OPTICAL SIGHT

Abstract

Optical sight (1) comprising an objective lens (20), an erect lens (30), a crosshair (40) and an eyepiece lens (50) on an optical axis (A) in a lens tube (10), the optical sight (1) being characterized in that it further comprises: a lens frame (24) in cylindrical shape and a plurality of fastening elements (60) configured to fasten the objective lens (20) to an inner side of the lens tube (10), wherein an inner peripheral surface of the lens frame (24) is capable of coming into contact with an outer peripheral surface of the objective lens (20) to hold the objective lens (20); an outer screw (24a) which can be screwed into an inner screw (11a) arranged on the inner peripheral surface of the lens tube (10), arranged on the outer peripheral surface of the lens frame (24); a plurality of through holes (61) are formed on a wall portion of the lens frame (24) corresponding to the outer peripheral surface of the objective lens (20) along a circumferential direction of the wall portion; wherein each of the plurality of fastening elements (60) is made of a metal or synthetic resin having a lower hardness than that of the lens tube (10) and has a shape such that the fastening element (60) can be inserted into the through-hole (61) and a height such that the fastening element (60) can protrude from the through-hole (61); and wherein an assembly including the objective lens (20), the lens frame (24) and the plurality of fastening elements (60) is screwed into the inner screw (11a) arranged on the inner peripheral surface of the lens tube (10).

Description

Technical field

[0001] The present invention relates to an optical aiming device or optical sight for aiming at a target. State of the art

[0002] Fig. 1 is a schematic view showing a configuration of a general optical sight 1. The optical sight 1 is, for example, a telescopic sight and is mounted on a rifle (not shown). The optical sight 1 includes an objective lens 20, an erecting lens 30, a reticle 40, and an eyepiece lens 50 on an optical axis A in a lens tube 10.

[0003] The reticle 40 is arranged at a position conjugate with an inverted image of the objective lens 20 and at a position coincident with an erect image of the erect lens 30. The reticle 40 indicates a line of sight (not shown). The line of sight is superimposed on the erect image of the erect lens 30. A user of the optical sight 1 can observe an object (target) through the eyepiece lens 50 by superimposing the line of sight on an erect image.

[0004] Fig. 4 is a partial cross-sectional view showing an internal structure of the optical sight 1 on the side of the objective lens 20. As in Fig. As shown in Figure 4, the lens tube 10 is configured by a tube body 11 and an end tube 12. The objective lens 20 is configured, for example, by three lenses 21 to 23. The first lens 21 and the second lens 22 are bonded together by an adhesive and form a first lens group. A third lens 23 configures a second lens group. This objective lens 20 is attached to an inner side of a lens frame 24 in a cylindrical shape. Fig. 5 and Fig. 6 show an assembly in which the objective lens 20 and other components are attached to the inside of the lens frame 24.

[0005] As in Fig. 5, three first male or outer screws 24a and a second outer screw 24b are arranged on an outer peripheral surface of the lens frame 24. The second outer screw 24b is located at a front end portion of the lens frame 24. A concave groove is formed on the back of the second outer screw 24b. Fig. An O-ring 27a shown in FIG. 4 is attached to the concave groove. The three first outer screws 24a are located between the rear side of the concave groove and a rear end portion of the lens frame 24. Two intervals of different widths are formed between the three first outer screws 24a. Four first elongated holes 160a are evenly formed with a positional change of 90° in the wider interval located at the front. Four second elongated holes 160b are evenly formed with a positional change of 90° in the narrower interval located at the rear. The first elongated hole 160a is larger than the second elongated hole 160b. An adhesive 160 for fixing the first lens 21 and the second lens 22 to the inner peripheral surface of the lens frame 24 is injected into the first elongated hole 160a.The adhesive 160 injected into the first elongated hole 160a flows between the outer peripheral surface of the second lens 22 and the inner peripheral surface of the lens frame 24. On the other hand, the adhesive 160 for attaching the third lens 23 to the inner peripheral surface of the lens frame 24 is injected into the second elongated hole 160b. The adhesive 160 injected into the second elongated hole 160b flows between the outer peripheral surface of the third lens 23 and the inner peripheral surface of the lens frame 24.

[0006] As in Fig. 6, the lens frame 24 has an inner diameter substantially equal to the outer diameter of the first lens 21, the second lens 22, and the third lens 23. The first lens 21 and the second lens 22 are fixed to the front inner peripheral surface of the lens frame 24. A contact portion with the first lens 21 is disposed on the front inner peripheral surface of the lens frame 24. An O-ring 27b is interposed between the contact portion and the first lens 21. The third lens 23 is fixed to the back of the second lens 22 on the inner peripheral surface of the lens frame 24. An interval tube 25 is interposed between the second lens 22 and the third lens 23. The spacer tube 25 forms a space with a predetermined width between the second lens 22 and the third lens 23. In addition, a pressure tube 26 is attached to the back of the third lens 23 on the inner peripheral surface of the lens frame 24.An outer screw 26a is disposed on the outer peripheral surface of the pressure tube 26. On the other hand, an inner screw 24c is disposed at a rear end portion on the inner peripheral surface of the lens frame 24. The outer screw 26a of the pressure tube 26 is screwed into the inner screw 24c of the lens frame 24. The pressure tube 26 pushes the first lens 21, the second lens 22, the third lens 23, and the spacer tube 25 forward and fixes the first lens 21, the second lens 22, the third lens 23, and the spacer tube 25 to the inner side of the lens frame 24. An adhesive (not shown) is injected between the outer screw 26a of the pressure tube 26 and the inner screw 24c of the lens frame 24 to maintain mutual screwing.

[0007] As in Fig. 4 is the lens frame 24, which forms the assembly of the objective lens 20 (see Fig. 5 and Fig. 6), is fixed to a front end portion of the tubular body 11. A female screw 11a is arranged on the inner peripheral surface of the front end portion of the tubular body 11. The first outer screw 24a of the lens frame 24 is screwed into the female screw 11a of the tubular body 11. An adhesive (not shown) is injected between the first outer screw 24a of the lens frame 24 and the female screw 11a of the tubular body 11 to maintain mutual screwing. In addition, the end tube 12 is fixed to the front end portion of the lens frame 24. A female screw 12a is arranged on the inner peripheral surface of the end tube 12. The female screw 12a of the end tube 12 is screwed into the second outer screw 24b of the lens frame 24. When the end tube 12 and the lens frame 24 are screwed together, a rear end surface of the end tube 12 comes into contact with a front end surface of the tube body 11.This generates a repulsive force between the rear end surface of the end tube 12 and the front end surface of the tubular body 11. The coupling between the lens frame 24 and the tubular body 11 and the coupling between the lens frame 24 and the end tube 12 are each maintained by the repulsive force. An adhesive (not shown) is injected between the second outer screw 24b of the lens frame 24 and the inner screw 12a of the end tube 12 to maintain the mutual screw connection.

[0008] Patent Literature 2 describes a riflescope having a lens holding tube with a half-shell pivot mount. A riflescope is described having a lens holding tube pivotally mounted at one end by means of an improved half-shell pivot device for windage and elevation adjustment. The riflescope may be a riflescope. The lens holding tube contains image erecting lenses that can be mounted for longitudinal adjustment to vary the magnification of the riflescope or fixed against longitudinal movement to provide a fixed magnification. The half-shell pivot mount includes a spherical pivot surface provided at one end of the lens holding tube, which is resiliently urged by a helical compression spring into contact with a conical stem surface provided by an inner shoulder on a surrounding body tube.The radius of curvature of the spherical pivot surface is centered on the point of view of a reticle when that reticle is mounted outside the lens holder tube, in order to maintain the alignment of the point of view with the optical axis of such lenses at various pivot positions of the lens holder tube, so that the reticle remains centered in the field of view of the erecting lenses. In a variable-magnification riflescope, the reticle is held in focus in a calibration position by means of a calibration spring at both maximum and minimum magnification of the erecting lenses. In the fixed-magnification riflescope design, the reticle is mounted in the focal plane of the eyepiece lens system, whereas in the variable-magnification riflescope it may be mounted in a calibration position slightly out of alignment with that focal plane.

[0009] Patent Literature 3 describes an optical instrument with a stabilizing element for inserting and adjusting an optical assembly into a holder, and a method for inserting the stabilizing element. The optical instrument includes an optical assembly having a plurality of optical elements, such as a lens, that defines an optical axis. A holder for an optical assembly has a shape that forms a gap with a defined width between the optical assembly and the holder. A stabilizing component is provided in the gap, which includes stabilizing elements for stably connecting the optical assembly and the holder. The stabilizing elements are deformed so that elastic forces act on the optical axis between the assembly and the holder in the radial direction. The thickness of the stabilizing element is greater than the width of the gap in an unassembled state.The optical assembly, the holder, and the stabilizing component are connected in a roughly positioned state by inserting the optical assembly into the holder. Furthermore, a method for mounting an optical assembly to a holder is disclosed.

[0010] Patent Literature 4 describes ball cage assemblies for centering axially thick lenses and related methods and systems. A ball cage-centered lens assembly is provided, including an axially thick lens, an outer mechanical cell, an intermediate cage positioned between the axially thick lens and the outer mechanical cell, and a plurality of deformable elements positioned within the cage, between the axially thick lens and the mechanical cell, and in contact with the axially thick lens and the outer mechanical cell. [Prior art literature][Patent literature] Patent Literature 1: Unexamined Japanese Patent Publication JP 2008-539388 A Patent Literature 2: US 4408842 A Patent literature 3: EP 2434324 A1 Patent literature 4: US 2015 / 0168665 A1 SUMMARY OF THE INVENTION [Problems to be solved]<Positionsabweichung der Objektivlinse>

[0011] The Fig. 4 is fixed to the lens frame 24, but is not fixed to the tube body 11. Therefore, there is a problem that if the Fig. When the optical sight 1 shown in FIG. 1 receives an impact in a diameter direction of the objective lens 20, the position of the objective lens 20 deviates slightly in the diameter direction. If the center of the objective lens 20 deviates from the optical axis A, the position of the inverted image formed by the objective lens 20 also deviates. As a result, the positions of the erect image formed by the erect lens 30 and the line of sight of the reticle 40 also deviate. Due to the slight positional deviation of the objective lens 20, a distant impact point is greatly displaced.

[0012] For example, a recoil from a firearm gives the optical sight 1 a shock in the diameter direction of the objective lens 20. A shock or impact value from a shot from a rifle with a large caliber or diameter can be 1000 G (1 G = 9.80665 m / s 2) or more. In addition, when the firearm is placed sideways, the optical sight 1 receives the impact in the diameter direction of the objective lens 20. The position of the objective lens 20 deviates slightly due to the impact in the diameter direction.

[0013] One reason for the positional deviation of the objective lens 20 is a fixed structure of the objective lens 20, which is Fig. 4. The first lens 21, the second lens 22, and the third lens 23 are fixed to the lens frame 24 but not fixed to the tubular body 11. In addition, a slight first clearance is provided between the outer peripheral surfaces of the first lens 21, the second lens 22, and the third lens 23 and the inner peripheral surface of the lens frame 24. The first clearance is necessary for inserting the first lens 21, the second lens 22, and the third lens 23 into the lens frame 24. In addition, a slight second clearance is provided between the first outer screw 24a of the lens frame 24 and the inner screw 11a of the tubular body 11. The second clearance is necessary for screwing the first outer screw 24a and the inner screw 11a together. The first lens 21, the second lens 22, and the third lens 23 may deviate slightly within a range of the first and second clearances due to the impact in the diameter direction. <Präzision der Schraube>

[0014] The first outer screw 24a of the lens frame 24 and the inner screw 11a of the tubular body 11 must have extremely high precision. As described above, the second clearance is arranged between the first outer screw 24a and the inner screw. The second clearance must be minimized because the second clearance causes the positional deviation of the objective lens 20. Therefore, the first outer screw 24a and the inner screw 11a must be manufactured by actual parts matching. That is, a specific tubular body 11 and a specific lens frame 24 are paired to modify the inner screw 11a of the specific tubular body 11 and / or the first outer screw 24a of the specific lens frame 24 and minimize the second clearance.The actual part matching of the first outer screw 24a and the inner screw 11a requires labor, time, and skill in processing and significantly reduces the production efficiency of the optical sight 1. Even if the second distance can be minimized, the objective lens 20 may deviate within the range of the second distance. <Handhabung von Klebstoff >

[0015] The Fig. The adhesive 160 shown in FIG. 5 is difficult to manage. That is, the adhesive 160 is injected into the first elongated hole 160a and the second elongated hole 160b formed on the outer peripheral surface of the lens frame 24. The first elongated hole 160a and the second elongated hole 160b are located between two first outer screws 24a. Therefore, the adhesive 160 injected into the first elongated hole 160a and the second elongated hole 160b is likely to stick to the first outer screw 24a. The adhesive 160 adhering to the first outer screw 24a hinders screwing with the inner screw 11a and renders the screw precision achieved by actual part matching meaningless. <Zweck der Erfindung>

[0016] The present invention has been made in view of the above-mentioned problems and aims to provide an optical sight capable of effectively preventing the positional deviation of the objective lens in the diameter direction and significantly improving the manufacturing efficiency. [Means of solving the problems]

[0017] (1) To achieve the above purpose, an optical sight of the present invention includes an objective lens, an erecting lens, a reticle, and an eyepiece lens on an optical axis in a lens tube, and further includes a lens frame in a cylindrical shape and a plurality of fixing members configured to fix the objective lens to an inner side of the lens tube, wherein an inner peripheral surface of the lens frame is capable of coming into contact with an outer peripheral surface of the objective lens to hold the objective lens; an outer screw capable of being screwed into a inner screw disposed on the inner peripheral surface of the lens tube is disposed on the outer peripheral surface of the lens frame; a plurality of through holes are formed on a wall portion of the lens frame, corresponding to the outer peripheral surface of the objective lens along a circumferential direction of the wall portion;each of the plurality of fastening members is made of a metal or synthetic resin with a lower hardness than that of the lens tube and has a shape such that the fastening member can be inserted into the through-hole and a height such that the fastening member can protrude from the through-hole; and an assembly including the objective lens, the lens frame, and the plurality of fastening members is screwed into the inner screw disposed on the inner peripheral surface of the lens tube.

[0018] (2) Preferably, in the optical sight according to the above item (1), at least three or more of the through holes are arranged at equal intervals along the circumferential direction of the wall portion of the lens frame.

[0019] (3) Preferably, in the optical sight according to the above item (1) or (2), a cross-sectional shape of the through-hole is a circle, and a shape of the fixing member is a sphere having a diameter substantially the same as an inner diameter of the through-hole.

[0020] (4) Preferably, the optical sight according to the above items (1) to (3) further includes a lubricant configured to hold the fastening member in the through hole. [Effect]

[0021] According to the optical sight of the present invention, it is possible to effectively prevent the positional deviation of the objective lens in the diameter direction and significantly improve the manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a configuration of a general optical sight. Fig. 2 is an exploded perspective view showing an optical sight according to an embodiment of the present invention. Fig. 3 is a partial cross-sectional view showing an internal structure of the optical sight of the embodiment on an objective lens side. Fig. 4 is a partial cross-sectional view showing the internal structure of a conventional optical sight on the objective lens side. Fig. 5 is a perspective view showing an assembly of the objective lens constituting the conventional optical sight. Fig. 6 is a cross-sectional view of the Fig. The objective lens assembly shown in Figure 5. DESCRIPTION OF THE EMBODIMENTS

[0022] Hereinafter, an optical sight according to an embodiment of the present invention will be described with reference to Fig. 2 and Fig. 3. In addition, the embodiment has the same configurations as in the previous technology in Fig. 1 and Fig. 4 to Fig. 6 are designated by the same reference numerals, and a detailed description thereof will be omitted. An optical sight 1 of the embodiment is, for example, a Fig. 1 and includes an objective lens 20, an erect lens 30, a crosshair 40 and an eyepiece lens 50 on an optical axis A in a lens tube 10. <Charakteristiken des optischen Visiers>

[0023] As in Fig. 2, the objective lens 20 is held on an inner peripheral surface of a lens frame 24 in a cylindrical shape. The optical sight 1 of the embodiment is characterized by a plurality of fastening members 60 and through holes 61 arranged on a wall portion of the lens frame 24. Each of the plurality of fastening members 60 is pressed against both a tubular body 11 and the objective lens 20 through the through hole 61. Thereby, the objective lens 20 is directly fixed to the tubular body 11 in the lens frame 24. The following describes in detail the plurality of fastening members 60 and the through holes 61, which are characteristics of the optical sight 1 of the embodiment.

[0024] As in Fig. 2, six through-holes 61 are formed on the wall portion of the lens frame 24. The six through-holes 61 form three pairs. Two through-holes 61 forming a pair are arranged front and rear along a direction of the optical axis A. Three pairs of the through-holes 61 are evenly arranged with a position change of 120° along a circumferential direction of the wall portion of the lens frame 24. The fastening member 60 is inserted into each of the six through-holes 61. The fastening member 60 is held in the through-hole 61 by a grease (not shown). This configures an assembly including the objective lens 20, the lens frame 24, the six fastening members 60, and other components. The lens frame 24 forming the assembly is fixed to a front end portion of the tubular body 11.In addition, an end tube 12 is attached to a front end portion of the lens frame 24.

[0025] Fig. 3 shows a coupling state of the tubular body 11, the lens frame 24, and the end barrel 12. A first outer screw 24a and a second outer screw 24b are arranged on an outer peripheral surface of the lens frame 24. The second outer screw 24b is located at the front end portion of the lens frame 24. A concave groove is formed on the back surface of the second outer screw 24b. An O-ring 27a is attached to the concave groove. The first outer screw 24a is continuously arranged between the back surface of the concave groove and a rear end portion of the lens frame 24. The first outer screw 24a of the lens frame 24 is screwed into an inner screw 11a of the tubular body 11. The second outer screw 24b of the lens frame 24 is screwed into an inner screw 12a of the end barrel 12.

[0026] The six through-holes 61 penetrate the first outer screw 24a of the lens frame 24. In addition, the positions of the six through-holes 61 correspond to the outer peripheral surface of the objective lens 20 held in the lens frame 24. More specifically, among the pairs of through-holes 61 arranged reciprocally, the position of the front through-hole 61 corresponds to the outer peripheral surface of a second lens 22, and the position of the rear through-hole 61 corresponds to the outer peripheral surface of a third lens 23.

[0027] The fastener 60 is inserted into each of the six through holes 61. The fastener 60 is made of a metal or synthetic resin with a lower hardness than that of the pipe body 11. Furthermore, the fastener 60 has a shape such that the fastener 60 can be inserted into the through hole 61 and a height such that the fastener 60 can protrude from the through hole 61. For example, a cross-sectional shape of the through hole 61 is a circle, and a shape of the fastener 60 is a sphere with a diameter substantially the same as an inner diameter of the through hole 61. For example, the diameter of the spherical fastener 60 is set to a size slightly exceeding the depth of the through hole 61.With this configuration, a lower part of the fastening member 60 is housed in the through-hole 61 and comes into contact with the outer peripheral surface of the objective lens 20 held in the lens frame 24. An upper part of the fastening member 60 slightly protrudes from the through-hole 61 toward the first external screw 24a. For example, the diameter of the spherical fastening member 60 is set to 2 mm, the inner diameter of the circular through-hole 61 is set to 2 mm, and the depth is set to 1.7 mm. In this case, the upper part of the fastening member 60 protrudes from the through-hole 61 by 0.3 mm toward the first external screw 24a. <Befestigung der Objektivlinse>

[0028] If the Fig. 2 is attached to the front end portion of the tubular body 11, the lubricant is applied to each of the six through holes 61 of the lens frame 24, and the fastening member 60 is inserted into each of the six through holes 61. The upper part of the fastening member 60, which is inserted into the through hole 61, is in a state of slightly protruding from the through hole 61. In this state, the first outer screw 24a of the lens frame 24 is screwed into the inner screw 11a of the tubular body 11. In a process of fully screwing the first outer screw 24a into the inner screw 11a, the upper part of the fastening member 60 is shaved off the inner screw 11a, and a groove that engages with the inner screw 11a is machined.

[0029] As in Fig. 3, of the pairs of fastening members 60 arranged at the front and rear, a lower part of the front fastening member 60 comes into contact with the outer peripheral surface of the second lens 22, and the rear fastening member 60 comes into contact with the outer peripheral surface of the third lens 23. On the other hand, the upper parts of all the fastening members 60 are firmly engaged with the inner screw 11a of the tube body 11. In this way, the second lens 22 and the third lens 23 are directly fixed to the tube body 11 via the six fastening members 60. As shown in Fig. 2, the three pairs of fixing members 60 evenly press and support three locations on the outer peripheral surfaces of the second lens 22 and the third lens 23. In addition, since the first lens 21 is bonded to the second lens 22 by an adhesive, the first lens 21 is fixed to the tube body 11 via the second lens 22 and the six fixing members 60. <Vermeidung der Positionsabweichung der Objektivlinse>

[0030] The optical sight 1 of the embodiment can effectively prevent the positional deviation of the objective lens 20 in the diameter direction by the plurality of fastening members 60 and through holes 61 arranged in the lens frame 24. That is, the plurality of fastening members 60 are interposed between the objective lens 20 held in the lens frame 24 and the tube body 11, and directly fix the objective lens 20 to the tube body 11. With this configuration, even if a first clearance is provided between the objective lens 20 and the lens frame 24 and a second clearance is provided between the first outer screw 24a and the inner screw 11a, the positional deviation of the objective lens 20 in the diameter direction is reliably prevented by the plurality of fastening members 60.

[0031] When the optical sight 1 of the embodiment is used for a firearm such as a rifle or the like, the center of a line of sight of the Fig. 1 is aimed so that it coincides with a point of impact of the firearm (zero-in). The positional deviation of the objective lens 20 in the diameter direction is effectively prevented by the plurality of fastening elements 60 and through holes 61, and as a result, the sighting of the zero-in reticle 40 is unlikely to be shifted. <Signifikante Verbesserung der Fertigungseffizienz>

[0032] In the conventional art, by minimizing the second clearance between the first outer screw 24a and the inner screw 11a, the positional deviation of the objective lens 20 in the diameter direction was prevented. On the other hand, in the optical sight 1 of the embodiment, the positional deviation of the objective lens 20 in the diameter direction can be effectively prevented by the plurality of fixing members 60. As a result, the range of tolerance between the first outer screw 24a and the inner screw 11a is expanded, and it is not necessary to strictly manage the second clearance. Thus, the optical sight 1 of the embodiment does not require actual part matching of the first outer screw 24a and the inner screw 11a and can be efficiently mass-produced.

[0033] In addition, since the optical sight 1 of the embodiment can directly fix the objective lens 20 to the tube body 11 by the plurality of fixing members 60, the Fig. 5 is not required. As a result, in a manufacturing process of the optical sight 1 of the embodiment, it is not necessary to strictly manage the adhesive 160 so that the adhesive 160 does not adhere to the first external screw 24a. Moreover, the optical sight 1 of the embodiment does not need to wait for the adhesive 160 to dry in the manufacturing process, although it takes a long time for the adhesive 160 to dry. <Verbesserung der Wartbarkeit>

[0034] For example, the dust mixed into the tube body 11 can be removed. In this case, the objective lens assembly 20 can be easily separated from the tube body 11 by loosening the screw connection between the first outer screw 24a and the inner screw 11a. Furthermore, when the first outer screw 24a and the inner screw 11a are screwed back in, all existing fasteners 60 are replaced with new ones. This directly attaches the objective lens 20 to the tube body 11 as before. < Other changes >

[0035] The optical sight of the present invention is not limited to the configuration of the above-described embodiment. For example, the cross-sectional shape of the through-hole is not limited to a circle. The shape of the fastening member is also not limited to a sphere. The cross-sectional shape of the through-hole can be changed to, for example, an oval, an ellipse, a polygon, or the like. On the other hand, it is sufficient if the fastening member has a shape such that at least the fastening member can be inserted into the through-hole, and the fastening member preferably has a shape corresponding to the cross-sectional shape of the through-hole.

[0036] As a material of the fastener, a metal or synthetic resin with a lower hardness than that of the material of the pipe body 11 can be used. For example, when the material of the pipe body 11 is aluminum or a magnesium alloy, the material of the fastener is a metal or synthetic resin with a lower hardness than that of the aluminum or magnesium alloy. The synthetic resin serving as the material of the fastener is not particularly limited, and a general engineering plastic or a super engineering plastic is preferable.

[0037] The number of the plurality of fastening elements and through holes arranged in the lens frame is not particularly limited and is preferably three or more, as shown in Fig.2. Furthermore, the plurality of fastening elements and through holes are preferably arranged uniformly along the circumferential direction of the wall portion of the lens frame. [List of reference symbols] 1 optical sight (telescope) 10 lens tube 11 Pipe body 11a Internal screw 12 end tube 12a internal screw 20 objective lens 21 first lens 22 second lens 23 third lens 24 lens frames 24a first outer screw 24b second outer screw 24c internal screw 25 spacer tube 26 Pressure tube 26a outer screw 27a, 27b O-ring 30 upright lens 40 crosshairs 50 eyepiece lens 60 Fastening element 61 through hole 160 Adhesive 160a first slot 160b second slot A optical axis

Claims

[1] Optical sight (1) comprising an objective lens (20), an erect lens (30), a crosshair (40) and an eyepiece lens (50) on an optical axis (A) in a lens tube (10), wherein the optical sight (1) characterized by is that it also includes: a lens frame (24) in cylindrical shape and a plurality of fastening elements (60) configured to fasten the objective lens (20) to an inner side of the lens tube (10), wherein an inner peripheral surface of the lens frame (24) is capable of coming into contact with an outer peripheral surface of the objective lens (20) to hold the objective lens (20); an outer screw (24a) which can be screwed into an inner screw (11a) arranged on the inner peripheral surface of the lens tube (10), arranged on the outer peripheral surface of the lens frame (24); a plurality of through holes (61) are formed on a wall portion of the lens frame (24) corresponding to the outer peripheral surface of the objective lens (20) along a circumferential direction of the wall portion; wherein each of the plurality of fastening elements (60) is made of a metal or synthetic resin having a lower hardness than that of the lens tube (10) and has a shape such that the fastening element (60) can be inserted into the through-hole (61) and a height such that the fastening element (60) can protrude from the through-hole (61); and wherein an assembly including the objective lens (20), the lens frame (24) and the plurality of fastening elements (60) is screwed into the inner screw (11a) arranged on the inner peripheral surface of the lens tube (10). [2] The optical sight (1) according to claim 1, wherein at least three or more of the through holes (61) are arranged at equal intervals along the circumferential direction of the wall portion of the lens frame (24). [3] Optical sight (1) according to claim 1 or 2, wherein a cross-sectional shape of the through hole (61) is a circle, and a shape of the fastening element (60) is a sphere having a diameter substantially equal to an inner diameter of the through hole (61). [4] Optical sight (1) according to any one of claims 1 to 3, further comprising: a lubricant configured to hold the fastener (60) in the through hole (61).

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