WO2024013969A1

WO2024013969A1 - Camera device including lens unit

Info

Publication number: WO2024013969A1
Application number: PCT/JP2022/027808
Authority: WO
Inventors: 賢一竹内; 秀則篠原; 武志芳賀
Original assignee: 日立Astemo株式会社
Priority date: 2022-07-15
Filing date: 2022-07-15
Publication date: 2024-01-18

Abstract

Provided is a camera device that reduces production costs by shortening the time of assembly work when a camera module is mounted to a housing, and that can also enhance mounting accuracy of the camera module to the housing. Accordingly, this camera device is configured to include a lens unit including: a lens barrel part in which a plurality of lenses are stored; a reference surface, which is a surface perpendicular to the optical axis of the lenses, and which is made to abut an external abutting surface; and a positioning structure that fixes the center position of the lenses or restricts the movement in the rotating direction thereof, in a state where the reference surface is made to abut the abutting surface.

Description

Camera device with lens unit

The present invention relates to a camera device having a lens unit.

Automotive stereo cameras (hereinafter referred to as "camera devices"), which are a type of external world recognition sensor for advanced driving assistance systems (ADAS) and autonomous driving (AD) systems, use left and right images captured synchronously by the left and right cameras. This is a device that calculates parallax information and measures the distance to an imaged object (another vehicle, pedestrian, obstacle, etc.) (hereinafter referred to as "distance measurement"). Distance measurement by the camera device is based on parallax information between the left and right images, so in order to achieve accurate distance measurement, it is necessary to accurately fix the left and right camera modules to the housing so that the parallax information can be calculated accurately. There is a need to.

FIG. 8 is an exploded perspective view of the main parts of a general camera device, viewed from the front. This camera device includes a highly rigid casing 100 that forms the front outer shell of the camera device, a left camera module 1L fixed to the back left side of the casing 100, and a right camera module 1L fixed to the back right side of the casing 100. It is equipped with 1R. If the distance between the optical axes of both camera modules is the baseline length L, the angle around the optical axis of the left camera module 1L is the roll angle θL, and the angle around the optical axis of the right camera module 1R is the roll angle θR, then this In order to ensure the desired distance measurement accuracy with a camera device, it is necessary to suppress the errors in the parallelism of both optical axes, the baseline length L, and the roll angles θL and θR within a predetermined range allowed by the camera device specifications. be.

Here, as a conventional technique for attaching a camera module to a housing of a camera device with high precision, an in-vehicle imaging device disclosed in Patent Document 1 is known. For example, paragraph 0018 of the same document states, ``The present invention provides an in-vehicle imaging device that is capable of highly accurate optical axis adjustment of the imaging unit with respect to the casing while minimizing precision machining of the casing. Paragraph 0019 states, ``The present invention provides a lens, and an optical axis of the lens as a normal line, when viewed from the optical axis direction of the lens. an image sensor section having a lens holder having three reference surfaces arranged so as to surround the lens; an insertion section through which the lens holder is inserted; an opposing surface facing the reference surface; a casing having three adhesive filling parts arranged so as to surround the insertion part and penetrating from the opposing surface side to the opposite side of the opposing surface, the imaging element section and the casing; "is characterized in that the mutual positional relationship is fixed only by the adhesive in the three adhesive filling parts."

In this way, Patent Document 1 discloses a method in which adhesive is filled in the adhesive filling portion of the housing with the reference surface of the lens holder in contact with the facing surface of the housing, and the positional relationship between the housing and the lens holder is adjusted. By fixing it, highly accurate optical axis adjustment is possible.

Patent No. 6941686

In recent years, there has been a demand for further cost reduction of camera devices, and Patent Document 1 also discloses that adhesives are used to fix the positional relationship between the housing and the lens holder, making it easier to precisely process and mold the housing. The cost is reduced by minimizing the required processing cost (see paragraph 0059 of the same document, etc.).

Regarding the camera structure for improving assembly work efficiency and reducing costs, for example, paragraph 0065 of the same document states, ``In the camera module 20L1 of this embodiment shown in FIGS. 5A and 5B, the camera module 20L1 is held in the lens holder 21L1. As shown in FIG. 5C, a concave shape 25L1 and a convex shape 26L1 having a height recessed from the reference surface 24L1 are formed inside the concave shape 25L1, as shown in FIG. 5C, on the reference surface 24L1 whose normal is the optical axis of the lens. The concave shape 25L1 and the convex shape 26L1 are formed at positions that serve as landmarks when looking into the reference surface 24L1 from the adhesive filling portion 14L of the housing 10."

However, even if this camera structure is adopted, the position of the lens holder must be adjusted so that the marks (concave shape, convex shape) on the reference surface can be seen when looking at the reference surface of the lens holder from the adhesive filled part of the housing. After that, there is no change in the assembly procedure of filling the adhesive-filled part of the housing with adhesive and fixing the positional relationship between the housing and the lens holder, so please check the position of the lens holder while looking into the adhesive-filled part. The production efficiency deteriorated due to the adjustment work required, which became an obstacle to further cost reduction. In addition, the mark is a reference for adjusting the position of the lens holder, and the mark itself does not have the function of regulating the positional relationship between the housing and the lens holder. There was also the problem that the accuracy of the relationship could not be ensured sufficiently.

Therefore, the present invention provides a camera device that can reduce production costs by shortening the assembly work time when attaching the camera module to the housing, and also improve the accuracy of attaching the camera module to the housing. The purpose is to

In order to solve the above problems, a camera device of the present invention includes a lens barrel section in which a plurality of lenses are housed, and a reference surface that is perpendicular to the optical axis of the lenses and that abuts on an external contact surface. and a positioning structure that fixes the center position of the lens or restricts movement in the rotational direction while the reference surface is in contact with the contact surface.

With the camera device of the present invention, it is possible to reduce production costs by shortening the assembly work time when attaching the camera module to the casing, and to improve the accuracy of attaching the camera module to the casing.

FIG. 1 is an exploded perspective view of main parts of a camera device according to an embodiment, seen from the rear. FIG. 2 is a perspective view of a camera module according to an embodiment. FIG. 2 is a top view of a camera module according to an embodiment. FIG. 3 is an enlarged view of the left camera module mounting portion on the back surface of the casing in one embodiment. FIG. 3 is a diagram illustrating a manufacturing procedure of a camera module according to an embodiment. FIG. 3 is a diagram illustrating a manufacturing procedure of a camera module according to an embodiment. FIG. 3 is a diagram illustrating a manufacturing procedure of a camera module according to an embodiment. FIG. 3 is a diagram illustrating a manufacturing procedure of a camera module according to an embodiment. FIG. 3 is a diagram illustrating a manufacturing procedure of a camera module according to an embodiment. FIG. 1 is an exploded perspective view of the main parts of a general camera device, seen from the front.

Embodiments of the camera device of the present invention will be described below with reference to the drawings.

<Structure of camera device>
First, the structure of a camera device according to an embodiment will be explained using FIGS. 1 to 4.

FIG. 1 is an exploded perspective view of the main parts of the camera device of this embodiment, viewed from the rear. The structure of the camera device of this embodiment is basically the same as that of FIG. 8 described above, but differs in the shape of the contact portion between the housing 100 and the camera module 1, which will be described later. Note that the camera device of this embodiment includes a main control that controls the camera module 1, processes the output signal of the camera module 1 to generate an image, and calculates parallax information by comparing the left and right images. A substrate, a back cover that covers the back of the casing 100, and the like are also provided, but these are not shown in FIG.

2 is a perspective view of the camera module 1, and FIG. 3 is a top view of the camera module 1. As shown in both figures, the camera module 1 includes a lens unit 10, an image sensor board 20, and wiring 30.

The lens unit 10 is a resin component that holds a plurality of lenses and also fixes the camera module 1 to the housing 100. A plurality of reference planes 12 arranged on the same plane perpendicular to the optical axis and a plurality of positioning pins 13 which are a structure for fixing the camera module 1 to the housing 100 are integrally molded. In addition, in FIGS. 2 and 3, three reference planes 12 are arranged in a substantially equilateral triangle shape to surround the lens barrel part 11, and two positioning pins are arranged on the same plane that includes the optical axis of the lens barrel part 11. 13, but if three or more reference planes 12 are arranged so as to surround the lens barrel part 11, and two or more positioning pins 13 are arranged so as to surround the lens barrel part 11, The number and arrangement of the reference plane 12 and the positioning pins 13 are not limited to those shown in the drawings.

The image sensor board 20 is a board on which the image sensor 21 is arranged on the optical axis of the lens barrel section 11, and is fixed to the lens unit 10 in a procedure described later. Note that the image sensor 21 is a CMOS image sensor or the like that captures an image in the optical axis direction through the lens barrel section 11.

The wiring 30 is FPC (Flexible printed circuits), FFC (Flexible Flat Cable), etc., which connects the image sensor board 20 and the main control board.

FIG. 4 is a rear view of the housing 100, showing an enlarged view of the vicinity of the fixed portion of the left camera module 1L. Note that the structure near the fixing part of the right camera module 1R is also the same, so the description of the right fixing part will be omitted below.

As shown here, three contact surfaces 101 are provided on the back surface of the housing 100 at positions facing the three reference surfaces 12 of the lens unit 10, and are connected to one positioning pin 13 of the lens unit 10. A positioning hole 102 is provided at an opposing position, and a positioning elongated hole 103 is provided at a position opposing the other positioning pin 13.

With this structure, when the three reference surfaces 12 are in contact with the opposing contact surfaces 101 and the two positioning pins 13 are inserted into the opposing positioning holes 102 and positioning elongated holes 103, the left camera The module 1L can be fixed to the housing 100. Note that since the positioning elongated hole 103 is formed long in the linear direction connecting the positioning hole 102 and the positioning elongated hole 103, even if there is some variation in the distance between the positioning pins 13 of the lens unit 10, both positioning pins 13 can be inserted into the positioning hole 102 and the positioning elongated hole 103.

Note that in this embodiment, the pin of the lens unit 10 is inserted into the hole of the housing 100 to position both of them, but it is also possible to insert the pin of the housing 100 into the hole of the lens unit 10 to position both of them. Also good. Furthermore, a recess into which the lens unit 10 is fitted may be provided in the housing 100 so that both can be positioned.

<Mechanism to suppress errors in parallelism of optical axis of camera device, base line length L, and roll angle θ>
The mechanism by which the above structure suppresses errors in the parallelism of the left and right optical axes, the base line length L, and the left and right roll angles θL and θR (see FIG. 8) of the camera device of this embodiment will be described.

As described above, the plurality of reference surfaces 12 of the lens unit 10 are formed on the same plane perpendicular to the optical axis of the lens barrel portion 11 of the lens unit 10 (that is, the optical axis of the camera module 1). Further, since the plurality of contact surfaces 101 of the housing 100 are formed as planes facing each of the plurality of reference surfaces 12 formed on the same plane, the contact surfaces 101 are also formed on the same plane. will be done.

Therefore, when attaching the left and

right camera modules

1L and 1R to the housing 100, if the reference plane 12, which is normal to the optical axis of the left and right lens units 10, is pressed against the opposing contact surface 101 of the housing 100. When the reference planes 12 of the left and

right camera modules

1L, 1R are pressed against the same plane, the same state is achieved, and the optical axes of the left and

right camera modules

1L, 1R perpendicular to the same plane become parallel.

In order to calculate accurate parallax information with a camera device, the left and right optical axes should be parallel to each other, the distance between the optical axes (baseline length L) of the left and

right camera modules

1L and 1R should be within a specified value, and, It is necessary to keep the left and right roll angles θL and θR within specified values.

In the camera module 1 of this embodiment, the pair of positioning pins 13 provided on the lens unit 10 are fitted into the positioning hole 102 and the positioning elongated hole 103 of the housing 100, so that each positioning pin 13 is attached to the housing. This serves as a reference for positioning with respect to the body 100 and a reference for roll rotation with respect to the housing 100, making it possible to simultaneously suppress errors in the position of the camera module 1 and the roll angle θ.

As shown in FIG. 8, the roll angle θ is the rotation angle of the camera module 1 with the optical axis as the rotation axis. When this roll angle θ exists, it causes rotation of the image captured by the image sensor 21. do. Therefore, even if the roll angle θ is fixed by the positioning pin 13 of the lens unit 10, if the image sensor 21 itself has the roll angle θ with respect to the optical axis, rotation of the captured image will occur. It turns out.

Therefore, in this embodiment, by using the left and

right camera modules

1L and 1R in which the relative relationship between the lens unit 10 and the image sensor 21 is fixed at an ideal position without rotation around the optical axis using the following manufacturing procedure, Errors in the parallelism between optical axes, the distance between optical axes (baseline length L), and left and right roll angles θL and θR can be easily suppressed.

<Procedure for fixing lens unit 10 to adjustment jig 200>
First, the procedure for fixing the lens unit 10 to the adjustment jig 200 for adjusting the camera module will be described using the perspective views of FIGS. 5A to 5C.

FIG. 5A is a perspective view of the adjustment jig 200 and the lens unit 10 before being fixed, viewed from above, and the arrow in the figure indicates the moving direction of the lens unit 10. As shown here, the adjustment jig 200 has a substantially U-shaped structure with a pair of protrusions, and is provided with a through hole 201 at a position scheduled to face the reference surface 12 of the lens unit 10. . The orthogonal coordinate system in the figure is a coordinate system set such that the X axis points in the long side direction of the lens unit 10, the Y axis points in the short side direction of the lens unit 10, and the Z axis points in the optical axis of the lens unit 10. be.

FIG. 5B is a perspective view of the lens unit 10 and adjustment jig 200 of FIG. 5A viewed from below. As shown here, a contact surface 202, a positioning V-groove 203, and a positioning plane 204 are formed on the bottom surface of the adjustment jig 200. The contact surface 202 is a plane formed to surround the lower end of the through hole 201 and simulates the function of the contact surface 101 in FIG. It is formed in the planned position. The positioning V-groove 203 is a groove on the adjustment jig 200 that simulates the function of the positioning hole 102 in FIG. The positioning plane 204 is a plane that simulates the function of the positioning elongated hole 103 in FIG.

FIG. 5C is a perspective view showing the lens unit 10 fixed to the adjustment jig 200. As shown in the figure, one positioning pin 13 of the lens unit 10 is made tangential to the two surfaces of the positioning V-groove 203 of the adjustment jig 200, and the other positioning pin 13 is made tangential to the positioning plane 204, so that the housing can be fixed. A state in which the positioning pin 13 of the lens unit 10 is fixed to the positioning hole 102 and the positioning elongated hole 103 of 100 is simulated, and movement of the lens unit 10 in the X-axis and Y-axis directions is regulated. Further, by applying negative pressure to the through hole 201 of the adjustment jig 200 and attracting the lens unit 10, movement of the lens unit 10 in the Z-axis direction is restricted. In this way, the lens unit 10 is fixed to the adjustment jig 200. Note that as a method of fixing the lens unit 10 to the adjustment jig 200, a method of mechanically fixing the lens unit 10 may be adopted, and in that case, the through hole 201 may be omitted.

As shown in FIGS. 5A and 5B, when attaching the lens unit 10 to the adjustment jig 200 from the Y direction, if the positioning pin 13 of the lens unit 10 interferes with the contact surface 202 of the adjustment jig 200, the lens unit 10 cannot be attached to the adjustment jig 200. Therefore, in this embodiment, the tip of the positioning pin 13 is positioned at a position farther from the contact surface 202 in the optical axis direction with the reference surface 12 in contact with the contact surface 202. By designing the lens unit 10 so that the tip of the pin 13 is lower than the reference plane 12 (see FIG. 5A), the above interference is prevented from occurring.

<Method for adjusting the relative relationship between the lens unit 10 and the image sensor 21>
Next, an adjustment method called Active Alignment, which adjusts the relative relationship between the lens unit 10 and the image sensor 21 to an ideal position without rotation around the optical axis, will be explained using FIGS. 6 and 7. This adjustment method is an adjustment method that simultaneously adjusts the vertical position (focus adjustment direction) and horizontal position (center optical axis position) of the image sensor 21 with respect to the lens unit 10, as well as the image tilt and roll angle of the lens unit 10. be.

FIG. 6 shows the center collimator C0 and peripheral collimator C1 installed in the imaging direction of the lens unit 10, and the image sensor board 20 and wiring 30 placed on the back side of the lens unit 10 in order to implement Active Alignment. show. In FIG. 6, the lens unit 10 is fixed to an adjustment jig 200 (not shown), and the relative relationship between the lens unit 10 and the image sensor substrate 20 can be adjusted.

Here, the central collimator C0 is a collimator placed on the object side so as to be coaxial with the optical axis of the lens unit 10. Further, the peripheral collimators C1 are four collimators arranged parallel to the central collimator C0 along the four sides of a virtual rectangular column whose central axis is the optical axis of the lens unit 10. Therefore, the peripheral collimators C1 are arranged one by one in the first to fourth quadrants of the XY coordinate system of the lens unit 10 shown in FIG. It becomes. Here, each collimator has, for example, a crosshair reticle, and this crosshair reticle can be observed at an infinite distance.

FIG. 7 is a diagram showing a procedure for adjusting the position and attitude of the image sensor 21 with respect to the lens unit 10, and R0 and R1 in the figure represent images formed on the image sensor 21 via the lens unit 10, respectively. This is a reticle cross image of the central collimator C0 and the peripheral collimator C1. In addition, as is obvious from the fact that the peripheral collimators C1 are arranged one by one from the first quadrant to the fourth quadrant of the XY coordinate system of the lens unit 10 in FIG. 6, even before adjustment, the XY coordinate system of the lens unit 10 In the XY coordinate system of the image sensor 21 that roughly matches the coordinate system, the reticle cross images R1 of the peripheral collimator C1 are formed one by one from the first quadrant to the fourth quadrant.

As shown in FIG. 7A, when the focus adjustment of the lens unit 10 is completed, the reticle cross image R0 captured through the lens unit 10 is set to the desired coordinates of the image sensor 21 (for example, the optical axis is If the camera module 1 is designed to be placed at the center of the image sensor 21, it is assumed that the camera module 1 is shifted from the center coordinates of the image sensor 21.

Therefore, as shown in FIG. 7B, the position of the image sensor 21 with respect to the lens unit 10 (i.e., the position of the image sensor 21 on which the image sensor 21 is arranged) (position of the substrate 20).

Next, as shown in FIG. 7(c), the relative relationship between the lens unit 10 and the image sensor 21 is adjusted to an ideal position without rotation around the optical axis. Specifically, from the coordinates of the four reticle cross images R1 projected on the XY coordinate system of the image sensor 21, the XY coordinate system of the image sensor 21 is calculated relative to the XY coordinate system of the lens unit 10 defined by the peripheral collimator C1. The rotation angle is calculated, and the rotation adjustment of the image sensor 21 (that is, the rotation adjustment of the image sensor substrate 20) is performed so that the roll angle θ of both XY coordinate systems becomes 0.

After adjusting the position and angle of the image sensor 21 in the steps shown in FIGS. The relative relationship can be fixed at an ideal position without rotation around the optical axis.

<Summary>
As described above, according to the camera device of this embodiment, errors in the parallelism between the optical axes of the left and right camera modules, the base line length, and the left and right roll angles can be easily suppressed.

DESCRIPTION OF SYMBOLS 1... Camera module, 10... Lens unit, 11... Lens barrel part, 12... Reference surface, 13... Positioning pin, 20... Image sensor board, 21... Image sensor, 30... Wiring, 100... Housing, 101... Contact Surface, 102...Positioning hole, 103...Positioning slot, 200...Adjustment jig, 201...Through hole, 202...Abutment surface, 203...V groove for positioning, 204...Plane for positioning, C0...Center collimator, R0... Reticle cross image of central collimator, C1... peripheral collimator, R1... reticle cross image of peripheral collimator

Claims

A lens barrel section in which multiple lenses are stored;
a reference surface that is perpendicular to the optical axis of the lens and that comes into contact with an external contact surface;
a positioning structure that fixes the center position of the lens or restricts movement in the rotational direction while the reference surface is in contact with the contact surface;
A camera device having a lens unit.
The camera device according to claim 1, further comprising a lens unit, wherein a plurality of the positioning structures are provided, and at least two of the plurality of positioning structures are provided in a plane normal to the central axis of the lens. camera equipment.
The camera device according to claim 1, wherein the optical axis of the lens barrel portion and the axes of the two or more pins provided as the positioning structure are on the same plane.
4. The camera device according to claim 3, wherein the optical axis of the lens barrel portion is surrounded by two or more pins provided as the positioning structure.
The camera device according to claim 1, wherein the tip of the pin provided as the positioning structure is located at a position farther from the contact surface in the optical axis direction of the lens with the reference surface in contact with the contact surface. A lens unit that is characterized by:
The camera device according to claim 1, wherein the positioning structure includes two pins, one of which is arranged to contact a concave first positioning part,
A camera device having a lens unit, wherein the other pin is arranged so as to contact a second positioning portion having a planar shape.
The camera device according to claim 1, wherein the contact surface is provided on an adjustment jig for fixing the lens unit,
A camera device having a lens unit, wherein the lens unit is aligned with an image pickup board while the reference surface is in contact with the contact surface.
The camera device according to claim 1, wherein the contact surface is provided on a camera housing to which the lens unit is assembled,
A camera device having a lens unit, wherein the lens unit is fixed to the camera housing with the reference surface in contact with the contact surface.