward the adhesive from a side surface of the first optical member excluding the entrance surface and the exit surface with an inclination with respect to the entrance surface of the first optical member. The optical unit according to claim 2. The incident surface of the second optical member is a convex curved surface, and a light receiving surface of an imaging element is disposed on the incident light exit surface of the first optical member, and the incident of the first optical member In the optical unit having a mask portion disposed on the surface,
The refractive index of the adhesive is not less than the refractive index of the second optical member,
The curing light is irradiated toward the adhesive from the side surface of the second optical member except the exit surface and the entrance surface with an inclination with respect to the exit surface of the second optical member. The optical unit according to claim 2. In the optical unit, the mask unit is provided on the incident surface or the exit surface of the second optical member, and the exit surface of the incident light of the first optical member is a convex curved surface.
The refractive index of the adhesive is not less than the refractive index of the first optical member,
The curing light is irradiated toward the adhesive from the side surface and the exit surface of the first optical member except the entrance surface, with an inclination with respect to the entrance surface of the first optical member. The optical unit according to claim 2.   The optical unit according to claim 1, wherein an outer shape of the surface on which the mask portion is provided and an outer shape of the mask portion are the same shape.   The optical unit according to claim 1, wherein an outer shape of the mask portion is set to be at least partly smaller than an outer shape of a surface on which the mask portion is provided.   The optical unit according to claim 3, wherein an antireflection film that prevents reflection of the curing light is provided on the side surface irradiated with the curing light.   6. The optical unit according to claim 1, wherein a chamfered portion is provided on a mask opening side of the mask portion to prevent destruction due to stress concentration of the adhesive cured by the curing light.   The optical unit according to claim 1, wherein the curing light is ultraviolet light, and the adhesive is a UV adhesive that is cured by the ultraviolet light.   An endoscope comprising the optical unit according to any one of claims 1 to 10 mounted on a distal end side of an insertion portion.

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