JP2010085715A - Lens assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens assembly that prevents chipping and deformation of an opening on an image-forming side. <P>SOLUTION: An annular ring member R1 for positioning a lens L4 is fit at a position put between a lens supporting part 103 provided on an edge on an image-forming side of a lens barrel 10 where a hollow part 100 is formed and the lens L4 coming into contact with the lens supporting part 103. An elastic member K is fit between a presser ring 11 and a lens L1. The lens supporting part 103 is reinforced by fitting the ring member R1, and also impulsive force when the lens L4 contacts the ring member R1 is moderated by the elastic member K, thereby the incidence of failure that the lens supporting part 103 is damaged is reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens assembly including a lens barrel having a hollow portion into which a plurality of optical members are inserted.

  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 are little expansion and contraction due to temperature and a mechanism for preventing internal reflection against strong light. In order to satisfy these requirements, a porous ceramic lens barrel has been considered (see, for example, Patent Documents 1 and 2). The present applicant has also proposed applying porous ceramics to optical components (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.

  However, porous ceramics have the drawback of being easily chipped, and how to compensate for this drawback becomes a problem.

  Here, how defects appear when porous ceramic is used for the lens barrel will be described with reference to FIG.

  FIG. 1 is a diagram showing a configuration example of a lens assembly applied to a vehicle-mounted camera, and FIG. 2 is a diagram for explaining a situation of a problem when the lens assembly is assembled. Moreover, FIG. 3 is a figure explaining another structure of the positioning part mentioned later. FIG. 1 shows a lens assembly as in Patent Document 4.

  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 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 optical members L1 to L4 and SP1 to SP3 are inserted from the objective side opening 101 with their optical axes aligned. In this example, as shown in FIG. 1, a plurality of lenses L1 to L4 and a plurality of spacing rings SP1 to SP3 are alternately arranged as a plurality of optical members in the hollow portion 100 of the lens barrel 10 sequentially. It is inserted.

  Further, in the lens assembly 1 in FIG. 1, a presser for pressing and fixing a plurality of optical members L <b> 1 to L <b> 4 and SP <b> 1 to SP <b> 3 inserted into the hollow portion 100 of the lens barrel 10 from the objective side opening 101. An annulus 11 is provided. The presser 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 opening side by the presser ring 11.

  Here, in the example of FIG. 1, the lens support portion 103 that positions the imaging side surface of the lens L4 located on the most imaging side by a line contact that makes a round around the optical axis causes the aperture stop and unnecessary light to pass. It is provided at a position where the image forming side opening 102 is formed so as to also serve as a stopper for cutting. For this reason, since the lens support part 103 forms the contour of the image forming side opening, it is formed at an acute angle on the cross section including the optical axis as shown in FIG.

  With such a configuration, after the lens L4 positioned on the most image forming side is accurately positioned by the lens support portion 103, the other lenses L1 to L3 are sequentially positioned on the most image forming side. This is performed in accordance with the lens L4 positioned at. However, as described above, since the porous ceramic has a defect that it is easily chipped, the lens support portion 103 of FIG. 1 may be chipped during assembly. When the chipping occurs, not only the commercial value of the appearance is deteriorated, but also incident light is irregularly reflected by the chipped part, and a part thereof enters the photographing surface, and there is a possibility that the image quality of the photographed image is deteriorated. Further, due to the chipping, the lens L4 may not be accurately positioned and tilted, and the image may be deteriorated.

  FIG. 2 shows a situation of a malfunction when a lens barrel made of porous ceramic is used, and shows a situation in which a large number of chips 1031 have entered a lens support portion 103 formed at an acute angle. . In order to prevent the occurrence of the chipping 1031, it is conceivable to reinforce the lens support portion 103 </ b> A by forming the positioning portion thick as shown in FIG. In the same manner as when the subject light is reflected at the portion indicated by reference numeral 1031A and a chip occurs, the image quality of the photographed image may be deteriorated by being mixed in the photographing surface. Therefore, it is necessary to form the lens support portion 103 at an acute angle as shown in FIG. 1 and to prevent chipping.

Here, the disadvantages of the porous ceramic lens barrel have been described. However, even if the lens barrel is manufactured using a non-porous ceramic material, it lacks something that is stronger than the porous ceramic. May occur. Alternatively, it is also conceivable to adopt a plastic lens barrel, for example, by designing the lens barrel to expand and contract due to temperature, with a strong resistance to expansion and contraction. In this plastic lens barrel, the problem of chipping does not occur as in the case of ceramic, but instead of the problem of chipping, the lens support portion 103 shown in FIG. There is a possibility that the position of the lens and other lenses may be shifted and the initial optical performance cannot be obtained.
JP 2006-289991 A JP 2006-292927 A JP 2007-238430 A JP 2007-279557 A

  In view of the above circumstances, an object of the present invention is to provide a lens assembly that prevents chipping and deformation of an imaging side opening.

The lens assembly of the present invention that achieves the above object includes a plurality of optical members that form an imaging optical system as a whole, including a first lens disposed on the most imaging side,
A hollow part having an objective-side opening and an imaging-side opening, wherein the plurality of optical members are inserted from the objective-side opening so that the first lens is disposed on the most imaging side; A lens support portion that is formed on the edge and projects in an annular shape inside the hollow portion, has an image forming side opening smaller in diameter than the diameter of the first lens, and positions the position of the first lens in the optical axis direction A lens assembly comprising:
A ring-shaped member having an opening having a smaller diameter than the diameter of the first lens is interposed at a position sandwiched between the lens support portion and the first lens.

  According to the lens assembly of the present invention, the diameter of the lens support portion 103 shown in FIG. 1 is smaller than the diameter of the first lens on the first lens L4 side surface inserted in the hollow portion 100. A ring-shaped member having an image forming side opening is inserted. Thus, when the ring-shaped member is inserted between the first lens L4 and the lens support portion 103, the lens support portion is chipped or deformed because the first lens does not directly contact the lens support portion. Is prevented.

  Even if the first lens is in direct contact with the lens support portion, the pressure on the lens support portion is dispersed by the ring-shaped member, so that the lens support portion is prevented from being chipped or deformed.

  Here, it is preferable that the ring-shaped member positions the imaging-side surface of the first lens by line contact that goes around the optical axis.

  Then, even if the first lens does not come into contact with the lens support portion, the lens is positioned by the ring-shaped member interposed between the first lens and the support portion.

  That is, the ring-shaped member has a function of dispersing by receiving the pressure concentrated on the lens support portion at a wide end surface when it is pressed by the presser ring, and a lens that contacts the lens at the outer peripheral edge. It has two functions: a function of positioning the head with high accuracy.

  Here, the ring-shaped member is preferably made of a material having a higher hardness than the lens barrel.

  As described above, when positioning is performed at the outer peripheral edge of the ring-shaped member, the outer peripheral edge of the ring-shaped member may be chipped or deformed. When a material having high hardness is used for the ring-shaped member as described above, chipping or deformation of the circumferential edge of the ring-shaped member when the first lens is in line contact with the outer peripheral edge of the ring-shaped member is prevented. Is done.

  The ring-shaped member may be made of an elastic member.

  When the ring-shaped member is formed of the elastic member, the same effect as that of the high-grade material is obtained, and the elastic member is crushed when the plurality of optical members are pressed by the presser ring. Therefore, the reflection surface becomes small.

  Further, in the case where the ring-shaped member is constituted by the elastic member, the elastic member is crushed and the first lens and the lens support portion come into contact when the plurality of optical members are pressed by the presser ring. At that time, the impact force at the time of contact is weakened by the elastic member, and the lens support portion is prevented from being chipped or deformed.

  Here, it is preferable that the lens support portion positions the surface of the first lens on the image forming side of the first lens by line contact that goes around the optical axis.

  The elastic member is preferably made of ethylene / propylene or silicon rubber. Furthermore, the lens barrel may be made of a porous ceramic. The porous material is a porous material having a porosity of 10% or more.

  As described above, a lens assembly that prevents chipping or deformation of the imaging side opening is realized.

  Embodiments of the present invention will be described below.

  FIG. 4 is a diagram showing a lens assembly 1A according to an embodiment of the present invention. FIG. 4 shows a surface obtained by cutting the lens assembly along the optical axis of the lens, as in FIG. FIG. 4 shows that a ring-shaped member R1 for positioning the first lens L4 is inserted at a position sandwiched between the lens support portion 103 and the first lens L4 according to the present invention and a presser foot. A view of the same structure as that in FIG. 1 is shown except that an elastic member K is inserted between the ring and the lens L1 located closest to the object side. In this example, a porous ceramic is used for the lens barrel, and a ceramic having a higher hardness than the porous ceramic is used for the ring-shaped member.

  With reference to FIG. 4, the difference in structure from the prior art will be described.

  The structure shown in FIG. 1 has a problem that the lens support portion 103 having a positioning function is missing when the plurality of optical members L1 to L4 and SP1 to SP3 in the lens barrel 10 are pressed by the presser ring 11 as described above. It was.

  Therefore, in the embodiment of FIG. 4, a ring-shaped member R1 for positioning the lens L4 is inserted at a position sandwiched between the lens support portion 103 and the lens L4. With this configuration, the ring-shaped member R1 receives and disperses the pressure concentrated on the lens support portion 103 at the end surface of the ring-shaped member R1 when the presser ring 11 is screwed into the lens barrel 10, thereby dispersing the lens. The supporting portion 103 is prevented from being chipped, and the ring-shaped member R1 is in line contact with the first lens L4 at the outer peripheral edge, whereby the plurality of lenses L1 to L4 are positioned with high accuracy.

  In the present embodiment, the ring-shaped member R1 is made of a ceramic having a hardness higher than that of the porous ceramic, so that the outer peripheral edge of the ring-shaped member R1 is prevented from being chipped when contacting the first lens L4. Yes.

  Further, as can be seen from FIG. 4, the outer peripheral edge of the ring-shaped member R <b> 1 contacts the first lens L <b> 4 so that the image-side surface of the first lens L <b> 4 makes a round contact around the optical axis. Thus, the positioning accuracy of the first lens L4 is improved, and the positioning accuracy of the other lenses L1 to L3 following the positioning is improved.

  With such a configuration, chipping and deformation of the imaging side opening are prevented, and high positioning accuracy can be obtained.

  In this embodiment, an example in which porous ceramic is used as the material of the lens barrel is shown, but a lens barrel using plastic may be used. At that time, a metallic member or a ceramic member can be used for the ring-shaped member. In the case of plastic, the same plastic and high hardness can be used as the material of the ring-shaped member.

  In the above embodiment, the elastic member K is inserted between the presser ring 11 and the lens L1 in order to reduce the impact when the lens L4 contacts the ring-shaped member R1. By doing so, damage to the lens L1 due to reaction force when the lens is brought into contact with the ring-shaped member R1 is also prevented.

  Further, as described above, metal, plastic, or ceramic can be used for the ring-shaped member R1 in accordance with the material of the lens barrel. Further, the ring-shaped member R1 is preferably made of a material having a hardness higher than that of the lens barrel 10 as in the above example. Then, the ring-shaped member R1 is ringed by an impact force when the first lens L4 comes into contact with the ring-shaped member R1. It is prevented that the outer peripheral edge of the member R1 is chipped or deformed.

  Here, depending on the structure of the ring-shaped member R1, there is a possibility that light is reflected by the ring-shaped member R1 and mixed into the imaging surface as in Patent Document 2.

  FIG. 5 is a diagram for explaining the structure of the ring-shaped member R1.

  FIG. 5A shows an example in which a ring-shaped member R11 having a shape in which the lens L4 support surface of the ring-shaped member does not reach the tip of the edge of the lens support portion 103 is inserted. FIG. 5B shows an example in which a ring-shaped member R12 having a shape in which the edge tip of the lens support portion 103 and the support surface of the ring-shaped member R1 are flush with each other is inserted. 5 (c) shows an example in which a ring-shaped member R13 having a shape in which a slope is formed from the tip end of the lens support portion 103 toward the lens L4 is inserted.

  A corresponding effect can be obtained with any of the configurations shown in FIGS. 5 (a) to 5 (c).

  However, in the case of ring-shaped members R11, R12, and R13 having the shapes shown in FIGS. 5 (a), 5 (b), and 5 (c), reference numerals A, B, and R of the ring-shaped members R11, R12, and R13 are used. It is necessary to take anti-reflection measures on the surface indicated by C. Otherwise, the light reflected by the portions indicated by reference signs A, B, and C of the ring-shaped members R11, R12, and R13 will be mixed into the imaging surface as in FIG.

  Since the ring-shaped members R11, R12, and R13 can be made of metal, plastic, or ceramic as described above, for example, using aluminum that is a metal as a material, FIGS. When manufacturing ring-shaped members R11, R12, and R13 having the shapes shown in (b) and FIG. An antireflection film may be formed by performing treatment. When the ring-shaped members R11, R12, and R13 having the shapes shown in FIGS. 5A, 5B, and 5C are manufactured using brass as a material, the ring-shaped members R11, Black oxidation treatment may be performed on the portions indicated by reference signs A, B, and C of R12 and R13.

  Furthermore, when using other metal materials, plastics, ceramic moldings, etc., it is conceivable to provide screw shading lines or matte coating.

  When antireflection surface treatment is applied to the portions indicated by reference signs A, B, and C in this way, ring-shaped members R11 and R12 having the structures shown in FIGS. 5A, 5B, and 5C are provided. , R13, the reflected light is not mixed into the imaging surface and the optical performance is not deteriorated.

  In addition, it is more preferable to make the reflecting surface C smaller in the configuration of FIG. 5C because unnecessary reflected light is less likely to be generated than in FIGS. 5A and 5B.

  Here, some materials suitable for the surface treatment are listed.

  As described above, stainless steel or the like may be used in addition to aluminum and brass as the metal material. As the plastic, use of PC / PCG (polycarbonate), PA (polyamide), PPA (polyphthalamide), PPS (polyphenylene sulfide), LCP (liquid crystal polymer), or the like is considered. As the ceramic, it is conceivable to use a ceramic mainly made of alumina, zirconia, magnesium titanate, cordierite, silicon carbide, silicon nitride, aluminum nitride, free-cutting ceramics, or the like.

  FIG. 6 is a view showing the camera unit 2 including the lens assembly 1A of FIG.

  FIG. 6 shows a view in which the camera unit 2 is cut along the optical axis and the cut surface is viewed from an oblique side.

A camera unit 2 shown in FIG. 6 includes the lens assembly 1A shown in FIG. 4, a camera body frame 20, and an image sensor 21. The image sensor 21 is mounted on an 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 of FIG. 4 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. Thereafter, 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. 4 can be incorporated into the camera unit 2 by such a simple procedure.

  Next, a second embodiment will be described.

  FIG. 7 is a diagram showing a lens assembly 1B according to the second embodiment of the present invention. FIG. 7A shows a surface obtained by cutting the lens assembly 1B along the optical axis of the lens, and FIG. 7B shows an enlarged view of the lens support portion 103. As shown in FIG. FIG. 7A shows a view of the same structure as FIG. 1 except that the elastic member P is provided at a position sandwiched between the lens support portion 103 and the first lens L4 according to the present invention. Yes.

  As shown in FIG. 7, the elastic member P has an effect of avoiding concentration of pressure on the lens support 103 applied when the presser ring 11 is screwed into the lens barrel, as in the first embodiment. By doing so, the rate at which the lens support 103 is damaged is reduced.

  Here, the elastic member P is positioned closest to the image formation side when the plurality of optical members L1 to L4 and SP1 to SP3 in the hollow portion 100 are effectively crushed and crushed by the presser ring 11. It is more preferable that the lens L4 to be brought into contact with the lens support portion 103 of the lens barrel 10.

  Therefore, the present applicant, by repeating experiments, for example, in a lens barrel having a diameter of about 10 mm and a length of about 20 mm, the elastic member P may be an elastic member having a rubber hardness of 20 to 90 in Shore A. Among them, it has been found that a better effect can be obtained when an elastic member having a Shore A hardness of 40 to 70 is used. It has also been found that ethylene / propylene rubber, silicon rubber or the like may be used as the material of the elastic member in order to obtain this hardness.

  Furthermore, it was confirmed that when the thickness of the elastic member P is changed from 0.03 mm to 0.5 mm, the elastic member P is appropriately crushed, and when the thickness is 0.1 mm to 0.4 mm, a suitable effect can be obtained. Yes.

  By the way, in order to exert the most suitable effect on the elastic member P, there is a tightening torque when the holding ring 11 is attached and the plurality of optical members L1 to L4 and SP1 to SP3 in the hollow portion 100 are tightened. . With respect to this tightening torque, it is preferable to adjust the tightening torque to about 0.5 to 7 cNm after suitably adjusting the thickness and hardness of the elastic member P, and further to about 1.5 to 4.5 cNm. Applicants have confirmed that most of the items will collapse properly when tightened with.

  FIG. 8 is a diagram showing the relationship between the tightening torque and the collapse amount of the elastic member P, and FIG. 9 shows that the plurality of optical members L1 to L4 and SP1 to SP3 in the hollow portion 100 are pressed by the presser ring 11. It is a figure explaining a state when the elastic member P is crushed effectively by this.

  FIG. 8 shows a change in the height of the lens barrel when the tightening torque is gradually increased within the above-described preferable tightening torque range (0.5 to 7 cNm). For comparison, FIG. 5 also shows the amount of change in the height of the lens barrel when the elastic member P is not inserted.

  As shown in FIG. 8, when the tightening torque is increased, the height of the elastic member P inserted is greatly changed due to the contraction of the height of the elastic member P inserted. To do. The difference in both height changes corresponds to the amount of collapse of the elastic member P.

  The present applicant manufactured an elastic member having such a hardness that the amount of crushing is 20 to 90% of the original thickness of the elastic member P, and confirmed the effect by experiment. As a result, the applicant confirms that when the elastic member has a hardness such that the amount of crushing is 40 to 80%, an elastic member that collapses to the extent that it contacts or does not contact the lens is obtained. I was able to.

  FIG. 9 shows that an appropriate crushing condition can be obtained by using the elastic member manufactured by the present applicant.

  In a state where the lens L4 is fixed to the lens frame 10 without contacting the lens support portion 103, the elastic member needs to be uniformly crushed in the circumferential direction. Thus, the lens L4 can be positioned without being inclined with respect to the optical axis of the photographing lens. More preferably, the lens L4 can be positioned with high accuracy without being inclined with respect to the optical axis by making line contact with the lens support portion 103 on the entire circumference.

  When the ring member is configured by the elastic member P in this way, as in the first embodiment, high positioning accuracy is obtained and the lens support portion 103 is prevented from being lost, and further, FIGS. 5B and 5C. ) Is not formed, and the effect of eliminating the need for matting or the like can also be obtained.

  Even if the elastic member P is crushed and the lens L4 comes into contact with the lens support portion 103, the impact force to the lens support portion 103 is weakened by the elastic member P, and the lens support portion 103 The lens L4 positioned on the image forming side is positioned, and the other lenses L1 to L3 are positioned following the lens L4.

  Finally, an example in which the lens assembly 1B of FIG. 7 is applied to an imaging device will be described.

  FIG. 10 is a view showing a camera unit 2B including the lens assembly 1B of FIG.

  FIG. 10 shows a view in which the camera unit 2B is cut along the optical axis and the cut surface is viewed from an oblique side.

  A camera unit 2B shown in FIG. 10 includes the lens assembly 1B shown in FIG. 7, a camera body frame 20, and an image sensor 21. The image sensor 21 is mounted on an 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 1B of FIG.

  When the camera unit 2 is assembled, the lens assembly 1B shown in FIG. 7 is first inserted into the camera body frame 20 while being screwed, and then the lens assembly 1B is bonded and fixed to the camera body frame 20. Thereafter, 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 1B of FIG. 4 can be incorporated into the camera unit 2 by such a simple procedure.

It is a figure which shows the structural example of the lens barrel applied to a camera. It is a figure explaining the condition of the malfunction at the time of the assembly of a lens assembly. It is a figure which shows another structural example of the lens barrel applied to a camera. It is a figure which shows the lens assembly 1 which is one Embodiment of this invention. It is a figure explaining the structure of ring-shaped member R1. It is a figure which shows the camera unit 2 provided with the lens assembly of FIG. It is a figure which shows the lens assembly 1B which is 2nd Embodiment of this invention. It is a figure which shows the relationship between the fastening torque of the presser ring 11, and the amount of collapse of the elastic member P. FIG. It is a figure explaining the state when the some optical members L1-L4 and SP1-SP3 in a hollow part are pushed in with the presser ring 11, and the elastic member P was crushed effectively. It is a figure which shows the camera unit 2B provided with the lens assembly 1B of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1A 1B Lens assembly 10 Lens barrel 100 Hollow part 101 Objective side opening 102 Imaging side opening 103 Positioning part 11 Presser ring 110 Mounting opening 111 Optical opening L1 to L4 Lens SP1 to SP3 Space ring SR1 Female screw SR2 Male screw 2 2B Camera unit

Claims (7)

A plurality of optical members including the first lens disposed on the most image forming side, and forming an image forming optical system as a whole;
A hollow portion having an objective-side opening and an imaging-side opening, wherein the plurality of optical members are inserted from the objective-side opening so that the first lens is disposed on the most imaging side; A lens support portion that is formed on the edge and projects in an annular shape inside the hollow portion, has an image forming side opening smaller in diameter than the diameter of the first lens, and positions the position of the first lens in the optical axis direction A lens assembly comprising:
A lens assembly comprising a ring-shaped member having an opening having a diameter smaller than the diameter of the first lens at a position sandwiched between the lens support portion and the first lens.   2. The lens assembly according to claim 1, wherein the ring-shaped member positions the imaging-side surface of the first lens by line contact that goes around the optical axis.   3. The lens assembly according to claim 1, wherein the ring-shaped member is made of a material having a hardness higher than that of the lens barrel.   The lens assembly according to claim 1, wherein the ring-shaped member is formed of an elastic member.   5. The lens assembly according to claim 4, wherein the lens support portion positions the imaging-side surface of the first lens by line contact that goes around the optical axis.   6. The lens assembly according to claim 4, wherein the elastic member is made of ethylene / propylene or silicon rubber.   The lens assembly according to claim 1, wherein the lens barrel is made of a porous ceramic.

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