Lens unit and imaging device

Abstract

The present invention addresses the problem of providing a lens unit and an imaging device capable of sufficiently securing an air discharge path and preventing foreign matter from invading into a lens barrel from the outside. [Solution] A lens unit (100A) is provided with an air passage (50) which opens at both ends of a lens barrel (2) on the image surface side and the object side and which connects the openings at both ends inside the lens barrel (2), and the end of the air passage (50) on the object side is provided with a gap (41) formed between the edge surface (L1c) of a front lens (L1) and the receiving surface (25) of the lens barrel (2).

Description

Technical Field

[0001] This invention relates to lens units and imaging devices. Background Technology

[0002] In automotive camera lenses, air channels are sometimes provided within the lens module to expel hot, expanding air or as a countermeasure against condensation. For example, Patent Document 1 discloses a camera module in which an air hole is provided from the front end of the lens barrel, extending along the optical axis of the lens, to the image side, in a lens barrel section that houses the lens.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-156627 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] To ensure adequate air venting, it is preferable to have structures for venting air to the outside on both the object side and the image side (image sensor side) of the lens unit. However, in the structure of Patent Document 1, foreign objects may enter the lens barrel through the air hole provided on the object side of the lens unit. If foreign objects enter the lens barrel, the image sensor will malfunction (e.g., unable to generate accurate image data). Therefore, it is desirable to develop a reliable lens unit that ensures adequate air venting and prevents foreign objects from entering the lens barrel from the outside.

[0008] Therefore, one objective of the present invention is to provide a lens unit and imaging device that can adequately ensure an air exhaust path and prevent foreign objects from entering the lens barrel from the outside.

[0009] Methods for solving problems

[0010] To address the aforementioned issues, one aspect of the present invention relates to a lens unit comprising: a lens assembly including a front lens having an edge portion extending radially outward from the outer edge of the lens surface; and a lens barrel housing the lens assembly and having a receiving surface facing the object side of the edge portion. The lens unit further includes a venting passage opening at both ends of the lens barrel on the image plane and object side, and communicating the openings at both ends within the lens barrel. The object-side end of the venting passage includes a gap formed between the edge portion and the receiving surface.

[0011] To address the aforementioned issues, one aspect of the present invention relates to a camera device comprising: a lens unit as described above; and an imaging element that receives light after passing through the lens group of the lens unit.

[0012] Invention Effects

[0013] According to one aspect of the present invention, a lens unit and imaging device that can adequately ensure an air exhaust path and prevent foreign objects from entering the lens barrel from the outside can be provided. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view schematically illustrating the structure of the lens unit according to Embodiment 1 of the present invention.

[0015] Figure 2 This is an exploded view showing a portion of the structure of the lens unit according to Embodiment 1 of the present invention after disassembly.

[0016] Figure 3 This is an enlarged cross-sectional view of a portion of the structure of the lens unit according to Embodiment 1 of the present invention.

[0017] Figure 4 This is an enlarged cross-sectional view of a portion of the structure of the lens unit according to Embodiment 1 of the present invention.

[0018] Figure 5 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 1 of the present invention.

[0019] Figure 6 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 1 of the present invention.

[0020] Figure 7 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 1 of the present invention.

[0021] Figure 8 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 1 of the present invention.

[0022] Figure 9 This is a cross-sectional view schematically illustrating the structure of the lens unit according to Embodiment 2 of the present invention.

[0023] Figure 10 These are plan views and enlarged views of a portion of the structure of the lens unit according to Embodiment 2 of the present invention.

[0024] Figure 11 This is an enlarged cross-sectional view of a portion of the structure of the lens unit according to Embodiment 2 of the present invention.

[0025] Figure 12 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 2 of the present invention.

[0026] Figure 13 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 2 of the present invention.

[0027] Figure 14 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 2 of the present invention.

[0028] Figure 15 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 2 of the present invention.

[0029] Figure 16 This is a diagram showing a modified example of the structure of the lens unit according to Embodiment 2 of the present invention.

[0030] Figure 17 This is a cross-sectional view schematically illustrating the structure of the lens unit according to Embodiment 3 of the present invention.

[0031] Figure 18 This is a cross-sectional view schematically illustrating the structure of a camera device with a lens unit according to Embodiment 4 of the present invention.

[0032] Explanation of reference numerals in the attached figures

[0033] L lens group

[0034] L1 front lens

[0035] L1a lens surface

[0036] L1c edge surface

[0037] L1d peripheral edge

[0038] L1e end

[0039] L1f edge

[0040] L1k Non-forming region

[0041] L1s air trench

[0042] L1x recess

[0043] L1y protrusion

[0044] 2. Lens tube

[0045] 2a Inner surface of cylinder

[0046] 2b Internal thread section

[0047] 3, 3A, 3B, 3C, 3D washers

[0048] 3a Outer periphery of washer

[0049] 3i Washer Inner Periphery

[0050] 3w notch

[0051] 4 Image side pressing ring

[0052] 4c External thread section

[0053] 20 Light incident section

[0054] 23 inner periphery

[0055] 24. Air grooves in the lens barrel

[0056] 25 bearing surface

[0057] 26 Bearing surface groove

[0058] 31 Front surface of the washer

[0059] 32 Washer back surface

[0060] 33 Through Hole

[0061] 40 Pressing ring air groove

[0062] 41 gap

[0063] Space 42 (Space 1)

[0064] 43 Second Space

[0065] 50 Ventilation path

[0066] 201 Lens tube body

[0067] 300 camera elements

[0068] 400 camera devices Detailed Implementation

[0069] [Implementation Method 1]

[0070] The following describes one embodiment of the present invention. Figure 1 This is a cross-sectional view schematically illustrating the structure of the lens unit according to Embodiment 1 of the present invention. Furthermore, detailed descriptions of the optical systems of each lens included in the lens unit are omitted from the illustrations.

[0071] like Figure 1 As shown, the lens unit 100A includes at least a lens barrel 2, a lens group L (lenses L1 to L6), a gasket 3, spacers S1 to S3, and an image-plane side pressing ring 4. Furthermore, for Figure 1Regarding the lens unit 100A shown, Figure 1 The left side of the attached diagram is the object side, while the right side is the side equipped with the imaging element described later, i.e., the image plane side.

[0072] Lens barrel 2 holds a lens group L inside. In this embodiment, six lenses L1 to L6 are held as lens group L. Lens L1 is the front lens L1 located closest to the object. Lens barrel 2 holds the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 sequentially on the image plane side relative to the front lens L1. Figure 1 The optical axis X of lens group L is shown in the figure. Furthermore, the optical axis X lies on the same line as the central axis of lens barrel 2. Hereinafter, the direction along the central axis of lens barrel 2 will be referred to as the axial direction.

[0073] The lens barrel 2 includes a light incident section 20 with an object-side opening. The opening diameter of the light incident section 20 is configured to be smaller than the outermost diameter of the front lens L1. In the light incident section 20, a lens barrel support section 21 is provided extending from the main body of the lens barrel 2 toward the central axis X.

[0074] The lens barrel support portion 21 is a portion whose opening diameter decreases as it moves toward the central axis X. The inner periphery of the lens barrel support portion 21 ( Figure 4 The inner periphery 23) defines the opening diameter of the light incident part 20. The lens barrel receiving part 21 will be described later.

[0075] use Figure 2 The interior of tube 2 will be described. Figure 2 This is an exploded diagram showing the structural elements of a portion of lens unit 100A. For ease of explanation, in... Figure 2 The illustration shows the lens barrel 2, the gasket 3 disposed on the light incident portion 20 side of the lens barrel 2, and the front lens L1; other structural elements are omitted from the illustration. Furthermore, Figure 2 This indicates the situation where the inside of the microscope tube 2 is observed from the image plane side towards the object side.

[0076] like Figure 2 As shown, an air groove 24 is provided on the inner surface 2a of the lens barrel 2, which is continuous from the image plane side to the object side.

[0077] The air groove 24 in the lens barrel has a shape that is recessed in the direction that expands the diameter of the inner surface 2a of the lens barrel 2. When structural elements such as the lens group L are housed inside the lens barrel 2, it can form a cavity between itself and the outermost diameter portion of each structural element. This cavity, as shown... Figure 1 As indicated by the middle arrow, a venting passage 50 extends continuously from the image plane side of the lens barrel 2 to the object side, forming an opening at both ends of the lens barrel 2 on both the image plane side and the object side, and connecting the openings at both ends. Figure 1It is part of the lens barrel air groove 24. In other words, the air groove 24 forms part of the venting passage 50. The openings at the image-side end of the venting passage 50 and the openings at the object-side end of the venting passage 50 will be described later.

[0078] 24 air grooves in the lens barrel Figure 2 As shown, the mirror tube 2 is provided at three equal intervals along the circumference of its inner surface 2a. Alternatively, the intervals may not be equal, and the number of locations may not be three, but it is preferable to provide two or more locations.

[0079] Figure 3 This is an enlarged view showing the end of the inner surface 2a of the lens barrel 2 on the image plane side and its periphery. At the end of the inner surface 2a of the lens barrel 2 on the image plane side, the aforementioned image plane side pressing ring 4 is configured to be threadedly engaged with the internal thread 2b provided on the lens barrel 2 by an external thread 4c provided on the outer peripheral surface of the image plane side pressing ring 4.

[0080] The image-side pressing ring 4 is a ring-shaped structure with an opening in the center to allow light passing through the sixth lens L6. An air groove 40 is provided on the object-side surface 4a of the image-side pressing ring 4. The air groove 40 is a groove that extends radially from the object-side surface 4a towards the image-side surface. When the image-side pressing ring 4 presses against the sixth lens L6 housed inside the lens barrel 2, the air groove 40 can form a cavity between itself and the peripheral surface of the sixth lens L6 surrounding the image-side lens surface.

[0081] The press ring air groove 40 is positioned to communicate with the image plane side end of the lens barrel air groove 24. The press ring air groove 40 and the lens barrel air groove 24 together form part of the aforementioned ventilation path 50. The opening near the center of the press ring air groove 40 forms the opening at the image plane side end of the ventilation path 50.

[0082] Furthermore, the circumferential positional relationship between the pressing ring air groove 40 and the lens barrel air groove 24 can be completely consistent, but is not limited to the case of complete consistency. For example, the lens barrel air groove 24 has a width that is longer in the circumferential direction, while the pressing ring air groove 40 is provided at multiple locations with a predetermined width along the annular surface 4a of the image-side pressing ring 4. With the image-side pressing ring 4 threadedly engaged with the inner surface 2a of the lens barrel 2, at least one pressing ring air groove 40 located in a position communicating with a certain lens barrel air groove 24 can be considered as a state where the opening on the image-side of the ventilation passage 50 is unobstructed. For example, the pressing ring air groove 40 is provided at four locations circumferentially along the annular surface 4a of the image-side pressing ring 4.

[0083] The structure of the material side in ventilation path 50 will be described next. For example... Figure 2As shown, on the object side inside the lens barrel 2, the washer 3 and the front lens L1 are sequentially housed. (Use) Figure 4 This section will be further explained.

[0084] Figure 4 yes Figure 1 An enlarged view of portion B within the dashed box shown. (See attached image.) Figure 4 As shown, the lens barrel 2 has an inner periphery 23 and a receiving surface 25. The inner periphery 23 forms the opening edge of the light incident portion 20. The receiving surface 25 is a surface facing the image plane and is opposite to the edge surface L1c of the front lens L1, which will be described later.

[0085] like Figure 4 As shown, the front lens L1 has a lens surface L1a on the object side and an edge surface L1c extending radially outward from the outer edge of the lens surface L1a. The edge surface L1c is the object-side surface of the flange-shaped edge portion L1f located at the outer edge of the front lens L1.

[0086] Washer 3 Figure 2 The image shows a ring-shaped structure, such as... Figure 4 As shown, it is held between the bearing surface 25 and the edge portion L1f (edge ​​surface L1c). Washer 3 is as follows... Figure 2 and Figure 4 As shown, the notch 3w is cut out at the outer periphery 3a of the washer. The notch 3w is cut from the outer periphery 3a of the washer toward the inner periphery 3i of the washer to a predetermined depth. The notch 3w is as follows... Figure 2 As shown, it is set at multiple locations along the outer periphery 3a of the washer.

[0087] like Figure 4 As shown, with the washer 3 held between the bearing surface 25 and the edge surface L1c, the washer 3 has a front surface 31 facing the object side and a rear surface 32 facing the image plane side. Figure 4 In the state shown, the front surface 31 of the washer abuts against the bearing surface 25, and the rear surface 32 of the washer abuts against the edge surface L1c.

[0088] Here, on the bearing surface 25, a bearing surface groove 26 (groove) extending from the inner periphery 23 to the outer diameter is provided. The bearing surface groove 26 extends from the position (middle part) where it overlaps with the notch 3w of the washer 3 in the axial direction of the lens barrel 2 to the inner periphery 23 of the bearing surface 25. The bearing surface groove 26 is as follows: Figure 2 As shown, it is formed along the inner perimeter 23 for a specified length in the outer diameter direction over the entire circumference.

[0089] The portion of the bearing surface groove 26 near the inner periphery 23 overlaps with the front surface 31 of the gasket. Thus, a gap 41 is provided, corresponding to the depth (length along the axial direction) of the groove in the bearing surface groove 26. On the other hand, at the position in the bearing surface groove 26 that overlaps with the notch 3w of the gasket 3, the bearing surface groove 26 communicates with the notch 3w, and this communication portion further connects to a space 42 having a width defined by the bearing surface 25 and the edge surface L1c in the notch 3w of the gasket 3. The gap 41 to the space 42 communicates with the aforementioned lens barrel air groove 24. In other words, the gap 41 is included at the object-side end of the aforementioned venting passage 50.

[0090] Here, as Figure 4 As shown, the axial width 41w of the gap 41 is breathable if it exceeds the minimum value of 0. On the other hand, the upper limit of the axial width 41w of the gap 41 is suitably set based on the viewpoint of preventing the ingress of harmful foreign matter, as described above. As an example, the axial width 41w of the gap 41 can be set to 50 μm. Thus, foreign matter larger than 50 μm present in the outside cannot pass through the gap 41 and cannot intrude into the ventilation path 50. 50 μm is an example of the upper limit value. Considering the use of the lens unit 100A of this embodiment, it can be suitably set according to the size of foreign matter that may exist in the usage environment. In most cases, dust and dirt may become foreign matter. Considering this case, for the upper limit value, the axial width 41w of the gap 41 is set to 55 μm or less, preferably 50 μm or less, and more preferably 45 μm or less.

[0091] Furthermore, as described above, the lower limit of the axial width 41w of the gap 41 can be greater than 0, but from the viewpoint of ventilation, the lower limit is set to 6 μm or more, preferably 8 μm or more, and more preferably 10 μm or more. The air discharged from inside the lens barrel 2 to the outside of the barrel through the ventilation passage 50 is at least one of the air generated inside the lens barrel 2 during the manufacturing process of the lens unit, and the air that expands inside the barrel due to the temperature difference.

[0092] The lens barrel 2 is made of metal. When the lens barrel 2 is made of metal, it can be machined on a lathe. By machining on a lathe, the bearing surface 25 of the bearing part 21 is machined circumferentially from the inner periphery 23 side, thereby forming a bearing surface groove 26 with a specified width 41w in the axial direction and a specified depth.

[0093] However, the lens barrel 2 is not limited to being made of metal; it can also be made of resin. The resin can be, for example, a resin capable of being insert-molded with conductive components (e.g., wiring). In this case, there can be one or more types of resin. Examples of such resin materials include super engineering plastics such as Reny (registered trademark) and polyphenylene sulfide (PPS). In addition to resin materials, additives such as plasticizers, UV absorbers, light stabilizers, and fillers can also be included. Automotive lenses are used for applications related to the safety and peace of mind of occupants during vehicle operation, such as autonomous driving, driver assistance, and surrounding monitoring. Therefore, high reliability is required for automotive lenses. Thus, super engineering plastics with high heat resistance, durability, and dimensional stability, as well as lower manufacturing costs compared to metal components and suitability for mass production, can be used to manufacture the lens barrel 2. As for the method of forming the bearing surface groove 26 on the bearing surface 25 of the lens barrel 2, a molding-based forming method can be used when the lens barrel 2 is made of resin.

[0094] Washer 3 can be made of resin, metal, or other materials.

[0095] The front lens L1 and other lenses L2 to L6 can be made of glass. However, they are not limited to glass and can also be made of resin.

[0096] As described above, according to the structure of the lens unit 100A of this embodiment, a gap 41 is included at the object-side end in the venting passage 50. Therefore, by implementing the gap 41 with a specific width (the aforementioned width 41w) that takes into account the size of the foreign object in order to prevent intrusion from the outside into the lens barrel 2, a lens unit 100A capable of preventing such intrusion is realized.

[0097] Furthermore, according to the structure of the lens unit 100A in this embodiment, since the notch 3w of the gasket 3 is included in the venting passage 50, it is not necessary to process the edge surface L1c of the front lens L1 to form a part of the venting passage 50. Therefore, a glass lens that is not suitable for such processing can be used as the front lens L1.

[0098] Furthermore, in this embodiment, the diameter of the inner surface of the lens barrel 2 remains approximately constant from the object side to the image plane side. In other words, the lens groups L1 to L6, the gasket 3, and the spacers S1 to S3 have the same outer diameter. However, this is just one example; it is also possible to provide a concave-convex shape on the inner circumferential surface of the lens barrel according to the outer diameter of the structural elements housed within the lens barrel.

[0099] [Example of a modified washer]

[0100] In addition, as mentioned above Figure 2 and Figure 4 The modified example of the washer shown can also be... Figure 5The illustrated washer. The following describes variations.

[0101] Figure 5 The washer 3A shown on the upper side of the attached diagram is... Figure 2 and Figure 4 Compared to the washer 3 shown, the number of notches 3w is greater. With such a large number of notches 3w, the width of each notch 3w (its length along the circumference of the washer 3) can also be greater than... Figure 2 and Figure 4 The notch 3w of the washer 3 shown is small in width. The shape of washer 3A is similar to... Figure 2 and Figure 4 Compared to the gasket 3 shown, it can increase the air permeability.

[0102] Figure 5 The washer 3B shown in the center of the attached diagram is... Figure 2 and Figure 4 Compared to washer 3, the number of notches 3w is less, but the width of each notch 3w (the length along the circumference of washer 3) is larger. The shape of washer 3B is also the same as that of washer 3A. Figure 2 and Figure 4 Compared to the gasket 3 shown, it can increase the air permeability.

[0103] Figure 5 The washer 3C shown on the lower side of the attached drawing is a plan view illustrating another variation. As the notch 3w described earlier, the notch extends radially from the cut-out position at the outer periphery 3a of the washer. However, the direction of extension is not limited to radial. For example, Figure 5 The washer 3C shown on the lower side of the attached diagram has a notch cut at the outer periphery 3a, and the notch 3w extends from this position in a radially inclined direction relative to the washer 3C. This washer 3C can also form part of the ventilation path 50. In the case of this notch 3w, the starting point of the notch 3w (on the side of the outer periphery 3a of the washer) communicates with the air groove 24 of the lens barrel, and at a position opposite to the end of the washer on the side of the inner periphery 3i of the washer in the notch 3w, the bearing surface groove 26 of the bearing surface 25 overlaps.

[0104] It can also exist as another type of washer. Figure 6 The washer 3D shown is of the form described above. The washer 3D does not have the notch 3w present in the other washers 3 described above. Instead, the washer 3D has a through hole 33 extending from the front surface 31 to the rear surface 32. Multiple through holes 33 are provided along the circumference of the annular front surface 31 and rear surface 32 of the washer. The through holes 33 are continuous with the venting passage 50 inside the lens barrel 2. Figure 7 This needs to be explained.

[0105] Figure 7This is a partially enlarged cross-sectional view of the lens unit 100B with 3D gaskets, which is related to the above. Figure 4 The corresponding figure shows that the bearing surface 25 has a bearing surface groove 26 extending from a position opposite to the through hole 33 in the axial direction of the lens barrel 2 to the inner periphery 23 of the bearing surface 25. The portion of the bearing surface groove 26 near the inner periphery 23 overlaps with the front surface 31 of the gasket on the image plane side. Thus, a gap 41 corresponding to the depth (length along the axial direction) of the groove 26 is provided in this portion of the bearing surface groove 26.

[0106] In the 3D configuration with gaskets, the outer peripheral end of the edge surface L1c side of the edge portion L1f of the front lens L1 is... Figure 4 The outer periphery of the edge surface L1c shown has more notches compared to the previous one. As a result, the edge surface L1c side of the front lens L1 in the through hole 33 is connected to the air groove 24 of the lens barrel.

[0107] By designing the washer 3D with a through hole 33, the strength of the outer periphery of the washer is higher than that of the washer 3 with a notch, thus giving it the advantage of being less prone to deformation and easier to handle.

[0108] [Other variations]

[0109] The aforementioned methods involve providing a bearing surface groove 26 on the bearing surface 25 of the lens barrel 2, and providing a gap 41 in the portion of the bearing surface groove 26 near the inner periphery 23. However, one aspect of the present invention is not limited to this. For example, it is possible to omit the bearing surface 25. Figure 4 The bearing surface groove 26 shown, and the end of the vent 50 on the object side includes a gap to prevent foreign matter from entering (in Figure 4 In the case of gap 41). According to this method, the bearing surface 25 does not require machining for setting the bearing surface groove 26. Hereinafter, using... Figure 8 This illustrates an example of a method where the bearing surface groove 26 is not provided.

[0110] Figure 8 This is a partially enlarged cross-sectional view of the lens unit 100C in this modified example, which is consistent with the above. Figure 4 The corresponding diagram. In the lens unit 100C, the notch 3w located in the gasket 3 and Figure 4 Compared to the notch 3w, it extends to a position closer to the inner periphery 3i of the washer.

[0111] The notch 3w, located near the inner periphery 3i of the washer, is situated in the inner diameter direction (close to the central axis of the lens barrel 2) of the bearing surface 25 of the lens barrel 2. Therefore, a gap 41' is provided between the notch 3w, near the inner periphery 3i of the washer, and the inner periphery 23. The gap 41' connects to a space 42 in the notch 3w, having a width defined by the bearing surface 25 and the edge surface L1c. The gap 41' communicates with the aforementioned lens barrel air groove 24. In other words, the gap 41' is included at the object-side end of the venting passage 50. The gap 41' has the same function as the gap 41 described above.

[0112] Specifically, as long as the radial width 41w of the gap 41' exceeds the minimum value of 0, it can function as a vent. On the other hand, the upper limit of the radial width 41w of the gap 41' is appropriately set based on the viewpoint of preventing the ingress of harmful foreign matter, as described above. As an example, the radial width 41w of the gap 41' can be set to 50 μm. Thus, foreign matter larger than 50 μm present externally cannot pass through the gap 41' and cannot intrude into the vent 50. 50 μm is an example of an upper limit value, and considering the use of the lens unit 100C, it can be appropriately set based on the size of foreign matter that may exist in the operating environment. In most cases, dust and dirt may become foreign matter. Taking this into consideration, for the upper limit value, the radial width 41w of the gap 41' is set to 55 μm or less, preferably 50 μm or less, and more preferably 45 μm or less.

[0113] Furthermore, the lower limit of the radial width 41w of the gap 41′ only needs to be greater than 0. From the viewpoint of air permeability, the lower limit is set to 6 μm or more, preferably 8 μm or more, and more preferably 10 μm or more.

[0114] [Implementation Method 2]

[0115] Other embodiments of the present invention will be described below. Furthermore, for ease of explanation, components having the same function as those described in the above embodiments will be labeled with the same reference numerals and will not be described again.

[0116] In Embodiment 1 described above, no groove forming part of the venting passage 50 is formed on the edge surface L1c of the front lens L1. In contrast, in this embodiment, a groove containing part of the venting passage 50 is formed on the edge surface L1c. Furthermore, in Embodiment 1, a gasket 3 is provided between the front lens L1 and the bearing surface 25 of the lens barrel bearing portion 21. In contrast, in this embodiment, a gasket is not provided between the front lens L1 and the bearing surface 25 of the lens barrel bearing portion 21.

[0117] The following uses Figures 9 to 11 The lens unit 100D of this embodiment is described. Figure 9 This is a cross-sectional view schematically illustrating the structure of the lens unit 100D according to Embodiment 2 of the present invention. Figure 9 It is the same as implementation method 1. Figure 1 The corresponding diagram. Furthermore, in Figure 9 The detailed description of the optical system of each lens in the lens unit 100D is omitted from the illustration. Figure 10 This is a plan view and a partial oblique view of the front lens L1 housed in the lens barrel 2 of the lens unit 100D. Figure 11 yes Figure 9 An enlarged view of section B within the dashed box shown. Figure 11 It is the same as implementation method 1. Figure 4 The corresponding diagram.

[0118] about Figure 9 The structural elements shown are due to the use of Figure 1 The explanation has already been provided, so the explanation will be omitted. The following will explain the differences.

[0119] Regarding the object side of the front lens L1, such as Figure 10 As shown, the lens has a lens surface L1a and an edge surface L1c extending radially outward from the outer edge of the lens surface L1a. The edge surface L1c is the object-facing portion of the flange-shaped edge portion L1f located at the outer edge of the front lens L1. Figure 10 The front lens L1 shown differs from the front lens L1 of Embodiment 1 in that an air groove L1s (concave-convex, first groove) communicating with the vent passage 50 is provided on the edge surface L1c. The air groove L1s is cut out at the outer periphery L1d of the edge surface L1c. Figure 10 The recess is provided at the end L1e and extends toward the lens surface L1a of the front lens L1.

[0120] The area outside the region where air grooves L1s are formed in the edge surface L1c (the non-forming region L1k) is as follows: Figure 11 As shown, it forms a structure that abuts against the bearing surface 25 of the bearing portion 21 of the lens barrel 2. The non-forming area of ​​the edge surface L1c abuts against the bearing surface 25, forming a space with a depth of air groove L1s (length along the axial direction of the lens barrel 2), and the notched end L1e of the air groove L1s communicates with the lens barrel air groove 24.

[0121] like Figure 11As shown, on the bearing surface 25, there is a bearing surface groove 26 (second groove) extending from a position opposite to the air groove L1s to the inner peripheral edge 23. The inner peripheral edge 23 is opposite to the aforementioned non-forming region L1k of the edge surface L1c. Therefore, a gap 41 is provided that corresponds to the depth (length along the axial direction) of the groove of the bearing surface groove 26.

[0122] On the other hand, at the position where the bearing surface groove 26 overlaps with the air groove L1s of the edge surface L1c, the bearing surface groove 26 communicates with the air groove L1s, forming a first space 42 with a width that combines the depth of the bearing surface groove 26 and the depth of the air groove L1s. Furthermore, on the outer diameter side of the first space 42, there is a position where the portion of the bearing surface 25 where the bearing surface groove 26 is not formed overlaps with the air groove L1s. At this position, a second space 43 with a width defined by the depth of the air groove L1s is connected to the first space 42.

[0123] The aforementioned gap 41, first space 42 and second space 43 are connected to the aforementioned lens tube air groove 24.

[0124] Here, regarding the gap 41, the same as the gap 41 in Embodiment 1, the axial width 41w is specified. Therefore, harmful foreign objects cannot pass through the gap 41 and cannot intrude into the ventilation passage 50. On the other hand, the same as the gap 41 in Embodiment 1 ensures ventilation, allowing air discharged from inside the lens barrel 2 through the ventilation passage 50 to be discharged to the outside of the lens unit 100D.

[0125] Similar to Embodiment 1, the front lens L1 can be made of glass. However, the material is not limited to glass, and the front lens L1 can also be made of resin, taking into account the processability of providing air grooves L1s on the edge surface L1c, as in this embodiment.

[0126] According to the structure of this embodiment, it is possible to realize a structure in which the air groove L1s provided on the edge surface L1c communicates with the lens barrel air groove 24 and the bearing surface groove 26, which constitute part of the ventilation passage 50. In addition, the gap 41 is also communicated with the lens barrel air groove 24 via the bearing surface groove 26 and the air groove L1s, realizing a structure in which the gap 41 is included in the object-side end of the ventilation passage 50.

[0127] According to the structure of this embodiment, the gasket of Embodiment 1 described above is not required, thus reducing the number of parts.

[0128] [A modified example of an air groove L1s provided on the edge surface L1c]

[0129] Not limited to this embodiment Figure 10The shape of the air groove L1s shown can be such that, through the unevenness provided on the edge surface L1c, a space forming part of the ventilation passage 50 is created between the edge surface L1c and the bearing surface 25. As an example, it could also be as follows: Figure 12 The edge surface L1c shown.

[0130] Figure 12 The edge surface L1c shown has a convex, elongated air groove L1s′ along its circumferential direction. Through the air groove L1s′, and... Figure 10 Compared to the air groove L1s method, it can ensure a larger area of ​​overlap with the bearing surface groove 26 formed on the entire circumference of the bearing surface 25. As a result, the ventilation of the ventilation path 50 is improved.

[0131] [Other variations]

[0132] In Embodiment 2 described above, the air groove L1s provided on the edge surface L1c includes a notched end L1e. Furthermore, in Embodiment 2 described above, the bearing surface 25 has a bearing surface groove 26 extending from a position opposite to the air groove L1s to the inner periphery 23. However, the structure is not limited to these structures; for example, it could also be... Figure 13 and Figure 14 The variation shown is an example of a variation.

[0133] Figure 13 This is a plan view of the object side showing a modified example of the front lens L1′. The front lens L1′ has a circular recess L1x on the edge surface L1c. The recess L1x is not cut off at the outer periphery L1d of the edge surface L1c, but is located on the inner diameter side of the edge surface L1c. Multiple recesses L1x are provided along the circumference of the edge surface L1c. Between the recesses L1x in the edge surface L1c, there are areas where no recess is formed (non-formed areas L1k).

[0134] Figure 14 Is to make Figure 13 The enlarged cross-sectional view shown is of the lens unit 100E in which the front lens L1′ abuts against the bearing surface 25 of the bearing portion 21. Figure 11 The corresponding diagram. (For example...) Figure 14 As shown, a gap 41 is formed between the edge surface L1c that abuts against the bearing surface 25 and the bottom surface of the recess L1x of the edge surface L1c.

[0135] like Figure 14As shown, the region L1p in the recess L1x of the edge surface L1c, near the lens surface L1a, is further towards the inner diameter than the inner periphery 23 of the bearing surface 25. Furthermore, the region L1q in the recess L1x of the opposite edge surface L1c, near the outer periphery L1d of the front lens L1, does not face the bearing surface 25, but opens towards the recess 27 formed between the bearing surface 25 and the inner surface 2a of the lens barrel 2.

[0136] Therefore, the region L1q in the recess L1x near the outer periphery L1d of the front lens L1 becomes the object-side opening of the venting passage 50. Furthermore, the structure connecting this region L1q to the internal space of the recess L1x further enables a structure connecting the region L1q near the outer periphery L1d to the recess 27 communicating with the lens barrel air groove 24. These constitute part of the venting passage 50, realizing a structure in which the gap 41 is included in the object-side end of the venting passage 50.

[0137] Here, the gap 41 is the same as the gap 41 in Embodiment 1, and its axial width 41w is defined. As a result, harmful foreign objects cannot pass through the gap 41 and cannot invade the ventilation passage 50. On the other hand, the same gap 41 as in Embodiment 1 ensures ventilation, allowing air discharged from inside the lens barrel 2 through the ventilation passage 50 to be discharged to the outside of the lens unit 100E.

[0138] [Other variations]

[0139] Figure 15 This indicates other variations. Figure 15 This is a plan view of the object side showing a modified example of the front lens L1′. The front lens L1′ has a circular protrusion L1y on the edge surface L1c. Multiple protrusions L1y are provided along the circumference of the edge surface L1c, and between the protrusions L1y in the edge surface L1c, there are areas where no protrusions are formed (non-protrusion areas L1h).

[0140] Figure 16 Is to make Figure 15 The enlarged cross-sectional view shown is of the lens unit 100F where the front lens L1′ abuts against the bearing surface 25 of the bearing portion 21. Figure 11 The corresponding diagram. (For example...) Figure 16 As shown, the protrusion L1y of the edge surface L1c abuts against the bearing surface 25. By having the protrusion L1y abut against the bearing surface 25 in this way, the non-protruding region L1h of the bearing surface 25 and the edge surface L1c... Figure 15 A gap 41 with an axial width defined as a specified size is formed between the bearing surface 25 and the edge surface L1c. This gap 41 has the same function as the gap 41 described above. In other words, the protrusion L1y has a height that forms the gap 41 between the bearing surface 25 and the edge surface L1c.

[0141] Like this, through Figure 15 and Figure 16 This method can also be used in the non-protruding region L1h between the bearing surface 25 and the edge surface L1c. Figure 15 A ventilation passage with a predetermined gap 41 in the axial direction is formed between the two parts. Thus, as in the manner shown in the various embodiments and modifications described above, harmful foreign objects are not allowed to enter the ventilation passage 50, and a ventilation passage that ensures ventilation is achieved.

[0142] In addition, Figure 15 and Figure 16 In this method, a protrusion L1y is formed on the edge surface L1c, but it is not limited to this. It is also possible to have a protrusion protruding toward the image plane on the bearing surface 25, and the protrusion abuts against the edge surface. Alternatively, it is possible to have protrusions on both the edge surface L1c and the bearing surface 25.

[0143] Alternatively, although not illustrated, in a structure where an air groove L1s is provided on the edge surface L1c, the end of the air groove L1s on its inner circumferential side can be located further inward than the inner circumferential edge 23 of the bearing portion 21. In this case, it is not necessary to provide the bearing surface groove 26 described above on the bearing portion 21. Instead, an opening is made at the end of the air groove L1s on its inner circumferential side, and the air groove L1s is included in a part of the ventilation passage 50. The cut-out end L1e of the air groove L1s communicates with the lens barrel air groove 24. In this configuration, the opening corresponding to the gap 41 described above can be defined as having a predetermined width 41w in the radial direction at the end of the air groove L1s on its inner circumferential side, or it can be defined as having a predetermined width 41w in the axial direction at the end of the air groove L1s on its inner circumferential side.

[0144] [Implementation Method 3]

[0145] Other embodiments of the present invention will be described below. Furthermore, for ease of explanation, components having the same function as those described in the above embodiments will be labeled with the same reference numerals and will not be described again.

[0146] In the above-described embodiments and variations, a receiving portion 21 is provided on the object side of the lens barrel 2. In contrast, in this embodiment, the difference from other embodiments is that the lens barrel 2 has a lens barrel body 201 and an object side pressing ring 202 installed at the object side end of the lens barrel body 201, and the receiving portion 21 is provided on the object side pressing ring 202.

[0147] exist Figure 17In this configuration, the object-side pressing ring 202 is installed on the lens barrel body 201 via a threaded engagement. Specifically, the thread 201a provided on the outer peripheral surface of the lens barrel body 201 engages with the thread 202a provided on the inner peripheral surface of the object-side pressing ring 202, which has an inner diameter larger than that of the outer peripheral surface of the lens barrel body 201.

[0148] exist Figure 17 In the example, compared with implementation method 2 Figure 9 As shown, the edge surface L1c of the front lens L1 abuts against the bearing surface 25 of the bearing portion 21 (of the object-side pressing ring 202). The object-side pressing ring 202 can be made of metal, as can the image-side pressing ring 4, or it can be made of other materials.

[0149] [Implementation Method 4]

[0150] This describes one embodiment of a camera device having the lens unit 100D described in Embodiment 2 above. Furthermore, the lens unit included in the camera device is not limited to the lens unit 100D, but may also be the lens unit of each of the above embodiments and variations.

[0151] Figure 18 This is a schematic diagram of the imaging device 400 according to this embodiment, and is a cross-sectional view along the optical axis. The imaging device 400 includes... Figure 9 The lens unit 100D shown, and the imaging element 300 disposed on the image plane side of the lens unit 100D.

[0152] The imaging element 300 receives light after it has passed through the lens groups L1 to L6 of the lens unit 100D. In addition, known optical components such as filters may be provided on the image plane side of the lens unit 100D or between the lens unit 100D and the imaging element 300.

[0153] In addition, the camera device 400 may also have a housing for storing the lens unit 100D and the camera element 300.

[0154] The lens unit 100D of the imaging device 400 has ventilation from the image plane side to the object side within the lens barrel 2. Furthermore, the ventilation path 50 includes a gap 41, thus preventing foreign objects from entering from the outside. If a foreign object were to enter the lens barrel 2, it could potentially pass through the image plane side pressing ring 4 and further into the imaging element 300, potentially affecting imaging performance. However, the imaging device 400 according to this embodiment can prevent the intrusion of foreign objects, thus enabling an imaging device that ensures both imaging performance and high reliability.

[0155] 〔Summarize〕

[0156] Based on the above description, it can be determined that the lens unit of the first aspect of the present invention includes: a lens group including a front lens having an edge portion extending radially outward from the outer edge of the lens surface; and a lens barrel housing the lens group and having a receiving surface facing the object side of the edge portion. The lens unit also includes: a venting passage opening at both ends of the lens barrel on the image plane side and the object side, and communicating the openings at both ends within the lens barrel. The object-side end of the venting passage includes a gap formed between the edge portion and the receiving surface. According to the first aspect, the venting passage, which opens at both ends of the lens barrel on the image plane side and the object side and communicates the openings at both ends within the lens barrel, sufficiently ensures an air discharge path from inside the lens barrel to the outside. Furthermore, according to the first aspect, the gap is included at the object-side end of the venting passage. Therefore, by implementing the gap with a specific width that takes into account the size of foreign objects to prevent intrusion into the lens barrel from the outside, a lens unit capable of preventing such intrusion can be realized.

[0157] The lens unit of the second embodiment of the present invention can also be configured as described in the first embodiment, wherein the lens unit further includes an annular washer held between the bearing surface and the edge portion, the washer including a notch cut at its outer periphery, the object-side end of the venting passage including the notch, and a gap formed between the washer and the bearing surface or the edge portion between the notch and the object-side opening. According to the second embodiment, the notch of the washer is included in the venting passage, thus eliminating the need to process the edge portion to form part of the venting passage. Therefore, as a front lens, a glass lens unsuitable for such processing can be suitably used.

[0158] The lens unit of the third embodiment of the present invention can also be configured in the second embodiment, wherein the bearing surface includes a groove extending from a position overlapping the notch in the axial direction of the lens barrel to the inner periphery of the bearing surface, the groove forming the gap. According to the third embodiment, an air discharge path from inside the lens barrel to the outside can be ensured through the groove. Furthermore, by implementing the groove with a specific width that takes into account the size of foreign objects to prevent intrusion into the lens barrel from the outside, a lens unit capable of preventing such intrusion can be realized.

[0159] The lens unit of the fourth embodiment of the present invention can also be configured in any of the first to third embodiments, wherein the lens unit further includes an annular washer held between the bearing surface and the edge portion, the washer having a through hole continuous with the venting passage within the lens barrel, and the bearing surface having a groove extending from a position opposite the through hole in the axial direction of the lens barrel to the inner periphery of the bearing surface, the groove forming the gap. According to the fourth embodiment, the through hole is continuous with the venting passage, thus ensuring an exhaust path for air from inside the lens barrel to the outside through the through hole and the groove of the bearing surface. Furthermore, by implementing the groove of the bearing surface with a specific width that takes into account the size of foreign objects to prevent intrusion into the lens barrel from the outside, a lens unit capable of preventing such intrusion can be realized.

[0160] The lens unit of the fifth embodiment of the present invention can also be configured in any of the first to fourth embodiments, wherein at least one of the bearing surface and the edge portion has a concave-convex shape forming the gap between the bearing surface and the edge portion. According to the fifth embodiment, the gap is formed by the concave-convex shape, thus ensuring an air exhaust path from the inside of the lens barrel to the outside. By achieving a specific size for the undulation of the concave-convex shape to take into account the size of foreign objects in order to prevent intrusion from the outside into the lens barrel, a lens unit capable of preventing such intrusion can be realized.

[0161] The lens unit of the sixth embodiment of the present invention can also be configured in the fifth embodiment, wherein the concave and convex shapes are grooves formed on the edge portion and extending to the center side beyond the inner periphery of the bearing surface, and the grooves constitute the gap. According to the sixth embodiment, an exhaust path for air from inside the lens barrel to the outside can be ensured through the grooves. By implementing the grooves with a specific width that takes into account the size of foreign objects in order to prevent intrusion into the lens barrel from the outside, a lens unit capable of preventing such intrusion can be realized.

[0162] The lens unit of the seventh embodiment of the present invention can also be configured in the fifth embodiment, wherein the concave and convex shapes are formed on the edge portion and communicate with the venting passage formed in the lens barrel on a peripheral side beyond the edge portion, and include: a first groove extending to a middle portion on a peripheral side beyond the inner periphery of the bearing surface; and a second groove formed on the bearing surface and extending from the middle portion to the inner periphery, wherein at least one of the first groove and the second groove constitutes the gap. According to the seventh embodiment, an exhaust path for air from inside the lens barrel to the outside can be ensured through the first groove and the second groove. In addition, by having at least one of the first groove and the second groove constitute the gap, the gap is achieved with a specific width that takes into account the size of foreign objects in order to prevent intrusion into the lens barrel from the outside, thereby enabling a lens unit that can prevent such intrusion.

[0163] The lens unit of the eighth embodiment of the present invention can also be configured in the fifth embodiment, wherein the concave-convex shape includes a protrusion formed on at least one of the bearing surface and the edge portion, and has a height that forms the gap between the bearing surface and the edge portion. According to the eighth embodiment, the protrusion has a height that forms the gap, thus ensuring an air discharge path from inside the lens barrel to the outside through the gap between the bearing surface and the edge portion separated by the protrusion. Furthermore, by implementing the gap with a specific width that takes into account the size of foreign objects to prevent intrusion into the lens barrel from the outside, a lens unit capable of preventing such intrusion can be realized.

[0164] In any of the first to eighth embodiments of the present invention, the lens barrel of the lens unit in the ninth embodiment can also be made of metal. According to the ninth embodiment, even with a metal lens barrel that is not easily machined, an air exhaust path from the inside of the lens barrel to the outside can be ensured, and foreign objects can be prevented from entering the lens barrel from the outside.

[0165] In the lens unit of the tenth embodiment of the present invention, in the fifth embodiment, the front lens may also be made of resin. According to the tenth embodiment, a groove forming the gap at the edge can be formed, thus achieving the gap well.

[0166] The lens unit of the 11th embodiment of the present invention can also be configured in any of the 1st to 10th embodiments, wherein the lens barrel has a lens barrel body and a pressing ring mounted on the object-side end of the lens barrel body, the pressing ring including the bearing surface. According to the 11th embodiment, the gap can be achieved between the pressing ring and the edge portion.

[0167] The imaging device according to the 12th aspect of the present invention includes: a lens unit as described in any one of the 1st to 10th aspects, and an imaging element that receives light after passing through the lens group of the lens unit. According to the 12th aspect, by having a lens unit that ensures an air discharge path from inside the lens barrel to the outside and prevents foreign objects from entering the lens barrel from the outside, an imaging device capable of high-precision imaging by the imaging element can be realized.

[0168] Based on this structure, a lens unit suitable for automotive cameras can be provided. This is expected to create an environment conducive to automation, such as autonomous driving in automobiles. Therefore, this invention is expected to contribute to achieving the Sustainable Development Goals (SDGs) related to promoting innovation and sustainable industrialization.

[0169] This invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of this invention.

Claims

1. A lens unit, comprising: A lens assembly, including a front lens having an edge portion extending radially outward from the outer edge of the lens surface; as well as The lens barrel houses the lens assembly and has a bearing surface facing the object side of the edge portion. Furthermore, the lens unit includes: A venting passage is provided, opening at both ends of the lens barrel on the image plane and the object side, and the openings at both ends are connected within the lens barrel. The object-side end of the ventilation path includes a gap formed between the edge and the bearing surface.

2. The lens unit as described in claim 1, The lens unit also includes an annular washer held between the bearing surface and the edge portion. The washer includes a notch cut at the outer periphery. The end of the venting passage on the object side includes the notch, and a gap is formed between the gasket and the bearing surface or the edge between the notch and the opening on the object side.

3. The lens unit as described in claim 2, The bearing surface includes a groove extending from a position overlapping the notch in the axial direction of the lens barrel to the inner periphery of the bearing surface. The grooves form the gaps.

4. The lens unit as described in claim 1, The lens unit also includes an annular washer held between the bearing surface and the edge portion. The gasket has a through hole that is continuous with the venting passage inside the lens barrel. The bearing surface has a groove extending from a position opposite the through hole in the axial direction of the lens barrel to the inner periphery of the bearing surface. The grooves form the gaps.

5. The lens unit as described in claim 1, At least one of the bearing surface and the edge portion has an unevenness that forms the gap between the bearing surface and the edge portion.

6. The lens unit as described in claim 5, The protrusions and depressions are grooves formed on the edge portion and extending to the center side beyond the inner periphery of the bearing surface. The grooves form the gaps.

7. The lens unit as described in claim 5, The irregularities include: A first groove is formed on the edge portion and communicates with the ventilation passage formed in the lens barrel on the outer periphery side of the edge portion, and extends to the middle portion on the outer periphery side of the bearing surface. as well as A second groove is formed on the bearing surface and extends from the middle portion to the inner periphery. At least one of the first groove and the second groove constitutes the gap.

8. The lens unit as described in claim 5, The irregularities include: A protrusion is formed on at least one of the bearing surface and the edge portion, and has a height that forms the gap between the bearing surface and the edge portion.

9. The lens unit as described in claim 1, The lens barrel is made of metal.

10. The lens unit as described in claim 5, The front lens is made of resin.

11. The lens unit as claimed in claim 1, The microscope tube has a microscope tube body and a pressing ring installed on the object-side end of the microscope tube body. The pressing ring includes the bearing surface.

12. A camera device, comprising: The lens unit as described in any one of claims 1 to 11; and The imaging element receives light after it has passed through the lens group of the lens unit.

Images