JP6807727B2 - Lens unit and camera module - Google Patents

Description

The present invention relates to a small lens unit provided in an in-vehicle camera mounted on a vehicle such as an automobile.

In recent years, in-vehicle cameras have been installed in automobiles to support parking and to prevent collisions by image recognition, and further applications to automatic driving have been attempted.
A camera module such as an in-vehicle camera generally includes a lens group consisting of a plurality of lenses in which a plurality of lenses are arranged along an optical axis, a lens barrel in which the lens group is housed, and a lens group. It includes a lens unit having an aperture member arranged between at least one lens.

When such a lens unit is used in an in-vehicle camera, water droplets may adhere to the lens surface exposed from the lens barrel in rainy weather. Since such water droplets adhering to the lens surface cause image deterioration, the lens surface is generally subjected to a water-repellent coating treatment or a hydrophilic coating treatment to prevent the water droplets from adhering, and the water droplets adhering to the lens surface are removed. In many cases, they try not to stay in that place.
Therefore, the water droplets adhering to the lens surface flow toward the outer peripheral side of the surface, but the flowing water droplets may stay on the outer peripheral portion of the lens, and the accumulated water droplets also cause image deterioration.

As an example of a lens unit in which water droplets are prevented from accumulating on the outer peripheral portion of the lens, the one described in Patent Document 1 is known.
This lens unit has an object-side lens that is located on the most object side of the lens barrel and whose surface, which is a convex curved surface, is exposed to the outside, and an annular pressing member is formed on the inner circumference of the end of the lens barrel. It is screwed and tightened to the portion, and the outer peripheral portion of the lens on the object side is locked to the end portion (end portion on the object side) of the lens barrel by the pressing member.
Then, in order to prevent water droplets adhering to the surface of the lens on the object side and flowing toward the outer peripheral side from staying on the outer peripheral portion of the lens, a groove is formed on the surface of the pressing member from the inner peripheral end to the outer peripheral end. Is formed, and water droplets are discharged to the outside through this groove.
In such a lens unit, water droplets can be discharged to the outside, but since a pressing member is used, the number of parts increases by that amount, and the pressing member is screwed onto the inner peripheral surface of the end of the lens barrel. Since it is necessary to form a screw portion on the inner peripheral surface of the end portion of the lens barrel in order to make the lens barrel possible, there is a problem that the cost is high.

On the other hand, as shown in FIGS. 5 and 6, for example, there is a lens unit whose cost is reduced by locking the object-side lens 21 to the object-side end of the lens barrel 20 by caulking.
In this lens unit, an inclined surface 21b is formed on the outer peripheral portion of the object-side lens 21, and a caulking portion 22 formed by caulking the end of the lens barrel 20 on the object side inward is engaged with the inclined surface 21b. It's stopped.

JP-A-2007-316167

However, since the edge portion 23 having a substantially V-shaped cross section is formed between the inclined surface 21b and the caulking portion 22 formed on the outer peripheral portion of the object side lens 21 along the circumferential direction of the object side lens 21. Even if the lens surface 21a of the object-side lens 21 is subjected to a water-repellent coating treatment or a hydrophilic coating treatment, water droplets flowing toward the outer peripheral side of the lens surface 21a stay at the edge portion 23, and the water droplets flow from the lens surface 21a to the outside. In many cases, it does not run off, and the water droplets deteriorate the image.

The present invention has been made in view of the above circumstances, and in a lens unit in which an object-side lens is locked to a lens barrel by a caulking portion formed by caulking the object-side end of the lens barrel inward. It is an object of the present invention to provide a lens unit capable of easily discharging water droplets to the outside from the outer peripheral portion of the lens surface of the lens on the object side.

In order to solve the above-mentioned problems, the lens unit of the present invention includes a plurality of lenses arranged along the optical axis, a lens barrel in which the plurality of lenses are housed, and the most object side of the plurality of lenses. A caulking portion formed by caulking the end of the lens barrel on the object side inward is provided with an object-side lens that is located and has a convex curved surface on the object-side surface, and is locked to the object-side lens. It is a lens unit that is
An inclined surface that is inclined toward the image side toward the outer side in the radial direction from the surface of the object-side lens is provided in an annular shape on the outer peripheral portion of the object-side lens.
The caulked portion is locked to the inclined surface,
The caulked portion is characterized in that a plurality of edges capable of breaking the surface tension of water droplets and a plurality of discharge portions for discharging water to the outside are provided at predetermined intervals in the circumferential direction.

In the present invention, an edge capable of destroying the surface tension of water droplets and a discharge portion for discharging water to the outside surround a caulking portion locked to an inclined surface provided on the outer peripheral portion of the object-side lens. Since a plurality of water droplets are provided at predetermined intervals in the direction, the water droplets that adhere to the lens surface and flow toward the outer peripheral side hit the edges, and the water droplets become running water after the surface tension is destroyed. It is discharged to the outside through the discharge part. Therefore, water droplets can be easily discharged to the outside from the outer peripheral portion of the lens surface of the object-side lens.

In the configuration of the present invention, the crimped portion is provided with a plurality of groove portions extending from the inner peripheral end to the outer peripheral end of the crimped portion at predetermined intervals in the circumferential direction.
It is preferable that the groove portion serves as the discharge portion and at least the opening edge of the groove portion serves as the edge.

According to such a configuration, the edge and the discharge portion can be easily provided only by forming the groove portion in the crimped portion. Then, the surface tension of the water droplet is destroyed by the edge, and the water can be easily discharged to the outside by the groove portion.

Further, in the above-mentioned configuration of the present invention, the groove width of the groove portion is wider on the tip side than on the groove bottom side.
It is preferable that a caulking piece forming the caulking portion that locks to the inclined surface is provided between the groove portions adjacent to each other in the circumferential direction.

According to such a configuration, a caulking piece that locks to the inclined surface of the outer peripheral portion of the object-side lens is provided between the grooves whose groove width is wider on the tip side than on the groove bottom side. One piece has a thick root and a thin tip. Therefore, it is possible to suppress a decrease in the lens locking force of the crimped piece that locks the object-side lens due to the formation of the groove in the crimped portion.
Further, since the groove width is wider on the tip side than on the groove bottom side, the side wall surface facing the groove is inclined so as to approach the groove bottom surface. Therefore, the water that has flowed into the groove can be effectively discharged to the outside.

According to the present invention, the water droplets adhering to the lens surface and flowing toward the outer peripheral side hit the edges, which destroys the surface tension of the water droplets and then becomes a water flow to the outside through the discharge portion. Since it is discharged to the outside, water droplets can be easily discharged to the outside from the outer peripheral portion of the lens surface of the lens on the object side.

It is a perspective view which shows the lens unit which concerns on embodiment of this invention. The same is a perspective view in which a part of the main part is cut out. The same is a schematic cross-sectional view. The same is a plan view. An example of a conventional lens unit is shown, and is a perspective view thereof. The same is a perspective view in which a part of the main part is cut out.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The lens unit of this embodiment is for a camera module such as an in-vehicle camera. For example, the lens unit is fixedly installed on the outer surface side of an automobile, and the wiring is drawn into the automobile and connected to a display or other device. Will be done.

As shown in FIGS. 1 to 4, the lens unit of the present embodiment includes a lens barrel 1 and a plurality of lenses 2 to 6 (see FIG. 3) housed in the lens barrel 1.
In addition to this, this lens unit includes a light-shielding filter, spacers, etc.
It includes an optical filter or the like that is arranged at one end of the image side (the side where the image sensor is arranged) in which the lenses 2 to 6 form an image.

As shown in FIG. 3, a plurality of lenses 2 to 6 fixed and supported by the lens barrel 1 are arranged in a state where their optical axes are aligned with each other, and each lens is arranged along one optical axis. 2 to 6 are arranged side by side to form a group of lenses used for imaging. Therefore, when the optical axis is simply described below, the optical axis of each lens 2 to 6 is shown and the optical axis of the lens group is shown.

The lens barrel 1 is made of nylon-based resin reinforced with glass fiber, and is formed in a tubular shape with both ends open. The lens barrel 1 may be made of another resin, or may be made of a metal such as stainless steel or an aluminum alloy.
One end of the lens barrel 1 (lower end in FIG. 3) is arranged as the image side toward the image sensor, and the other end (upper end in FIG. 3) is arranged as the object side toward the image sensor. .. In the present embodiment, the lens 2 side is the object side.
The lens (object-side lens) 2 located closest to the object side is a glass lens. The other lenses 3 to 6 may be glass lenses or resin lenses.
A plurality of lenses 2 to 6 and a light-shielding filter and a spacer are sequentially inserted and installed with respect to the lens barrel 1 from the object side (upper side) to the image side (lower side).

Inside the lens barrel 1, a plurality of (four) cylindrical housing portions having different diameters are provided on the image side (lower side in FIG. 3) of the object side lens 2. The diameter of these accommodating portions gradually increases from the image side (lower side in FIG. 3) to the object side (upper side in FIG. 3), and lenses 6 to 3 are sequentially accommodated in these accommodating portions from the lower side. ing.
The object-side lens 2 is slightly separated from the upper surface of the accommodating portion closest to the object side. Further, on the outer peripheral surface of the lens 2 on the object side, a reduced diameter portion having a smaller diameter is provided on the image side portion of the lens 2, and an O ring 8 as a sealing member is provided on the reduced diameter portion. The outer peripheral surface of the side lens 2 and the inner peripheral surface of the lens barrel 1 are sealed by the object-side end of the lens barrel 1. This prevents fine particles such as water and dust from entering the lens barrel 1 from the end of the lens unit on the object side.

Further, as shown in FIGS. 1 to 4, the object-side lens 2 has a convex curved surface (lens surface) 2a protruding from the object-side end of the lens barrel 1, and is an outer peripheral portion of the object-side lens 2. In addition, an inclined surface 2b that is inclined toward the image side toward the outer side in the radial direction from the surface (lens surface) 2a of the object-side lens 2 is provided in an annular shape.

On the other hand, a caulking portion 10 formed by caulking the end portion of the lens barrel 1 on the object side (upper end portion in FIGS. 1 to 3) inward in the radial direction by thermal caulking is provided. .. The caulking portion 10 locks the object-side lens 2 to the end portion of the lens barrel 1 on the object side, and the caulking portion 10 has an edge capable of destroying the surface tension of water droplets and water to the outside. A discharge unit for discharging is provided as follows.

That is, the end portion of the lens barrel 1 on the object side is bent inward in the radial direction at a predetermined angle by thermal caulking, and the bent portion (caulking portion 10) is bent along the circumferential direction of the lens barrel 1. A plurality of groove portions 11 are formed at predetermined intervals (constant intervals).
The groove portion 11 is formed so as to extend from the inner peripheral end 10a of the caulking portion 10 toward the outer peripheral end 10b, and the groove width (groove width in the circumferential direction) is wider on the tip side than on the groove bottom side. There is.
Further, the groove portion 11 is composed of a groove bottom surface 12 and inner wall surfaces 13 and 13 that rise from the edge portion of the groove bottom surface 12 in the circumferential direction at right angles to the groove bottom surface 12 and face each other in the circumferential direction. Further, the opening of the groove portion 11 facing the radial inward side of the lens barrel 1 is closed by the inclined surface 2b of the object-side lens 2, and the opening of the groove portion 11 facing the radial outer side of the lens barrel 1 is opened to the outside. ing.

The groove bottom surface 12 is a surface orthogonal to the optical axis of the object-side lens 2. Further, as shown in FIG. 2, the inner wall surface 13 is formed in a pentagonal shape, and has two edges 13a and 13b forming a part of the opening edge of the groove portion 11. The edge 13a is inclined with respect to a surface perpendicular to the optical axis at an angle substantially equal to the bending angle of the crimped portion 10. That is, the edge 13a is inclined toward the object side (upper side in FIG. 2) toward the inside of the object side lens 2.
The edge 13b is inclined to the opposite side of the edge 13a, and is arranged substantially at right angles to the inclined surface 2b of the object-side lens 2.
Further, an edge 13c is formed between the adjacent groove portions 11 and 11. The edge 13c is arranged substantially parallel to the inclined surface 2b, and extends in the circumferential direction of the object-side lens 2 from the intersection of the edge 13a and the edge 13b.
Such edges 13a to 13c are located on the outer peripheral side of the inclined surface 2b of the object-side lens 2. Further, the groove width of the groove portion 11 is smaller than, for example, the diameter of water droplets adhering to the surface 2a of the object-side lens 2. Therefore, the water droplets that try to enter the groove 11 will hit at least the edges 13a and 13b at the opening edge of the groove 11.

The edges 13a to 13c are edges capable of destroying the surface tension of water droplets. That is, the water droplets adhering to the lens surface 2a of the object-side lens 2 flow toward the outer peripheral side (diameter outer side) of the lens surface 2a, and in some cases, the water droplets flow while increasing in diameter.
The flowing water droplet hits at least one edge of the edges 13a to 13c, and the surface tension of the water droplet is destroyed by the impact of hitting the edge. Such edges 13a and 13b are open edges of the groove portion 11. Further, the edge 13c is not an opening edge of the groove portion 11, but is an edge formed on the upper surface of the caulking piece 15 described later.

Further, the groove portion 11 is a discharge portion for discharging water that has become easy to flow due to the surface tension being broken by the edges 13a to 13c. That is, the water droplet whose surface tension is destroyed by the edges 13a to 13c becomes a water flow and flows into the groove portion 11, flows outward through the groove bottom surface 12, and faces the radial outside of the lens barrel 1, which is the groove portion 11. It is designed to flow out from the opening.

Further, a caulking piece 15 that locks to the inclined surface 2b of the outer peripheral portion of the object-side lens 2 is provided between the groove portions 11 and 11 adjacent to each other in the circumferential direction. The caulking portion 10 is composed of the plurality of caulking pieces 15.
The side surfaces of the caulking piece 15 facing the circumferential direction (circumferential direction of the lens barrel 1) are formed by the inner wall surfaces 13 and 13 of the adjacent groove portions 11 and 11. Therefore, it can be said that the above-mentioned edges 13a to 13c are formed by the edges on the upper surface side of the caulking piece 15.

As described above, according to the present embodiment, the caulking portions 10 locked to the inclined surface 2b provided on the outer peripheral portion of the object-side lens 2 are provided with edges 13a to 13c capable of destroying the surface tension of water droplets. Since a plurality of discharge portions (groove portions) 11 for discharging water to the outside are provided at predetermined intervals in the circumferential direction, the water droplets adhering to the lens surface 2a and flowing toward the outer peripheral side are the edges 13a to Upon hitting 13c, the surface tension of the water droplet is destroyed by this, and the water droplet becomes a water stream and is discharged to the outside through the discharge portion discharge portion (groove portion) 11. Therefore, water droplets can be easily discharged to the outside from the outer peripheral portion of the lens surface 2a of the object-side lens 2.

Further, the caulking portion 10 is provided with a plurality of groove portions 11 extending from the inner peripheral end 10a of the caulking portion 10 toward the outer peripheral end 10b at predetermined intervals in the circumferential direction, and the groove portions 11 serve as discharge portions and the groove portions 11 Since the opening edges of the above are the edges 13a to 13c, the edges 13a to 13c and the discharge portion (groove portion 11) can be easily provided only by forming the groove portion 11 in the caulking portion 10. Then, the surface tension of the water droplet is destroyed by the edges 13a to 13c, and the water flow can be easily discharged to the outside by the groove portion 11.

Further, the groove portion 11 has a groove width wider on the tip side than on the groove bottom side, and the caulking piece 15 is locked to the inclined surface 2b of the object side lens 2 between the groove portions 11 and 11 adjacent to each other in the circumferential direction. The caulking piece 15 has a thick root portion and a thin tip portion. Therefore, it is possible to suppress a decrease in the lens locking force of the caulking piece 15 due to the formation of the groove portion 11 in the caulking portion 10.
Further, since the groove width of the groove portion 11 is wider on the tip side than on the groove bottom side, the facing inner wall surfaces 13 and 13 of the groove portion 11 are inclined so as to approach the groove bottom surface 12. Therefore, the water that has flowed into the groove 11 can be effectively discharged to the outside.

In the present embodiment, the groove bottom surface 12 of the groove portion 11 is a surface orthogonal to the optical axis of the object-side lens 2, but instead, the groove bottom surface 12 is imaged toward the outer side in the radial direction of the lens barrel 1. It may be an inclined surface that inclines to the side. In this way, water can be efficiently discharged along the inclined surface.

1 Lens barrel 2 Object side lens 2a Lens surface (surface)
2b Inclined surface 3 to 6 Lens 10 Caulking part 11 Groove part (Discharging part)
12 Groove bottom surface 13 Inner wall surface 13a to 13c Edge

Claims (4)

A plurality of lenses arranged along the optical axis, a lens barrel in which the plurality of lenses are housed, and the lens surface of the plurality of lenses located on the object side most and having a convex curved surface on the object side. A lens unit including a lens on the object side, and a caulking portion formed by caulking the end portion of the lens barrel on the object side inward is locked to the lens on the object side.
The caulking portion locks the outer peripheral portion of the object-side lens surface of the object-side lens ,
The caulking portion is composed of a large number of caulking pieces provided over the entire circumference at predetermined intervals in the circumferential direction.
A groove extending from the inner peripheral end to the outer peripheral end of the crimped portion is provided between all the caulked pieces adjacent to each other in the circumferential direction.
A lens unit characterized in that at least the opening edge of the groove portion is an edge on the object-side lens surface that can destroy the surface tension of water droplets toward the outer peripheral portion. The large number of caulking pieces are characterized in that the root portion is thick and the tip portion is thin in the circumferential direction, and the object-side lens is locked to the lens barrel at both the tip portion and the root portion. The lens unit according to claim 1. The groove has a lens unit according to claim 1 or 2, the groove width, characterized in that it is wider toward the leading end side from the groove bottom side. A camera module including the lens unit according to any one of claims 1 to 3.

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