WO2017221458A1

WO2017221458A1 - Optical apparatus

Info

Publication number: WO2017221458A1
Application number: PCT/JP2017/006180
Authority: WO
Inventors: 山下　知暁
Original assignee: オリンパス株式会社
Priority date: 2016-06-23
Filing date: 2017-02-20
Publication date: 2017-12-28
Also published as: JPWO2017221458A1

Abstract

According to the present invention, a first lens 56a, an annular member 70, and a second lens 56b are sequentially arranged from an object side to an image surface side along an optical axis O, the first lens 56a is liquid-tightly fixed by an adhesive 75 disposed between a first hole 55a and the first lens 56a, and the second lens 56b is liquid-tightly fixed by an adhesive 76 disposed between a second hole 55b and the second lens 56b. A space S surrounded by the side surface of the annular member 70 on the second lens 56b side, the inner diameter surface of a third hole 55c, and the lens surface of the second lens 56b on an light incident side, is filled with an adhesive 77 to cause the adhesion layer of the adhesive 76 to be extended. As a result, the resistance with respect to passage of moisture into a space R between the first lens 56a and the second lens 56b is increased so as to prevent incursion of moisture therein.

Description

Optical device

The present invention relates to an optical device having a lens fixed to a lens frame with an adhesive.

The optical device is used in various observation devices such as an endoscope, and converts an optical image of a subject formed by a lens into an image signal using a solid-state imaging device such as a CCD or a CMOS and displays the image signal on a monitor. Various observations are possible. A lens used in such an optical device is generally fixed by being bonded to a frame body such as a lens tube with an adhesive as disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-258129. It is.

When the optical device is applied as an optical system at the tip of an endoscope, the endoscope is used in a harsh environment with high temperature and humidity, and is exposed to high-temperature steam during sterilization and cleaning. It is assumed that the optical system is also exposed to the same conditions due to the moisture that has passed through. For this reason, even after the endoscope is dried, moisture containing moisture remains in the interior, and when the endoscope is used, the moisture may condense on the lens surface of the optical system and cause cloudiness in the field of view. .

In particular, many objective optical systems at the distal end of an endoscope arrange a plurality of lenses in order from the object side to the image plane side and form an observation window by the lens at the distal end. When a plurality of lenses of the objective optical system are a first lens and a second lens in order from the front end side, the adhesion between the second lens and the lens frame is between the first lens and the second lens. There is a risk that moisture may penetrate and remain through the layers. For this reason, when a fluid such as water is sprayed to clean the outer surface of the first lens, which is an observation window, when the endoscope is used, a temperature difference occurs between the inside and outside of the first lens, and the inner surface side of the first lens. There is a risk of clouding in the field of view.

The present invention has been made in view of the above circumstances, and between the second lens and the lens frame to the space between the first lens and the second lens arranged in order from the object side to the image plane side. It is an object of the present invention to provide an optical device that can prevent moisture from entering through the adhesive layer and avoid the occurrence of fogging in the field of view.

An optical device according to an aspect of the present invention includes a first lens and a second lens in order from the object side to the image plane side, and the light incident surface of the first lens is exposed to the outside of the optical device. An optical member, an annular member having an aperture through which the light beam of the optical system passes, a first hole that holds the first lens along the optical axis of the optical system, and a first hole that holds the second lens A lens frame having at least two holes and a third hole for holding the annular member, wherein the first lens and the second lens are each fixed to the lens frame with an adhesive, and the annular When the member is disposed close to either the light incident side surface or the light emission side surface of the second lens, the annular member, the third hole, and the second lens are in a predetermined space. The predetermined space is filled with an adhesive.

The block diagram of an endoscope system concerning a 1st embodiment of the present invention. Same as above, longitudinal sectional view showing the configuration of the distal end portion of the endoscope Same as above, vertical section showing the configuration of the imaging unit Same as above, longitudinal sectional view showing the front lens group unit Same as above, longitudinal sectional view showing a modification of the annular member The longitudinal cross-sectional view around a front group lens concerning 2nd Embodiment of this invention Same as above, enlarged view showing an adhesive layer between the annular member and the second lens A longitudinal sectional view around the front lens group according to the third embodiment of the present invention Same as above, enlarged view showing a gap between the annular member and the second lens A longitudinal sectional view around the front lens group according to the fourth embodiment of the present invention

Embodiments of the present invention will be described below with reference to the drawings.
(First form)
FIG. 1 shows an endoscope system 1 configured around an endoscope 2 having the optical device of the present invention. In the present embodiment, an endoscope system 1 includes an endoscope 2 that acquires an optical image of a site to be observed in a subject, a light source device 3 that supplies illumination light to the endoscope 2, and an endoscope. The video processor 4 is a signal processing device that performs signal processing on the imaging unit mounted on the mirror 2, and a color monitor 5 is a display device that displays an endoscopic image.

The endoscope 2 includes an elongated insertion portion 6 to be inserted into a subject, an operation portion 7 provided at the base end of the insertion portion 6, a universal cord 8 extended from the operation portion 7, An endoscope connector 9 provided at an end of the universal cord 8. The endoscope connector 9 is detachably connected to the light source device 3 so that illumination light is supplied from the light source device 3 to a light guide (not shown) in the endoscope 2.

Further, one end of a connection cable 10 is connected to the endoscope connector 9, and an electrical connector 10 a provided at the other end of the connection cable 10 is detachably connected to the video processor 4. The video processor 4 is connected to the color monitor 5 via a video cable (not shown).

The insertion portion 6 includes a hard distal end portion 11 provided at the distal end, a bendable bending portion 12 provided at the rear end of the distal end portion 11, and extends from the rear end of the bending portion 12 to the front end of the operation portion 7. And a flexible tube portion 13 having flexibility.

On the distal end surface of the distal end portion 11, an observation window 15, a plurality of illumination windows 16 (only one is shown in FIG. 1), a distal end opening 17a of a treatment instrument channel 17 (see FIG. 2), and a cleaning nozzle (not shown) Is provided. As shown in FIG. 2, an imaging unit 30 provided in the distal end portion 11 is disposed inside the observation window 15 (on the back side).

In addition, an illumination lens is attached to the illumination window 16, and a light guide for transmitting illumination light from the light source device 3 is connected to the illumination lens (none of which is shown). The illumination light transmitted by the light guide is emitted to the front side of the distal end surface via the illumination lens, and thereby the observation target site in the subject that is the visual field range by the imaging unit 30 is illuminated.

The operation portion 7 includes a bend preventing portion 18a for a portion where the proximal end of the insertion portion 6 is extended, a treatment instrument insertion port 18b disposed on a lower side portion, and a grip portion provided in the middle portion. The operation unit body 18c to be configured, a bending operation unit 19 including two

bending operation knobs

19a and 19b provided on the upper side, an air / water supply control unit 21, a suction control unit 22, and a plurality of switches are included. In addition, a switch unit 23 that mainly operates an imaging function and an operation lever 24 for moving a moving lens 66 (see FIG. 3) provided in the imaging unit 30 forward and backward are provided.

In addition, the treatment instrument insertion port 18b of the operation unit 7 communicates with the treatment instrument channel 17 inserted into the insertion unit 6 therein, and opens at the distal end opening 17a of the distal end portion 11.

Next, the configuration of the distal end portion 11 of the endoscope 2 will be described with reference to FIG. As shown in FIG. 2, an imaging unit 30 is disposed inside the distal end portion 11. The imaging unit 30 is inserted and disposed in a hard tip rigid member 25 and is fixed to the tip rigid member 25 by a set screw 27 from the side surface direction.

Further, an O-ring 28 for ensuring liquid tightness with the distal end hard member 25 is disposed on the outer peripheral portion on the distal end side of the imaging unit 30. A distal end cover 25 a that constitutes the distal end surface of the distal end portion 11 is bonded and fixed to the distal end side of the distal end rigid member 25.

Note that the distal end opening 17a, which is a hole formed in the distal end cover 25a, constitutes the opening of the treatment instrument channel 17 in the distal end portion 11 as described above.

A plurality of bending pieces 26 constituting the bending portion 12 are connected to the proximal end side of the distal end rigid member 25, and the outer circumferences of the distal end rigid member 25 and the bending piece 26 are integrally formed by the distal end insertion portion rubber member 12a. Is covered. The distal end outer peripheral portion of the distal end insertion portion rubber member 12 a is fixed to the distal end rigid member 25 by a pincushion bonding portion 29.

In addition, about members, such as the washing tube arrange | positioned at the front-end | tip part 11, and the light guide bundle for illumination, since they are well-known structures conventionally, those description is abbreviate | omitted.

Next, the detailed configuration of the imaging unit 30 will be described with reference to FIG. The imaging unit 30 according to the present embodiment includes a solid-state imaging element unit 31 and an observation optical system unit 32 as an optical device connected to the front end side of the solid-state imaging element unit 31. .

The solid-state image pickup device unit 31 has a solid-state image pickup device holding frame 35. The solid-state image pickup device holding frame 35 includes a cover glass or the like on the image pickup surface side which is the front side of the solid-state image pickup device chip 37 made of CCD, CMOS or the like. It is held via the optical member 36. A laminated substrate 38 is electrically connected to the back side of the solid-state image sensor chip 37 via an FPC (not shown) or the like. Further, a plurality of communication lines branched from the cable 39 are connected to the laminated substrate 38. The cable 39 is inserted into the endoscope 2 and is electrically connected to the video processor via the electrical connector 10a.

Further, a reinforcing frame 40 is connected to the outer peripheral portion of the base end of the solid-state image sensor holding frame 35, and a heat shrinkable tube 41 that covers the distal end portion of the cable 39 is provided on the outer periphery of the reinforcing frame 40. In the space formed by the reinforcing frame 40 and the heat shrinkable tube 41 from the base end portion of the solid-state image sensor holding frame 35, an adhesive for holding and protecting the solid-state image sensor unit 31 in a liquid-tight manner. Or the like.

The observation optical system unit 32 according to the present embodiment includes a focus switching type observation optical system 33 that realizes a focusing function or a zooming function by changing an optical characteristic (focal length) by moving an internal lens forward and backward. Configured.

More specifically, the observation optical system unit 32 includes a front group lens unit 45 positioned on the distal end side, a rear group lens unit 46 connected to the proximal end side of the front group lens unit 45, and the front group lens unit 45. The movable lens unit 48 is configured to move between the lens unit 45 and the rear lens group unit 46 in the direction of the optical axis O of the optical system.

The front group lens unit 45 includes a front group lens frame 55 that forms a fixed lens frame, and a front group lens 56 that includes a plurality of fixed lenses held by the front group lens frame 55. . In the present embodiment, the front group lens 56 includes a first lens 56a and a second lens 56b arranged in order from the object side to the image plane side at the tip, as shown in FIG. 4 described later. An objective optical system is configured, and an observation window 15 at the distal end of the insertion portion 6 is formed by the first lens 56a. The first lens 56a and the second lens 56b are fixed in the front group lens frame 55 via an adhesive.

The rear group lens unit 46 includes a rear group lens frame 57 constituting a fixed lens frame, and a rear group lens 58 composed of a plurality of fixed lenses held by the rear group lens frame 57. . A solid-state image sensor holding frame 35 is fitted to the outer periphery on the base end side of the rear group lens frame 57, thereby connecting the solid-state image sensor unit 31 and the observation optical system unit 32.

A support rod 57a protruding in the outer diameter direction is provided in the middle of the rear lens group frame 57, and a guide tube 67 for supporting the drive rod 80 so as to be able to advance and retract in the optical axis O direction on the support rod 57a. Is fixed. The drive rod 80 moves the moving lens unit 48 forward and backward in the direction of the optical axis O, and is driven forward and backward by an actuator (not shown).

A rear stopper 68 is provided on the outer periphery of the guide tube 67 on the front end side in order to define the retreat side position of the moving lens unit 48. The rear stopper portion 68 of the present embodiment is configured by a ring-shaped member having an internal thread on the inner periphery. The rear stopper portion 68 is screwed with a male screw provided on the outer periphery on the tip side of the guide tube 67, and the position of the retracting side of the movable lens unit 48 can be finely adjusted according to the screwed state. It is possible.

The front end side of the rear group lens frame 57 is connected to the front group lens frame 55 via an intermediate frame 61 constituting a fixed lens frame. The intermediate frame 61 is provided with a slit 61 a penetrating the inner peripheral side and the outer peripheral side of the intermediate frame 61. The slit 61 a extends in the same direction as the optical axis O direction, and the base end side of the slit 61 a is open at the base end of the intermediate frame 61.

Here, the intermediate frame 61 is fitted with the rear lens group frame 57 in a state where the rotational position around the optical axis O is positioned so that the support rod 57a is positioned on the proximal end side of the slit 61a. Further, the open end portion on the proximal end side of the slit 61 a is closed by the joining of the rear group lens frame 57 and the intermediate frame 61. The intermediate frame 61 is provided with a front stopper portion 61b for defining the position of the moving lens unit 48 on the advancing side at a position facing the support rod 57a across the slit 61a.

The moving lens unit 48 includes a moving lens frame 65 and a moving lens 66 held by the moving lens frame 65. In the present embodiment, the moving lens frame 65 is disposed in the intermediate frame 61 that is a fixed lens frame, and can move forward and backward in the direction along the optical axis O.

Also, the moving lens frame 65 is provided with an operation rod 65a as a moving frame convex portion protruding in the outer peripheral direction. The operating rod 65a passes through the slit 61a of the intermediate frame 61 and protrudes to the outer peripheral side of the intermediate frame 61, and is opposed to the front stopper portion 61b and the support rod 57a (rear side stopper portion 68). A distal end portion of the driving rod 80 is fixed to the operation rod 65a.

In order to reduce sliding resistance of the moving lens frame 65 with respect to the intermediate frame 61, a predetermined clearance is provided between the inner peripheral surface of the intermediate frame 61 and the outer peripheral surface of the moving lens frame 65. A predetermined clearance is also provided between 61a and the operating rod 65a. Further, in order to liquid-tightly close the slit 61a, a region from the front stopper portion 61b to the support rod 57a is sealed with a cover 69.

The adjustment (focus adjustment) of the relative position of the front group lens unit 45 and the rear group lens unit 46 at the advanced position of the moving lens unit 48 as described above presses the operation rod 65a against the front stopper portion 61b and the operation rod 65a. Is carried out in a state where it is pressed against one of the left and right side walls of the slit 61a (for example, the left side wall).

That is, the focus adjustment at the advancing position of the moving lens unit 48 is performed by observing the image picked up by the solid-state image pickup device unit 31 with the operating rod 65a pressed as described above, This is performed by adjusting the position with the intermediate frame 61 and adjusting the positions of the rear lens group frame 57 and the intermediate frame 61. Then, the front group lens frame 55, the rear group lens frame 57, and the intermediate frame 61 after the position adjustment as described above are fixed with an adhesive or the like.

Further, the adjustment (focus adjustment) of the movable lens unit 48 relative to the front group lens unit 45 and the rear group lens unit 46 at the retracted position is performed by pressing the operation rod 65a against the rear stopper 68 and the operation rod. This is performed in a state where 65a is pressed against the other side wall (for example, the right side wall) of the slit 61a.

That is, the adjustment of the moving lens unit 48 at the retracted position is performed by guiding the rear stopper portion 68 while observing an image picked up by the solid-state image pickup device unit 31 with the operating rod 65a pressed as described above. This is done by adjusting the screwed state with respect to the tube 67. Then, the rear stopper portion 68 after the position adjustment is performed in this way is fixed to the guide tube 67 with an adhesive or the like.

Here, as described above, the slit 61a is provided in the intermediate frame 61 in which the movable lens unit 48 is disposed, and the slit 61a opens through the inner peripheral side and the outer peripheral side of the intermediate frame 61. The part is formed. When the endoscope 2 is sterilized and washed, moisture containing moisture may remain slightly in the endoscope 2 even after it is dried. In such a case, moisture may enter the intermediate frame 61 through the slit 61a, and moisture may enter the front group lens unit 45 from the intermediate frame 61 and may become cloudy when the endoscope is used.

In particular, when a fluid such as water or air is sprayed from a nozzle (not shown) provided on the distal end surface of the distal end portion 11 in order to clean the outer surface of the first lens 56a forming the observation window 15, the first lens 56a is cleaned. There may be a temperature difference between the inside and outside of the lens 56a, and fogging may occur on the inner surface side of the first lens 56a. The fogging on the inner surface side of the first lens 56a is a space between the first lens 56a and the second lens 56b through an adhesive layer between the outer diameter surface of the second lens 56b and the inner diameter surface of the front lens group frame 55. It is thought to be due to moisture that has entered R.

For this reason, the front group lens unit 45 is located between the outer diameter surface of the second lens 56b and the inner diameter surface of the front group lens frame 55 on the front side of the second lens 56b disposed on the back side of the first lens 56a. An annular member 70 is provided for extending the adhesive layer to prevent moisture from entering. Hereinafter, the detailed configuration of the front lens group unit 45 will be described with reference to FIG.

The front group lens frame 55 serving as a housing of the front group lens unit 45 has a first hole 55a that holds the first lens 56a, a second hole 55b that holds the second lens 56b, and a first hole that holds the annular member 70. And at least three holes 55c. In the present embodiment, the first lens 56a is formed such that the light incident side surface exposed to the outside of the tip is a flat surface serving as the observation window 15, and the image surface side surface serving as the light emitting side is formed as a concave surface. ing. The second lens 56b is formed of, for example, an uneven lens.

In the present embodiment, the third hole 55c is provided between the first hole 55a and the second hole 55b. That is, the first hole 55a, the third hole 55c, and the second hole 55b are arranged in order from the object side to the image plane side along the optical axis O, and formed so that the inner diameter becomes smaller in order. Yes. The rear end side of the second hole 55b is formed as a positioning portion 55d with which the lens outer peripheral portion on the light emitting side of the second lens 56 abuts.

The first lens 56a held in the first hole 55a is liquid-tightly fixed by an adhesive 75 filled between the inner diameter surface of the first hole 55a and the outer diameter surface of the first lens 56a. The second lens 56b held in the second hole 55b is liquid-tightly fixed by an adhesive 76 filled between the inner diameter surface of the second hole 55b and the outer diameter surface of the second lens 56b.

Further,

diaphragm members

71 and 72 for restricting the ambient light of the lens are disposed on the light emitting side of the first lens 56a and the light emitting side of the second lens 56b, respectively. The diaphragm member 71 is sandwiched between the outer peripheral portion of the inner surface of the first lens 56a and the end surface of the step portion from the first hole 55a to the third hole 55c, and is fixed in a liquid-tight manner by an adhesive. . The aperture member 72 is fixed to the back side of the positioning portion 55d with an adhesive.

An annular member 70 is disposed in the third hole 55c provided between the first hole 55a and the second hole 55b. The annular member 70 has an opening 70a that enters the second lens 56b through the light beam from the first lens 56a, and is disposed close to the outer peripheral portion of the light incident surface of the second lens 56b.

In the present embodiment, the annular member 70 is arranged so that the peripheral edge portion of the opening 70a is in contact with the lens surface of the second lens 56b on the circumference centered on the optical axis O and is in line contact. . Then, an adhesive 77 is formed in a predetermined space S formed by the side surface of the annular member 70 on the second lens 56b side, the inner diameter surface of the third hole 55c, and the outer periphery of the lens surface on the light incident side of the second lens 56b. Is filled.

The filling of the adhesive 77 is performed after the second lens 56b is attached to the second hole 55b and the adhesive 76 is filled into the clearance between the outer diameter surface of the second hole 55b and the inner diameter surface of the second lens 56b. That is, after the adhesive 76 has sufficiently penetrated into the clearance between the second hole 55b and the second lens 56b and cured, a predetermined amount of the adhesive 77 is applied to the outer periphery of the second lens 56b, and the annular member 70 is applied to the second member 56b. The space 77 is filled with the adhesive 77 by fitting into the three holes 55c. The application amount of the adhesive 77 is set in consideration of the volume of the space S formed by the annular member 70, the second lens 56b, and the third hole 55c.

Note that the

adhesives

75, 76, and 77 have fluidity that can penetrate even narrow gaps, and have a property that it is difficult to pass moisture containing moisture after curing. These adhesives 77 may have basically the same properties as 75, 76 and 77, but the properties are adjusted in accordance with the site to be applied (ambient environment), the amount applied, the curing time, etc. It may be used. Further, the diaphragm member 71 and the first lens 56a are fixed by the adhesive after the annular member 70 is bonded and fixed.

Thereby, the adhesive 77 in the space S between the annular member 70, the second lens 56b, and the third hole 55c is joined to the adhesive 76 between the second hole 55b and the second lens 56b. The adhesive layer can be extended to increase moisture passage resistance. As a result, even if moisture that has entered through the slit 61a of the intermediate frame 61 joined to the front lens group frame 55 attempts to enter the space R between the first lens 56a and the second lens 56b, the increased passage resistance causes It is possible to effectively prevent moisture from entering.

FIG. 5 shows an example in which the shape of the annular member 70 is slightly changed so as to function as an optical diaphragm that restricts the incident light to the second lens 56b. An annular member 90 shown in FIG. 5 is formed in a thin plate shape, and has an opening 90 a that functions as an optical diaphragm having a smaller diameter than the opening 70 a of the annular member 70. The space S formed by the annular member 90, the second lens 56 b, and the third hole 55 c is filled with an adhesive 77 like the annular member 70, and the second hole 55 b and the second lens are filled with the adhesive 77. The adhesive layer by the adhesive 76 between 56b is extended.

Also in such an annular member 90, it is possible to increase the passage resistance of moisture that attempts to enter the space R between the first lens 56a and the second lens 56b, and effectively prevent moisture from entering. be able to. Further, the annular member 90 can block unnecessary incident light to the second lens 56b by using the opening 90a as an optical diaphragm.

Thus, in the present embodiment, the first lens 56a at the distal end of the endoscope and the second lens 56b behind the first lens 56a are respectively connected to the first hole 55a and the second hole of the front lens group frame 55. When fixing to 55b with an adhesive, the annular member 70 (90) is disposed in the third hole 55c between the first hole 55a and the second hole 55b. The annular member 70 (90) is disposed close to the outer periphery of the light incident surface of the second lens 56b to form a space between the outer periphery of the second lens 56b, and this space is filled with an adhesive. Thus, the adhesive layer of the second lens 56b is extended.

Accordingly, it is possible to effectively prevent moisture from entering by increasing the passage resistance of moisture into the space between the first lens 56a and the second lens 56b, and the first lens 56a serving as an observation window. Clouding can be prevented.

(Second form)
Next, the second embodiment will be described. In the second form, as shown in FIG. 6, a thin annular member 100 is disposed along the lens surface of the second lens 56b.

Specifically, the annular member 100 has an opening 100a through which the light beams of the first lens 56a and the second lens 56b pass, and is formed of a member that can be deformed into a predetermined shape such as a metal thin plate. The thin plate-like annular member 100 is disposed in a curved shape along the outer peripheral surface of the lens on the light incident surface side of the second lens 56b.

Such an annular member 100 is deformed into a curved surface shape when assembled, for example, as a flat part in a state before assembly. That is, after the second lens 56b is mounted in the second hole 55b and fixed with the adhesive 76, the adhesive 77 is applied to the outer periphery of the second lens 56b, and the third hole 55c and the second lens 56b are flattened. The annular member 100 is pressed. As a result, the annular member 100 is deformed into a curved shape along the lens surface of the second lens 56b, and as shown in FIG. 7, the space S between the peripheral edge of the annular member 100 and the lens surface of the second lens 56b. Becomes a thin film-like gap δ, and the adhesive 77 penetrates into the gap δ to form a thin film-like adhesive layer.

The annular member 100 may be formed into a curved shape in advance using a material such as a resin in consideration of the curvature of the lens surface of the second lens 56b.

Thereby, also in the 2nd form, the penetration resistance of moisture can be effectively prevented by increasing the passage resistance of moisture into the space between the first lens 56a and the second lens 56b. The fogging of the first lens 56a can be prevented. In addition, in the second embodiment, since the adhesive layer between the annular member 100 and the second lens 56b is very thin, the moisture passage resistance is increased, and moisture can be prevented from entering more effectively.

(Third form)
Next, the third embodiment will be described. As shown in FIG. 8, in the third embodiment, the annular member 110 is positioned and arranged so as not to contact the lens surface of the second lens 56b.

The annular member 110 of the third form has an opening 110a through which the light beams of the first lens 56a and the second lens 56b pass, and the second lens 56b has a peripheral edge on the side facing the second lens 56b of the opening 110a. A curved surface portion 110b having substantially the same curvature as the lens surface is formed. The annular member 110 is positioned by contacting a side surface with a positioning portion 55e formed by a step portion from the third hole 55c to the second hole 55b.

The positioning part 55e of the annular member 110 is set to a position where the curved surface part 110b of the annular member 110 is fixed with a predetermined gap δ1 without contacting the second lens 56b fixed by the second hole 55b. Yes. After the second lens 56b is fixed to the second hole 55b with the adhesive 76, the adhesive 77 applied to the outer periphery of the second lens 56b penetrates and fills the gap δ1 by capillary action.

In the third embodiment, as in the second embodiment, since the adhesive is infiltrated into the thin film-like narrow gap, it is possible to increase the moisture passage resistance and prevent moisture from entering more effectively. In this case, since the annular member 110 of the third form has higher rigidity than the annular member 100 of the second form, unnecessary deformation during the assembling work can be prevented, and workability can be improved. Furthermore, since the annular member 110 is not in direct contact with the second lens 56b, there is no risk of scratching the lens surface (particularly the coating layer), and workability can be improved.

Note that the gap δ1 between the annular member 110 and the second lens 56b is not only a shape having a constant gap distance δ1 with the lens surface of the second lens 56b, but also a plurality of gap distances δ11 as shown in FIG. , Δ12 (δ11 <δ12), and vibration resistance can be improved while improving workability.

(4th form)
Next, the fourth embodiment will be described. In the fourth embodiment, as shown in FIG. 10, an annular member 120 is disposed on the light exit side of the second lens 56b ′.

For this reason, in the fourth embodiment, the outer peripheral portion of the second lens 56b 'having a concave surface on the light incident side is disposed so as to contact the back side of the first lens 56a. The annular member 120 is formed in substantially the same shape as the annular member 110 of the third form, has an opening 120a through which the light beams of the first lens 56a and the second lens 56b ′ pass, and the second lens 56b of the opening 120a. A curved surface portion 120b having a curvature substantially similar to that of the lens surface of the second lens 56b ′ is formed on the peripheral edge on the side facing “′”.

The annular member 120 is attached to the third hole 55c formed on the image plane side of the second lens 56b 'after the first lens 56a and the second lens 56b' are bonded and fixed. That is, after the first lens 56a is bonded and fixed to the first hole 55a, the second lens 56b ′ is assembled from the rear of the first lens 56a so as to press the first lens 56a, and the second lens 56b ′ is attached to the second lens 56b ′. Adhering and fixing to the hole 55b.

Then, an adhesive 77 is applied to the outer peripheral portion on the back side of the second lens 56 b ′, and the annular member 120 is assembled so as to crush the adhesive 77. At this time, since the curvature of the curved surface portion 110b of the annular member 120 and the curvature of the lens surface of the second lens 56b ′ facing the curved surface portion 120b are substantially the same, the annular member 120, the third hole 55c, and the second lens. The adhesive 77 penetrates into the gap δ3 between 56b ′ and a thin adhesive layer is generated.

In addition, you may form the curved surface part 120b of the cyclic | annular member 120 in step shape similarly to FIG. 9 of 3rd form.

Also in the fourth embodiment, as in the third embodiment, it is possible to prevent unnecessary deformation of the annular member 120 during the assembly operation and improve workability, and the thin film-like adhesive layer further increases moisture passage resistance. It can be increased to effectively prevent moisture from entering.

This application is filed on the basis of the priority claim of Japanese Patent Application No. 2016-124471 filed in Japan on June 23, 2016, and the above-mentioned contents include the present specification, claims and drawings. Is quoted in

Claims

An optical system having a first lens and a second lens in order from the object side to the image plane side, the light incident surface of the first lens being exposed to the outside of the optical device;
An annular member having an aperture through which the light beam of the optical system passes;
A lens frame having at least a first hole for holding the first lens, a second hole for holding the second lens, and a third hole for holding the annular member along the optical axis of the optical system. When,
Have
The first lens and the second lens are each fixed to the lens frame with an adhesive,
The annular member, the third hole, and the second lens are predetermined by disposing the annular member close to either the light incident side surface or the light emitting side surface of the second lens. Form a space of
An optical device, wherein the predetermined space is filled with an adhesive.
The annular member has a surface shape along a light incident side surface or a light output side surface of the second lens, and is formed with respect to the light incident side surface or the light output side surface of the second lens. The optical device according to claim 1, wherein the optical device is disposed at a predetermined interval.
The optical device according to claim 2, wherein the annular member is formed of a thin plate member.
The optical device according to claim 2, wherein the annular member is positioned and arranged so as to have an interval that does not contact the light incident side surface or the light emission side surface of the second lens. .
The optical apparatus according to claim 2, wherein the annular member has a surface shape with a plurality of steps along a light incident side surface or a light output side surface of the second lens.
The optical device according to claim 1, wherein the annular member is formed so that the aperture can be used as an optical aperture.