Optical device and lens module thereof

Abstract

An optical device and a lens module thereof. The lens module includes a lens barrel, an object-end lens, a pressing member, a waterproof seal, and an outer cover. The lens barrel includes an opening portion and a mounting portion. The object-end lens is disposed on the mounting portion. The object-end lens includes a lens body and a first radical flange. The first radial flange includes a first outer circumferential wall and an annular inclined surface. The waterproof seal is disposed in an accommodation space formed by the the opening portion of the lens barrel, the object-end lens and the pressing member. The outer cover includes a connecting portion and a second radial flange. The second radial flange is configured to push the pressing member against the waterproof seal, thereby forcing the waterproof seal against the annular inclined surface and the mounting portion. The pressing member is disposed between the waterproof seal and the outer cover.

Description

Technical Field

[0001] This invention relates to the technical field of waterproof structures for optical devices, and more particularly to an optical device and its lens module. Prior Technology

[0002] Please refer to Figure 1, which illustrates the structure of a prior art waterproof lens. In the structure of lens L, the outermost lens element LE of lens L is mounted in the mounting structure of the annular mounting part B1 of lens barrel B. The side wall LW of lens L abuts against the inner surface of lens barrel B. Therefore, water vapor from the external environment may enter the lens interior through the tiny gap at the contact point between lens L and lens barrel B, and condense or even breed mold on the optical surfaces of each lens element, thereby affecting the image quality of each lens element.

[0003] The existing solution involves placing an O-ring R between the outermost lens element LE and the mounting portion B1. When the top cover C of the lens L is screwed onto the lens barrel B, the top cover C pushes against the outermost lens element LE, causing the outermost lens element LE to compress the O-ring R, resulting in elastic deformation and a sealing effect. However, since the surface of the outermost lens element LE where the O-ring R is located is also assembled with the adjacent lens element L1 via a spacer ring R1, the assembly tolerance between the outermost lens element LE and the adjacent lens element L1 affects the amount of deformation of the O-ring R. Thus, when the assembly tolerance is too large, the gap between the outermost lens element LE and the mounting portion B1 becomes too large, resulting in insufficient deformation or even no deformation of the O-ring R, thereby losing the sealing effect. In addition, when the ambient temperature affects the waterproof lens, since the lens barrel B and the top cover C are made of metal, while the outermost lens element LE is made of glass, the thermal expansion rates of the lens barrel B and the outermost lens element LE are different, increasing the gap between the outermost lens element LE and the mounting portion B1 of the lens barrel B. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an optical device and its lens module, the waterproof structure of which can avoid the influence of lens assembly tolerances and enable the sealing component to perform its sealing effect.

[0005] An embodiment of the lens module of the present invention includes a lens barrel, a receiving end lens, a contact member, a waterproof seal, and an outer cover. The lens barrel includes an opening and a mounting portion, which are arranged along the optical axis of the lens module. The receiving end lens is disposed in the mounting portion and includes a lens body and a first radial flange extending radially from the lens body away from the optical axis. The first radial flange includes a first outer peripheral wall abutting against the mounting portion and an annular inclined surface facing the opening and connected to the first outer peripheral wall. The waterproof seal is disposed in a receiving space formed between the opening of the lens barrel, the receiving end lens, and the contact member. The outer cover includes a connecting portion and a second radial flange extending radially from the connecting portion near the optical axis. The second radial flange causes the contact member to press against the waterproof seal, thereby causing the waterproof seal to abut against the annular inclined surface and the mounting portion. The contact member is disposed between the waterproof seal and the outer cover.

[0006] In another embodiment, the inner surface of the opening and the inner surface of the mounting portion are flush, or the inner surface of the opening and the inner surface of the mounting portion are arranged in a stepped shape.

[0007] In another embodiment, the lens module satisfies the condition 68%≦A2 / A1≦125%, where A2 is the cross-sectional area of ​​the waterproof seal and A1 is the cross-sectional area of ​​the accommodating space.

[0008] In another embodiment, the abutment is an annular rib integrally formed with the second radial flange of the outer cover.

[0009] In another embodiment, the lens body includes a second outer peripheral wall connected to the annular inclined surface, and the abutment corresponds to the second outer peripheral wall.

[0010] In another embodiment, the lens body includes a first optical surface and a second optical surface disposed opposite to each other, the first optical surface being closer to the object side of the lens module than the second optical surface, and the first radial flange being connected to the second optical surface.

[0011] In another embodiment, the lens body further includes a stop slope connecting the first optical surface and the second outer peripheral wall, and the second radial flange abuts against the stop slope.

[0012] In another embodiment, when the second radial flange abuts against the stop slope, the distance between the second radial flange and the annular slope is less than the sum of the thicknesses of the waterproof seal and the abutment.

[0013] In another embodiment, the joint and the lens barrel are joined by a structure in which internal and external threads are screwed together.

[0014] The optical device of the present invention includes the above-described lens module, which includes at least one lens with positive refractive power and at least one lens with negative refractive power.

[0015] The lens module of the present invention assembles a waterproof seal on the annular inclined surface of the lens at the receiving end facing the opening. This avoids the problem of poor sealing effect caused by insufficient deformation of the waterproof seal due to the assembly tolerance between the lenses. Simple Explanation of the Diagram

[0016]

[0017] Figure 1 is a cross-sectional view of a waterproof lens of the prior art.

[0018] Figure 2 is a cross-sectional view of a first embodiment of the lens module of the present invention.

[0019] Figure 3 is a magnified view of a portion of the lens module in Figure 2.

[0020] Figure 4 is a cross-sectional view of a second embodiment of the lens module of the present invention. Implementation

[0021] Please refer to Figures 2 and 3, which illustrate a first embodiment of the lens module of the present invention. The lens module 1 of this embodiment includes a lens barrel 10, a plurality of lens elements 20, a waterproof seal 30, an outer cover 40, an abutment 50, and at least one spacer ring SR. At least one of the lens elements 20 has positive refractive power, and at least another has negative refractive power. The spacer ring SR is disposed between the lens elements 20 to ensure the distance between them.

[0022] The lens module 1 has an optical axis O. The lens barrel 10 is cylindrical, and the optical axis O coincides with the axis of the lens barrel 10. The lens barrel 10 includes an opening 11 and a plurality of mounting portions 12a and 12b. The opening 11 and the mounting portions 12a and 12b are also cylindrical and arranged along the direction of the optical axis O. A plurality of lens elements 20 are correspondingly disposed on the plurality of mounting portions 12a and 12b and arranged along the direction of the optical axis O.

[0023] The lens 20 includes an object receiving lens 20a, which is disposed in the mounting portion 12a of the lens barrel 10. The object receiving lens 20a includes a lens body 20a1 and a first radial flange 20a2 extending radially from the lens body 20a1 away from the optical axis O. The lens body 20a1 includes a first optical surface 20a11 and a second optical surface 20a12 disposed opposite to each other. The first optical surface 20a11 is closer to the object side of the lens module 1 than the second optical surface 20a12. Therefore, the first optical surface 20a11 is away from the other lenses 20, and the second optical surface 20a12 is close to the other lenses 20. The first radial flange 20a2 is connected to the second optical surface 20a12. Both the first optical surface 20a11 and the second optical surface 20a12 include an optical active area and a non-optical active area. Light from the outside passes through the optical active area to produce an optical effect (e.g., imaging). The non-optical active area of ​​the second optical surface 20a12 abuts against a spacer ring SR, and the spacer ring SR abuts against a lens 20 adjacent to the object receiving lens 20a, thereby forming an appropriate distance between the object receiving lens 20a and the adjacent lens 20 via the spacer ring SR. The first radial flange 20a2 includes a first outer peripheral wall 20a21 abutting against the inner surface of the mounting portion 12a of the lens barrel 10, an annular inclined surface 20a22 facing the opening 11 and connected to the first outer peripheral wall 20a21, and a bottom wall 20a23 connected to the non-optical active area of ​​the second optical surface 20a12.

[0024] A waterproof seal 30 is disposed in a receiving space formed between the opening 11 of the lens barrel 10, the object receiving lens 20a, and the abutment member 50. In this embodiment, the waterproof seal 30 is an O-ring.

[0025] The outer cover 40 includes a connecting portion 41 and a second radial flange 42 extending radially from the connecting portion 41 near the optical axis O. The connecting portion 41 is cylindrical. When assembling the lens module 1, it can be axially moved to the lens barrel 10 by means of the structure of the external thread of the lens barrel 10 and the internal thread of the connecting portion 41, so that the second radial flange 42 can approach or move away from the waterproof seal 30.

[0026] The abutment 50 is disposed between the waterproof seal 30 and the outer cover 40. The second radial flange 42 abuts against the abutment 50, and the joint 41 moves along the optical axis O, so that the second radial flange 42 abuts against the abutment 50, thereby further pressing the abutment 50 against the waterproof seal 30, thereby causing the waterproof seal 30 to undergo appropriate elastic deformation and abut against the inner surface of the annular inclined surface 20a22 and the mounting portion 12a of the lens barrel 10. In this way, the waterproof seal 30 can reliably seal the abutment between the first outer peripheral wall 20a21 and the inner surface of the mounting portion 12a of the lens barrel 10, thereby preventing moisture from the external environment from entering the interior of the lens barrel 10.

[0027] The lens body 20a1 of the receiving end lens 20a includes a second outer peripheral wall 20a13 and a stop slope 20a14. The second outer peripheral wall 20a13 is connected to the annular slope 20a22, and the abutment member 50 corresponds to the second outer peripheral wall 20a13. The stop slope 20a14 connects the first optical surface 20a11 and the second outer peripheral wall 20a13, and the stop slope 20a14 is located between the first optical surface 20a11 and the second outer peripheral wall 20a13. The outer cover member 40 is coupled to the lens barrel 10 and continuously moves relative to it along the optical axis O until the second radial flange 42 abuts against the stop slope 20a14, thereby limiting the axial movement stroke of the outer cover member 40.

[0028] When the second radial flange 42 abuts against the stop slope 20a14, the distance between the second radial flange 42 and the annular slope 20a22 is less than the sum of the thicknesses of the waterproof seal 30 and the abutment.

[0029] In this embodiment, when abutment members 50 of different thicknesses are installed, the degree of deformation caused by pressing the waterproof seal 30 can be adjusted. However, the invention is not limited to this. In other embodiments, the abutment member can also be an integral structure with the second radial flange of the outer cover, that is, the abutment member is an annular rib provided on the second radial flange. Similarly, the degree of deformation caused by pressing the waterproof seal 30 can be adjusted by using annular ribs of different thicknesses.

[0030] As mentioned above, a receiving space is formed between the opening 11 of the lens barrel 10, the receiving end lens 20a, and the abutment member 50 to accommodate the waterproof seal 30. It is worth noting that a fill ratio R can be defined as the ratio of the cross-sectional area A2 of the waterproof seal 30 to the cross-sectional area A1 of the receiving space. If the fill ratio R is too small, it means that the cross-sectional area A2 of the waterproof seal 30 is small, resulting in poor sealing. However, if the fill ratio R is too large, it means that the cross-sectional area A2 of the waterproof seal 30 is large, and the waterproof seal 30 will be excessively compressed after assembly, potentially causing permanent deformation or even preventing the top cover from locking properly. Therefore, in this invention, the fill ratio R satisfies the condition 68% ≤ A2 / A1 ≤ 125%, where A2 is the cross-sectional area of ​​the waterproof seal 30 and A1 is the cross-sectional area of ​​the receiving space.

[0031] Please refer to Figure 4, which shows the second embodiment of the present invention. Components identical to those in the first embodiment are labeled with the same symbols, and their descriptions are omitted. The difference between the second and first embodiments is that the inner surfaces of the opening 11' and the mounting portion 12a' in the first embodiment (Figure 3) are flush, while the inner surfaces of the opening 11' and the mounting portion 12a' in the second embodiment (Figure 4) are arranged in a stepped pattern. This difference allows the lens barrel 10 to provide a larger accommodating space than the first embodiment under the same external shape. In other words, the fill rate R of the second embodiment is smaller than that of the first embodiment under the same external shape.

[0032] The lens module 1 of the present invention can be used in different optical devices, such as action photography lenses or vehicle lenses.

[0033] The lens module of the present invention assembles a waterproof seal onto the annular inclined surface of the lens at the receiving end, which faces the opening. This avoids the problem of poor sealing performance caused by insufficient deformation of the waterproof seal due to the assembly tolerance between lenses, as seen in previous technologies. Furthermore, since the waterproof seal of the present invention abuts against the annular inclined surface of the lens at the receiving end, when the gap between the lens at the receiving end and the lens barrel increases due to ambient temperature, the waterproof seal can adjust its compression according to the change in the gap between the lens at the receiving end and the lens barrel by abutting against the annular inclined surface, thus maintaining its sealing effect.

[0034] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the invention are still within the scope of the patent. Furthermore, no embodiment or claim of the present invention needs to achieve all the objectives, advantages, or features disclosed in the invention. In addition, the abstract and headings are merely for assisting in patent document searches and are not intended to limit the scope of the invention.

[0035] 1: Lens Module

[0036] 10: Lens tube

[0037] 11,11': Opening

[0038] 12a, 12a', 12b: Installation section

[0039] 20: Lenses

[0040] 20a: Lens at the receiving end

[0041] 20a1: Lens body

[0042] 20a11: First optical surface

[0043] 20a12: Second optical surface

[0044] 20a13: Second peripheral wall

[0045] 20a14: Stop slope

[0046] 20a2: First radial flange

[0047] 20a21: First outer peripheral wall

[0048] 20a22: Annular inclined plane

[0049] 20a23: Bottom wall

[0050] 30: Waterproof sealant

[0051] 40: Outer cover

[0052] 41: Joint

[0053] 42: Second radial flange

[0054] 50: Attachment

[0055] B: Lens tube

[0056] B1: Installation Department

[0057] C: Top cover

[0058] SR: Spacer ring

[0059] L: Lens

[0060] L1: Lens

[0061] LE: Outermost lens

[0062] LW: Sidewall

[0063] O: Optical axis

[0064] R1: Spacer ring

[0065] RO: Ring

Claims

1. A lens module having an optical axis, the lens module comprising: A lens barrel, including an opening and a mounting portion, the opening and the mounting portion being arranged along the optical axis; a receiving end lens disposed on the mounting portion, the receiving end lens including a lens body and a first radial flange extending radially from the lens body away from the optical axis, the first radial flange including a first outer peripheral wall abutting against the mounting portion and an annular inclined surface facing the opening and connected to the first outer peripheral wall; a contact member; a waterproof seal disposed in a receiving space formed between the opening of the lens barrel, the receiving end lens, and the contact member; an outer cover comprising a connecting portion and a second radial flange extending radially from the connecting portion near the optical axis, the second radial flange causing the contact member to press against the waterproof seal, thereby causing the waterproof seal to abut against the annular inclined surface and the mounting portion; wherein the contact member is disposed between the waterproof seal and the outer cover.

2. The lens module as described in claim 1, wherein the inner surface of the opening and the inner surface of the mounting portion are flush, or the inner surface of the opening and the inner surface of the mounting portion are arranged in a stepped manner.

3. The lens module as described in claim 1, wherein the lens module satisfies the condition 68%≦A2 / A1≦125%, where A2 is the cross-sectional area of ​​the waterproof seal and A1 is the cross-sectional area of ​​the accommodating space.

4. The lens module as claimed in claim 1, wherein the abutment is an annular rib integrally formed with the second radial flange of the outer cover.

5. The lens module as claimed in claim 1, wherein the lens body includes a second peripheral wall connected to the annular inclined surface, and the abutment corresponds to the second peripheral wall.

6. The lens module as claimed in claim 5, wherein the lens body includes a first optical surface and a second optical surface disposed opposite to each other, the first optical surface being closer to the object side of the lens module than the second optical surface, and the first radial flange being connected to the second optical surface.

7. The lens module as claimed in claim 6, wherein the lens body further includes a stop slope connecting the first optical surface and the second outer peripheral wall, and the second radial flange abuts against the stop slope.

8. The lens module as claimed in claim 7, wherein when the second radial flange abuts against the stop slope, the distance between the second radial flange and the annular slope is less than the sum of the thicknesses of the waterproof seal and the abutment.

9. The lens module as described in claim 7, wherein the joint and the lens barrel are joined by a structure in which internal and external threads are engaged.

10. An optical device comprising a lens module as described in any one of claims 1 to 9, the lens module comprising at least one lens having positive refractive power and at least one lens having negative refractive power.

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