JP6332964B2 - Lens unit and imaging device - Google Patents

Description

  The present invention relates to a lens unit including a plurality of lenses and an imaging apparatus equipped with the lens unit, and more particularly to a lens unit and an imaging apparatus used in an outdoor environment as an in-vehicle camera, a surveillance camera, or the like.

  As a conventional lens unit, a cylindrical lens holder that holds a lens, a plurality of lenses that are housed and fixed in the lens holder (a waterproof lens positioned in the forefront of the optical axis direction, and are sequentially arranged behind the lens) A second lens, a third lens, and a fourth lens), a seal ring (O-ring) fitted between the outer periphery of the waterproof lens positioned in front and the lens holder, etc. , To reduce the diameter so that the seal ring is mounted, and to form an annular groove that defines an inclined surface (conical taper surface), first the fourth lens is fitted into the lens holder, and then the third lens is fitted. Next, the second lens is fitted, and a waterproof lens fitted with a seal ring is fitted so that it comes into contact with the front surface of the second lens from the front side of the second lens. While the optical axes of the waterproof lens, the second lens, the third lens, and the fourth lens are aligned (alignment is performed), the tip portion of the lens holder is thermally deformed to waterproof the lens and other lenses. A waterproof lens assembly (or a lens unit) is known (see, for example, Patent Document 1 and Patent Document 2).

However, in this lens unit, the waterproof lens, the second lens, the third lens, and the fourth lens are all in contact with each other in the optical axis direction, and the waterproof lens located at the foremost (outermost side) Since the second lens is pressed against the second lens positioned behind the second lens, the second lens presses the third lens, and the third lens presses the fourth lens, the most waterproof When an external force (or impact force) or the like is applied from the outside to the lens for use or when the seal ring is deformed (expanded), the second lens, the third lens, and the third lens are also affected. There is a possibility that the axis may shift, and conversely, there is a possibility that the waterproof lens may be displaced due to the displacement of the second lens, the third lens, and the fourth lens.
Furthermore, since the annular groove of the waterproof lens is formed so as to form an inclined surface (conical tapered surface), the seal ring is compressed in the radial direction perpendicular to the optical axis (elastic deformation for waterproofing). In addition to the above, there is also a state of undergoing compressive deformation in a direction intersecting the optical axis, and there is a concern about deterioration of the seal ring due to changes over time, durability, and the like.

JP 2008-216706 A JP 2011-059396 A

  The present invention has been made in view of the circumstances of the above prior art, and its object is to simplify the structure, facilitate assembly work, and to a seal ring (O-ring) during assembly. While preventing damage and reducing costs, even if an external force (or impact force) is applied to the lens located on the foremost (outermost) side, the lens placed inside is not affected. It is an object of the present invention to provide a lens unit that can prevent shaft misalignment and the like, and can improve waterproofness and durability as a whole, and an imaging device equipped with the lens unit.

The lens unit of the present invention is disposed behind the front lens and the cylindrical lens holder having an axial center in the optical axis direction of the lens, the front lens that is sequentially arranged and held in the optical axis direction in the lens holder. A lens unit comprising a plurality of lenses including at least a second lens, and a seal ring disposed between the foremost lens and the lens holder, wherein the foremost lens has a predetermined outer diameter. A cylindrical reduced diameter outer peripheral portion having a diameter smaller than that of the fitting outer peripheral portion, an annular surface connecting the fitting outer peripheral portion and the reduced outer peripheral portion, and a rear end of the reduced outer peripheral portion. A cylindrical fitting inner peripheral portion that fits the fitting outer peripheral portion of the foremost lens and faces the reduced diameter outer peripheral portion in the radial direction perpendicular to the optical axis; The annular contact surface of the front lens is in the optical axis direction A lens receiving portion to be brought into contact with, an annular facing surface facing the annular surface of the foremost lens in the optical axis direction, and a lens fixing portion for fixing the second lens in a non-contact state with the foremost lens, In the state where it is not in contact with at least one of the annular surface and the annular opposing surface, it is arranged to be compressed in the radial direction between the reduced diameter outer peripheral portion and the fitting inner peripheral portion.
According to this configuration, in the relationship between the foremost lens and the second lens, the second lens is arranged so that the lens of the lens holder (when other lenses are included behind the second lens, press those lenses). The front lens is fixed by the fixing portion, and the annular contact surface is contacted with the lens receiving portion while the seal ring is sandwiched between the outer peripheral portion of the reduced diameter and the inner peripheral portion of the fitting so as not to contact the second lens. Since the fitting outer peripheral part is fitted to the fitting inner peripheral part and fixed to the lens holder, the second lens (second lens) is applied even if an external force (impact force) is applied to the front lens. When other lenses are included behind the second lens, it is possible to prevent the second lens and other lenses from being affected. The seal ring is fitted in a compressed state only in the radial direction, and is not in contact with at least one surface between the annular surface of the foremost lens and the annular opposing surface of the lens holder in the optical axis direction. Therefore, even when the seal ring expands, the protrusion can be prevented and the influence of the deformation on the deviation of the optical axis can be prevented. Thereby, the shift | offset | difference of an optical axis etc. can be prevented as a whole, and waterproof improvement, durability improvement, etc. can be achieved.

The said structure WHEREIN: The structure by which the fitting outer peripheral part of the foremost lens is press-fit with respect to the fitting inner peripheral part of a lens holder is employable.
According to this configuration, since the fitting outer peripheral portion of the front lens is press-fitted with respect to the fitting inner peripheral portion of the lens holder, the seal ring protrudes between the fitting outer peripheral portion and the fitting inner peripheral portion. This can be surely prevented and the front lens can be firmly fixed to the lens holder.

In the above configuration, a configuration in which the inner diameter of the seal ring is smaller than the outer diameter of the outer peripheral portion of the reduced diameter of the front lens can be adopted.
According to this configuration, after the seal ring is fitted in the reduced diameter outer peripheral portion in advance, the front lens is fitted in the lens holder (the inner peripheral portion of the lens holder) to prevent the seal ring from being bitten or damaged. However, the forefront lens and the seal ring can be securely fitted and fixed at predetermined positions, and therefore, the assembling work can be facilitated.

In the above configuration, the lens receiving portion is an annular receiving surface formed in an annular shape, and the annular opposing surface is formed to be recessed (concave) toward the rear in the optical axis direction from the annular receiving surface. A configuration can be employed.
According to this configuration, when the foremost lens is fitted into the lens holder, the annular abutment surface of the foremost lens can be incorporated in a state of being in intimate contact with the annular receiving surface of the lens holder, and the seal ring Since the housing space is formed in a concave shape further toward the rear in the optical axis direction than the contact position between the two, even if the seal ring expands, the seal ring protrudes (is pinched) between the contact interfaces between the two. Can be prevented.

In the above configuration, the lens unit may include a configuration including a heat caulking portion that fixes the front lens by thermal caulking.
According to this configuration, the forefront lens can be more securely fixed to the lens holder while achieving cost reduction and the like without using other components by caulking of the heat caulking portion.

The image pickup apparatus of the present invention includes a lens optical system that holds a plurality of lenses, an image pickup element that is arranged behind the lens optical system in the optical axis direction, and a housing that houses the lens optical system and the image pickup element. An imaging apparatus is characterized in that any of the lens units having the above-described configuration is employed as the lens optical system.
According to this configuration, by providing the lens holder having the above configuration, an imaging device that is excellent in waterproofness, impact resistance, etc., and that is particularly suitable for use in an outdoor environment as an in-vehicle camera, a surveillance camera, or the like. Can be obtained.

  According to the lens unit having the above configuration, the structure is simplified, the assembling work is facilitated, the seal ring is prevented from being damaged at the time of assembling, and the cost is reduced. Even if an external force (or impact force) is applied to the lens in the position, the lens placed inside can be prevented from being affected and the optical axis can be prevented from shifting. As a whole, the waterproof property is improved and the durability is improved. Improvement and the like can be achieved, and by using this lens unit, an imaging device suitable for use in an outdoor environment as an in-vehicle camera, a surveillance camera, or the like can be obtained.

It is a disassembled perspective view which shows the imaging device carrying the lens unit which concerns on this invention. It is sectional drawing of the imaging device shown in FIG. It is an external appearance perspective view of the lens unit mounted in the imaging device shown in FIG. It is sectional drawing of the lens unit shown in FIG. FIGS. 3A and 3B show an assembling operation of the lens unit shown in FIG. 3, in which FIG. 3A is a cross-sectional view showing a state in which the front lens attached with a seal ring is sucked by the suction head, and FIG. It is sectional drawing which shows the state which inserts into a lens holder. 2A and 2B show another embodiment of a lens unit according to the present invention, in which FIG. 3A is an external perspective view seen from the front diagonal, and FIG. 2B is an external perspective view seen from the rear diagonal. FIG. 7 is an exploded perspective view of the lens unit shown in FIG. 6. It is sectional drawing of the lens unit shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
This imaging apparatus is applied as an in-vehicle camera provided outside a vehicle body, and as shown in FIGS. 1 and 2, a lens unit U as a lens optical system, and behind the lens unit U in the optical axis L direction. An image sensor 10 disposed on the substrate, a substrate 20 on which the image sensor 10 is mounted, a lens unit U, a housing main body 30 as a housing for accommodating the substrate 20, a housing cover 40, and the like.

The imaging device 10 is, for example, a CCD (charge coupled device), and after being mounted on the substrate 20, a predetermined position in the housing body 30 together with the substrate 20 (in the optical axis L direction, behind the lens unit U). ) To be fixed.
As shown in FIG. 1, the substrate 20 has a substantially rectangular outer contour, and is formed so as to mount the image pickup device 10 and other electronic components, and using screws or the like at predetermined positions in the housing body 30. Fastened and fixed.

  The housing body 30 is formed using a resin material or the like. As shown in FIGS. 1 and 2, the housing body 30 is a housing portion 31 that houses the substrate 20, a fixing portion 32 that fixes the substrate 20, and an attachment that is attached to a vehicle body or the like. The part 33, the housing part 40, etc. are provided with the coupling | bond part 34 etc. which fasten and couple | bond with a screw | thread etc.

  The housing cover 40 is formed using a resin material or the like. As shown in FIGS. 1 and 2, the housing portion 41 that houses the lens unit U, the fixing portion 42 that positions and fixes the lens unit U, and the lens An opening 43 that exposes the foremost lens 50 of the unit U and a coupling portion 44 that is coupled to the coupling portion 34 of the housing body 30 by screws or the like are provided.

  As shown in FIGS. 1, 2, 3, and 4, the lens unit U is a cylindrical lens holder 50 having an axis in the optical axis L direction, and from the front side in the optical axis L direction with respect to the lens holder 50. A front lens 60, a second lens 70, and a plurality of other lenses 80 arranged behind the second lens 70 (a third lens 81, a fourth lens 82, a fifth lens 83, a 6 lens 84), a seal ring 90 disposed between the front lens 60 and the lens holder 50, and the like.

  The lens holder 50 is formed in a cylindrical shape having a shaft center in the optical axis L direction of the lens using a resin material or the like. As shown in FIGS. 2, 3, and 4, the fixed portion of the housing cover 40 is formed. A flange-shaped portion 51 that is positioned and fixed to 42, a large-diameter outer cylindrical portion 52 that is formed in front of the flange-shaped portion 51 in the optical axis L direction and accommodates the foremost lens 60, and an optical axis that is longer than the flange-shaped portion 51 A small-diameter outer cylindrical portion 53 that is formed rearward in the L direction and accommodates the second lens 70 and the other lens 80 and a fitting outer peripheral portion 61 of the foremost lens 60 are fitted, and a reduced-diameter outer peripheral portion 62 and the optical axis L are perpendicular to each other. A cylindrical fitting inner peripheral portion 54 facing in the radial direction, an annular receiving surface 55 as a lens receiving portion for contacting the annular contact surface 64 of the foremost lens 60 in the optical axis L direction, and the annular surface of the foremost lens 60 63, an annular facing surface 56 facing the optical axis L direction, A lens fixing portion 57 that fixes the second lens 70 in a non-contact state with the lens 60, an accommodation holding portion 58 a that accommodates and holds the third lens 81 and the fourth lens 82 among the other lenses 80, and an annular contact portion 58b, the fifth lens 83 among the other lenses 80 is accommodated and fixed (or the aperture plate or the diaphragm plate is sandwiched and fixed as appropriate), and the sixth lens 84 is rearward in the optical axis L direction. A lens fixing portion 59 and the like for receiving and fixing from the side are provided.

As shown in FIGS. 1 to 3, the bowl-shaped portion 51 is formed in an annular shape and has notches 51 a formed at predetermined intervals in the circumferential direction, and fixes the lens unit U to the housing cover 40. In this case, the large-diameter outer cylindrical portion 52 is passed through the opening 43 and is fixed while positioning the position in the optical axis L direction and the angular position around the optical axis L with respect to the fixed portion 42. ing.
As shown in FIG. 2, the large-diameter outer cylinder portion 52 is formed so as to define a cylindrical outer peripheral surface having an outer diameter dimension that passes through the opening 43 of the housing cover 40 in a non-contact manner. In addition, an annular heat caulking portion 52a is provided which is formed to be tapered by reducing the outer diameter at the tip end side in the optical axis L direction.
In addition, as for the large diameter outer cylinder part 52, it is also possible to engage | insert a desired sealing member between the outer peripheral surface and the inner peripheral surface of the opening part 43 as needed.
As shown in FIG. 2, the small-diameter outer cylinder portion 53 has a cylindrical outer peripheral surface having an outer diameter smaller than that of the large-diameter outer cylinder portion 52 so as to accommodate and hold the second lens 70 and the other lens 80. Are defined.

As shown in FIG. 4, the fitting inner peripheral portion 54 is fitted with the fitting outer peripheral portion 61 of the foremost lens 60 in a light press-fit state and has a predetermined radial direction perpendicular to the reduced diameter outer peripheral portion 62 and the optical axis L. It is formed so as to define a cylindrical inner peripheral surface facing each other with a gap.
As shown in FIG. 4, the annular receiving surface 55 is formed so as to receive the annular contact surface 64 of the foremost lens 60 in contact with the second lens 70 in the optical axis L direction. In order to hold the lens in a non-contact state, only the front lens 60 is received and positioned in the optical axis L direction.

As shown in FIG. 4, the annular facing surface 56 defines an annular surface that faces the annular surface 63 of the foremost lens 60 in the direction of the optical axis L in a region where the fitting inner peripheral portion 54 and the annular receiving surface 55 are connected. In addition, it is formed so as to be recessed (concave) toward the rear in the optical axis L direction from the annular receiving surface 55.
Here, since the annular facing surface 56 is formed to be recessed (concave) toward the rear in the optical axis L direction relative to the annular receiving surface 55, when the foremost lens 60 is fitted into the lens holder 50, The annular contact surface 64 of the lens 60 can be incorporated in a state in which the annular contact surface 64 of the lens holder 50 is in intimate contact with the annular receiving surface 55 of the lens holder 50. Since it is formed in a concave shape toward the rear in the direction of the axis L, even when the seal ring 90 expands, it is possible to prevent the seal ring 90 from protruding (sandwiched) at the contact interface between them.
As shown in FIG. 4, the lens fixing portion 57 accommodates the second lens 70 by fitting it from the front in the direction of the optical axis L, and a part thereof can be bonded and fixed with an adhesive or the like (for example, bonding) It is formed so as to have an agent reservoir.

As shown in FIG. 4, the housing holding portion 58 a is formed so as to have an inner diameter that allows the third lens 81 and the fourth lens 82 to be stacked and accommodated in the optical axis L direction.
As shown in FIG. 4, the annular contact portion 58b is formed so as to contact and receive the rear end surface 82b of the fourth lens 82 in a state where the third lens 81 and the fourth lens 82 are overlapped in the optical axis L direction. The third lens 81 and the fourth lens 82 are sandwiched and fixed in cooperation with the rear end surface 72 of the second lens 70 fitted from the front in the optical axis L direction.
As shown in FIG. 4, the lens fixing portion 58c positions the fifth lens 83 in the optical axis L direction while fitting and accommodating the fifth lens 83 from the front in the optical axis L direction, and bonds a part thereof. It is formed so that it can be bonded and fixed with an agent or the like (for example, provided with an adhesive reservoir).
As shown in FIG. 4, the lens fixing portion 59 positions the sixth lens 84 in the optical axis L direction while fitting and accommodating it from the rear in the optical axis L direction, and a part of the sixth lens 84 is adhesively fixed by an adhesive or the like. It is formed so that it can be obtained (for example, provided with an adhesive reservoir).

  As shown in FIGS. 2 to 4, the foremost lens 60 has a meniscus shape having a convex surface on the object side and a concave surface on the image surface side, and is a wide-angle glass disposed in the forefront of the lens unit U in the optical axis L direction. A fitting outer peripheral portion 61 that is a lens and has a predetermined outer diameter, a cylindrical reduced outer peripheral portion 62 that is smaller in diameter than the fitting outer peripheral portion 61, a fitting outer peripheral portion 61, and a reduced outer peripheral portion 62 are connected. An annular surface 63 and an annular contact surface 64 formed continuously at the rear end of the reduced diameter outer peripheral portion 62 are provided.

As shown in FIG. 4, the fitting outer peripheral portion 61 defines a cylindrical outer peripheral surface having a predetermined outer diameter, and is fitted into the fitting inner peripheral portion 54 of the lens holder 50 in a light press-fit state. It is formed to be.
Here, since the fitting outer peripheral portion 61 is press-fitted into the fitting inner peripheral portion 54 of the lens holder 50, the seal ring 90 protrudes from between the fitting outer peripheral portion 61 and the fitting inner peripheral portion 54. Can be reliably prevented, and the foremost lens 60 can be firmly fixed to the lens holder 50.

As shown in FIG. 4, the reduced diameter outer peripheral portion 62 defines a cylindrical outer peripheral surface having a smaller outer diameter than the fitting outer peripheral portion 61 (reduced diameter), and holds the seal ring 90 in place. It is formed to be able to. Here, the outer diameter of the reduced diameter outer peripheral portion 62 is formed to be slightly larger than the inner diameter of the seal ring 90.
As shown in FIG. 4, the annular surface 63 is formed as an annular plane facing the optical axis L direction in the step region so as to connect the fitting outer peripheral portion 61 and the reduced outer peripheral portion 62, and the front lens 60 is the lens. In the state of being incorporated in the holder 50, it faces the annular facing surface 56 in the optical axis L direction. The annular surface 63 abuts (contacts) the seal ring 90 in the optical axis L direction when the foremost lens 60 is assembled into the lens holder 50 with the seal ring 90 fitted in the reduced diameter outer peripheral portion 62 in advance. It is supposed to be received.
As shown in FIG. 4, the annular contact surface 64 is formed as an annular flat surface that is continuous with the rear end of the reduced diameter outer peripheral portion 62 and faces in the direction of the optical axis L, and the foremost lens 60 is incorporated into the lens holder 50. In this state, it comes into contact with the annular receiving surface 55 in the direction of the optical axis L.
In the state in which the second lens 70 and the third lens 81 to the fifth lens 83 are incorporated, the foremost lens 60 is fitted into the reduced diameter outer peripheral part 62 from the front in the optical axis L direction. It fits into the peripheral portion 54 and is fixed in a non-contact state with the second lens 70.

As shown in FIGS. 2 and 4, the second lens 70 is a plastic lens having a biconcave shape having a concave surface on the object side and a concave surface on the image surface side, and disposed behind the front lens 60. A fixing portion 71 fixed to the 50 lens fixing portions 57, a rear end surface 72 that contacts and presses the front end surface 81 a of the third lens 81, and the like.
Then, the second lens 70 is fixed so that the fifth lens 83 is accommodated, and after the third lens 81 and the fourth lens 82 are accommodated in an overlapping manner, the front lens 81a of the third lens 81 is pressed. It is fitted from the front in the direction of the optical axis L and is fixed by an adhesive or the like.

As shown in FIGS. 2 and 4, the third lens 81 is a plastic lens having a meniscus shape having a convex surface on the object side and a concave surface on the image surface side, and is disposed behind the second lens 70. A front end surface 81a with which the rear end surface 72 of the lens 70 abuts, a rear end surface 81b that abuts against and presses against the front end surface 82a of the fourth lens 82, and the like.
The third lens 81 is accommodated from the front of the fourth lens 82 and is arranged so that the rear end surface 81b abuts against and presses the front end surface 82a of the fourth lens 82 in the optical axis L direction. The front end surface 81 a is pressed and fixed by the rear end surface 72 of the two lens 70.

As shown in FIGS. 2 and 4, the fourth lens 82 is a plastic lens having a meniscus shape having a convex surface on the object side and a concave surface on the image surface side, and is disposed behind the third lens 81. A front end surface 82a with which the rear end surface 81b of the lens 81 abuts, a rear end surface 82b with which the annular abutting portion 58b of the lens holder 50 abuts, and the like are provided.
The fourth lens 82 is accommodated from the front of the fifth lens 83 and is disposed such that the rear end surface 82b abuts against the annular abutting portion 58b in the optical axis L direction. The front end face 82a is pressed and fixed.

As shown in FIGS. 2 and 4, the fifth lens 83 is a plastic lens having a convex flat shape having a convex surface on the object side and a flat surface on the image surface side, and disposed behind the fourth lens 82. A rear end surface 83b that abuts on the lens fixing portion 58c of the holder 50 is provided.
The fifth lens 83 is housed in the lens holder 50 from the front in the direction of the optical axis L, and is disposed so that the rear end surface 83b contacts the lens fixing portion 58c, and is fixed by an adhesive or the like. ing.

As shown in FIGS. 2 and 4, the sixth lens 84 is a plastic lens having a biconvex shape having a convex surface on the object side and a convex surface on the image surface side and disposed behind the fifth lens 83. A front end surface 84 a that contacts the lens fixing portion 59 of the holder 50 is provided.
The sixth lens 84 is accommodated in the lens holder 50 from the rear in the direction of the optical axis L, and the front end surface 84a is disposed so as to contact the lens fixing portion 59, and is fixed by an adhesive or the like. It has become.

As shown in FIGS. 1, 2, and 4, the seal ring 90 is an O-ring formed in an annular shape using a rubber material, and the inner diameter thereof is the outer diameter of the reduced diameter outer peripheral portion 62 of the front lens 60. The front lens 60 is fitted into the lens holder 50 so that the reduced diameter outer peripheral portion 62 and the fitted inner peripheral portion 54 are opposed to each other in the radial direction. In the state of being incorporated in the combined inner peripheral portion 54), it is compressed to a predetermined compression margin in the radial direction perpendicular to the optical axis L, and is not in contact with at least one of the annular surface 63 and the annular opposing surface 56 in the optical axis L direction. It is formed in the dimension which becomes a state.
Here, since the inner diameter of the seal ring 90 is formed to be smaller than the outer diameter of the reduced diameter outer peripheral portion 62 of the foremost lens 60, after the seal ring 90 is fitted in the reduced diameter outer peripheral portion 62 in advance, When fitting into the lens holder 50 (the fitting inner peripheral portion 54), the seal ring 90 can be prevented from being bitten or damaged, and the seal lens 90 can be prevented from falling off while the front lens 60 and the seal ring 90 are removed. It can be surely fitted and fixed at a predetermined position, and therefore, the assembly work can be facilitated.

Next, the assembling work of the lens unit U having the above configuration will be described with reference to FIGS. 5 (a) and 5 (b).
First, with respect to the lens holder 50, the sixth lens 84 is fitted into the lens fixing portion 59 from the rear in the optical axis L direction and fixed by an adhesive or the like, and the fifth lens fixing portion 58c is fixed from the front in the optical axis L direction. The lens 83 is fitted and fixed with an adhesive or the like, the fourth lens 82 is fitted from the front of the fifth lens 83 to the housing holding portion 58a and the annular contact portion 58b, and then the third lens 81 is fitted, The second lens 70 is fitted into the lens fixing portion 57 from the front of the third lens 81 and is fixed by an adhesive or the like while pressing the third lens 81 and the fourth lens 82.
Subsequently, as shown in FIG. 5A, the front lens 60 is sucked and held by air suction using the suction head H, and the seal ring 90 is fitted into the reduced diameter outer peripheral portion 62.
Subsequently, as shown in FIG. 5B, the lens holder 50 into which the second lens 70 and the other lenses 80 (the third lens 81 to the sixth lens 84) are fitted is positioned by jigs J1 and J2. In this state, the front lens 60 (and the seal ring 90) sucked and held by the suction head H is brought close to the front of the lens holder 50, and the front lens 60 (the fitting outer peripheral portion of the front lens 60 is moved while moving the suction head H). 61) is fitted into the fitting inner peripheral portion 54, and the annular contact surface 64 of the foremost lens 60 is brought into contact with the annular receiving surface 55.
Thereafter, using a heat caulking machine, the heat caulking portion 52a is thermally deformed to perform heat caulking.
Thus, the assembly of the lens unit U is completed. The foremost lens 60, the second lens 70, and the other lenses 80 (the third lens 81, the fourth lens 82, the fifth lens 83, and the sixth lens 84) are each set at a predetermined reference axis when assembled. The optical axis is adjusted.

According to the lens unit U configured as described above, in the relationship between the foremost lens 60 and the second lens 70, the second lens 70 is configured to press the other lenses 80 (the third lens 81 and the fourth lens 82). The front lens 60 is sandwiched between the reduced diameter outer peripheral portion 62 and the fitting inner peripheral portion 54 so as not to contact the second lens 70. While the annular contact surface 64 is brought into contact with the annular receiving surface 55 and the fitting outer peripheral portion 61 is fitted into the fitting inner peripheral portion 54 and fixed to the lens holder 50, an external force that pushes into the front lens 60. Even if (impact force) is applied, it is possible to prevent the second lens 70 and the other lenses 80 (81, 82) from being affected.
The seal ring 90 is fitted in a compressed state only in the radial direction perpendicular to the optical axis L, and between the annular surface 63 of the foremost lens 60 and the annular opposing surface 56 of the lens holder 50 in the optical axis L direction. Therefore, even when the seal ring 90 expands, it can be prevented from protruding and its deformation can be prevented from affecting the deviation of the optical axis L. it can. Thereby, the shift | offset | difference of the optical axis L etc. can be prevented as a whole, and the improvement of waterproofness, the improvement of durability, etc. can be achieved.

FIGS. 6 to 8 show other embodiments of the lens unit according to the present invention. The same components as those of the above-described embodiments are denoted by the same reference numerals and description thereof is omitted.
As shown in FIGS. 6A, 6B, 7 and 8, the lens unit U ′ according to this embodiment includes a cylindrical lens holder 50 ′ having an axis in the optical axis L direction, and a lens holder. The aperture plate 100 and the third lens 81 arranged behind the foremost lens 60, the second lens 70 ', and the second lens 70' that are arranged and fixed sequentially from the front side in the optical axis L direction with respect to 50 '. ', A diaphragm plate 110, a fourth lens 82', and a seal ring 90 'disposed between the foremost lens 60 and the lens holder 50'.

The lens holder 50 ′ is formed in a cylindrical shape having a shaft center in the optical axis L direction of the lens using a resin material or the like, and is positioned on the fixing portion 42 of the housing cover 40 as shown in FIG. A large-diameter outer cylinder portion 52 that is fixed and accommodates the foremost lens 60, is formed behind the large-diameter outer cylinder portion 52 in the direction of the optical axis L, and the second lens 70 and other lenses (third lens 81 ′, The fourth lens 82 '), the small-diameter outer cylinder portion 53 that accommodates the aperture plate 100 and the diaphragm plate 110, the fitting outer peripheral portion 61 of the foremost lens 60, and the radial direction perpendicular to the reduced outer peripheral portion 62 and the optical axis L. In the cylindrical fitting inner peripheral portion 54, the annular receiving surface 55 as a lens receiving portion for contacting the annular contact surface 64 of the foremost lens 60 in the optical axis L direction, and the annular surface 63 of the foremost lens 60 and the light. Annular facing opposite in the axis L direction 56 ′, a lens fixing portion 57 that fixes the second lens 70 ′ in a non-contact state with the foremost lens 60, an accommodation holding portion 58a that accommodates and holds the third lens 81 ′ and the fourth lens 82 ′, and an annular contact Part 58b and the like.
The annular facing surface 56 ′ is formed so as to be located on the same plane as the annular receiving surface 55 in the optical axis L direction.

As shown in FIG. 8, the second lens 70 ′ is a plastic lens having a meniscus shape having a convex surface on the object side and a concave surface on the image surface side, and is disposed behind the front lens 60. A fixing portion 71 fixed to the lens fixing portion 57, a rear end surface 72 that abuts against and presses the front end surface 81a of the third lens 81 ′ through the aperture plate 100, and the like.
The second lens 70 ′ is formed so that the fourth lens 82 ′, the diaphragm plate 110, the third lens 81 ′, and the aperture plate 100 are sequentially stacked and accommodated, and then the aperture plate 100 is pressed from the front. It is fitted from the front in the direction of the axis L and is fixed by an adhesive or the like.

As shown in FIG. 8, the third lens 81 ′ is a plastic lens that has a meniscus shape having a convex surface on the object side and a concave surface on the image surface side, and is disposed behind the second lens 70 ′. 70 ′ includes a front end surface 81a that the rear end surface 72 presses through the aperture plate 100, a rear end surface 81b that presses the front end surface 82a of the fourth lens 82 ′ through the diaphragm plate 110, and the like.
The third lens 81 ′ is accommodated from the front of the fourth lens 82 ′ with the diaphragm plate 110 sandwiched therebetween and is arranged so as to press in the direction of the optical axis L, and the aperture plate 100 is moved by the second lens 70 ′. It is pressed and fixed through.

As shown in FIG. 8, the fourth lens 82 ′ is a plastic lens that has a biconvex shape having a convex surface on the object side and a convex surface on the image surface side, and is disposed behind the third lens 81 ′. A front end surface 82a pressed through the diaphragm plate 110 by the rear end surface 81b of the lens 81 ′, a rear end surface 82b that contacts the annular contact portion 58b of the lens holder 50 ′, and the like are provided.
The fourth lens 82 ′ is disposed so that the rear end surface 82 b contacts the annular contact portion 58 b, and is pressed and fixed by the third lens 81 ′ through the diaphragm plate 110.

  The seal ring 90 ′ is formed in a size that is fitted in the fitting inner peripheral portion 54 of the lens holder 50 ′ in advance, and the optical axis between the reduced diameter outer peripheral portion 62 and the fitting inner peripheral portion 54 of the front lens 60. Compressed and accommodated in a radial direction perpendicular to L, and arranged so as to be in a non-contact state with at least one of the annular surface 63 and the annular facing surface 56 ′ (here, the annular surface 63) in the optical axis L direction. Has been.

Also in the lens unit U ′ having the above-described configuration, in the relationship between the front lens 60 and the second lens 70 ′, the second lens 70 ′ includes other lenses (third lens 81 ′ and The fourth lens 82 '), the aperture plate 110, and the diaphragm plate 110 are pressed by the lens fixing portion 57 of the lens holder 50' so that the foremost lens 60 is not in contact with the second lens 70 '. The annular contact surface 64 is brought into contact with the annular receiving surface 55 while the seal ring 90 'is sandwiched between the reduced diameter outer peripheral portion 62 and the fitted inner peripheral portion 54, and the fitted outer peripheral portion 61 is fitted into the fitted inner periphery. The second lens 70 ′ and other lenses (81 ′, 82 ′) even if an external force (impact force) that pushes into the front lens 60 is applied because it is fitted to the portion 54 and fixed to the lens holder 50 ′. ) It is possible to stop.
The seal ring 90 'is fitted in a compressed state only in the radial direction perpendicular to the optical axis L. In the optical axis L direction, the annular surface 63' of the foremost lens 60 and the annular opposing surface 56 'of the lens holder 50' are fitted. Is not in contact (non-compressed) with at least one of the surfaces (annular surface 63), so that even when the seal ring 90 'expands, it can be prevented from protruding and the deformation of the optical axis L can be prevented. The influence on the deviation can be prevented. Thereby, the shift | offset | difference of the optical axis L etc. can be prevented as a whole, and the improvement of waterproofness, the improvement of durability, etc. can be achieved.

In the above embodiment, as the lenses incorporated in the lens units U and U ′, in addition to the front lens 60 and the second lenses 70 and 70 ′, the third lenses 81 and 81 ′, the fourth lenses 82 and 82 ′, or Although the case where the fifth lens 83 and the sixth lens 84 are included has been described, the present invention is not limited to this, and the present invention may be adopted in a lens configuration composed of other combinations.
In the above embodiment, the configuration in which the fitting outer peripheral portion 61 of the foremost lens 60 is fitted into the fitting inner peripheral portion 54 of the lens holder 50, 50 ′ by press-fitting is shown, but the present invention is not limited to this. Alternatively, a fitting state in which the press-fitting allowance is zero may be applied.
In the above-described embodiment, the case where the annular receiving surface 55 is employed as the lens receiving portion that receives the annular contact surface 64 of the foremost lens 60 has been described. As long as it can be positioned at a predetermined position in the L direction, a plurality of protrusions arranged at equal intervals in the circumferential direction other than the annular shape, or other forms may be adopted.

  As described above, the lens unit of the present invention achieves the foremost (most most) while achieving simplification of the structure, facilitating assembly work, preventing damage to the seal ring during assembly, and reducing costs. Even if an external force (or impact force) is applied to the lens located on the outside), the lens placed inside can be prevented from being affected, and the optical axis can be prevented from shifting. Since it can achieve improved durability, it can be applied as a lens optical system for an imaging device used in an outdoor environment as an in-vehicle camera, a surveillance camera, etc., or an imaging device used in other severe environments It is also useful as a lens optical system.

10 Image sensor 20 Substrate 30 Housing body (housing)
40 Housing cover (housing)
U, U 'lens unit (lens optical system)
L Optical axes 50, 50 ′ Lens holder 52a Thermal caulking portion 54 Fitting inner peripheral portion 55 Annular receiving surface (lens receiving portion)
56, 56 ′ annular facing surface 57 lens fixing portion 60 frontmost lens 61 fitting outer peripheral portion 62 reduced diameter outer peripheral portion 63 annular surface 64 annular contact surface 70, 70 ′ second lens 81, 81 ′ third lens 82, 82 ′ Fourth lens 83 Fifth lens 84 Sixth lens 90, 90 'Seal ring 100 Aperture plate 110 Aperture plate

Claims (2)

A cylindrical lens holder having an axis in the optical axis direction of the lens, a foremost lens that is sequentially arranged and held in the optical axis direction in the lens holder, and a second lens disposed behind the foremost lens. A lens unit comprising at least a plurality of lenses, and a seal ring disposed between the foremost lens and the lens holder,
The foremost lens connects a fitting outer peripheral portion having a predetermined outer diameter, a cylindrical reduced outer peripheral portion whose diameter is smaller than that of the fitting outer peripheral portion, and the fitting outer peripheral portion and the reduced outer peripheral portion. Including an annular surface and an annular contact surface formed continuously at the rear end of the reduced diameter outer peripheral portion,
The lens holder includes a cylindrical fitting inner peripheral portion that fits the fitting outer peripheral portion of the foremost lens and faces the reduced diameter outer peripheral portion in a radial direction perpendicular to the optical axis, and an annular contact of the front lens. A lens receiving portion for contacting the surface in the optical axis direction, an annular facing surface facing the annular surface of the foremost lens in the optical axis direction, and lens fixing for fixing the second lens in a non-contact state with the foremost lens. Part
The seal ring is disposed in a radially compressed manner between the reduced diameter outer peripheral portion and the fitting inner peripheral portion in a state that is not in contact with at least one of the annular surface and the annular facing surface,
The lens receiving portion is an annular receiving surface formed in an annular shape,
The annular facing surface is formed so as to be recessed rearward in the optical axis direction than the annular receiving surface.
A lens unit characterized by that. An imaging apparatus comprising: a lens optical system that holds a plurality of lenses; an imaging element that is disposed behind the lens optical system in an optical axis direction; and a housing that houses the lens optical system and the imaging element. ,
The lens optical system is the lens unit according to claim 1.
An imaging apparatus characterized by that.

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