JP2022182405A - Lens unit, camera module, on-vehicle system, and vehicle - Google Patents

Abstract

To provide a lens unit which reduces pressure acting on a lens and can suppress deformation of the lens, a camera module, an on-vehicle system, and a vehicle.SOLUTION: In a lens unit 11, a lens barrel 12 is formed of a resin. Lenses 14, 15, 17 and 18 constituting a lens group L stored in the lens barrel 12 are made of glass, are assembled in the lens barrel 12 by press fitting, and its radial outer peripheral ends 14a, 15a, 17a and 18a in a cross section in the direction of an optical axis O are brought into point contact with the inner surface 12d of the lens barrel 12.SELECTED DRAWING: Figure 1

Description

The present invention particularly relates to a lens unit, a camera module, an in-vehicle system, and a vehicle equipped with the in-vehicle system, which constitute an in-vehicle camera mounted in a vehicle such as an automobile.

In recent years, automobiles are equipped with in-vehicle cameras to support parking and prevent collisions by image recognition. In general, a camera module such as an in-vehicle camera includes at least a lens group consisting of a plurality of lenses arranged along an optical axis, a barrel housing and holding the lens group, and a lens group. A lens unit having an aperture member disposed between lenses at one location is provided (see, for example, Patent Document 1).

2. Description of the Related Art Conventionally, there are various types of lens units in which lenses are incorporated into a lens barrel. For example, due to factors such as the materials of the lens barrel and lenses, the lens may be assembled to the lens barrel via a spacer or the like, or the lens may be directly attached to the inner surface of the lens barrel using the shape of the inner surface of the lens barrel. The lens is lightly press-fitted with a diameter difference, or the lens is assembled into the lens barrel in a state where the outer periphery of the lens and the inner peripheral side of the lens barrel are in point contact in a cross section orthogonal to the optical axis direction. In particular, in a form in which a lens and a lens barrel are assembled in a state of point contact, for example, there is an assembly form in which a lens having a circular cross section is press-fitted into a lens barrel having a polygonal inner peripheral surface.

JP 2013-231993 A

By the way, in general, including the above-mentioned form in which the lens is press-fitted into the lens barrel and assembled in a state where the outer periphery of the lens and the inner peripheral side of the lens barrel are in point contact in a cross section orthogonal to the optical axis direction, When the lens is incorporated into the barrel, as shown in FIG. 13, the outer peripheral surface of the lens and the inner peripheral surface of the lens barrel are in line contact in the cross section along the optical axis direction. 13, the lenses 102 and 103 are assembled to the lens barrel 100 via the spacer 110, and each lens 102 and 103 is a straight line along the optical axis O direction in the cross section along the optical axis O direction. Linear portions 102b and 103b, which are fitted in line contact (line contact with a certain length) to the inner surface 100a of the lens barrel 100, are attached to the side end surfaces (edges) of the annular outer peripheral flanges 102a and 103a. have.

However, when the lenses 102 and 103 are press-fitted into the lens barrel 100 in such a lens built-in state, a compressive stress directed radially inward always acts on the lenses 102 and 103. In the above-described form in which the lens is press-fitted into the lens barrel in a state where the outer periphery of the lens and the inner peripheral side of the lens barrel are in point contact in a cross section orthogonal to the above, the lens barrel is made of resin and the lens is made of glass. , the lenses 102 and 103 may be deformed by a large pressure acting on the edges (straight portions) 102b and 103b, which are the press-fit surfaces, and the desired optical performance may not be obtained. In recent years, when glass has become thinner and high assembly accuracy and high optical performance are required, even a slight deformation of a lens has a large impact on optical performance. ) is an urgent issue.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens unit, a camera module, an in-vehicle system, and a vehicle capable of reducing the pressure acting on the lens and suppressing deformation of the lens.

In order to solve the above problems, the present invention provides a cylindrical lens barrel that forms an inner housing space for housing and holding lenses, and a lens that is incorporated in the inner housing space of the lens barrel and has a plurality of lenses. A lens unit comprising a lens group arranged along an axis,
The lens barrel is made of resin,
At least one lens that constitutes the lens group is made of glass and is incorporated into the lens barrel by press-fitting. characterized by being in point contact with each other.

According to the above configuration of the present invention, since the radial outer peripheral edge of the lens is in point contact with the inner surface of the lens barrel in a cross section along the direction of the optical axis, the lens made of glass is placed inside the lens barrel made of resin. In the unique press-fitting form of press-fitting, the pressure acting on the lens can be reduced and deformation of the lens can be suppressed. Therefore, desired optical characteristics can be obtained without deteriorating optical performance.

Here, the term "point contact" includes contact areas within a certain range. direction) is 1/3 or less of the edge thickness.

In the above configuration, the lens that is in point contact with the lens barrel has an arc at its radially outer edge in a cross section along the direction of the optical axis, and the apex of this arc may be in point contact with the inner surface of the lens barrel. preferable. According to this, it is possible to realize a substantially uniform stress distribution without stress concentration in the action area of the lens where the compressive stress acts radially inward from the lens barrel to the lens. It can contribute to deformation suppression.

In the above configuration, the lens that is in point contact with the lens barrel in the cross section along the direction of the optical axis also makes point contact with the inner surface of the lens barrel in the cross section perpendicular to the direction of the optical axis. may be According to this, a fitting form in which a lens made of glass is press-fitted into a lens barrel made of resin in a state of point contact in a cross section perpendicular to the direction of the optical axis, that is, a specification in which deformation of the lens is particularly likely to occur due to compressive stress. In the press fitting mode, the pressure acting on the lens can be effectively reduced, and deformation of the lens can be reliably suppressed.

Here, "point contact" in a cross section orthogonal to the direction of the optical axis includes cases involving contact areas within a certain range. It is assumed that the contact length with the lens barrel is 1/3 or less of the edge thickness. Moreover, such a point contact state is realized by, for example, press-fitting a lens having a circular cross section into a lens barrel having a polygonal inner peripheral surface, but the present invention is not limited to this.

In the above configuration, the contact point of the lens that makes point contact with the lens barrel is the perpendicular bisector of the line segment along the optical axis direction that defines the lens thickness dimension at the center of the lens in the cross section along the optical axis direction. is preferably located at the radially outer end portion closest to the radial centerline. This means that the contact point is located on the radial centerline if the radially outer edge portion of the lens lies on the radial centerline. According to this, it is possible to further effectively reduce the pressure acting on the lens from the lens barrel, thereby further enhancing the effect of suppressing lens deformation.

Test data demonstrating such a high lens deformation suppressing effect are shown in FIGS. 9 to 12. FIG.
Here, (a) of FIG. 9 shows a conventional press-fitting configuration of a lens into a lens barrel, that is, line contact between the outer peripheral surface of the lens A and the inner peripheral surface of the lens barrel B in a cross section along the direction of the optical axis O. The press-fitting configuration is shown. Specifically, the lens A is a meniscus lens that is convex toward the image side. A linear portion Aa that is fitted in a line contact state is provided on the side end surface (edge) of the annular outer peripheral flange Ab. In such a press-fitting configuration, deformation amount data at five measurement points P1, P2, P3, P4, and P5 on the surface (R1 surface) Ac facing the object side of the lens A is shown in FIG. b) as a table and FIG. 9(c) as a graph. The measurement point P1 is a point on the optical axis O (lens center) (deformation -3.92E-03), and the measurement point P2 is a point on the surface Ac 0.56 mm away from the optical axis O in the radial direction. (deformation amount -3.03E-03), and the measurement point P3 is a point on the surface Ac 1.37 mm away from the optical axis O in the radial direction (deformation amount -2.66E-03), and the measurement point P4 is a point on the surface Ac 1.86 mm away from the optical axis O in the radial direction (deformation amount -2.01E-03), and the measurement point P5 is 2.29 mm away from the optical axis O in the radial direction. It is a point on the surface Ac (deformation -1.37E-03). Further, the deformation amount data at the five measurement points Q1, Q2, Q3, Q4, and Q5 on the rear surface (R2 surface) Ad of the lens A facing the image side is shown in a table in FIG. 9(e) as a graph, respectively. The measurement point Q1 is a point on the optical axis O (lens center) (deformation amount -3.68E-03), and the measurement point Q2 is a point on the rear surface Ad which is 0.56 mm away from the optical axis O in the radial direction. (deformation amount -3.61E-03), the measurement point Q3 is a point on the rear surface Ad 1.37 mm away from the optical axis O in the radial direction (deformation amount -3.25E-03), and the measurement point Q4 is a point on the rear surface Ad 1.86 mm away from the optical axis O in the radial direction (deformation amount -2.87E-03), and the measurement point Q5 is 2.29 mm away from the optical axis O in the radial direction. It is a point on the rear surface Ad (deformation amount -2.41E-03). As can be seen from these data, on the surface Ac, even at the radially outermost measurement point P5, there is an absolute value of deformation of 1.37E-03 (= 1.37 × 10 ^-3 ) mm. At the measurement point P1 on the inner optical axis O, the absolute value of the deformation amount is 3.29E-03 mm. On the other hand, the amount of deformation is further increased on the rear surface Ad. Here, the minus sign indicates the direction of change.

On the other hand, (a) of FIG. 10 shows the form of press-fitting of the lens into the lens barrel according to the present invention. Point contact with the inner surface Ba, and the contact point AAa is the perpendicular bisector of the line segment MN along the optical axis O direction that defines the lens thickness dimension D at the center of the lens A. It shows a press-fit configuration located at the radially outer edge AA closest to the line L1. In particular, in this example, the contact point AAa is positioned on the radial centerline L1. In such a press-fitting form, the deformation amount data at five measurement points P1, P2, P3, P4, and P5 on the surface (R1 surface) Ac facing the object side of the lens A is shown in FIG. b) as a table and FIG. 10(c) as a graph. The measurement point P1 is a point on the optical axis O (lens center) (deformation 4.96E-04), and the measurement point P2 is a point on the surface Ac 0.83 mm away from the optical axis O in the radial direction. Yes (deformation amount 5.60E-04), the measurement point P3 is a point on the surface Ac 1.30 mm away from the optical axis O in the radial direction (deformation amount 6.42E-04), and the measurement point P4 is It is a point on the surface Ac that is 2.04 mm away from the optical axis O in the radial direction (deformation amount 7.49E-04), and the measurement point P5 is on the surface Ac that is 2.35 mm away from the optical axis O in the radial direction. It is a point (deformation amount 7.42E-04). Further, the deformation amount data at the five measurement points Q1, Q2, Q3, Q4, and Q5 on the rear surface (R2 surface) Ad of the lens A facing the image side is shown in a table in FIG. 10(e) as a graph respectively. The measurement point Q1 is a point on the optical axis O (lens center) (deformation amount 2.45E-04), and the measurement point Q2 is a point on the rear surface Ad which is 0.59 mm away from the optical axis O in the radial direction. Yes (deformation amount 2.59E-04), the measurement point Q3 is a point on the rear surface Ad 1.38 mm away from the optical axis O in the radial direction (deformation amount 3.24E-04), and the measurement point Q4 is It is a point on the rear surface Ad 1.86 mm away from the optical axis O in the radial direction (deformation amount 3.87E-04), and the measurement point Q5 is on the rear surface Ad 2.29 mm away from the optical axis O in the radial direction. It is a point (deformation amount 4.45E-04). As can be seen from these data, in such a press-fitting configuration, the amount of deformation is greatly reduced overall compared to the conventional press-fitting configuration shown in FIG.

FIG. 11(a) shows the press-fitting configuration of the present invention of the lens into the lens barrel, that is, in a cross section along the direction of the optical axis O, the radial outer peripheral edge AA of the lens A is the inner surface Ba of the lens barrel B. , and the contact point AAa is located at the radially outer edge AA farthest from the radial center line L1. In such a press-fitting configuration, the deformation amount data at the five measurement points P1, P2, P3, P4, and P5 on the surface (R1 surface) Ac facing the object side of the lens A is shown in FIG. b) as a table and FIG. 11(c) as a graph. The measurement point P1 is a point on the optical axis O (lens center) (deformation -2.24E-03), and the measurement point P2 is a point on the surface Ac 0.59 mm away from the optical axis O in the radial direction. (deformation amount -2.20E-03), and the measurement point P3 is a point on the surface Ac 1.30 mm away from the optical axis O in the radial direction (deformation amount -2.01E-03), and the measurement point P4 is a point on the surface Ac 1.70 mm away from the optical axis O in the radial direction (deformation amount -1.81E-03), and the measurement point P5 is 2.20 mm away from the optical axis O in the radial direction. It is a point on surface Ac (deformation -1.46E-03). Further, the deformation amount data at the five measurement points Q1, Q2, Q3, Q4, and Q5 on the rear surface (R2 surface) Ad of the lens A facing the image side is shown in a table in FIG. 11(e) as a graph, respectively. The measurement point Q1 is a point on the optical axis O (the center of the lens) (deformation amount -2.24E-03), and the measurement point Q2 is a point on the rear surface Ad which is 0.59 mm away from the optical axis O in the radial direction. (deformation amount -2.21E-03), the measurement point Q3 is a point on the back surface Ad 1.12 mm away from the optical axis O in the radial direction (deformation amount -2.12E-03), and the measurement point Q4 is a point on the rear surface Ad 1.63 mm away from the optical axis O in the radial direction (deformation amount -1.98E-03), and the measurement point Q5 is 2.07 mm away from the optical axis O in the radial direction. It is a point on the rear surface Ad (amount of deformation -1.80E-03). As can be seen from these data, in such a press fit configuration, the amount of deformation is generally reduced compared to the conventional press fit configuration shown in FIG. 9, but the press fit configuration shown in FIG. Compared to , the degree of reduction in the amount of deformation is small.

FIG. 12(a) shows a form of press-fitting of the lens into the lens barrel according to the present invention. , and the contact point AAa is farther from the radial center line L1 than in the case of FIG. 10 and closer to the radial center line L1 than in the case of FIG. 4 shows a press-fit configuration, positioned. In such a press-fitting configuration, deformation amount data at five measurement points P1, P2, P3, P4, and P5 on the surface (R1 surface) Ac facing the object side of the lens A is shown in FIG. b) as a table and FIG. 12(c) as a graph. The measurement point P1 is a point on the optical axis O (lens center) (deformation amount -1.26E-03), and the measurement point P2 is a point on the surface Ac 0.59 mm away from the optical axis O in the radial direction. (deformation amount -1.21E-03), the measurement point P3 is a point on the surface Ac 1.07 mm away from the optical axis O in the radial direction (deformation amount -1.11E-03), and the measurement point P4 is a point on the surface Ac 1.70 mm away from the optical axis O in the radial direction (deformation amount -8.75E-04), and the measurement point P5 is 2.35 mm away from the optical axis O in the radial direction. It is a point on the surface Ac (deformation amount -5.51E-04). Further, the deformation amount data at the five measurement points Q1, Q2, Q3, Q4, and Q5 on the rear surface (R2 surface) Ad of the lens A facing the image side is shown in a table in FIG. 12(d). 12(e) as a graph, respectively. The measurement point Q1 is a point on the optical axis O (the center of the lens) (deformation amount -1.38E-03), and the measurement point Q2 is a point on the rear surface Ad which is 0.56 mm away from the optical axis O in the radial direction. (deformation amount -1.36E-03), the measurement point Q3 is a point on the rear surface Ad 1.11 mm away from the optical axis O in the radial direction (deformation amount -1.28E-03), and the measurement point Q4 is a point on the rear surface Ad 1.86 mm away from the optical axis O in the radial direction (deformation amount -1.08E-03), and the measurement point Q5 is 2.29 mm away from the optical axis O in the radial direction. It is a point on the rear surface Ad (deformation amount -9.19E-04). As can be seen from these data, in such a press-fitting configuration, the amount of deformation is generally reduced compared to the conventional press-fitting configuration shown in FIG. 9 and the press-fitting configuration shown in FIG. , the degree of reduction in the amount of deformation is small compared to the press-fitting configuration shown in FIG.

As can be seen from a comparison of FIGS. 10, 11 and 12, the farther the contact point AAa is from the radial center line L1, the smaller the degree of reduction in the amount of deformation compared to the conventional FIG. In other words, the closer the contact point AAa is to the radial center line L1, the greater the degree of reduction in the amount of deformation). In the cross section, if it is positioned at the radial outer edge AA closest to the radial center line L1, the pressure exerted from the barrel B on the lens A can be more effectively reduced, and the lens deformation suppressing effect can be further enhanced. It can be said that

The present invention also provides a camera module having the lens unit described above, an in-vehicle system having the camera module, and a vehicle equipped with the in-vehicle system. Such a camera module, in-vehicle system, and vehicle can also provide the same effects as the lens unit described above.

According to the present invention, since the radial outer peripheral edge of the lens is in point contact with the inner surface of the lens barrel in a cross section along the direction of the optical axis, the glass lens is press-fitted into the resin lens barrel. The unique press-fitting configuration reduces the pressure acting on the lens and suppresses deformation of the lens.

1 is a schematic cross-sectional view (a cross-sectional view along an optical axis) of a lens unit according to an embodiment of the invention; FIG. 2 is a cross-sectional view perpendicular to the optical axis direction at the position of the second lens of the lens unit of FIG. 1; FIG. 1(a) is an enlarged cross-sectional view of a main part showing a state in which another lens (a lens that is in point contact with the lens barrel) that can constitute the lens group of the lens unit of FIG. 1 is press-fitted into the lens barrel. ), and (b) is an enlarged view of part X of (a). (a) to (c) show a lens press-fitting form in which the radial outer peripheral edge of the lens and the inner surface of the lens barrel are in line contact in a cross section along the direction of the optical axis. 1(b) is an enlarged cross-sectional view of a main portion of a meniscus lens, (c) is an enlarged cross-sectional view of a main portion of a biconcave lens, and (d) is a point contact state in which the present invention is applied to (a). (e) is an enlarged cross-sectional view of a main part in a point contact state in which the present invention is applied to (b), and (f) is a main part in a point contact state to which the present invention is applied in (c). It is an expanded sectional view. FIG. 10 is an enlarged view of a main part showing another form of contact points of the lens that are in point contact with the lens barrel; 2 is a schematic cross-sectional view of a camera module having the lens unit of FIG. 1; FIG. 1 is a schematic diagram of a vehicle equipped with an in-vehicle system having a camera module according to an embodiment of the present invention; FIG. FIG. 8 is a block diagram showing the configuration of an imaging device that constitutes the in-vehicle system of FIG. 7; (a) is a schematic diagram showing a conventional press-fitting configuration in which the outer peripheral surface of the lens and the inner peripheral surface of the lens barrel are in line contact in a cross section along the optical axis direction; Table showing deformation amount data at five measurement points on the surface (R1 surface) facing the object side of the lens in the press-fitting form, (c) is a graph of the table of (b), ( d) is a table showing deformation amount data at five measurement points on the back surface (R2 surface) of the lens facing the image side in the press-fitting configuration of (a); It is the figure which graph-ized the table|surface. (a) is a portion of the radial outer peripheral end of the lens that is in point contact with the inner surface of the lens barrel in a cross section along the optical axis direction, and the contact point is closest to the radial center line. Schematic diagram showing the press-fitting configuration, (b) is the deformation at five measurement points on the surface (R1 surface) facing the object side of the lens in the press-fitting configuration of (a) (c) is a graphical representation of the table of (b), and (d) is the press fit configuration of (a) on the back surface (R2 surface) facing the image side of the lens. FIG. 10 is a table showing deformation amount data at five measurement points in , and (e) is a graph of the table in (d). In (a), in a cross section along the optical axis direction, the radial outer peripheral edge of the lens is in point contact with the inner surface of the lens barrel, and the contact point is the radial outer peripheral edge farthest from the radial center line. (b) is a schematic diagram showing the press-fitting configuration positioned at the site, (b) shows five measurement points on the surface (R1 surface) facing the object side of the lens in the press-fitting configuration of (a). A table showing deformation amount data, (c) is a graph of the table of (b), and (d) is the back surface (R2 surface) facing the image side of the lens in the press-fitting configuration of (a). It is a table showing deformation amount data at the five measurement points above, and (e) is a graph of the table of (d). In (a), the radial outer peripheral end of the lens is in point contact with the inner surface of the lens barrel in the cross section along the optical axis direction, and the contact point is farther from the radial center line than in the case of FIG. Schematic diagram showing a press-fitting configuration positioned at a portion of the radially outer peripheral edge closer to the radial centerline than in the case of FIG. A table showing deformation amount data at five measurement points on the surface (R1 surface) facing the side, (c) is a graph of the table of (b), (d) is the press fit of (a) FIG. 4E is a table showing deformation amount data at five measurement points on the rear surface (R2 surface) of the lens facing the image side in the fitted state, and (e) is a graph of the table of (d). (a) is an enlarged cross-sectional view (cross-sectional view along the optical axis) of a main portion of a conventional lens unit in which the outer peripheral surface of the lens and the inner peripheral surface of the lens barrel are in line contact; It is a Y section enlarged view.

Embodiments of the present invention will be described below with reference to the drawings. This embodiment can realize highly reliable systems, particularly in sensing systems, and contribute to the development of robust infrastructure. of the SDGs (Sustainable Development Goals) advocated by Develop quality, reliable, sustainable and resilient infrastructure, including regional and transboundary infrastructure, to support human and human well-being.”
The lens unit of this embodiment described below is particularly for a camera module such as an in-vehicle camera, and is fixedly installed on the outer surface side of an automobile, for example, and the wiring is drawn into the automobile. connected to a display or other device. 1 to 12, the hatching of lenses is omitted.

FIG. 1 shows a lens unit 11 according to one embodiment of the invention. As shown in the figure, the lens unit 11 of the present embodiment includes a resin cylindrical lens barrel (barrel) 12 and a plurality of lenses arranged in an inner accommodation space S of the lens barrel 12, for example, an object side lens. , a first lens 13, a second lens 14, a third lens 15, a fourth lens 16, a fifth lens 17, and a fifth lens 18; It has These lenses 13 to 18 and diaphragm member 22 are partially arranged with a spacer 30 separating the lenses 14, 15, 17 and 18 in the optical axis direction.

Further, in the present embodiment, the diaphragm member 22 is positioned between the third lens 15 and the spacer 30, limits the amount of transmitted light, and determines the F-number, which is an index of brightness. , or a "light-shielding diaphragm" that shields light rays that cause ghosts and aberrations.
A vehicle-mounted camera having such a lens unit 11 includes the lens unit 11, a substrate having an image sensor (not shown), and an installation member (not shown) for installing the substrate in a vehicle such as an automobile.

A plurality of lenses 13, 14, 15, 16, 17, and 18 incorporated and held in the inner housing space S of the lens barrel 12 are stacked with their optical axes aligned. , lenses 13, 14, 15, 16, 17, and 18 are arranged along one optical axis O to constitute a group of lenses L used for imaging. In this case, the two fourth and fifth lenses 16 and 17 positioned on the image side constitute a cemented lens (bonded lens) 40 . The first lens 13, which constitutes the lens group L and is positioned closest to the object side, is a spherical glass lens having a convex surface on the object side and a concave surface on the image side. At least one of 17, 18 is also a glass lens. Especially in this embodiment, all the lenses 13, 14, 15, 16, 17, 18 are glass lenses, but the present invention is not limited to this. At least one of the lenses 13, 14, 15, 16, 17, 18 may be a resin lens. The surfaces of these lenses 13, 14, 15, 16, 17, and 18 are provided with an antireflection film, a hydrophilic film, a water-repellent film, or the like, as required.

A substantially cylindrical cap 23 as a fastening member is screwed to the object-side end 12b (upper end in FIG. 1) of the lens barrel 12. The first lens 13 is secured to the lens barrel 12 by the cap 23. It is fixed to the object-side end 12b. Specifically, the cap 23 has a female threaded portion 23a formed on the inner peripheral surface of the peripheral side wall of the cap 23 and screwed into a male threaded portion 12a formed on the outer peripheral surface of the object-side end portion 12b of the lens barrel 12. , and a radially inner peripheral edge portion 23b of the flange-shaped upper end is abutted against the outer peripheral edge portion of the surface of the first lens 13 facing the object side. is fixed to the object-side end portion 12b, and the lens group L is held in the lens barrel 12 in the optical axis direction. When the lens barrel is made of resin, the first lens 13 may be fixed not by the cap 23 but by a crimping portion provided at the image-side end of the lens barrel and crimped radially inward.

An inner flange portion 24 having an opening smaller in diameter than the sixth lens 18 is provided at the image-side end (lower end in FIG. 1) of the lens barrel 12 . and the cap 23, a plurality of lenses 13, 14, 15, 16, 17, and 18 forming the lens group L and the aperture member 22 are sandwiched and held in the optical axis direction.

A stepped diameter reduction portion 13aa is provided on the outer peripheral side surface 13a of the first lens 13, the diameter of which is reduced at the image side portion of the lens 13. The diameter reduction portion 13aa is provided with a seal member such as an O-ring. 26 is installed. The O-ring 26 is radially compressed between the outer peripheral side surface 13a of the first lens 13 and the inner peripheral surface of the object side end portion 12b of the lens barrel 12, thereby 12b and the first lens 13 are sealed, thereby preventing fine particles such as water and dust from entering the lens barrel 12 from the object-side end of the lens unit 11. .

An outer peripheral side wall surface (hereinafter simply referred to as a side wall) 12c of the lens barrel 12 is provided with a flange-like shape projecting radially outward of the lens barrel 12, and can be used to assemble the lens unit 11 to other members. Two flanges 25A, 25B are provided. In this case, a covering case or the like is assembled to the first flange 25A positioned on the object side, while the second flange 25B positioned on the image side is used for positioning when the lens barrel 12 is installed on the vehicle-mounted camera. With this positioning, the distance between a package sensor (imaging element; imaging sensor) 304, which will be described later, arranged at the imaging position of the lens group L and the lenses 13, 14, 15, 16, 17, 18 is Precisely controlled. Note that depending on the configuration of the camera, it is not necessary to have two flanges, and only the flange 25B used when installing the lens barrel 12 on the body of the vehicle-mounted camera may suffice.

In the present embodiment, the four glass lenses 14, 15, 17, and 18, excluding the first lens 13 and the fourth lens 16 which does not contact the lens barrel 12, are press-fitted into the lens barrel 12. The radial outer ends 14a, 15a, 17a, and 18a are in point contact with the inner surface 12d of the lens barrel 12 in the illustrated cross section along the direction of the optical axis O. As shown in FIG. In particular, in the present embodiment, these lenses 14, 15, 17, and 18, which are in point contact with the lens barrel 12, have their radial outer peripheral ends 14a, 15a, 17a, and 18a in a cross section along the direction of the optical axis O. An arc is formed, and point contact is made with the inner surface 12d of the lens barrel 12 at the vertex of this arc.

Furthermore, in the present embodiment, the lenses 14, 15, 17, and 18 that are in point contact with the lens barrel 12 in the cross section along the direction of the optical axis O are perpendicular to the direction of the optical axis O, as shown in FIG. Also in the cross section, the radial outer ends 14a, 15a, 17a, and 18a are in point contact with the inner surface 12d of the lens barrel 12 (point contact with the lens barrel 12 in the circumferential direction). A gap C is formed between the cylinder 12 and the inner surface 12d. 2 shows a point contact state of the second lens 14 as an example (a cross-sectional view perpendicular to the optical axis direction at the position of the second lens 14 of the lens unit 11 in FIG. 1 is shown. there). Such a point contact state is particularly achieved in this embodiment, as shown in FIG. However, it is not limited to this.

FIG. 3A shows another lens A (a lens that is in point contact with the lens barrel 12 in a cross section along the direction of the optical axis O) that can constitute the lens group L of the lens unit 11 of FIG. FIG. 3 is an enlarged cross-sectional view (cross-sectional view along the optical axis) showing the press-fitted state, and FIG. 3B is an enlarged view of the X portion of FIG. 3A. As shown in the figure, these lenses A are biconvex lenses, and have an annular outer peripheral flange Ab on their radially outer sides, and their radially outer peripheral ends AA that form circular arcs point against the inner surface 12 d of the lens barrel 12 . The contact point AAa, which is the vertex of the arc, is the radial center line L1 that is the perpendicular bisector of the line segment MN along the optical axis O direction that defines the lens thickness dimension D at the center of the lens A. located above.

4(a) to 4(c) show a conventional lens press-fitting form in which the radial outer peripheral edge of the lens A and the inner surface 12d of the lens barrel 12 are in line contact in a cross section along the direction of the optical axis O. 1A is an enlarged sectional view of essential parts of a biconvex lens, (b) is an enlarged sectional view of essential parts of a meniscus lens, and (c) is an enlarged sectional view of essential parts of a biconcave lens. Each lens A has a linear portion Aa that fits in line contact with the inner surface 12d of the lens barrel 12 extending linearly along the direction of the optical axis O, on the side end surface (edge) of the annular outer peripheral flange Ab. have. On the other hand, FIG. 4(d) is an enlarged cross-sectional view of the main part of the point contact state in which the present invention is applied to FIG. 4(a), and FIG. FIG. 4(f) is an enlarged cross-sectional view of the essential part in the point contact state to which the invention is applied, and FIG. 4(c) is an enlarged cross-sectional view of the essential part in the point contact state to which the invention is applied. As in the case of FIG. 3, each lens A is in point contact with the inner surface 12d of the lens barrel 12 at the radially outer peripheral edge AA forming an arc, and the contact point AAa, which is the vertex of the arc, is in radial direction. It is positioned on the directional centerline L1.

FIG. 5 shows another form of the contact point AAa of the lens A that makes point contact with the lens barrel 12 in a cross section along the direction of the optical axis O. As shown in FIG. The lens A shown in (a) of FIG. 5 is a biconvex lens in which the curvature of the surface Ac facing the object side is larger than the curvature of the back surface Ad facing the image side. A portion of the outermost radial outer edge AA, which is a combination of a straight line and a curved line (such as an arc), is located on the radially outermost portion, that is, the contact point AAa with the lens barrel 12 is located on the radial center line L1. there is In this case, the position of the contact point AAa is biased toward the surface Ac side. Further, the lens A shown in FIG. 5B is a biconcave lens in which the curvature of the surface Ac facing the object side is smaller than the curvature of the back surface Ad facing the image side. AA is a combination of a straight line and a curved line (such as an arc), and the portion of the radially outer peripheral end AA that is positioned most radially outward, that is, the contact point AAa with the lens barrel 12 is positioned on the radial centerline L1. is doing. In this case, the position of the contact point AAa is biased toward the surface Ac side. The lens A shown in (c) of FIG. 5 is a meniscus lens in which the curvature of the surface Ac facing the object side is larger than the curvature of the back surface Ad facing the image side. AA forms an arc shape, and the portion of the radially outer peripheral end AA that is located furthest in the radial direction, that is, the contact point AAa with the lens barrel 12 is the end of the radially outer peripheral end AA that is closest to the radial center line L1. It is the edge.

6 is a schematic cross-sectional view of the camera module 300 of this embodiment having the lens unit 11 having the configuration shown in FIG. As shown, this camera module 300 comprises the lens unit 11 according to FIG. 1 with a filter 99 attached.

The camera module 300 includes a front case (camera case) 301 which is an exterior component, and a mount (pedestal) 302 that holds the lens unit 11 . The camera module 300 also includes a sealing member 303 and a package sensor (imaging element; imaging sensor) 304 .

The front case 301 is connected to the first flange 25A via a sealing member (O-ring) 303, and is a member that exposes the object-side end of the lens unit 11 and covers the other portions for waterproofing. be. The mount 302 is arranged inside the front case 301, and its object-side end 302a is in contact with and adheres to the image side surface 25Ba of the second flange 25B. It is fixed placed on the The sealing member 303 is a member inserted between the inner surface of the front case 301 and the object side surface of the first flange 25A of the lens barrel 12, and is used to keep the inside of the front case 301 airtight. is a member of

The package sensor 304 is arranged on the substrate 306 inside the mount 302 and is arranged at a position to receive the image of the object formed by the lens unit 11 . The package sensor 304 has a CCD, a CMOS, or the like, and converts the light that is condensed through the lens unit 11 and reaches it into an electrical signal. The converted electrical signal is converted into analog data or digital data, which are components of image data captured by the camera.

FIG. 7 schematically shows a vehicle 40 equipped with an in-vehicle system including an imaging device 50 including the camera module 300 of FIG. As illustrated, the imaging device 50 can be mounted on the vehicle 40, and FIG. The imaging device 50 mounted on the vehicle 40 can also be called a vehicle-mounted camera, and can be installed at various locations on the vehicle 40 . For example, the first imaging device 50a may be arranged at or near the front bumper as a camera for monitoring the front when the vehicle 40 is running. Also, the second imaging device 50b that monitors the front may be arranged in the vicinity of the rearview mirror (Inner Rearview Mirror) in the interior of the vehicle 40 . The third imaging device 50c may be arranged on the dashboard or in the instrument panel as a camera for monitoring the driving conditions of the driver. The fourth imaging device 50 d may be installed at the rear of the vehicle 40 for monitoring the rear of the vehicle 40 . The imaging devices 50a and 50b can be called front cameras. The third imaging device 50c can be called an in-camera. The fourth imaging device 50d can be called a rear camera. The imaging device 50 is not limited to these, and includes imaging devices installed at various positions, such as a left side camera that captures an image of the left rear side and a right side camera that captures an image of the right rear side.

An image signal of an image captured by the imaging device 50 can be output to the information processing device 42 and/or the display device 43 inside the vehicle 40 . The information processing device 42 and the display device 43 constitute an in-vehicle system together with the imaging device 50 . The information processing device 42 in the vehicle 40 includes a device that processes the image signal acquired by the imaging device 50, recognizes the image, and assists the driver in driving. Further, the information processing device 42 includes, for example, a navigation device, a collision damage mitigation braking device, an inter-vehicle distance control device, a lane departure warning device, and the like, but is not limited to these. The display device 43 displays images processed and output by the information processing device 42 , but can also receive image signals directly from the imaging device 50 . The display device 43 may employ a liquid crystal display (LCD), an organic EL (Electro-Luminescence) display, or an inorganic EL display, but is not limited to these. The display device 43 can display to the driver an image signal output from an imaging device 50 that captures an image of a position that is difficult for the driver to see, such as a rear camera.

FIG. 8 shows the configuration of an imaging device that constitutes the in-vehicle system of FIG. As illustrated, an imaging device 50 according to one embodiment includes a control unit 52, a storage unit 54, and the camera module 300 of FIG. 2 described above.

The control unit 52 controls the camera module 300 and processes electrical signals output from the imaging element 304 of the camera module 300 . This control unit 52 may be configured as a processor, for example. Control unit 52 may also include one or more processors. The processor may include a general-purpose processor that loads a specific program to execute a specific function, and a dedicated processor that specializes in specific processing. The dedicated processor may include an application specific IC (Integrated Circuit). An application specific IC is also called an ASIC (Application Specific Integrated Circuit). A processor may include a programmable logic device. A programmable logic device is also called a PLD (Programmable Logic Device). The PLD may include an FPGA (Field-Programmable Gate Array). The control unit 52 may be either an SoC (System-on-a-Chip) in which one or more processors cooperate, or a SiP (System In a Package).

The storage unit 54 stores various information or parameters related to the operation of the imaging device 50 . The storage unit 54 may be configured by a semiconductor memory or the like, for example. The storage unit 54 may function as a work memory for the control unit 52 . The storage unit 54 may store captured images. The storage unit 54 may store various parameters and the like for the control unit 52 to perform detection processing based on the captured image. The storage unit 54 may be included in the control unit 52 .

As described above, the camera module 300 captures a subject image formed via the lens unit 11 with the image sensor 304 and outputs the captured image. An image captured by the camera module 300 is also called a captured image.

The imaging device 304 may be configured by, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device). The imaging element 304 has an imaging surface on which a plurality of pixels are arranged. Each pixel outputs a signal specified by current or voltage according to the amount of incident light. A signal output by each pixel is also referred to as imaging data.

The imaging data of all pixels may be read by the camera module 300 and taken into the control section 52 as a captured image. A captured image read out for all pixels is also referred to as a maximum captured image. The imaging data may be read out by the camera module 300 for some pixels and captured as a captured image. In other words, imaging data may be read from pixels in a predetermined capture range. The imaging data read from pixels in a predetermined capturing range may be captured as a captured image. The predetermined capture range may be set by the controller 52 . The camera module 300 may acquire a predetermined capture range from the control section 52 . The imaging element 304 may capture an image within a predetermined capture range of the subject image formed via the lens unit 11 .

As described above, according to the present embodiment, the radial outer ends 14a, 15a, 17a, and 18a (radially Since the outer peripheral end AA) is in point contact with the inner surface 12d of the lens barrel 12, the glass lenses 14, 15, 17, and 18 (lenses A) are press-fitted into the resin lens barrel 12. In the press fitting mode, the pressure acting on the lenses 14, 15, 17, 18 (lens A) can be reduced, and deformation of the lenses 14, 15, 17, 18 (lens A) can be suppressed. Therefore, desired optical characteristics can be obtained without deteriorating optical performance.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the present invention, the shapes of lenses, barrels, and the like are not limited to the embodiments described above. Further, part or all of the above-described embodiments may be combined without departing from the gist of the present invention, or part of the configuration may be omitted from one of the above-described embodiments. good too.

Reference Signs List 11 lens unit 12 lens barrel 12d inner surface 13, 14, 15, 16, 17, 18 lenses 14a, 15a, 17a, 18a radial outer peripheral end 40 vehicle 42 information processing device (processing device)
43 Display device 50 Imaging device 52 Control unit 300 Camera module 304 Imaging element A Lens AA Radial outer peripheral edge AAa Contact point L Lens group L1 Radial center line S Inner accommodation space

Claims (8)

A cylindrical lens barrel forming an inner housing space for housing and holding lenses, and a lens group incorporated in the inner housing space of the lens barrel and formed by arranging a plurality of lenses along an optical axis. A lens unit comprising
The lens barrel is made of resin,
At least one lens that constitutes the lens group is made of glass and is incorporated into the lens barrel by press-fitting. A lens unit that is in point contact with the lens. The lens, which is in point contact with the lens barrel, forms an arc at its radially outer edge in a cross section along the direction of the optical axis, and is in point contact with the inner surface of the lens barrel at the vertex of the arc. The lens unit according to claim 1. The lens, which is in point contact with the lens barrel in a cross section along the direction of the optical axis, also has a radial outer peripheral end in point contact with the inner surface of the lens barrel in a cross section perpendicular to the direction of the optical axis. 3. The lens unit according to claim 1, wherein the lens unit comprises: The contact point of the lens that makes point contact with the lens barrel is the perpendicular bisector of a line segment along the optical axis direction that defines the lens thickness dimension at the center of the lens in a cross section along the optical axis direction. 4. The lens unit according to any one of claims 1 to 3, wherein the lens unit is positioned at the radially outer peripheral end portion closest to the radial centerline. 5. The lens unit of claim 4, wherein said contact point is located on said radial centerline. A camera module comprising: the lens unit according to any one of claims 1 to 5; and an imaging device that converts light condensed through a lens group of the lens unit into an electrical signal. An in-vehicle system mounted in a vehicle,
7. An image capturing apparatus comprising: the camera module according to claim 6; and a control unit that controls the camera module and processes an electrical signal output from the image sensor of the camera module;
a processing device for processing an image signal acquired by the imaging device;
a display device for displaying an image processed and output by the processing device;
An in-vehicle system comprising: A vehicle equipped with the in-vehicle system according to claim 7.

Images