JP2010085720A - Lens assembly, and assembly method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens assembly having structure capable of preventing the degradation of optical performance when using a lens frame made of ceramic, and to provide an assembly method for the lens assembly. <P>SOLUTION: A plurality of optical members L1 to L4 and SP1 to SP3 are fit in a lens barrel 10 made of ceramic (S301). An adhesive is applied to either one of a female screw SR1 of the lens barrel 10 made of ceramic and a male screw SR2 of a presser ring 11 (S302). Then, the presser ring 11 is screwed in the lens barrel 10 (S303). When the adhesive is cured, assembly is finished. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens assembly used in a vehicle-mounted camera and an assembling method of the lens assembly.

  Recently, cameras have been deployed in automobiles. Many of the cameras deployed in automobiles display the state of a driver's blind spot on the display screen by utilizing the fact that navigation systems are widespread and display screens are provided in the driver's seat. .

  By the way, automobiles are sometimes exposed to the outdoors in the hot weather in summer and the coldest outdoors in winter, and the on-vehicle camera needs to operate normally under such an extremely wide temperature environment. In order to guarantee this normal operation, the performance required for lens assemblies applied to in-vehicle cameras does not cause general characteristics such as light weight and robustness, and does not cause blur due to temperature changes. Therefore, there is little expansion and contraction due to temperature. In order to satisfy these requirements, a ceramic lens barrel has been considered (see, for example, Patent Documents 1 and 2). Further, the present applicant has proposed to apply a porous ceramic to an optical component (see, for example, Patent Document 3). The term “porous” as used in the specification of Patent Document 3 refers to a porous body having a porosity of 10% or more.

  Here, in Patent Document 4, for example, a lens assembly in which a lens is fixed to a lens barrel by inserting a lens and a spacing ring from the front opening of the lens barrel and screwing a presser ring on the front side of the lens barrel. Is described. A configuration when a ceramic lens barrel is applied to the configuration of Patent Document 4 will be described.

  FIG. 1 is a diagram illustrating a configuration example of a lens assembly including a ceramic lens barrel.

  First, the configuration of the lens assembly will be briefly described with reference to FIG.

  The lens assembly 1 shown in FIG. 1 includes a ceramic lens barrel 10, and the lens barrel 10 is provided with a hollow portion 100 having an objective-side opening 101 and an imaging-side opening 102. A male screw SR1 is formed on the outer periphery of the lens barrel 10 on the objective side, and a plurality of lenses L1 to L4 and a plurality of spacing rings SP1 to SP3 are inserted from the objective side opening 101 with their optical axes aligned. In this example, a plurality of lenses L1 to L4 and a plurality of spacing rings SP1 to SP3 are alternately inserted as a plurality of optical members into the hollow portion 100 of the lens barrel 10 sequentially.

  Further, in the lens assembly 1 of FIG. 1, a plurality of lenses L1 to L4 and a plurality of spacing rings SP1 to SP3 inserted in the hollow portion 100 of the lens barrel 10 are pressed and fixed from the object side opening 101. A holding ring 11 is provided. The holding ring 11 includes a mounting opening 110 into which a portion on the objective side of the lens barrel 10 enters, and a central portion of the lens L1 that is inserted closest to the object among a plurality of optical members that are inserted into the lens barrel. An internal opening SR is formed on the inner wall on the inner side of the mounting opening, and a female screw SR2 is formed on the inner wall of the mounting opening. The male screw SR1 and the female screw SR2 are screwed into the object side most closely. The peripheral edge of the objective side surface of the lens L1 is pressed.

  The lens assembly 1 shown in FIG. 1 is assembled by pressing the plurality of lenses L1 to L4 and the plurality of spacing rings SP1 to SP3 in the lens barrel 10 toward the image forming side opening by the presser ring 11.

  Here, if the material of the lens barrel 10 shown in FIG. 1 is ceramic, a screw SR1 that is screwed with the screw SR2 of the presser ring 11 is provided on the lens barrel 10, and the presser ring 11 and the lens barrel 10 are screwed together. There is a problem that the ceramic surface of the threaded portion on the lens barrel side is scraped off by sliding friction between the presser ring 11 and the lens barrel 10 to generate ceramic dust. If the dust can be cleaned at the time of assembly, there is no problem. However, after the press ring 11 is screwed to the lens barrel 10, the dust cannot be cleaned and removed, so the screws SR1 and SR2 Will be kept in between.

Therefore, after the camera equipped with the lens assembly of FIG. 1 is mounted on the automobile, the dust retained between the screw SR1 and the screw SR2 is slightly changed between the screw SR1 and the screw SR2 due to vibration or the like. There is a risk of being led to the lens side through a gap and sticking to the lens. If dust scraped off from the ceramic adheres to the lens, the optical performance will deteriorate.
JP 2006-289991 A JP 2006-292927 A JP 2007-238430 A JP 2007-279777 A

  In view of the above circumstances, the present invention has an object to provide a lens assembly having a structure capable of preventing deterioration of optical performance when a ceramic lens barrel is used, and a method for assembling the lens assembly. And

The first lens assembly of the present invention that achieves the above object comprises:
A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members inserted into the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall of the mounting opening, and the object-side surface of the first optical member is threaded by the male screw and the female screw. With a presser ring that presses the periphery,
An adhesive is hardened at a threaded portion between the male screw and the female screw.

  According to the lens assembly of the present invention, after the female screw of the presser ring is screwed to the male screw of the lens barrel, dust is sealed in the screwed portion by curing of the adhesive applied in advance. For this reason, when the camera on which the lens assembly is mounted is mounted on an automobile, dust that has been retained in the screwing portion is prevented from being guided to the lens side and attached to the lens. Further, in addition to the conventional assembly, it is only necessary to add a simple process of applying an adhesive before screwing the presser ring.

  Here, the adhesive is preferably a silicon adhesive that cures at room temperature, or an epoxy adhesive that cures by ultraviolet rays or heat. When any one of these adhesives is used, the adhesive can be suitably cured after the press ring and the lens barrel are screwed together.

  Further, the presser ring may have an injection port that penetrates to the outer wall on the inner wall of the mounting opening and receives the injection of the adhesive into the screwed portion.

  The adhesive injected into the screwed portion from the injection port is a low-viscosity adhesive, and its viscosity is preferably 10,000 mPa · s or less, and more preferably 5000 mPa · s or less.

  When it has the viscosity, the adhesive is cured after it has penetrated into the threaded portion in a lubricating manner, and a suitable effect can be obtained.

  Here, it is conceivable to use, as the adhesive having the above-mentioned viscosity, a silicon-based adhesive that cures at normal temperature, an epoxy-based adhesive that cures by ultraviolet rays or heat, an instantaneous adhesive, or the like.

The second lens assembly of the present invention that achieves the above object has an objective-side opening and an imaging-side opening, and a male screw is formed on the outer periphery of the objective-side, and a plurality of optical members are formed from the objective-side opening. A ceramic lens barrel with the optical axis aligned,
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members inserted into the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the peripheral portion of the objective-side surface of the first optical member is formed by screwing the male screw and the female screw. With a presser ring
The adhesive that seals between the image forming side end surface of the attachment opening of the presser ring and the part of the outer wall of the lens barrel adjacent to the part covered with the presser ring is cured. Features.

  According to the second lens assembly of the present invention, an image forming side end surface of the presser ring that forms the mounting opening, and a portion of the outer wall of the lens barrel that is adjacent to the portion covered by the presser ring. The ceramic dust is confined in the threaded portion by the adhesive being applied and the applied adhesive being cured.

  At this time, if a low-viscosity adhesive is used in the same manner as described above, the adhesive penetrates into the screwed portion between the male screw of the presser ring and the female screw of the lens barrel. Dust is suitably sealed at the threaded portion. As the adhesive having a low viscosity, it is conceivable to use a silicon-based adhesive that cures at room temperature, an ultraviolet-cured or heat-cured epoxy-based adhesive, an instantaneous adhesive, or the like.

  Here, the lens barrel is preferably made of a porous ceramic.

  A porous body is a porous body having a porosity of 10% or more.

  Even if it is a porous ceramic, a suitable effect will be exhibited if the above-mentioned adhesive is used.

The first assembling method of the present invention for achieving the above object is
A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members inserted into the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the object-side surface of the first optical member is threaded by the male screw and the female screw. A method of assembling a lens assembly including a presser ring that presses a peripheral edge,
An optical member loading step of loading the plurality of optical members into the lens barrel;
An adhesive application step of applying an adhesive to at least one of the male screw and the female screw;
A presser ring mounting step is provided in which the male screw and the female screw are screwed together to press the first optical member with the presser ring.

  According to the first assembling method of the present invention, an adhesive application step is added to the conventional assembling process, and ceramic dust is confined and fixed in the screwed portion by an adhesive. It is possible to prevent deterioration of optical performance due to ceramic dust that may occur when this lens assembly is used in a vehicle-mounted camera.

  The operation of the adhesive application step is simple and does not require skill or time, so that the manufacturing cost is not increased significantly.

The second assembling method of the present invention that achieves the above-described object is as follows.
A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members inserted into the lens barrel. Furthermore, the inner wall on the inner side of the mounting opening is formed with a female screw that is screwed with the male screw, and the inner wall has an injection port that penetrates to the outer wall and receives the injection of the adhesive, A method of assembling a lens assembly comprising a presser ring that presses a peripheral edge of a surface on the objective side of a first optical member by screwing a male screw and a female screw,
An optical member loading step of loading the plurality of optical members into the lens barrel;
A presser ring mounting step for screwing the male screw and the female screw to press the first optical member with the presser ring;
An adhesive injection step of injecting an adhesive from the injection port.

  According to the second assembly method of the present invention, an adhesive injection step is provided at the end of the assembly in which the injection port is provided in the presser ring, an adhesive is injected from the injection port, and penetrates into the threaded portion. By doing so, the ceramic dust can be confined and fixed in the screwing portion.

  For this reason, it becomes possible to prevent deterioration of optical performance due to ceramic dust that may occur when this lens assembly is used in a vehicle-mounted camera.

  When the presser ring is formed of a molded product, the injection port is formed at the same time as molding, and the operation of injecting the adhesive from the injection port is simple, so that the manufacturing cost is not increased significantly.

  However, when the material of the presser ring is metal, the injection port is manufactured by cutting, but the operation of opening the injection port by cutting is relatively easy.

Furthermore, the third assembling method of the present invention for achieving the above object is
A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members inserted into the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the object-side surface of the first optical member is threaded by the male screw and the female screw. A method of assembling a lens assembly including a presser ring that presses a peripheral edge,
An optical member loading step of loading the plurality of optical members into the lens barrel;
A presser ring mounting step in which the male screw and the female screw are screwed together to press the first optical member with the presser ring;
It has an adhesive application step of applying an adhesive to a portion of the presser ring straddling the imaging side end face of the attachment opening entrance and the outer wall of the lens barrel.

  According to the third assembly method of the present invention, an adhesive application step is added to the conventional assembly process, and ceramic dust is confined and fixed to the screwed portion by the adhesive. Further, it is possible to prevent deterioration of optical performance due to ceramic dust that may occur when this lens assembly is used in a vehicle-mounted camera.

  The operation of the adhesive application step is simple and does not require skill or time, so that the manufacturing cost is not increased significantly.

  As described above, a lens assembly having a structure capable of preventing deterioration of optical performance when a ceramic lens barrel is used, and an assembling method of the lens assembly are realized.

  Embodiments of the present invention will be described below.

  FIG. 2 is a diagram showing a configuration of the lens assembly of the present embodiment.

  The lens assembly 1A shown in FIG. 2 has a structure in which an adhesive is applied and applied in advance to a threaded portion (portion indicated by symbol A) between the female screw SR2 of the presser ring 11 and the male screw SR1 of the barrel. 1 is the same as that shown in FIG. 1 except that the adhesive is cured.

  The adhesive ring 11 is screwed into the lens barrel 10 after the adhesive is applied to the portion A indicated by the reference numeral in FIG. That is, after the adhesive is applied to one of the male screw SR1 of the lens barrel 10 and the female screw SR2 of the presser ring, the presser ring 11 is screwed into the lens barrel 10.

  In this way, when dust is generated by scraping the ceramic surface of the lens barrel by rubbing when screwed into the female screw SR2 of the presser ring and the male screw SR1 of the lens barrel, the dust adheres to the adhesive of the threaded portion. In this state, the adhesive is cured, so that when the lens assembly 1A of the present embodiment is used in a vehicle-mounted camera, the ceramic dust is prevented from being guided and attached to the lens side 2.

  Note that the material of the presser ring in the above embodiment may be a metal such as aluminum, or may be ceramic.

  Here, the adhesive is preferably a silicon adhesive that cures at room temperature, or an epoxy adhesive that cures by ultraviolet rays or heat. If any of those adhesives is used, the adhesive can be suitably cured after screwing the presser ring and the lens barrel.

  FIG. 3 is a process diagram illustrating an assembling method of the lens assembly of FIG.

  First, a plurality of lenses L1 to L4 and spacing rings SP1 to SP3 are loaded into the lens barrel 10 in a loading step S301. In the next adhesive application step S302, an adhesive is applied to at least one of the male screw SR1 and the female screw SR2. Then, in the presser ring mounting step S303, the male screw SR1 and the female screw SR2 are screwed together to press the lens L1 positioned closest to the object side with the presser ring, and then the adhesive is cured.

  In this way, the simple operation of applying the adhesive in the adhesive application step S302 can be performed, and the ceramic dust can be confined in the threaded portion by the hardening of the adhesive. Deterioration of optical performance when the assembly is used can be prevented.

  Since the operation of the adhesive application step S302 in this assembling method is simple and does not require skill or time, the manufacturing cost does not increase so much.

  As described above, a lens assembly having a structure capable of preventing deterioration in optical performance when a ceramic lens barrel is used, and a method for assembling the lens assembly are realized.

  FIG. 4 is a diagram for explaining the second embodiment.

  FIG. 4 shows a perspective view of the lens assembly 1B as viewed obliquely from above.

  The structure is the same as that shown in FIG. 1 except that an injection port 112 is provided in the presser ring 11B.

  The presser ring 11 shown in FIG. 4 has a mounting opening 110 into which a portion on the objective side of the lens barrel 10 enters, and a first one that is inserted closest to the object among a plurality of optical members loaded in the lens barrel. An optical opening 111 that exposes the central portion of the optical member is formed, and a female screw SR2 that is screwed with the male screw SR1 shown in FIG. 1 is formed on the inner wall inside the mounting opening, and the inner wall penetrates to the outer wall. The injection port 112 that receives the injection of the adhesive is provided, and the peripheral portion of the objective-side surface of the first optical member L1 is pressed by screwing the male screw and the female screw.

  After the assembly is completed from the injection port 112, an adhesive is injected to infiltrate the screw into the screwed portion. In this case, it is preferable to use a low-viscosity adhesive, such as a silicon-based adhesive that cures at room temperature, an ultraviolet-cured or heat-cured epoxy-based adhesive, an instantaneous adhesive, etc. Can be considered. Further, the viscosity of the adhesive injected from the injection port 112 into the screwed portion is preferably 10,000 mPa · s or less, and more preferably 5000 mPa · s or less.

  FIG. 5 is a view for explaining an assembling method of the lens assembly of FIG.

  First, in the first optical member loading step S501, the plurality of lenses L1 to L4 and the plurality of spacing rings SP1 to SP3 are loaded into the lens barrel 10. In the next presser ring mounting step S502, the male screw SR1 and the female screw SR2 are screwed together to press the first lens L1 according to the present invention with the presser ring 11. Finally, in an adhesive injection step S503, an adhesive is injected from the injection port 112 to complete the assembly.

  Thus, the injection port 112 is provided in the presser ring 11 and the simple operation of injecting the adhesive in the adhesive application step S503 is finally performed, and the ceramic dust is confined in the threaded portion by the hardening of the adhesive. By fixing, it is possible to prevent deterioration of optical performance when this lens assembly is used in a vehicle-mounted camera.

  Since the operation of the adhesive injection step S503 in this assembling method is simple and does not require skill or time, the manufacturing cost does not increase so much.

  As described above, a lens assembly having a structure capable of preventing deterioration in optical performance when a ceramic lens barrel is used, and a method for assembling the lens assembly are realized.

  FIG. 6 is a diagram for explaining the third embodiment.

  The structure of the lens assembly 1C shown in FIG. 6 is the same as that shown in FIG. 1 except that the adhesive ring A1 is applied to a portion of the presser ring 11 that spans the imaging side end face that forms the mounting opening and the outer wall of the lens barrel. Same as the configuration.

  After the presser ring 11 is screwed and screwed into the lens barrel 10, an adhesive is applied to a portion of the presser ring 11 that spans the imaging-side end surface forming the mounting opening 110 and the lens barrel outer wall. At this time, it is preferable that the adhesive penetrates from the portion A1 of the presser ring 11 which extends over the imaging-side end surface forming the mounting opening 110 and the outer wall of the lens barrel toward the screwing portion. In order to realize this, it is preferable to use a low-viscosity adhesive as described above, and a silicon-based adhesive that cures at room temperature, an ultraviolet curing, or a thermal curing as an adhesive having a low viscosity. It is conceivable to use an epoxy adhesive or an instantaneous adhesive.

  In the configuration shown in FIG. 6, a corresponding effect can be obtained even if the adhesive is not permeated into the screw portion and is cured only at the portion straddling the outer wall of the lens barrel to seal the gap between the presser ring and the lens barrel. can get. At this time, one having a higher viscosity than the above case can be used, and the viscosity is preferably 1000000 mPa or less, more preferably 30000 mPa or less.

  FIG. 7 is a view for explaining an assembling method of the lens assembly of FIG.

  First, a plurality of optical members L1 to L4 and SP1 to SP3 are loaded into the lens barrel 10 in the first optical member loading step S701. In the next presser ring mounting step S <b> 702, the male screw and the female screw are screwed together to hold the lens L <b> 1 with the presser ring 11. Lastly, in the adhesive injection step S703, the adhesive is applied to the portion A1 of the presser ring 11 that spans the image forming side end surface that forms the mounting opening 110 and the outer wall of the lens barrel.

  In this way, in the adhesive application step to the presser ring 11, the work of applying the adhesive to the portion of the presser ring 11 that spans the imaging side end surface forming the mounting opening 110 and the outer wall of the lens barrel is finally performed. By fixing the ceramic dust in the threaded portion by fixing the adhesive, it is possible to prevent deterioration of optical performance when the lens assembly is used in a vehicle-mounted camera.

  The operation of the adhesive injection step S703 in this assembling method is very simple and does not require skill or time, so that the manufacturing cost is not increased so much.

  As described above, a lens assembly having a structure capable of preventing deterioration in optical performance when a ceramic lens barrel is used, and a method for assembling the lens assembly are realized.

  Finally, the lens assembly of FIG. 2 showing the first embodiment, the lens assembly of FIG. 4 showing the second embodiment, or the lens assembly of FIG. 6 showing the lens assembly showing the third embodiment. A configuration of a camera provided with any one of the lens assemblies will be described.

  FIG. 8 is a view showing the camera unit 2 including the lens assembly of FIG.

  FIG. 8 shows a surface obtained by cutting the camera unit 2 along the optical axis.

  The camera unit 2 shown in FIG. 8 includes the lens assembly 1 </ b> A of FIG. 2, a camera body frame 20, and an image sensor 21. The image sensor 21 is mounted on the image sensor substrate 210 and is mounted on the camera body frame 20. It is fixed to the adhesive. Screw portions are respectively formed on the outer peripheral surface of the lens frame 10 and the inner peripheral surface of the camera body frame 20 of the lens assembly 1A of FIG.

  When the camera unit 2 is assembled, the lens assembly 1A shown in FIG. 2 is first inserted into the camera body frame 20 while being screwed, and then the lens assembly 1A is bonded and fixed to the camera body frame 20. Then, the substrate 210 on which the image sensor 21 such as a CCD solid-state image sensor is mounted is bonded and fixed to the camera body frame 20. The lens assembly 1A shown in FIG. 1 can be incorporated into the in-vehicle camera unit 2 by such a simple procedure.

  If the lens assembly can be easily incorporated into the camera unit in this way, the cost of the camera unit can be reduced.

It is a figure which shows the structure of the lens assembly provided with the ceramic lens barrel. It is a figure which shows the structure of the lens assembly of this embodiment. It is process drawing explaining the assembly method of the lens assembly of FIG. It is a figure explaining 2nd Embodiment. It is a figure explaining the assembly method of the lens assembly of FIG. It is a figure explaining 3rd Embodiment. It is a figure explaining the assembly method of the lens assembly of FIG. It is a figure which shows the camera unit 2 provided with the lens assembly of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1A 1B 1C Lens assembly 10 Lens barrel 100 Hollow part 101 Objective side opening 102 Imaging side opening 11 11B Presser ring 110 Mounting opening 111 Optical opening 112 Inlet L1 to L4 Lens SP1 to SP3 Space ring SR1 Male screw SR2 Female screw

Claims (7)

A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members loaded in the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the object-side surface of the first optical member is screwed by the male screw and the female screw. With a presser ring that presses the periphery,
A lens assembly, wherein an adhesive is cured at a threaded portion between the male screw and the female screw.   The lens assembly according to claim 1, wherein the presser ring has an injection port that penetrates the outer wall of the inner wall of the mounting opening and receives the injection of the adhesive into the screwed portion. A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members loaded in the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the object-side surface of the first optical member is screwed by the male screw and the female screw. With a presser ring that presses the periphery,
The adhesive that seals between the image forming side end face of the attachment opening of the holding ring and the portion of the outer wall of the lens barrel adjacent to the portion covered by the holding ring is cured. Characteristic lens assembly.   4. The lens assembly according to claim 1, wherein the lens barrel is made of a porous ceramic. A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members loaded in the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the object-side surface of the first optical member is screwed by the male screw and the female screw. A method of assembling a lens assembly including a presser ring that presses a peripheral edge,
An optical member loading step of loading the plurality of optical members into the lens barrel;
An adhesive application step of applying an adhesive to at least one of the male screw and the female screw;
An assembly method comprising: a presser ring mounting step of screwing the male screw and the female screw to press the first optical member with the presser ring. A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members loaded in the lens barrel. Furthermore, the inner wall on the inner side of the mounting opening is formed with a female screw that is screwed with the male screw, and the inner wall has an injection port that penetrates to the outer wall and receives the injection of the adhesive, A method of assembling a lens assembly comprising a presser ring that presses a peripheral edge of a surface on the objective side of the first optical member by screwing the male screw and the female screw,
An optical member loading step of loading the plurality of optical members into the lens barrel;
A presser ring mounting step of screwing the male screw and the female screw to press the first optical member with the presser ring;
And an adhesive injection step of injecting an adhesive from the injection port. A ceramic lens barrel having an objective-side opening and an imaging-side opening and having a male screw formed on the outer periphery of the objective-side, and a plurality of optical members are inserted with the optical axes aligned from the objective-side opening;
A plurality of optical members inserted in the lens barrel;
A mounting opening into which a portion on the objective side of the lens barrel enters, and an optical opening for exposing a central portion of the first optical member inserted in the most objective side among the plurality of optical members loaded in the lens barrel. A female screw threadedly engaged with the male screw is formed on the inner wall inside the mounting opening, and the object-side surface of the first optical member is screwed by the male screw and the female screw. A method of assembling a lens assembly including a presser ring that presses a peripheral edge,
An optical member loading step of loading the plurality of optical members into the lens barrel;
A presser ring mounting step of screwing the male screw and the female screw to press the first optical member with the presser ring;
An assembly method, comprising: an adhesive application step of applying an adhesive to a portion of the presser ring straddling the imaging-side end surface of the mounting opening entrance and the lens barrel outer wall.

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