WO2024014106A1

WO2024014106A1 - Lens unit, camera module, imaging system, and moving body

Info

Publication number: WO2024014106A1
Application number: PCT/JP2023/018074
Authority: WO
Inventors: 翔太米川
Original assignee: マクセル株式会社
Priority date: 2022-07-14
Filing date: 2023-05-15
Publication date: 2024-01-18
Also published as: JP2024011141A

Abstract

Provided are a lens unit in which play that occurs in a lens can be suppressed and a prescribed inter-surface sensitivity can be ensured, a camera module, an imaging system, and a moving body.　A middle wall 26 having a light passage hole 25 that is orthogonal to an optical axis and through which light passes is provided between an object-side end of a lens barrel 12 and an image-side end thereof, lenses 13, 14, 15 are inserted from the object-side end of the lens barrel 12 closer to the object side than the middle wall 26, lenses 16, 17 are inserted from the image-side end of the lens barrel 12 closer to the image side than the middle wall 26, the lenses 14, 15, 16 for which an inter-surface sensitivity, which is the sensitivity of image formation with respect to a lens inter-surface distance, becomes a high inter-surface sensitivity higher than the inter-surface sensitivity between the other lenses are contacted by the middle wall 26, and the optical axis direction of the lenses 14, 15, 16 is thereby positioned.

Description

Lens units, camera modules, imaging systems and moving objects

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

In the past, vehicles have been equipped with in-vehicle cameras to support parking and prevent collisions through image recognition, and attempts are also being made to apply this to autonomous driving. In addition, a camera module such as such a vehicle-mounted camera generally includes a lens group in which a plurality of lenses are arranged along the optical axis, a lens barrel that accommodates and holds this lens group, and at least one part of the lens group. The lens unit includes a diaphragm member disposed between lenses at one location (for example, see Patent Document 1).

JP2013-231993A

By the way, for example, as shown in FIG. 6, when the lens unit 1 is configured by inserting a plurality (for example, six lenses) of lenses L1 to L6 into the lens barrel 2 in order from the object side (upper side in the figure). When the lens unit 1 is exposed to a high temperature or humid environment, the extension of the lens barrel 2 in the optical axis direction due to temperature changes or hygroscopic expansion may be larger than the extension amount of the entire lens group in the optical axis direction. In this case, a gap is created between the lenses, which causes backlash (backlash in the thrust direction) in the lenses. As a result, the lens is affected by tilting and the like, resulting in deterioration of optical performance.
In addition, if the amount of expansion in the optical axis direction due to temperature changes or hygroscopic expansion of the lens barrel 2 is greater than the amount of expansion in the optical axis direction of the entire lens group, the inter-plane sensitivity, which is the sensitivity of imaging to the distance between lens surfaces, will decrease. It becomes difficult to ensure a predetermined inter-plane sensitivity between lenses where the sensitivity is highest.

The present invention has been made in view of the above circumstances, and aims to provide a lens unit, a camera module, an imaging system, and a moving object that can suppress backlash occurring in a lens and ensure a predetermined surface-to-plane sensitivity. .

In order to solve the above problems, a lens unit of the present invention includes a lens group in which a plurality of lenses are arranged along the optical axis, and a lens barrel that accommodates and holds this lens group.
An intermediate wall that is perpendicular to the optical axis and has a light passage hole through which light passes is provided between the object side end and the image side end of the lens barrel,
A lens is inserted from the object side end of the lens barrel on the object side of the intermediate wall, and a lens is inserted from the image side end of the lens barrel on the image side of the intermediate wall,
By contacting the intermediate wall with a lens that has a high inter-plane sensitivity in which the inter-plane sensitivity, which is the sensitivity of imaging to the distance between lens surfaces, is higher than the inter-plane sensitivity between other lenses, the lens It is characterized by positioning in the optical axis direction.

Here, "interplane sensitivity" refers to the sensitivity of how much influence the imaging of the lens group has (sensitivity of imaging to the distance between lens surfaces). "Influence on image formation of lens groups" refers to the degree of out-of-focus (out-of-focus) caused by changes in the distance between lens surfaces. For example, when the length along the optical axis changes due to thermal expansion, etc., a gap is created between the lenses in the lens group in the lens unit, and the lens moves due to the gap, causing the lens to move in the optical axis direction. If the lenses arranged along the line are misaligned, the position of the captured image will shift, resulting in blurred images and decreased resolution.
Therefore, "a lens that has a high inter-plane sensitivity in which the inter-plane sensitivity, which is the sensitivity of imaging to the distance between lens surfaces, is higher than the inter-plane sensitivity between other lenses, is brought into contact with the intermediate wall." , which means that the lens that most affects out-of-focus and resolution degradation is brought into contact with the intermediate wall.
Also, "a lens that has a high inter-plane sensitivity in which the inter-plane sensitivity, which is the sensitivity of imaging to the distance between lens surfaces, is higher than the inter-plane sensitivity between other lenses, is brought into contact with the intermediate wall." In addition, the flange surface of the lens with high surface-to-surface sensitivity is brought into contact with the surface facing the object side and/or the surface facing the image side of the intermediate wall. This includes the fact that the lens, which becomes taller, is held in contact with it.

In the present invention, the lens is inserted from the object-side end of the lens barrel on the object side of the intermediate wall provided between the object-side end and the image-side end of the lens barrel, and the lens is inserted from the object-side end of the lens barrel, and On the image side, since the lens is inserted from the image side end of the lens barrel, the inside of the lens barrel can be divided by the intermediate wall into two storage spaces, the object side and the image side. For this reason, it is possible to suppress the accumulated play between the lenses conventionally inserted into the entire lens barrel to a minimum as the accumulated play between the lenses on the object side and the image side of the intermediate wall between the lenses in each housing space. can. Therefore, the backlash that occurs in the lens can be suppressed compared to the conventional case.
Additionally, by providing the intermediate wall, the number of lenses is reduced on the object side and image side of the intermediate wall, making it possible to control variations in lens height (height in the optical axis direction) due to tolerances. As a result, the backlash of the lens in the thrust direction due to temperature changes can be reduced.

Furthermore, even if the amount of expansion in the optical axis direction due to temperature changes or hygroscopic expansion of the lens barrel is greater than the amount of expansion in the optical axis direction of the entire lens group, the amount of expansion of the lens barrel portion on the object side from the intermediate wall is The amount of elongation is smaller than the amount of elongation of the entire barrel, and the amount of elongation of the lens housed on the object side of the intermediate wall is also smaller than the amount of elongation of the entire lens group, and the amount of elongation of the lens barrel portion on the image side of the intermediate wall is The amount of elongation is smaller than the amount of elongation of the entire tube, and the amount of elongation of the lens housed on the image side of the intermediate wall is also smaller than the amount of elongation of the entire lens group.Furthermore, a lens with high surface-to-plane sensitivity is placed on the intermediate wall. Since the lens is positioned in the optical axis direction by being in contact with it, it is possible to suppress the lens shift that most affects out-of-focus and resolution reduction, and it is possible to ensure a predetermined surface-to-plane sensitivity.

Further, in the configuration of the present invention, an object-side adjacent lens that is adjacent to the intermediate wall in the optical axis direction and located on the object side from the intermediate wall is in contact with the object-side surface of the intermediate wall, An image-side adjacent lens that is adjacent to the intermediate wall in the optical axis direction and located on the image side of the intermediate wall is brought into contact with the image-side surface of the intermediate wall, and the object-side adjacent lens and the image side The inter-plane sensitivity between the side adjacent lenses may be the high inter-plane sensitivity.

According to such a configuration, it is possible to reliably ensure inter-plane sensitivity between the object-side adjacent lens and the image-side adjacent lens, which are arranged with the intermediate wall sandwiched in the optical axis direction.

Further, in the configuration of the present invention, an object-side adjacent lens that is adjacent to the intermediate wall in the optical axis direction and located on the object side from the intermediate wall is in contact with the object-side surface of the intermediate wall, An image-side adjacent lens that is adjacent to the intermediate wall in the optical axis direction and located on the image side of the intermediate wall is brought into contact with the image-side surface of the intermediate wall,
an intermediate lens is held in contact with the light passage hole of the intermediate wall;
The inter-plane sensitivity between the object-side adjacent lens and the intermediate lens and/or the inter-plane sensitivity between the image-side adjacent lens and the intermediate lens may be the high inter-plane sensitivity.

According to such a configuration, inter-plane sensitivity between the object-side adjacent lens and the intermediate lens and/or inter-plane sensitivity between the image-side adjacent lens and the intermediate lens can be ensured.

The present invention also provides a camera module having the lens unit, an imaging system having the camera module, and a moving body equipped with the imaging system. The same effects as those of the lens unit described above can also be obtained by such a camera module, an imaging system, and a moving body. Note that the term "mobile object" refers to any object that can be moved, and includes, for example, a vehicle.

According to the present invention, it is possible to suppress backlash that occurs in the lens, and to ensure a predetermined surface-to-plane sensitivity.

1 is a schematic cross-sectional view showing a lens unit according to an embodiment of the present invention. It is a graph showing the lens spacing sensitivity in the same figure. 1 is a schematic cross-sectional view showing a camera module according to an embodiment of the present invention. 1 is a schematic diagram of a vehicle as a moving object on which an imaging system (in-vehicle system) including a camera module according to an embodiment of the present invention is mounted. 5 is a block diagram showing the configuration of an imaging device that constitutes the imaging system shown in FIG. 4. FIG. FIG. 2 is a schematic cross-sectional view of essential parts of an example of a conventional lens unit.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but this embodiment is based on "9. Create a foundation for industry and technological innovation" of the Sustainable Development Goals (SDGs) advocated by the United Nations. ``9.1 Providing quality, reliable, sustainable and resilient infrastructure, including regional and cross-border infrastructure, to support economic development and human well-being with a focus on affordable and equitable access for all.'' Contributing to the development of (resilient) infrastructure.
The lens unit of this embodiment described below is particularly for use in camera modules such as in-vehicle cameras, and is, for example, fixedly installed on the outer surface of a car, and the wiring is led into the car to be used as a display. and other devices. Further, in FIGS. 1, 3, and 6, hatching is omitted for a plurality of lenses.

FIG. 1 shows a lens unit 11 according to an embodiment. This lens unit 11 is, for example, for an in-vehicle camera, and is installed on the outside of a car with at least the object-side end (upper end in FIG. 1) of the lens unit 11 exposed.

The lens unit 11 includes a cylindrical lens barrel 12, a plurality of (for example, five)

lenses

13, 14, 15, 16, 17 disposed within the lens barrel 12, and one aperture member 20. There is. The vehicle-mounted camera including the lens unit 11 includes the lens unit 11, a substrate (not shown) having an image sensor, and an installation member (not shown) for installing the substrate in a vehicle such as an automobile.
The first lens 13 located closest to the object side and the third lens 15 third from the object side are glass lenses, the second lens 14 second from the object side, and the fourth lens 16 fourth from the object side. The fifth lens 17, which is the fifth lens from the object side, is a resin lens, but is not limited to this (for example, the

lenses

13 and 15 may be resin lenses).
Further, the surfaces of the lenses 13 to 17 are provided with an anti-reflection film, a hydrophilic film, a water-repellent film, etc., if necessary.

A plurality of lenses 13 to 17 fixed and supported by the lens barrel 12 are arranged with their respective optical axes aligned, and the lenses 13 to 17 are arranged along one optical axis O. This state constitutes one lens group L used for imaging.
Further, the fourth lens 16 and the fifth lens 17 are bonded together using an adhesive to form a bonded lens 18.

The aperture member 20 is arranged between the second lens 14 and an intermediate wall 26, which will be described later. The diaphragm member 20 is an "aperture diaphragm" that limits the amount of transmitted light and determines the F value, which is an index of brightness, or a "shading diaphragm" that blocks light rays that cause ghosts and aberrations.

In addition, in this embodiment, thermosetting adhesives G1 and G2 are provided between the first lens 13 and the lens barrel 12, and the adhesives G1 and G2 cause the object side end of the lens barrel 12 to The section is hermetically sealed. The adhesive G1 is interposed between the upper end of the outer peripheral surface of the flange portion of the first lens 13 (upper end in the optical axis direction) and the inner peripheral surface of the object-side opening on the object side of the lens barrel 12. , these are glued together.
Furthermore, the adhesive G2 is interposed between the lower end of the outer circumferential surface of the flange of the first lens 13 and the lower surface of the flange (the surface facing the image side) and the opening at the tip of the lens barrel 12. , these are glued together. The ridgeline between the outer peripheral surface and the lower surface of the flange portion of the first lens 13 is a chamfered C surface 13c. Further, the opening at the tip end of the lens barrel 12 is provided with a proximity surface 12c that faces the object side and is approached by the flange portion of the first lens 13. A groove-shaped adhesive reservoir 12p is formed in an annular shape in the circumferential direction on the proximal surface 12c. The adhesive G2 is filled between the C surface 13c and the inner circumferential surface of the distal end portion of the lens barrel 12 and the proximal surface 12c, and then flows into the adhesive reservoir 12p.

Further, in the lens barrel 12, when the lens group L is installed and housed in the inner housing space, the caulking part 23 at the object side end (the upper end in FIG. 1) heats the lens barrel 12 radially inward. By being caulked, the first lens 13 located closest to the object side of the lens group L is fixed to the object side end of the lens barrel 12 in the optical axis direction by the caulking portion 23. Note that the means for fixing the first lens 13 to the object side end of the lens barrel 12 in the optical axis direction is not limited to such a caulking portion 23. For example, when the lens barrel 12 is particularly made of metal, the first lens 13 is fixed to the object side end of the lens barrel 12 in the optical axis direction by a cap screwed onto the object side end of the lens barrel 12. may be done.

Further, an intermediate wall 26 is provided between the object-side end and the image-side end of the lens barrel 12, which is perpendicular to the optical axis O and has a light passage hole 25 through which light passes. The intermediate wall 26 is provided integrally with the lens barrel 12 at approximately the center of the lens barrel 12 in the optical axis direction, and the first housing portion 31 is provided on the object side (upper side in FIG. 1) than the intermediate wall 26. A second accommodating portion 32 is provided on the image side (lower side in FIG. 1) than the intermediate wall 26. The second accommodating portion 32 has a smaller diameter than the first accommodating portion 31, and has an inner diameter surface formed in the shape of a cylindrical surface or a rectangular cylindrical surface coaxial with the optical axis O.
Further, the first accommodating portion 31 has an inner diameter surface formed in a cylindrical shape or a rectangular cylindrical shape coaxial with the optical axis O.

The intermediate wall 26 has a light passage hole 25 in the center thereof through which light passes. The light passage hole 25 is a circular through hole provided through the intermediate wall 26 in the optical axis direction, and has an inner diameter surface 25a against which the outer peripheral surface of the third lens 15 comes into contact, and an inner diameter surface 25a. It has a contact surface 25b that is continuously provided and supports the third lens 15 by abutting the outer circumferential portion of the lens surface facing the image side of the third lens 15. The inner diameter surface 25a is formed in the shape of a cylindrical surface coaxial with the optical axis O, and the contact surface 25b is formed in the shape of a conical surface whose diameter decreases toward the image side and is coaxial with the optical axis O.
The third lens 15 has its outer circumferential surface press-fitted or in contact with the inner diameter surface 25a and is bonded to the inner diameter surface 25a, and the outer circumferential portion of the lens surface facing the image side is in contact with the abutment surface 25b, so that the intermediate wall 26 It is attached to the light passage hole 25.

The first accommodating section 31 includes a first lens accommodating section 31a that is disposed at the object side end of the lens barrel 12 and accommodates the first lens 13, and a first lens accommodating section 31a that is disposed on the image side of the first lens accommodating section 31a. , and a second lens accommodating portion 31b that accommodates the second lens 14.
The first lens housing portion 31a is formed to have a larger diameter than the second lens housing portion 31b (the diameter in the direction perpendicular to the optical axis O is larger). Further, the first lens accommodating portion 31a includes the proximal surface 12c to which the flange portion of the first lens 13 is brought close, and the second lens accommodating portion 31b has the lower surface (the surface facing the image side) of the second lens 14. It is provided with a contact surface 31f that is brought into contact with the contact surface 31f. This contact surface 31f is constituted by the upper surface of the intermediate wall 26 (the surface facing the object side).
The inner diameter surface of the first lens housing portion 31a and the inner diameter surface of the second lens housing portion 31b are formed into cylindrical surfaces coaxial with the optical axis O, and further coaxial with the inner diameter surface of the second lens housing portion 32. ing.

On the object side (upper side) of the intermediate wall 26, the first lens 13 is housed in the first lens housing part 31a of the first housing part 31, and the second lens 14 is housed in the second lens housing part 31b. .
When the first lens 13 and the second lens 14 are housed in the first housing part 31, the third lens 15 is housed in the lens barrel 12 before that. That is, after inserting the third lens 15 into the lens barrel 12 from the upper end opening (object side end opening), the third lens 15 is attached to the light passage hole 25 of the intermediate wall 26 . In this case, the outer circumferential surface of the third lens 15 is press-fitted or in contact with the inner diameter surface 25a of the light passage hole 25 and is bonded, and the outer circumferential portion of the lens surface facing the image side is brought into contact with the abutment surface 25b. The third lens 15 is attached to the 26 light passing holes 25. Thereby, the third lens 15 is positioned in the optical axis direction and the radial direction.

Next, the diaphragm member 20 and the second lens 14 are inserted through the upper end opening (object side end opening) of the lens barrel 12, and the second lens 14 is attached to the contact surface 31f via the diaphragm member 20. By press-fitting or abutting the second lens 14 on the inner diameter surface of the second lens accommodating portion 31b, the second lens 14 is positioned in the optical axis direction and the radial direction. In this state, the upper surface (surface facing the object side) 14f of the flange portion of the second lens 14 projects slightly upward (toward the object side) from the proximity surface 12c. Note that the lens surface 14s of the second lens 14 facing the object side protrudes from the upper surface 14f toward the object side, and enters inside the concave lens surface 13s of the first lens 13 facing the image side.
Next, the first lens 13 is inserted through the upper end opening (object side end opening) of the lens barrel 12, and the first lens 13 is brought into contact with the upper surface 14f of the flange portion of the second lens 14. The first lens 14 is positioned in the optical axis direction and the radial direction by press-fitting or abutting the first lens 13 on the inner diameter surface of the first lens accommodating portion 31a.

Before the first lens 13 is brought into contact with the upper surface 14f of the second lens 14, on the radially outer side of the adhesive reservoir 12p of the proximal surface 12c of the first lens accommodating section 31a, the proximal surface 12c and the first lens accommodating section 31a are connected. The corners where the inner diameter surface intersects are filled with the adhesive G2, and the upper part of the inner diameter surface of the first lens accommodating portion 31a is filled with the adhesive G1. Then, the first lens 13 is brought into contact with the upper surface 14f of the flange portion of the second lens 14, and the first lens 13 is press-fitted or brought into contact with the inner diameter surface of the first lens accommodating portion 31a. Adhesives G1 and G2 spread between the lens barrel 12 and the object side end of the lens barrel 12 to be hermetically sealed.
Next, by thermally caulking the caulking portion 23 at the object side end of the lens barrel 12 radially inward, the first lens 13 is attached to the object side end of the lens barrel 12 in the optical axis direction. Fix it with. Further, by fixing the first lens 13, the second lens 14 is pressed against the contact surface 31f and fixed.

As described above, the second accommodating portion 32 is provided on the image side (lower side) of the intermediate wall 26 . The second accommodating portion 32 is formed in a cylindrical shape or a prismatic cylindrical shape coaxial with the optical axis O, and its upper surface (the surface facing the image side) is brought into contact with the flange portion of the fourth lens 15. This is a contact surface 33f. This contact surface 33f is constituted by the lower surface of the intermediate wall 26 facing the image side.
When storing the fourth lens 16 and the fifth lens 17 in such a second housing part 32, first, the fourth lens 16 and the fifth lens 17 are bonded together with an adhesive, and the bonded lens 18 I'll leave it as that. Further, an optical filter 35 such as an infrared cut filter is attached to the fifth lens 17 by adhesive or the like.

Next, the bonded lens 18 is inserted through the lower end opening (image side end opening) of the lens barrel 12 with the fourth lens 16 facing the object side (upper side), and then the flange of the fourth lens 16 is inserted. The bonded lens 18 (the fourth lens 16 and the fifth lens 17) is pressed into contact with the contact surface 33f, and the fifth lens 17 is press-fitted or brought into contact with the inner diameter surface of the second accommodating portion 32 and bonded. Positioning is performed in the optical axis direction and radial direction.

Here, in this embodiment, a second lens (object lens) adjacent to the intermediate wall 26 in the optical axis direction and located on the object side from the intermediate wall 26 is attached to the object side surface (abutment surface 31f) of the intermediate wall 26. A fourth lens, which is adjacent to the intermediate wall 26 in the optical axis direction and located closer to the image side than the intermediate wall 26, is in contact with the image side surface (contact surface 33f) of the intermediate wall 26. The upper surface (surface facing the object side) of the flange portion of the (image side adjacent lens) 16 is in contact with the lens.
The inter-plane sensitivity between the second lens (object side adjacent lens) 14 and the third lens 15 and the inter-plane sensitivity between the third lens 15 and the fourth lens (image side adjacent lens) 16 are different from each other in the other optical axis direction. The inter-plane sensitivity is higher than the inter-plane sensitivity between adjacent lenses (for example, the inter-plane sensitivity between the first lens 13 and the second lens 14).

For example, as shown in FIG. , the fourth lens L4 and the fifth lens L5, the inter-plane sensitivity between the second lens L2 and the third lens L3 and the inter-plane sensitivity between the third lens L3 and the fourth lens L4 are The inter-plane sensitivity is higher than the inter-plane sensitivity between the second lens L2 and the inter-plane sensitivity between the fourth lens L4 and the fifth lens L5.
In Figure 2, the horizontal axis indicates the amount of deviation (μm) from the design value of the distance between adjacent lenses in the optical axis direction, and the vertical axis indicates MTF, which represents the spatial reproduction performance of the contrast of the subject on the image plane. Expressed as a frequency characteristic, it indicates the optical performance of the lens. On the horizontal axis, a value of "0" indicates that the distance (spacing) between the lenses is the design value, the more negative the distance, the closer the distance between the lenses, and the more positive the value, the wider the distance between the lenses. Indicates that the amount of deviation from the design value (interval) increases.
Further, on the vertical axis, the maximum value is set as "100%", and the closer it is to 100%, the better the optical performance is.
Therefore, the inter-plane sensitivity increases as the MTF (optical performance) on the vertical axis decreases. For example, the inter-plane sensitivity between the third lens L3 and the fourth lens L4 is the same as that between the first lens L1 and the second lens L2. When the surface-to-surface sensitivity becomes high compared to the surface-to-surface sensitivity of However, it becomes less than 40%.
Therefore, in this embodiment, the second lens L2, the third lens L3, and the fourth lens L4, which have high surface-to-plane sensitivity, are brought into contact with the intermediate wall 26.

Note that in this embodiment, the third lens (intermediate lens) 15 is brought into contact with the contact surface 25b of the intermediate wall 26, but the third lens (intermediate lens) 15 may be omitted. In this case, the inter-plane sensitivity between the second lens 14 (object side adjacent lens) and the fourth lens 16 (image side adjacent lens) becomes high inter-plane sensitivity.
Further, in the present embodiment, the lens barrel 12 is constructed as an integral body having the intermediate wall 26, but the lens barrel 12 is formed by dividing the lens barrel 12 into a plurality of substantially cylindrical divided lens barrels in the optical axis direction. It may also be configured by joining. In this case, at least one of the plurality of divided lens barrels of the lens barrel 12 may be provided with an intermediate wall on which a lens with high surface-to-plane sensitivity is brought into contact.

As described above, in this embodiment, even if the amount of expansion in the optical axis direction due to temperature changes or hygroscopic expansion of the lens barrel 12 is greater than the amount of expansion in the optical axis direction of the entire lens group L, the object The amount of elongation of the side (upper) part of the lens barrel 12 (first accommodating portion 31) is smaller than the amount of elongation of the entire lens barrel 12, and the amount of elongation of the first lens 13 and the first lens accommodated in the first accommodating portion 31 The amount of elongation of the second lens 14 is also smaller than the amount of elongation of the entire lens group L, and the amount of elongation of the portion of the lens barrel 12 on the image side (lower side) of the intermediate wall 26 (second accommodating portion 32) is smaller than the amount of elongation of the entire lens barrel 12. At the same time, the amount of expansion of the fourth lens 16 and the fifth lens 17 accommodated in the second housing portion 32 also becomes smaller than the amount of expansion of the entire lens group L.
The second lens 14 (object-side adjacent lens) with high surface-to-plane sensitivity is in contact with the contact surface 31f of the intermediate wall 26, and the third lens (intermediate lens) 15 is in contact with the contact surface 25b of the intermediate wall 26. The fourth lens 16 (adjacent lens on the image side) is positioned in the optical axis direction by coming into contact with the contact surface 33f of the intermediate wall 26, so that the second lens 14 and the third lens 15 are and between the third lens 15 and the fourth lens 16, it is possible to suppress the misalignment of the

lenses

14, 15, and 16 (misalignment in the optical axis direction) that most affects defocus and resolution degradation, and to maintain a predetermined surface-to-plane sensitivity. Can be secured.

In the present embodiment, the first lens 13 is arranged from the object side end of the lens barrel 12 to the object side of the intermediate wall 26 provided between the object side end and the image side end of the lens barrel 12. The second lens 14 is inserted, and the fourth lens 16 and the fifth lens 17 are inserted from the image side end of the lens barrel 12 on the image side than the intermediate wall 26. It can be divided into two storage spaces (first storage section 31 and second storage section 32) on the object side and the image side. For this reason, the accumulated play between the lenses conventionally inserted into the entire lens barrel can be suppressed to a small level as the accumulated play between the lenses on the object side and the image side of the intermediate wall 26 between the lenses in each housing space. I can do it. Therefore, the backlash that occurs in the lens can be suppressed compared to the conventional case.
Further, by providing the intermediate wall 26, the number of lenses is reduced on the object side and the image side of the intermediate wall 26, and variations in lens height (height in the optical axis direction) due to tolerance can be controlled. As a result, the backlash of the lens in the thrust direction due to temperature changes can be reduced.

FIG. 3 is a schematic cross-sectional view of a camera module 300 of this embodiment having the lens unit 11 shown in FIG. 1. As illustrated, the camera module 300 includes a lens unit 11.

The camera module 300 includes an upper case (camera case) 301 that is an exterior component, and a mount (pedestal) 302 that holds the lens unit 11. Further, the camera module 300 includes a seal member 303 and a package sensor (imaging device; image sensor) 304.

The upper case 301 is a member that is engaged with the flange portion 27 provided in the shape of a brim on the outer peripheral surface of the lens barrel 12, and exposes the object-side end of the lens unit 11 and covers other parts. The mount 302 is disposed inside the upper case 301 and has a female thread 302a that screws into the male thread 11a of the lens unit 11. The seal member 303 is a member inserted between the inner surface of the upper case 301 and the outer peripheral surface of the lens barrel 12 of the lens unit 11, and is a member for maintaining airtightness inside the upper case 301.

The package sensor 304 is placed inside the mount 302, facing the infrared cut filter 35, and is placed at a position to receive the image of the object formed by the lens unit 11. Moreover, the package sensor 304 includes a CCD, CMOS, etc., and converts the light that is focused and reaches through the lens unit 11 into an electrical signal. The converted electrical signals are converted into analog data and digital data, which are constituent elements of image data taken by the camera.

FIG. 4 schematically shows a vehicle 240 as a moving body on which an in-vehicle system (imaging system) including an imaging device 250 including the camera module 300 shown in FIG. 3 is mounted. As illustrated, the imaging device 250 can be mounted on the vehicle 240, and FIG. 4 is an example of the arrangement of the mounting position of the imaging device 250 in the vehicle 240. The imaging device 250 mounted on the vehicle 240 can also be called an on-vehicle camera, and can be installed at various locations on the vehicle 240. For example, the first imaging device 250a may be disposed at or near the front bumper as a camera that monitors the front when the vehicle 240 is traveling. Further, the second imaging device 250b that monitors the front may be placed near an interior rearview mirror of the vehicle 240. The third imaging device 250c may be disposed on the dashboard, inside the instrument panel, or the like as a camera that monitors the driving status of the driver. The fourth imaging device 250d may be installed at the rear of the vehicle 240 for monitoring the rear of the vehicle 240. The

imaging devices

250a, 250b can be called front cameras. The third imaging device 250c can be called an in-camera. The fourth imaging device 250d can be called a rear camera. The imaging device 250 is not limited to these, and includes imaging devices installed at various positions, such as a left side camera that images the left rear side and a right side camera that images the right rear side.

The image signal of the image captured by the imaging device 250 may be output to the information processing device 242 and/or the display device 243 in the vehicle 240. These information processing device 242 and display device 243 together with imaging device 250 constitute an in-vehicle system. The information processing device 242 in the vehicle 240 includes a device that processes the image signal acquired by the imaging device 250, recognizes the image, and assists the driver in driving. Further, the information processing device 242 includes, for example, a navigation device, a collision damage mitigation braking device, an inter-vehicle distance control device, a lane departure warning device, etc., but is not limited thereto. The display device 243 displays images processed and output by the information processing device 242, but can also directly receive image signals from the imaging device 250. Further, the display device 243 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 243 can display to the driver an image signal output from an imaging device 250 that captures an image at a position that is difficult for the driver to see, such as a rear camera (can output information to the occupants). ).

FIG. 5 shows the configuration of an imaging device that constitutes the in-vehicle system shown in FIG. 4. As illustrated, the imaging device 250 according to the embodiment includes a control section 252, a storage section 254, and the camera module 300 shown in FIG. 3 described above.

The control unit 252 controls the camera module 300 and processes electrical signals output from the image sensor 304 of the camera module 300. This control unit 252 may be configured as a processor, for example. Further, the control unit 252 may 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 specialized for specific processing. A dedicated processor may include an application-specific integrated circuit (IC). ICs for specific applications are called ASICs (Application
Also called Specific Integrated Circuit. The processor may include a programmable logic device. A programmable logic device is also called a PLD (Programmable Logic Device). PLD is an FPGA (Field-Programmable
Gate Array). The control unit 252 may be either an SoC (System-on-a-Chip) or an SiP (System In a Package) in which one or more processors cooperate.

The storage unit 254 stores various information or parameters related to the operation of the imaging device 250. The storage unit 254 may be composed of, for example, a semiconductor memory. The storage unit 254 may function as a work memory for the control unit 252. The storage unit 254 may store captured images. The storage unit 254 may store various parameters and the like for the control unit 252 to perform detection processing based on the captured image. The storage unit 254 may be included in the control unit 252.

As described above, the camera module 300 uses the image sensor 304 to capture a subject image formed through the lens unit 11, and outputs the captured image. The image captured by the camera module 300 is also referred to as a captured image.

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

The image data may be read out by the camera module 300 for all pixels and taken into the control unit 252 as a captured image. The captured image read out for all pixels is also referred to as the maximum captured image. The image data may be read out by the camera module 300 for some pixels and captured as a captured image. In other words, the imaging data may be read from pixels within a predetermined capture range. Image data read from pixels in a predetermined capture range may be captured as a captured image. The predetermined capture range may be set by the control unit 252. The camera module 300 may acquire a predetermined capture range from the control unit 252. The image sensor 304 may capture an image within a predetermined capture range of the subject image formed through the lens unit 11.

Note that the present invention is not limited to the embodiments described above, and can be implemented with various modifications without departing from the gist thereof. For example, in the present invention, the shapes of lenses, lens barrels, etc. are not limited to the embodiments described above. Further, without departing from the gist of the present invention, some or all of the embodiments described above may be combined, or a part of the configuration from one of the embodiments described above may be omitted. .

11 Lens unit 12 Lens barrel 13 to 17 Lens 14 Object side adjacent lens 15 Intermediate lens 16 Image side adjacent lens 25 Light passage hole 26 Intermediate wall 240 Vehicle (moving object)
242 Processing device 243 Display device 250 Imaging device 252 Control unit 300 Camera module 304 Imaging device L Lens group O Optical axis

Claims

A lens unit having a lens group in which a plurality of lenses are arranged along an optical axis, and a lens barrel that accommodates and holds this lens group,
An intermediate wall that is perpendicular to the optical axis and has a light passage hole through which light passes is provided between the object side end and the image side end of the lens barrel,
A lens is inserted from the object side end of the lens barrel on the object side of the intermediate wall, and a lens is inserted from the image side end of the lens barrel on the image side of the intermediate wall,
By contacting the intermediate wall with a lens that has a high inter-plane sensitivity in which the inter-plane sensitivity, which is the sensitivity of imaging to the distance between lens surfaces, is higher than the inter-plane sensitivity between other lenses, the lens A lens unit characterized by being positioned in the optical axis direction.
An object-side adjacent lens adjacent to the intermediate wall in the optical axis direction and located on the object side from the intermediate wall is in contact with the object-side surface of the intermediate wall, and the object-side adjacent lens is in contact with the image-side surface of the intermediate wall. , an image-side adjacent lens adjacent to the intermediate wall in the optical axis direction and located on the image side of the intermediate wall is brought into contact with the intermediate wall, and an inter-plane distance between the object-side adjacent lens and the image-side adjacent lens is The lens unit according to claim 1, wherein the sensitivity is the high surface-to-surface sensitivity.
An object-side adjacent lens adjacent to the intermediate wall in the optical axis direction and located on the object side from the intermediate wall is in contact with the object-side surface of the intermediate wall, and the object-side adjacent lens is in contact with the image-side surface of the intermediate wall. , an image-side adjacent lens that is adjacent to the intermediate wall in the optical axis direction and located on the image side of the intermediate wall is in contact with the intermediate wall;
an intermediate lens is held in contact with the light passage hole of the intermediate wall;
The inter-plane sensitivity between the object-side adjacent lens and the intermediate lens and/or the inter-plane sensitivity between the image-side adjacent lens and the intermediate lens is the high inter-plane sensitivity. The lens unit according to claim 1.
A camera module comprising the lens unit according to any one of claims 1 to 3 and an image sensor that converts light collected through the lens group of the lens unit into an electrical signal.
An imaging device comprising: the camera module according to claim 4; and a control unit that controls the camera module and processes electrical signals output from an image sensor of the camera module;
a processing device that processes an image signal acquired by the imaging device;
a display device that displays an image processed and output by the processing device;
An imaging system comprising:
A mobile object equipped with the imaging system according to claim 5 and outputting information to a passenger using the display device.