Lens barrel and imaging device

Abstract

To provide a lens barrel which allows for adjusting inter-lens alignment, offers superior waterproofness, and has a simple configuration.SOLUTION: An alignment frame (150) is engaged with a fixed barrel (140) via a bayonet structure, and an adhesive is injected to a recess from the outside to be cured and fixed. A gap leading from the periphery of a front lens into a lens optical system and an opening of an outer frame cylinder leading to the bayonet structure are watertightly sealed with respective O-rings (160, 170).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a lens barrel and an imaging device. [Background technology]

[0002] Demand for high-resolution lenses is increasing in fields such as surveillance and medicine. To improve lens performance and increase yield rates, optical axis alignment between lens groups within a lens barrel is often required. A known optical axis alignment method uses a spring or other biasing member to correct optical axis misalignment between lens groups. Such conventional techniques include a technique that includes lens frame alignment and dustproofing (see, for example, Patent Document 1), a technique that adjusts the optical axis direction of the lens frame using a bayonet-like shape (see, for example, Patent Document 2), a mechanism that uses spring biasing to align the lens frame (see, for example, Patent Document 3), and a mechanism that adjusts the position of the lens frame using spring biasing and a bayonet-like shape (see, for example, Patent Document 4). Patent Document 1 also discloses a technique that seals gaps created during alignment with a sealing member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-61513 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-145631 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-111932 [Patent Document 4] Japanese Patent Application Publication No. 2019-28416 Summary of the Invention [Problem to be solved by the invention]

[0004] As lens barrels become smaller and higher resolution, there is a demand for alignment mechanisms that can be used in small spaces. Furthermore, when an alignment mechanism is introduced, gaps naturally form in the lens barrel, so a sealed structure is needed to provide waterproofing and other measures.

[0005] However, the above-mentioned conventional technologies leave room for further consideration in terms of achieving both a structure that enables alignment and a sealing structure that closes the gap formed thereby. For example, Patent Document 1 does not disclose a structure for adjusting the lens frame in the Z-axis direction when aligning the lens frame, and although a sealing structure that is dustproof is disclosed, it is difficult to say that it is sufficient from the perspective of waterproofing. Furthermore, Patent Document 2 does not disclose a sealing structure that can support alignment in the XY plane and waterproofing, and Patent Document 3 does not disclose a structure that enables alignment in the Z-axis direction or a sealing structure that can support waterproofing. Patent Document 4 discloses an alignment structure that adjusts between the lens and the sensor substrate, but does not disclose a structure that enables alignment between the lenses, nor does it disclose a sealing structure that can support waterproofing.

[0006] An object of one aspect of the present invention is to provide a lens barrel that is capable of aligning lenses, has excellent waterproof properties, and has a simple configuration. [Means for solving the problem]

[0007] In order to solve the above problem, a lens barrel according to one embodiment of the present invention comprises a fixed barrel portion that holds a reference lens, an alignment frame that holds a lens to be aligned that is to be placed on the optical axis of the reference lens and that engages with the fixed barrel portion via a bayonet structure, a recess formed on one of the fixed barrel portion and the alignment frame facing the other and that can accommodate adhesive that is injected from outside the fixed barrel portion with which the alignment frame is engaged, a first seal member that watertightly seals the gap between the peripheral portion of a front lens included in the reference lens or the lens to be aligned and the fixed barrel portion or the alignment frame that holds the front lens, and a second seal member formed on the fixed barrel portion that watertightly seals an opening that leads to the bayonet structure. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to realize a lens barrel that is capable of aligning lenses, has excellent waterproof properties, and has a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram schematically illustrating an imaging device according to a first embodiment of the present invention. [Figure 2] FIG. 1 is an exploded perspective view of an imaging device according to a first embodiment of the present invention. [Figure 3] 2 is a longitudinal cross-sectional view schematically showing the cross section of the imaging device of FIG. 1 taken along line AA. [Figure 4] FIG. 2 is a diagram schematically showing a fixed barrel section as viewed from the image plane side in the first embodiment of the present invention. [Figure 5] FIG. 2 is a diagram schematically illustrating an alignment frame as viewed from the image plane side in the first embodiment of the present invention. [Figure 6] 5A and 5B are diagrams for explaining engagement of an alignment frame with a fixed barrel portion in the first embodiment of the present invention. [Figure 7] FIG. 10 is an exploded perspective view of an imaging device according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a longitudinal sectional view of an imaging device according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a diagram schematically showing a fixed barrel section as viewed from the image plane side in a second embodiment of the present invention. [Figure 10] FIG. 10 is a diagram schematically illustrating a first alignment frame as viewed from the image plane side in a second embodiment of the present invention. [Figure 11] FIG. 10 is a diagram schematically illustrating a second alignment frame as viewed from the image plane side in a second embodiment of the present invention. [Figure 12] 10A and 10B are diagrams illustrating engagement of a first alignment frame and a second alignment frame with a fixed barrel portion in a second embodiment of the present invention. [Figure 13] FIG. 10 is an exploded perspective view of an imaging device according to a third embodiment of the present invention. [Figure 14] FIG. 10 is a longitudinal sectional view of an imaging device according to a third embodiment of the present invention. [Figure 15]10 is an enlarged cross-sectional view showing an engagement portion between a fixed barrel portion and an alignment frame in a third embodiment of the present invention. FIG. [Figure 16] FIG. 10 is a diagram illustrating tilt adjustment in the third embodiment of the present invention. [Figure 17] FIG. 10 is an exploded perspective view of an imaging device according to a fourth embodiment of the present invention. [Figure 18] FIG. 10 is a longitudinal sectional view of an imaging device according to a fourth embodiment of the present invention. [Figure 19] FIG. 10 is a diagram schematically illustrating an alignment frame as viewed from the image plane side in a fourth embodiment of the present invention. [Figure 20] FIG. 10 is a diagram schematically showing a fixed barrel section as viewed from the image plane side in a fourth embodiment of the present invention. [Figure 21] 10A and 10B are diagrams illustrating engagement of an alignment frame with a fixed barrel portion in a fourth embodiment of the present invention. [Figure 22] FIG. 10 is an exploded perspective view of an imaging device according to a fifth embodiment of the present invention. [Figure 23] FIG. 10 is a longitudinal sectional view of an imaging device according to a fifth embodiment of the present invention. [Figure 24] FIG. 11 is a diagram schematically showing a fixed barrel section as viewed from the image plane side in a fifth embodiment of the present invention. [Figure 25] FIG. 10 is an enlarged cross-sectional view showing the engagement and sealing portions between the fixed barrel and the alignment frame in the fifth embodiment of the present invention. [Figure 26] FIG. 10 is an exploded perspective view of an imaging device according to a sixth embodiment of the present invention. [Figure 27] FIG. 10 is a longitudinal sectional view of an imaging device according to a sixth embodiment of the present invention. [Figure 28] FIG. 13 is a diagram schematically showing a fixed barrel section as viewed from the image plane side in a sixth embodiment of the present invention. [Figure 29] 13 is an enlarged cross-sectional view showing an engagement portion between a fixed barrel portion and an alignment frame in a sixth embodiment of the present invention. FIG. [Figure 30] FIG. 13 is an enlarged cross-sectional view showing a sealing portion of a fixed barrel portion according to a sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0011] [composition] FIG. 1 is a diagram schematically illustrating an imaging device according to this embodiment. FIG. 2 is an exploded perspective view of the imaging device according to this embodiment. FIG. 3 is a longitudinal cross-sectional view schematically illustrating a cross section of the imaging device of FIG. 1 taken along line AA. As shown in FIG. 1, imaging device 10 is composed of a box-shaped main body 11 and a cylindrical lens barrel 12. Main body 11 is composed of a housing section 111, a board section 112, and an imaging element 13. Imaging element 13 is a solid-state imaging element such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor. In this way, imaging device 10 has lens barrel 12 and imaging element 13.

[0012] The housing 111 and the substrate 112 are made of, for example, a metal such as aluminum or a resin. The housing 111 is an outer frame having a box-like shape, and the substrate 112 is an outer frame having the shape of one side of the box-like shape. The imaging element 13 is disposed in the center of the inner surface of the substrate 112. The substrate 112 is tightly adhered to the edge of the opening of the housing 111.

[0013] Lens barrel 12 includes a cylindrical outer frame tube 120 that stands on the other side of housing 111. Outer frame tube 120 is molded integrally with housing 111. A first threaded portion 130 is provided around the tip of the inner circumferential surface of outer frame tube 120. Inside outer frame tube 120, fixed barrel portion 140, alignment frame 150, and O-rings 160 and 170 are housed.

[0014] FIG. 4 is a diagram showing a schematic view of the fixed barrel portion as viewed from the image plane side in this embodiment.

[0015] The fixed barrel portion 140 is a substantially cylindrical member and is composed of a tube portion 141 and a flange portion 142. The fixed barrel portion 140 is, for example, a one-piece molded product made of resin. The tube portion 141 holds two lenses, a first lens 143 and a second lens 144, inside the tube portion 141 and arranged on the same optical axis. In this way, the fixed barrel portion 140 holds two lenses. The lens held by the fixed barrel portion 140 is also referred to as a "reference lens." The first lens 143 corresponds to the front lens in the optical system of the lens barrel.

[0016] It should be noted that first lens 143 (front lens) is the lens located closest to the object in lens barrel 12. If fixed barrel portion 140 has multiple lenses (multiple reference lenses), the lens located closest to the object is first lens 143.

[0017] The flange portion 142 is a portion that spreads outward from one end side (object side) of the tubular portion 141. In a plan view, the flange portion 142 has three guide holes 1421 arranged at equal intervals in the circumferential direction. The guide holes 1421 have a substantially L-shaped planar shape, with the short side of the substantially L-shape extending in the radial direction of the flange portion 142 and the long side of the substantially L-shape extending toward the inner periphery of the flange portion 142. In addition, an outer peripheral wall 145 is provided around the outer periphery of the flange portion 142.

[0018] A second threaded portion 1451 that screws into the first threaded portion 130 of the outer frame cylinder 120 is formed on the outer peripheral surface of the outer peripheral wall 145. The fixed barrel portion 140 is fixed to the outer frame cylinder 120 by the screw engagement of the first threaded portion 130 and the second threaded portion 1451, and is thus integrated with the outer frame cylinder 120. In this way, the fixed barrel portion 140 is fixed to the inside of the outer frame cylinder 120 of the lens barrel 12.

[0019] A step 1422 of a specific thickness is formed between the outer peripheral wall 145 and the long side of the guide hole 1421 on the object-side principal surface of the flange portion 142. Furthermore, an uneven portion 1452 formed of unevenness extending in the axial direction (parallel in the circumferential direction) is formed on the inner peripheral surface of the outer peripheral wall 145 at a position overlapping with the step 1422 in the circumferential direction. Furthermore, an annular first fitting groove 146 and a second fitting groove 147 are formed from the inside on the inner peripheral edge of the principal surface of the flange portion 142. Furthermore, a step 1423 of a specific thickness is formed between adjacent guide holes 1421 in the circumferential direction on the image-plane-side principal surface of the flange portion 142.

[0020] FIG. 5 is a diagram showing a schematic view of the alignment frame 150 as seen from the image plane side in this embodiment. The alignment frame 150 is a substantially cylindrical body whose diameter on the image plane side is smaller than its diameter on the object side. The alignment frame 150 is, for example, a one-piece molded product made of resin. The alignment frame 150 holds a third lens 151 and a fourth lens 152 therein, on the same optical axis. The lenses held by the alignment frame 150 are also called "lenses to be aligned."

[0021] The alignment frame 150 has three claws 153 that protrude further toward the object side along the axial direction from the edge on the object side that has a larger diameter. The claws 153 are arranged at equal intervals in the circumferential direction.

[0022] The claw portion 153 has an insertion shaft portion 1531 that is inserted into the short side portion of the guide hole 1421, and an engagement portion 1532 that spreads outward from the tip of the insertion shaft portion 1531. Two grooves 1533 that extend circumferentially and are parallel to each other in the radial direction are formed in the tip surface (the end surface on the object side) of the engagement portion 1532. The outermost groove 1533 is a recess that is open to the outer periphery.

[0023] 6 is a diagram illustrating the engagement of the alignment frame with the fixed barrel portion in this embodiment. To engage the alignment frame 150 with the fixed barrel portion 140, first, the claws 153 are inserted into the guide holes 1421 of the fixed barrel portion 140 (left diagram in FIG. 6). Next, the alignment frame 150 is engaged with the fixed barrel portion 140 by rotating it along the long side of the guide holes 1421 relative to the fixed barrel portion 140 (right diagram in FIG. 6). The flange portion 142 of the fixed barrel portion 140, the guide holes 1421, and the claws 153 of the alignment frame 150 form a bayonet structure that engages the alignment frame 150 with the fixed barrel portion 140, and the alignment frame 150 engages with the fixed barrel portion 140 via the bayonet structure.

[0024] The base end surface of the engaging portion 1532 rides up and slides on the step portion 1422. A groove 1533 that opens toward the outer periphery of the engaging portion 1532 faces the uneven portion 1452 of the flange portion 142. The fixed barrel portion 140 that engages the alignment frame 150 is formed with a recess 180 that has the outermost groove 1533 and the uneven portion 1452 facing it as side walls and has an opening on the object side. In this way, the recess 180 is formed by the groove 1533 of the alignment frame 150 that faces the uneven portion 1452 of the fixed barrel portion 140.

[0025] Furthermore, when the claw portion 153 is inserted into the guide hole 1421 of the fixed barrel portion 140 and the alignment frame 150 is rotated relative to the fixed barrel portion 140, the object side edge of the alignment frame 150 abuts against the step portion 1423 on the image plane side of the flange portion 142.

[0026] The position of alignment frame 150 is adjusted relative to fixed barrel portion 140 so that the optical axes of third lens 151 and fourth lens 152 in alignment frame 150 coincide with the optical axes of first lens 143 and second lens 144 in fixed barrel portion 140. This adjustment of the optical axes will be described in more detail later.

[0027] The O-ring 160 is fitted into the first fitting groove 146 of the fixed barrel portion 140. The first lens 143 is held by the fixed barrel portion 140 in contact with the O-ring 160 from the object side.

[0028] The O-ring 170 is fitted into the second fitting groove 147 of the fixed barrel portion 140. Without the O-ring 170, a gap is formed between the fixed barrel portion 140 and the outer barrel 120 at the object-side end of the lens barrel. This gap has an opening 190 between the front lens and the outer barrel 120, which leads to the bayonet structure and into the fixed barrel portion, the alignment frame, or the image sensor. When the fixed barrel portion 140 approaches the edge of the outer barrel 120 due to screwing into the outer barrel 120, the O-ring 170 is pressed against the inner surface of the outer barrel 120, and is in close contact with both the inner surface of the outer barrel 120 and the bottom surface of the second fitting groove 147. The O-ring 170 watertightly seals the opening 190 formed in the fixed barrel portion 140 and leading to the bayonet structure.

[0029] [assembly] First, O-ring 160 is fitted into first fitting groove 146 of fixed barrel portion 140, and first lens 143 and second lens 144 are placed in fixed barrel portion 140. Furthermore, O-ring 170 is fitted into second fitting groove 147. First lens 143 and second lens 144 are positioned on the same specific optical axis by being held in fixed barrel portion 140. Third lens 151 and fourth lens 152 are also placed in alignment frame 150. Third lens 151 and fourth lens 152 are also positioned on the same specific optical axis by being held in alignment frame 150.

[0030] Next, the claws 153 of the alignment frame 150 are inserted into the guide holes 1421 of the fixed barrel 140, and the alignment frame 150 is rotated relative to the fixed barrel 140. As a result, the engagement portions 1532 of the claws 153 come into contact with the step portions 1422 on the object side of the flange 142 of the fixed barrel 140, and a recess 180 is formed by the groove 1533 on the outer periphery of the engagement portions 1532 and the outer circumferential wall 145 of the flange 142. Furthermore, on the image plane side of the flange 142, the object side edge of the alignment frame 150 comes into contact with the step portion 1423. After the alignment frame 150 is engaged with the fixed barrel 140, the position of the alignment frame 150 relative to the fixed barrel 140 is adjusted so that the optical axis of the lens in the fixed barrel 140 and the optical axis of the lens in the alignment frame 150 are aligned (for example, substantially aligned with the optical axis OA of the image sensor).

[0031] Next, the fixed barrel portion 140, to which the alignment frame 150 is engaged and fixed, is inserted into the outer frame tube 120, and the second screw portion 1451 of the fixed barrel portion 140 is screwed into the first screw portion 130 of the outer frame tube 120 to fix the fixed barrel portion 140 inside the outer frame tube 120.

[0032] Next, the position of the imaging element 13 is adjusted so that the optical axis of the imaging element 13 on the substrate part 112 is aligned with the optical axis of the lens in the lens barrel 12. Then, adhesive is applied to the edge of the opening of the main body 11, and the substrate part 112 is attached. In this way, the imaging device 10 is obtained.

[0033] Here, the alignment of the lens will be described by defining two axes that are orthogonal to the optical axis OA of the imaging device 10 and that are orthogonal to each other as the X axis and the Y axis, respectively, and defining the optical axis OA as the Z axis.

[0034] [X and Y direction adjustment] The fixed barrel 140, which is engaged with the alignment frame 150, is placed on the adhesive base. The adhesive base has three or more alignment pins that can be advanced and retracted radially using screws. The fixed barrel 140 is supported by the adhesive base so that the optical axis is positioned at the center in the radial direction. Then, the tips of the alignment pins are advanced to the alignment frame 150.

[0035] Next, a UV (ultraviolet) curable adhesive is poured into recess 180 formed on the object side of flange 142 of fixed barrel 140, surrounded by engagement portion 1532 of alignment frame 150 and uneven portion 1452 of fixed barrel 140. Because recess 180 opens on the object side of fixed barrel 140 engaged with alignment frame 150, adhesive can be poured from the outside of fixed barrel 140 and can be accommodated therein.

[0036] Next, the alignment pins are advanced and retracted as appropriate to center the optical axis in alignment frame 150. The diameter of claw portions 153 of alignment frame 150 is slightly different from the diameter of guide holes 1421 of fixed barrel portion 140. Therefore, by advancing and retracting the alignment pins, the position of the optical axis of alignment frame 150 in the XY plane is adjusted within the range of this diameter difference. In this way, the position of alignment frame 150 in the XY plane is adjusted so that the optical axis of the lens in alignment frame 150 is aligned with the optical axis of the lens in fixed barrel portion 140.

[0037] Next, with the alignment frame 150 supported by the alignment pins in an optimal position relative to the fixed barrel portion 140, ultraviolet rays are irradiated from a UV irradiator onto the adhesive that has been poured into and housed in the recess 180. This ultraviolet irradiation hardens the adhesive in the recess 180, and the alignment frame 150 is fixed to the fixed barrel portion 140.

[0038] When the position of the alignment frame 150 relative to the fixed barrel portion 140 in the XY plane needs to be readjusted, the adhesive that has hardened in the recess 180 is peeled off, and the position of the alignment frame 150 is adjusted using the same procedure as above.

[0039] [Z-direction adjustment] In this embodiment, on the object side of flange 142 of fixed barrel 140, engagement portion 1532 of alignment frame 150 can abut against step 1422. Also, on the image plane side of flange 142 of fixed barrel 140, the object side edge of alignment frame 150 can abut against step 1423. Therefore, depending on the dimensional accuracy of step portions 1422, 1423 in molding fixed barrel 140, the distance (thrust distance) in the Z axis between the lens of alignment frame 150 and the lens of fixed barrel 140 can be adjusted to the desired distance (design value).

[0040] [Seal structure] The substrate 112 is adhered with an adhesive to the edge of the opening of the main body 11. Therefore, the imaging device 10 can exhibit sufficient waterproofing at the joint between the main body 11 and the substrate 112.

[0041] Furthermore, the housing 111 of the main body 11 and the outer frame 120 of the lens barrel 12 are integrally molded, so that sufficient waterproofing is achieved between the main body 11 and the lens barrel.

[0042] An O-ring 160 fitted in the first fitting groove 146 is interposed between the fixed barrel portion 140 and the front lens (first lens 143). The O-ring 160 is sandwiched between the object-side edge of the fixed barrel portion 140 and the periphery of the front lens, and is in close contact with both the fixed barrel portion 140 and the front lens around its entire circumference. In this way, the O-ring 160 watertightly seals the gap between the periphery of the front lens and the fixed barrel portion 140 that holds the front lens. Therefore, the imaging device 10 is sufficiently waterproof against the inside of the fixed barrel portion 140.

[0043] An O-ring 170 fitted in the second fitting groove 147 is interposed between the fixed barrel portion 140 and the open end of the outer frame tube 120. The O-ring 170 is sandwiched between the inner surface of the outer frame tube 120 and the fixed barrel portion 140, and is in close contact with both the outer frame tube 120 and the fixed barrel portion 140 around the entire circumference near the open end of the outer frame tube 120 in the gap that runs from the outer frame tube 120 and the fixed barrel portion 140 to the bayonet structure. In this way, the O-ring 170 watertightly seals the opening 190 formed in the fixed barrel portion 140 that leads to the bayonet structure. Therefore, the imaging device 10 is sufficiently waterproof against the outside of the fixed barrel portion 140 and the inside of the outer frame tube 120.

[0044] [Summary of Embodiment 1] As is clear from the above description, the imaging device (10) has a lens barrel (12) and an imaging element (13). The lens barrel has a fixed barrel portion (14) that holds a reference lens (first lens 143 and second lens 144), an alignment frame (150) that holds lenses to be aligned (third lens 151 and fourth lens 152) to be positioned on the optical axis of the reference lens and that engages with the fixed barrel portion via a bayonet structure, a recess (180) formed in the alignment frame facing the fixed barrel portion and capable of containing adhesive that is injected from the outside of the fixed barrel portion with which the alignment frame engages, a first seal member (O-ring 160) that watertightly seals the gap between the peripheral edge of the front lens included in the reference lens and the fixed barrel portion that holds the front lens, and a second seal member (O-ring 170) that watertightly seals an opening (190) formed in the fixed barrel portion that leads to the bayonet structure.

[0045] As described above, the imaging device and lens barrel of this embodiment are simply constructed with a small number of parts. The alignment frame that holds the lens can be fixed at any position in the X and Y directions relative to the fixed barrel section that holds the lens. Furthermore, the object side of the protrusion in the bayonet structure on the alignment frame side serves as the contact surface, determining the thrust distance between the lens in the fixed barrel section and the lens in the alignment frame. Furthermore, when the fixed barrel section with the alignment frame engaged is inserted into the lens barrel, gaps that could serve as a route for water intrusion are blocked by two O-rings. Therefore, the imaging device of this embodiment exhibits sufficiently high waterproof performance.

[0046] In the lens barrel, the reference lens includes the front lens. That is, the fixed barrel portion has the front lens, and the fixed barrel portion is fixed to the outer barrel, so no force is applied to the alignment frame when the O-ring is tightly attached to the outer barrel. This configuration is therefore even more effective from the perspective of achieving both waterproofness and alignment effects.

[0047] In addition, in the lens barrel, the fixed barrel portion is fixed to the inside of the outer frame of the lens barrel. This configuration is even more effective in terms of preventing the alignment frame from shifting in position relative to the fixed barrel portion when the fixed barrel portion is fixed to the outer frame of the lens barrel.

[0048] Furthermore, in the lens barrel, the second seal member is an O-ring that fits tightly between the outer frame and the fixed lens barrel in the direction along the optical axis in the gap that leads from between the outer frame and the front lens to the bayonet structure. This configuration is even more effective in terms of improving waterproofing with a simple configuration.

[0049] Similarly, in a lens barrel, it is even more effective to use an O-ring as the first sealing member from the viewpoint of improving waterproofing with a simple configuration.

[0050] Furthermore, in the lens barrel, the recess into which adhesive can be injected from the outside has an uneven portion (1452) on its outer wall surface. This increases the adhesive surface area. This configuration is therefore even more effective in increasing the adhesive strength of the alignment frame to the fixed barrel.

[0051] Furthermore, in the imaging device, the main body and the lens barrel are integrally molded, with no seams between them, which is even more effective in terms of improving the waterproofing of the imaging device.

[0052] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0053] The imaging device of this embodiment has two alignment frames in the lens barrel, and the fixed barrel section is configured to engage with each alignment frame independently via a bayonet structure. Otherwise, the imaging device of this embodiment is configured substantially the same as the first embodiment described above.

[0054] [composition] Fig. 7 is an exploded perspective view of the imaging device according to this embodiment. Fig. 8 is a longitudinal cross-sectional view of the imaging device according to this embodiment. As shown in Fig. 7, imaging device 20 has a housing 111, a substrate 112, an imaging element 13, an outer cylinder frame 120, and a lens barrel, and the lens barrel has a fixed barrel 240, a first alignment frame 250, a second alignment frame 260, and O-rings 160 and 170.

[0055] The fixed barrel 240 holds a first lens 143 and a second lens 144 as reference lenses. The fixed barrel 240 is configured to be able to independently engage with the first alignment frame 250 and the second alignment frame 260 via a bayonet structure. FIG. 9 is a schematic diagram showing the fixed barrel 240 as seen from the image plane side in this embodiment. The fixed barrel 240 has a tube 141, a flange 242, an outer peripheral wall 145, and an inner peripheral wall 244. The inner peripheral wall 244 is a convex rib that rises from the object-side principal surface of the flange 242.

[0056] The flange portion 242 has three guide holes 2421 in addition to the three guide holes 1421. The three guide holes 2421 are arranged at equal intervals in the circumferential direction of the flange portion 242. The guide holes 1421 and the guide holes 2421 are arranged alternately in the circumferential direction of the flange portion 242. The guide holes 2421 have a substantially L-shaped planar shape. The long side of the substantially L-shaped portion extends along the outer peripheral wall 145 of the flange portion 242. The short side of the substantially L-shaped portion extends in the radial direction of the flange portion 242.

[0057] Furthermore, the flange portion 242 has three sets of step portions 1422, 1423 and concave-convex portions 1452, as well as three sets of step portions 2422, 2423 and concave-convex portions 2452. That is, a step portion 2422 of a specific thickness is formed between the long side portion of the guide hole 2421 on the object-side principal surface of the flange portion 142 and the inner circumferential wall 244. Furthermore, a concave-convex portion 2452 formed of concaves and convexes extending in the axial direction (arranged in parallel in the circumferential direction) is formed on the outer circumferential surface of the inner circumferential wall 244 at a position overlapping the step portion 2422 in the circumferential direction. Furthermore, a step portion 2423 of a specific thickness is formed between adjacent guide holes 2421 on the image-plane-side principal surface of the flange portion 242.

[0058] Fig. 10 is a diagram showing a first alignment frame as viewed from the image plane side in this embodiment, and Fig. 11 is a diagram showing a second alignment frame as viewed from the image plane side in this embodiment.

[0059] The first alignment frame 250 is a substantially cylindrical member, and holds the third lens 151 at its end on the image plane side. The first alignment frame 250 has substantially the same structure as the alignment frame 150 in the above-described first embodiment, except that it further has three notches 254 arranged at equal intervals in the circumferential direction on its outer periphery. The notches 254 are arranged at equal intervals with respect to the claws 153, and are formed in a shape that allows engagement portions 2632 of claws 263 of the second alignment frame 260, which will be described later, to pass through along the axial direction.

[0060] The second alignment frame 260 is a substantially cylindrical member, and holds the fourth lens 152 at its end on the image plane side. The second alignment frame 260 is configured to contain the first alignment frame 250, which is also engaged with the fixed barrel portion 240, when engaged with the fixed barrel portion 240.

[0061] The second alignment frame 260 has three claws 263 that correspond to the three sets of guide holes 2421, steps 2422 and 2423, and uneven portion 2452 that the fixed barrel section 240 has. The claws 263 protrude along the axial direction from the object-side edge of the second alignment frame 260 and have a configuration similar to that of the claws 153.

[0062] That is, the claw portion 263 has an insertion shaft portion 2631 that can be inserted into the long side portion of the guide hole 2421, and an engagement portion 2632 that can be inserted into the short side portion of the guide hole 2421. The engagement portion 2632 extends toward the center from the tip of the insertion shaft portion 2631. The engagement portion 2632 has two grooves 2633 on its tip surface that extend circumferentially and are parallel to each other in the radial direction. The groove on the center side opens toward the center and is a recess that is open toward the inner periphery.

[0063] [assembly] The lens barrel and imaging device 20 in this embodiment are assembled in the same manner as the imaging device 10 described above, except that a second alignment frame 260 is further engaged with the fixed barrel portion 240. Figure 12 is a diagram for explaining the engagement of the first alignment frame and the second alignment frame with the fixed barrel portion in this embodiment.

[0064] To engage the first alignment frame 250 with the fixed barrel section 240, first, the claws 153 are inserted into the guide holes 1421 of the fixed barrel section 240 (see the left diagram in FIG. 12). Next, the first alignment frame 250 is engaged with the fixed barrel section 240 by rotating it along the long side of the guide holes 1421 relative to the fixed barrel section 240 (see the right diagram in FIG. 12). The flange section 242 of the fixed barrel section 240, the guide holes 1421, and the claws 153 of the first alignment frame 250 form a bayonet structure that engages the first alignment frame 250 with the fixed barrel section 240. When the first alignment frame 250 is engaged with the fixed barrel section 240, a recess 180 is formed, with the outermost groove 1533 and the uneven portion 1452 facing it as side walls, and with an opening on the object side.

[0065] To engage the second alignment frame 260 with the fixed barrel portion 240, first, the claws 253 of the second alignment frame 260 are passed through the notches 254 of the first alignment frame 250 engaged with the fixed barrel portion 240, and inserted into the guide holes 2421 of the fixed barrel portion 240 (see the left diagram in FIG. 12 ). Next, the second alignment frame 260 is engaged with the fixed barrel portion 240 by rotating it along the long side of the guide holes 2421 relative to the fixed barrel portion 240 (see the right diagram in FIG. 12 ). The flange portion 242 of the fixed barrel portion 240, the guide holes 2421, and the claws 253 of the second alignment frame 260 form a bayonet structure that engages the second alignment frame 260 with the fixed barrel portion 240. The fixed barrel section 240 with which the second alignment frame 260 is engaged is formed with a recess 280 having the innermost groove 2633 and the uneven section 2452 facing it as side walls, and an opening on the object side.

[0066] [X and Y direction adjustment] The lens alignment in the lens barrel of this embodiment is performed in the same manner as in Embodiment 1. That is, the fixed barrel portion 240, to which the first alignment frame 250 and the second alignment frame 260 are engaged, is placed on an adhesive base. This adhesive base has two sets of three alignment pins that can be advanced and retracted radially using screws. The fixed barrel portion 240 is supported by the adhesive base so that the optical axis is centered radially, and the tips of the alignment pins in each set are advanced to the first alignment frame 250 and the second alignment frame 260, respectively.

[0067] Next, a UV-curable adhesive is injected into recesses 180 and 280 that open to the object side in flange 242 of fixed barrel 240. Because recesses 180 and 280 both open to the object side of fixed barrel 240 with first alignment frame 250 and second alignment frame 260 engaged, adhesive can be injected from the outside of fixed barrel 240 and can be accommodated therein.

[0068] Next, each set of alignment pins is advanced or retracted as appropriate to center the optical axis in the first alignment frame 250 and the second alignment frame 260. The diameter of the claw portions 153 of the first alignment frame 250 is slightly different from the diameter of the guide hole 1421 of the fixed barrel portion 240, and the diameter of the claw portions 253 of the second alignment frame 260 is slightly different from the diameter of the guide hole 2421 of the fixed barrel portion 240. Therefore, by advancing or retracting the alignment pins, the positions in the XY plane of the optical axes in the first alignment frame 250 and the second alignment frame 260 are adjusted within the range of this diameter difference.

[0069] Next, ultraviolet rays are irradiated from a UV irradiator onto the adhesive injected into and housed in the recesses 180 and 280. This ultraviolet irradiation hardens the adhesive in the recesses 180 and 280, and the first alignment frame 250 and the second alignment frame 260 are fixed to the fixed barrel portion 240, respectively.

[0070] [Z-direction adjustment] The thrust spacing of the lenses in the lens barrel of this embodiment is the same as in Embodiment 1. That is, on the object side of the flange portion 242 of the fixed barrel portion 240, the engagement portion 1532 of the first alignment frame 250 can abut against the step portion 1422, and the engagement portion 2532 of the second alignment frame 260 can abut against the step portion 2422. Furthermore, on the image plane side of the flange portion 242 of the fixed barrel portion 240, the object side edge of the first alignment frame 250 can abut against the step portion 1423, and the object side edge of the second alignment frame 260 can abut against the step portion 2423. Therefore, depending on the dimensional accuracy of steps 1422, 1423 and steps 2422, 2423 in the molding of fixed barrel portion 240, the thrust distance between the lens of first alignment frame 250 and the lens of fixed barrel portion 240, and the thrust distance between the lens of second alignment frame 260 and the lens of fixed barrel portion 240 are adjusted to the desired (design value) distance.

[0071] [Seal structure] The sealing structure of the imaging device and lens barrel in this embodiment is substantially the same as that in the above-described embodiment 1. Therefore, in this embodiment, the same waterproofness as in the above-described embodiment 1 is achieved.

[0072] [Summary of Embodiment 2] The lens barrel 22 in this embodiment has two alignment frames, a first alignment frame 250 and a second alignment frame 260, each of which independently engages with the fixed barrel portion 240. Therefore, in this embodiment, in addition to the effects of the first embodiment described above, it is possible to align the lens in each of the multiple alignment frames with the fixed barrel portion with high precision.

[0073] [Embodiment 3] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0074] The imaging device of this embodiment is configured so that the tilt of the optical axis of the lens to be aligned held by the alignment frame in the lens barrel can be adjusted (tilt adjustment).Other than that, the imaging device of this embodiment is configured substantially the same as the first embodiment described above.

[0075] [composition] Fig. 13 is an exploded perspective view of the imaging device according to this embodiment. Fig. 14 is a longitudinal cross-sectional view of the imaging device according to this embodiment. As shown in Fig. 13, imaging device 30 has substantially the same configuration as imaging device 10 in embodiment 1, except that imaging device 30 further includes spring 310 and washer 320 and includes fixed barrel 340 instead of fixed barrel 140.

[0076] The spring 310 abuts against the principal surface on the image plane side of the flange portion 142 of the fixed barrel portion 340, and also abuts against a step portion that widens toward the center from the inner wall surface of the tube portion of the alignment frame 150. The spring 310 biases the alignment frame 150 relative to the fixed barrel portion 340 in a direction widening along the axial direction.

[0077] Fixed barrel 340 has a flange 342. Compared to flange 142 of fixed barrel 140, flange 342 has a recess 3422 instead of step 1422 on the object-side principal surface. Furthermore, flange 342 does not have step 1423 on the image-plane-side principal surface, and has an inner peripheral wall 344 that rises from the inner peripheral edge of flange 342 toward the image plane side. One end of spring 310 is fitted onto inner peripheral wall 344 in fixed barrel 340.

[0078] 15 is an enlarged cross-sectional view showing the engagement portion between the fixed barrel portion and the alignment frame in this embodiment. The fixed barrel portion 340 has a recess 3422 at the position of the step portion 1422. The recess 3422 has substantially the same planar shape as the washer 320, and has a depth less than the thickness of the washer 320.

[0079] The washer 320 is, for example, a thin metal piece having a specific thickness. The washer 320 is housed in the recess 3422. Therefore, the washer 320 is interposed between the flange portion 342 of the fixed barrel portion 340 and the engagement portion 1532 of the alignment frame 150 in the axial direction.

[0080] The biasing force of spring 310 biases engagement portion 1532 of alignment frame 150 engaged with fixed barrel portion 340 toward washer 320 in fixed barrel portion 340. In this way, spring 310 corresponds to a biasing member that biases alignment frame 150 engaged with fixed barrel portion 340 in a direction pressing it against fixed barrel portion 340 along optical axis OA.

[0081] Washer 320 is housed in recess 3422 and is interposed in the axial direction between fixed barrel portion 340 and alignment frame 150. In this way, washer 320 corresponds to a spacer in the bayonet structure that is arranged between fixed barrel portion 340 and alignment frame 150 in the direction along optical axis OA.

[0082] [assembly] Washer 320 having a specific thickness is housed in recess 3422 of fixed barrel portion 340, and with one end of spring 310 fitted into inner peripheral wall 344, spring 310 is interposed between fixed barrel portion 340 and alignment frame 150, and alignment frame 150 is engaged with fixed barrel portion 340. The method of engaging alignment frame 150 with fixed barrel portion 340 is carried out in the same manner as in the first embodiment described above.

[0083] [X and Y direction adjustment] The position adjustment of the alignment frame 150 in the X and Y directions is performed in the same manner as in the first embodiment described above.

[0084] [Z-direction adjustment] In this embodiment, the thrust distance between the lens of the fixed barrel portion 340 and the lens of the alignment frame 150 is adjusted by the thickness of the three washers 320 housed in the three recesses 3422 of the fixed barrel portion 340 .

[0085] In this embodiment, the tilt of the optical axis of the lens in the centering frame 150 can be adjusted by setting the thickness of the three washers 320.

[0086] FIG. 16 is a diagram illustrating tilt adjustment in this embodiment. When the three washers 320 have the same thickness, only the thrust distance between the lens in the fixed barrel 340 and the lens in the alignment frame 150 is adjusted according to the thickness of the washers 320. Here, the thicknesses of the three washers 320 are made different depending on the circumferential position of the fixed barrel 340. Because a portion of the alignment frame 150 in the bayonet structure (the engagement portion 1532) is pressed against the fixed barrel 340 by the spring 310, the optical axis of the lens in the alignment frame 150 tilts within a range of adjustment angle θ according to the position and thickness of the washer 320. In this way, in this embodiment, tilt adjustment of the optical axis of the lens in the alignment frame 150 is achieved.

[0087] [Seal structure] The sealing structure of the imaging device and lens barrel in this embodiment is substantially the same as that in the above-described embodiment 1. Therefore, in this embodiment, the same waterproofness as in the above-described embodiment 1 is achieved.

[0088] [Summary of Embodiment 3] This embodiment further includes a spring (310) that biases the alignment frame engaged with the fixed barrel in a direction that presses it against the fixed barrel along the optical axis, and a washer (320) that is arranged between the fixed barrel and the alignment frame in the bayonet structure in the direction along the optical axis, thereby making it possible to further achieve tilt adjustment of the lens in the alignment frame.

[0089] [Embodiment 4] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0090] The imaging device of this embodiment is configured such that in the lens barrel, the alignment frame holds a reference lens including a front lens, and the fixed lens barrel holds a lens to be aligned. Otherwise, the imaging device of this embodiment is configured substantially the same as the third embodiment described above.

[0091] [composition] Fig. 17 is an exploded perspective view of the imaging device according to this embodiment. Fig. 18 is a longitudinal cross-sectional view of the imaging device according to this embodiment. As shown in Fig. 17, the lens barrel of imaging device 40 is made up of fixed barrel section 440, spring 310, alignment frame 450, washer 320, and O-rings 160 and 170.

[0092] 19 is a diagram showing a schematic view of the alignment frame 450 as seen from the image plane side in this embodiment. The alignment frame 450 is a substantially cylindrical body whose diameter on the image plane side is smaller than its diameter on the object side. The alignment frame 450 has an outer diameter smaller than the inner diameter of the fixed barrel portion 440, and can be housed inside through the object side opening of the fixed barrel portion 440. The alignment frame 450 holds a first lens 143 and a second lens 144 on the same optical axis as lenses to be aligned. The first lens 143 is the front lens, and therefore, in this embodiment, the lenses to be aligned include the front lens.

[0093] The alignment frame 450 has three claws 453 at its object-side end that protrude outward from its outer circumferential surface. The claws 453 are plate-like portions that protrude from the outer circumferential surface of the alignment frame 450 and have a substantially rectangular planar shape. The claws 453 have recesses 4532 on their object-side principal surface. The recesses 4532 are capable of accommodating the washer 320, have substantially the same planar shape as the washer 320, and have a depth that is less than the thickness of the washer 320. The alignment frame 450 also has an inner circumferential wall 444 that stands up toward the image plane, located more inward than the claws 453. A spring 310 is fitted onto the inner circumferential wall 444.

[0094] 20 is a diagram showing a schematic view of the fixed barrel 440 as seen from the image plane side in this embodiment. The fixed barrel 440 is a generally cylindrical body whose diameter on the image plane side is smaller than its diameter on the object side. The fixed barrel 440 holds a third lens 151 and a fourth lens 152 therein as reference lenses on the same optical axis. The fixed barrel 440 also has a second threaded portion 1451 on its outer circumferential surface on the object side.

[0095] Furthermore, the fixed barrel 440 has three notches 444 and three recesses 480 on the inner circumferential side of the object-side end face. The notches 444 and recesses 480 are all arranged at equal intervals in the circumferential direction and are arranged alternately. Each of the notches 444 is formed in a shape that allows the claws 453 of the alignment frame 450 to pass through. Each of the recesses 480 is formed on the object-side end face of the fixed barrel 440 by a frame portion that protrudes from the object-side end face, so that the object side and inner circumferential side are open on that end face.

[0096] [assembly] 21 is a diagram illustrating engagement of the alignment frame with the fixed barrel in this embodiment. In this embodiment, spring 310 is inserted from the opening on the larger diameter side of fixed barrel 440. In addition, washer 320 of a specific thickness is placed in recess 4532 of claw portion 453 of alignment frame 450.

[0097] Next, the claws 453 of the alignment frame 450 are aligned with the notches 444 of the fixed barrel 440, and the alignment frame 450 is pushed toward the inside of the fixed barrel 440 while the spring 310 is fitted into the inner peripheral wall 444 (left diagram in FIG. 21 ). Then, in this state, the alignment frame 450 is rotated relative to the fixed barrel 440 to engage with the fixed barrel 440. The claws 453 of the alignment frame 450 are biased by the spring 310 toward the object-side end of the fixed barrel 440, but are restricted by this object-side end. In this way, the claws 453 of the alignment frame 450 and the object-side end of the fixed barrel form a bayonet structure. By engaging the alignment frame 450 with the fixed barrel 440, the recessed portion 480 faces the outer peripheral surface of the alignment frame 450 in the radial direction. Therefore, the recess 480 is formed by the frame portion and the outer peripheral surface of the alignment frame 450 and opens to the object side.

[0098] Next, adhesive is poured into the recess 480 that opens to the object side. Then, the position adjustment and tilt adjustment of the alignment frame 450 are performed. The position adjustment and tilt adjustment of the alignment frame 450 are performed in the same manner as in the above-described third embodiment. Thereafter, the adhesive is hardened, and the alignment frame 450 is fixed to the fixed barrel portion 440.

[0099] Next, the second screw portion 1451 of the fixed barrel portion 440, inside which the alignment frame 450 is fixed, is screwed into the first screw portion 130 of the outer frame tube 120, thereby fixing the fixed barrel portion 440 within the outer frame tube 120.

[0100] [Seal structure] The sealing structure of the imaging device and lens barrel in this embodiment is substantially the same as that in the above-described embodiment 1. Therefore, in this embodiment, the same waterproofness as in the above-described embodiment 1 is achieved.

[0101] [Summary of the fourth embodiment] In this embodiment, the front lens is held by the centering frame 450. As described above, this embodiment is suitable from the viewpoint of achieving centering of the lens disposed on the object side and tilt adjustment of the optical axis.

[0102] [Embodiment 5] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0103] In the imaging device of this embodiment, the fixed lens barrel is integrally molded with the outer frame, which is composed of two members: the main body and the mount cover. Other than that, the imaging device of this embodiment is configured substantially the same as the third embodiment described above.

[0104] [composition] Fig. 22 is an exploded perspective view of the imaging device according to this embodiment. Fig. 23 is a longitudinal sectional view of the imaging device according to this embodiment. As shown in Fig. 22, the outer barrel frame of imaging device 50 is made up of fixed barrel portion 540 and mount cover 550.

[0105] 24 is a diagram showing a schematic view of the fixed barrel portion 540 in this embodiment as seen from the image plane side. The fixed barrel portion 540 is integrally molded with the portion of the outer frame 120 that is closer to the main body 11 than the first screw portion 130 in embodiment 1. Otherwise, the fixed barrel portion 540 has substantially the same configuration as the fixed barrel portion 340 in the embodiment described above.

[0106] Mount cover 550 has substantially the same configuration as the tip portion including first thread portion 130 of outer frame cylinder 120 in embodiment 1. Mount cover 550 is integrated with fixed barrel portion 540 by threaded engagement between first thread portion 130 and second thread portion 1451 of fixed barrel portion 540. Note that a gasket 560 for improving airtightness is interposed between mount cover 550 and fixed barrel portion 540.

[0107] [assembly] In this embodiment, engagement of the alignment frame 150 and lens alignment are performed before the housing part 111 is closed with the substrate part 112. Engagement of the alignment frame 150 and lens alignment are performed in the same manner as in the third embodiment described above.

[0108] Next, housing 111 is closed with substrate 112, and mount cover 550 is fixed to fixed barrel 540 via gasket 560. By fixing mount cover 550 to fixed barrel 540, substantially the same configuration as in the third embodiment is realized.

[0109] Alternatively, the alignment frame 150 may be engaged with the fixed barrel 540, and then the housing 111 may be closed with the base plate 112, and the position of the alignment frame 150 engaged with the fixed barrel 540 may be adjusted from the object side. In this case, it is possible to perform alignment of the lens to be aligned in the alignment frame 150 with the image sensor 13 already attached.

[0110] [Seal structure] Fig. 25 is an enlarged cross-sectional view showing the engagement portion and sealing portion between the fixed barrel portion and the alignment frame in this embodiment. As shown in Fig. 25, mount cover 550 is fixed to fixed barrel portion 540 by screwing together the threads. Therefore, imaging device 50 has sufficient waterproofing at the joint between mount cover 550 and fixed barrel portion 540. In addition, mount cover 550 is fixed to fixed barrel portion 540 via gasket 560. Therefore, imaging device 50 has sufficient airtightness at the joint between mount cover 550 and fixed barrel portion 540.

[0111] [Summary of Embodiment 5] In this embodiment, the fixed barrel portion (540) is integrated with the outer frame of the lens barrel. Therefore, in this embodiment, it is possible to perform lens alignment in the alignment frame even when the image sensor is attached. Furthermore, in this embodiment, since the lens is aligned while fixed to the outer frame, it is even more effective in preventing misalignment of the lens when the fixed barrel portion is attached after alignment.

[0112] [Embodiment 6] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0113] In the imaging device of this embodiment, the fixed lens barrel is integrally molded with the outer frame including the mount cover, and a sheet-like sealing member is used instead of an O-ring to watertightly seal the gap formed by the fixed lens barrel. Otherwise, the imaging device of this embodiment is substantially configured in the same way as the previously described fifth embodiment.

[0114] [composition] Fig. 26 is an exploded perspective view of the imaging device according to this embodiment. Fig. 27 is a longitudinal cross-sectional view of the imaging device according to this embodiment. As shown in Fig. 26, the imaging device 60 has a fixed barrel unit 640, an alignment frame 150, a substrate unit 112, an O-ring 160, a spring 310, a washer 320, and a sealing tape 670.

[0115] 28 is a diagram schematically showing the fixed barrel portion as seen from the image plane side in this embodiment. In the fixed barrel portion 640, the flange portion 342 is directly connected to the outer frame tube 120. The fixed barrel portion 640 has a groove 620 extending circumferentially on the outer peripheral surface of the outer frame tube 120 between the flange portion 342 and the tip of the outer frame tube 120. In other words, the wall surface of the groove 620 on the image plane side is the flange portion 342. A step is formed on both opening edges of the groove 620 along the circumferential direction, recessed from the outer peripheral surface of the outer frame tube 120, and a sealing tape 670 is affixed to this step.

[0116] [assembly] 29 is an enlarged cross-sectional view showing the engagement portion between the fixed barrel portion and the alignment frame in this embodiment. The engagement of the alignment frame 150 with the fixed barrel portion 640 is performed in the same manner as in the third embodiment described above. In this embodiment, the groove 1533 on the outside of the engagement portion 1532 opens toward the outer periphery. Therefore, when the alignment frame 150 engages with the fixed barrel portion 640, the groove 1533 and the object-side wall surface of the groove 620 form a recess 680 that opens toward the outer periphery. In this way, in this embodiment, the recess 680 that opens into the interior of the groove 620 is formed by the engagement of the alignment frame 150 with the fixed barrel portion 640.

[0117] An adhesive is injected into the recess 680 from the outer periphery of the outer frame tube 120, and after the position and tilt of the alignment frame 150 are adjusted, the adhesive is cured and the alignment frame 150 is fixed to the fixed barrel part 640. The position and tilt of the alignment frame 150 in this embodiment are adjusted in the same manner as in the third embodiment described above.

[0118] Next, sealing tape 670 is attached to the entire periphery of the step at the opening of recessed rib 620 to close recessed rib 620. Recessed rib 620 is a space that leads to a bayonet structure formed by fixed barrel portion 640, and sealing tape 670 that covers and closes the opening of recessed rib 620 along the circumferential direction of outer frame tube 120 corresponds to the second sealing member in this embodiment.

[0119] [Seal structure] 30 is an enlarged cross-sectional view showing the sealed portion of the fixed barrel portion in this embodiment. The gap from the front lens to the inside of the fixed barrel portion 640 is sealed with an O-ring 160. Therefore, the imaging device 60 is sufficiently waterproof against the inside of the fixed barrel portion 640.

[0120] Furthermore, the recessed rib 620 faces the bayonet structure and serves as an opening for a gap that leads to the imaging element 13 via the bayonet structure. The recessed rib 620 is sealed all around with sealing tape 670, which adheres firmly using the step as an overlapping margin, sealing the recessed rib 620 watertightly. Therefore, the imaging device 60 has sufficient waterproofing against the imaging element 13.

[0121] [Summary of Embodiment 6] In this embodiment, the fixed lens barrel portion (640) has a groove (620) extending circumferentially on the outer peripheral surface of the outer frame tube, and a recess (680) for accommodating adhesive opens into the groove. The opening of the groove is closed by a member (sealing tape 670) that covers the outer frame tube along the circumferential direction. This embodiment can achieve lens centering and waterproofing with fewer parts than the previous embodiments. Thus, this embodiment is even more effective in terms of achieving lens centering and waterproofing with a simpler configuration.

[0122] [Modification] In embodiment 2, there may be three or more alignment frames. This configuration is preferable from the viewpoint of improving the accuracy of centering lenses including heavier lenses by centering the heavier lenses individually.

[0123] 〔summary〕 In the above-described embodiment, the lens barrel has a plurality of lens groups, and the centering of one of the lens groups is performed in a direction perpendicular to and parallel to the optical axis. The lens group to be centered is held by the centering frame.

[0124] Moreover, biasing the alignment frame in a direction parallel to the optical axis by an elastic member such as a spring is suitable for performing tilt adjustment of the lens group to be aligned.

[0125] The alignment frame has claws extending in the radial direction, and the fixed barrel is configured to engage with the claws. An adhesive is then injected from the outside into recesses formed by both the alignment frame and the fixed barrel. This makes it possible to fix the alignment frame to the fixed barrel after position and tilt adjustments.

[0126] In this embodiment, the gap between the front lens and the fixed barrel portion or the centering frame is sealed with an O-ring, which is preferable from the viewpoint of waterproofing.

[0127] In the above-described embodiment of the present invention, a bayonet structure and a biasing spring are used, which allows for space saving and simplification with a small number of parts, and further provides an alignment mechanism that can achieve high water resistance and / or high airtightness.

[0128] As is clear from the above description, the lens barrel (10) in this embodiment of the present invention includes a fixed barrel portion (140) that holds a reference lens, an alignment frame (150) that holds a lens to be aligned to the optical axis of the reference lens and engages with the fixed barrel portion via a bayonet structure, a recess (180) formed on one of the fixed barrel portion and the alignment frame facing the other and capable of containing adhesive injected from outside the fixed barrel portion with which the alignment frame is engaged, a first seal member (O-ring 160) that provides a watertight seal between the peripheral portion of the front lens included in the reference lens or the lens to be aligned and the fixed barrel portion or alignment frame that holds the front lens, and a second seal member (O-ring 170) formed on the fixed barrel portion that provides a watertight seal for an opening that leads to the bayonet structure. This configuration realizes a lens barrel that is capable of alignment between lenses, has excellent waterproofing, and is simply configured.

[0129] In an embodiment of the present invention, the lens barrel may further include a biasing member (spring 310) that biases the alignment frame engaged with the fixed barrel portion in a direction that presses the alignment frame against the fixed barrel portion along the optical axis, and a spacer (washer 320) that is arranged between the fixed barrel portion and the alignment frame in the direction along the optical axis in the bayonet structure. This configuration is even more effective from the viewpoint of further realizing tilt adjustment of the optical axis of the lens to be aligned with a simple configuration.

[0130] In an embodiment of the present invention, the reference lens may include a front lens, which is even more effective from the viewpoint of more reliably maintaining the centering state when fixing the lens group to the outer barrel frame.

[0131] In the embodiment of the present invention, the lens to be aligned may include a front lens, which is even more effective from the viewpoint of aligning the lens group on the object side.

[0132] In an embodiment of the present invention, the fixed barrel portion may be fixed to the inside of the outer frame portion of the lens barrel. This configuration is even more effective in terms of suppressing lens misalignment when fixing the aligned lens group to the imaging device.

[0133] In an embodiment of the present invention, the fixed barrel portion may be integral with the outer frame portion of the lens barrel, which is even more effective in preventing lens misalignment when the aligned lens group is fixed to the imaging device.

[0134] In an embodiment of the present invention, the second seal member may be an O-ring that fits tightly to the outer frame and the alignment frame or fixed barrel in the direction along the optical axis in the gap that leads from between the outer frame and the front lens to the bayonet structure. This configuration is even more effective from the perspective of improving waterproofness with a simple configuration.

[0135] In an embodiment of the present invention, the fixed barrel portion may have a groove extending in a circumferential direction on the outer peripheral surface of the outer frame portion, the recessed portion may open into the groove, and the second sealing member may be a member that covers and closes the opening of the groove along the circumferential direction of the outer frame portion. This configuration is even more effective from the viewpoint of reducing the number of parts and simplifying the configuration.

[0136] In an embodiment of the present invention, the lens barrel may have two or more alignment frames, each of which may be independently engaged with the fixed barrel portion. This configuration is even more effective from the viewpoint of independently achieving alignment of multiple lens groups.

[0137] In an embodiment of the present invention, an imaging device includes the lens barrel and an imaging element described above. Therefore, according to the embodiment of the present invention, it is possible to realize an imaging device with high performance and excellent waterproofing with a simple configuration.

[0138] This configuration enables imaging devices to be more compact, with improved performance and waterproofing. This will promote the use of imaging devices and reduce waste plastics by improving the utilization rate of production parts. This is expected to contribute to the development of industrial infrastructure and the achievement of the Sustainable Development Goals (SDGs) related to environmental conservation.

[0139] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0140] 10, 20, 30, 40, 50, 60 Imaging device 11 Main unit 12 Lens barrel 13 Image sensor 111 Housing 112 Circuit board section 120 outer frame tube 140, 240, 340, 440, 540, 640 Fixed lens barrel 141 Cylinder part 142, 242, 342 flange 143 First Lens 144 Second Lens 145 Outer wall 146 First fitting groove 147 Second fitting groove 150, 450 Alignment Frame 151 Third Lens 152 Fourth Lens 153, 253, 263, 453 Claws 160, 170 O-ring 180, 280, 480, 680, 3422, 4532 recesses 190 Opening 244, 344, 444 Inner wall 260 Second alignment frame 310 Spring 320 washer 550 Mount Cover 560 Gasket 670 Sealing Tape 620 Concave line 1421, 2421 guide holes 1422, 1423, 2422, 2423 Stepped section 1452, 2452 Uneven part 1531, 2631 Insertion shaft 1532, 2532, 2632 Engagement part OA optical axis θ Adjustment angle

Claims

1. a fixed lens barrel portion that holds a reference lens; an alignment frame that holds a lens to be aligned on the optical axis of the reference lens and engages with the fixed lens barrel via a bayonet structure; a recess formed in one of the fixed barrel portion and the alignment frame facing the other, the recess being capable of accommodating adhesive injected from the outside of the fixed barrel portion engaged with the alignment frame; a first seal member that watertightly seals a gap between a peripheral portion of a front lens included in the reference lens or the lens to be aligned and the fixed barrel portion or the alignment frame that holds the front lens; a second seal member that watertightly seals an opening that is formed in the fixed barrel portion and leads to the bayonet structure; A lens barrel having:

2. a biasing member that biases the alignment frame engaged with the fixed barrel portion in a direction along the optical axis so as to press the alignment frame against the fixed barrel portion; The lens barrel according to claim 1 , further comprising a spacer disposed between the fixed barrel portion and the alignment frame in the bayonet structure in the direction along the optical axis.

3. The lens barrel according to claim 1 , wherein the reference lens includes the front lens.

4. 3. The lens barrel according to claim 1, wherein the lens to be aligned includes the front lens.

5. 5. The lens barrel according to claim 1, wherein the fixed barrel portion is fixed to the inside of an outer frame portion of the lens barrel.

6. 5. The lens barrel according to claim 1, wherein the fixed barrel portion is integral with an outer frame portion of the lens barrel.

7. The lens barrel according to claim 5 or 6, wherein the second sealing member is an O-ring that is in close contact with the outer frame portion and the alignment frame or the fixed barrel portion in a direction along the optical axis in a gap that leads from between the outer frame portion and the front lens to the bayonet structure.

8. the fixed barrel portion has a recessed line extending in a circumferential direction on an outer peripheral surface of the outer frame portion, The recessed portion is open to the inside of the groove, The second sealing member is a member that covers and closes the opening of the recessed strip along the circumferential direction of the outer frame portion. The lens barrel according to claim 6.

9. 9. The lens barrel according to claim 1, further comprising two or more of the centering frames, each of which independently engages with the fixed barrel portion.

10. An imaging device comprising the lens barrel according to any one of claims 1 to 9 and an imaging element.

Images