WO2023276232A1

WO2023276232A1 - Imaging device

Info

Publication number: WO2023276232A1
Application number: PCT/JP2022/004804
Authority: WO
Inventors: 盛一加藤; 謙大角; 直樹岡; 成人廣畑
Original assignee: 日立Astemo株式会社
Priority date: 2021-07-01
Filing date: 2022-02-08
Publication date: 2023-01-05
Also published as: DE112022001866T5; JP2023006962A

Abstract

Provided is an imaging device which, even though having a structure with fewer fastening points and vibration-proof members, is suitable for size reduction enabling reduction of vibration of a circuit substrate in the imaging device and vibration to a sensor such as an imaging element. This imaging device is provided with an imaging element, a substrate for processing an image, and a casing to which the substrate is fixed by substrate fixing parts at a plurality of spots. The substrate has a plurality of cantilever parts that are regions outside of polygonal regions having, at the respective vertexes, the substrate fixing parts. The natural frequencies of the cantilever parts are different between the cantilever parts.

Description

Imaging device

The present invention relates to an imaging device that is mounted on a vehicle such as a four-wheeled motor vehicle or a motorcycle and captures an image of the front of the vehicle.

In recent years, with the aim of realizing a safe and comfortable motorized society, the installation of driver assistance systems in vehicles such as four-wheeled vehicles and motorcycles is progressing. Among them, there is a collision damage mitigation braking system that automatically decelerates before colliding with an obstacle, an automatic distance control system that automatically tracks while maintaining the distance between the vehicle and the preceding vehicle at a substantially constant distance according to the speed, Development of systems that pursue safety, convenience, and comfort for drivers and passengers, such as lane departure prevention devices and traffic sign recognition, is progressing. Such a system uses an external recognition device that recognizes vehicles, pedestrians, and the like and measures the distance to the object.

For an imaging device, which is a type of device for recognizing the external world, it is essential to ensure a clear field of view in order to accurately recognize the external world. The imaging device is subject to the vibration of the vehicle running, and the imaging device is affected by the vibration of the device, causing the image to vibrate and the image to vibrate, making it difficult to recognize the external world. There is a possibility that repeated strain will be applied to the circuit element that is attached to the cable, or disconnection will occur in the solder part.

Here, Patent Document 1 is known as a conventional technique for suppressing disconnection due to repeated strain applied to circuit elements on a circuit board in an environment subject to running vibration of a vehicle. For example, in the abstract of the same document, the problem is described as "installing a vibration isolating member in an electronic device comprising an electronic board on which an electronic component having a plurality of terminals is mounted and a support for supporting the electronic board. The electronic board 3 and the terminal block 2 are arranged so that the vibration mode of the electronic board 3 at the time of resonance prevents disconnection of the electronic component 3b. An electronic device is disclosed that is "fastened into a mode of vibration that can be restrained from occurring."

JP 2020-161547 A

Specifically, as described in paragraph 0018 of the same document, the electronic device of Patent Document 1 is a power conversion device that is mounted on a vehicle such as a hybrid vehicle or an electric vehicle and supplies power to a driving motor. . In this power converter, as shown in FIGS. 1 and 3 of the document, by using many screws 4 for fixing the electronic board 3 to the terminal block 2 and increasing the fastening points P of the electronic board 3, the electronic The substrate 3 was made to be in a suppressible vibration mode. For this reason, the power conversion device of Patent Document 1 has a structure that is unsuitable for miniaturization because the area of the fastening portion that occupies the area of the electronic substrate increases, resulting in an increase in the size of the electronic substrate. In the case of an in-vehicle power conversion device in which the demand for .DELTA.

On the other hand, imaging devices, which are often installed on the upper inner surface of the windshield, are strongly required to be smaller so as not to block the driver's field of vision as much as possible. It is not preferable to apply the vibration mode suppressing structure of Patent Document 1 as it is, which causes complication.

Further, as a structure for suppressing vibration of the electronic board without using the vibration mode suppressing structure of Patent Document 1, a structure in which a vibration isolating member is provided on the electronic board is known. This leads to an increase in the size of the device, an increase in the number of parts, and a complicated manufacturing process.

The present invention has been made in view of the above problems, and even with a structure in which the number of fastening points and vibration-proof members is reduced, the vibration of the circuit board in the image pickup device and the vibration transmitted to the sensor such as the image pickup device can be reduced. It is an object of the present invention to provide an imaging device that reduces both.

The present application includes a plurality of means for solving the above-described problems, and to give an example, an imaging device, a substrate for processing an image, a housing in which the substrate is fixed by a plurality of substrate fixing portions, wherein the substrate has a plurality of cantilever portions that are regions outside a polygonal region having the substrate fixing portion at each vertex, and the eigenfrequency of the cantilever portions differs for each of the cantilever portions. is achieved by

According to the imaging apparatus of the present invention, even with a structure in which fastening points and vibration-isolating members are reduced, both vibration of the circuit board inside the imaging apparatus and vibration transmitted to sensors such as imaging elements can be reduced. .
As a result, it is possible to reduce the optical axis vibration of the imaging device due to the vibration of the vehicle. In addition, it is possible to provide an imaging device in which the possibility of disconnection of circuit elements is low. Furthermore, since the number of fastening parts and vibration-proof members can be reduced, the effective area of the circuit board can be increased, and as a result, it is possible to provide an imaging device that achieves reduction in size and weight.

1 is an external perspective view of an imaging apparatus according to Embodiment 1. FIG. 1 is a see-through perspective view of an imaging apparatus according to a first embodiment; FIG. FIG. 10 is a see-through perspective view of an imaging device of a comparative example; FIG. 4 is a vibration mode simulation diagram of a circuit board of an imaging device of a comparative example; 4A and 4B are explanatory diagrams of a substrate fixing portion of the imaging device according to the first embodiment; FIG. 4A and 4B are explanatory diagrams of the vibration reduction effect of the imaging apparatus according to the first embodiment; FIG. FIG. 11 is an explanatory diagram of a substrate fixing portion of the imaging device of Example 2; FIG. 11 is an explanatory diagram of a substrate fixing portion of the imaging device of Example 3; FIG. 11 is an explanatory diagram of a substrate fixing portion of the imaging device of Example 4; FIG. 11 is an explanatory diagram of a substrate fixing portion of the imaging device of Example 5; FIG. 11 is an explanatory diagram of a substrate fixing portion of the imaging device of Example 6; FIG. 11 is a see-through perspective view of an imaging apparatus according to a seventh embodiment; FIG. 4 is an explanatory diagram of a board fixing portion of an imaging device of a comparative example; FIG. 4 is an explanatory diagram of a board fixing portion of an imaging device of a comparative example; FIG. 12 is an explanatory diagram of a substrate fixing portion of the imaging device of Embodiment 7; FIG. 12 is an explanatory diagram of a substrate fixing portion of the imaging device of Embodiment 8; FIG. 12 is an explanatory diagram of a substrate fixing portion of the imaging device of Embodiment 9;

The imaging device of the present invention will be described below with reference to the drawings. Note that the components denoted by the same reference numerals have the same functions, and redundant description will be omitted unless otherwise specified.

First, an imaging device 101 according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 6. FIG.

FIG. 1 is an external perspective view of an imaging device 101 of this embodiment mounted on a vehicle such as a four-wheeled motor vehicle or a motorcycle, and FIG. 2 is a see-through perspective view of the imaging device 101. In order to clearly explain the arrangement of the components in each figure, in this embodiment, the positive direction is the optical axis direction (forward direction) of the imaging device 101, and the positive direction is the upward direction of the imaging device 101. An orthogonal coordinate system is set up, which consists of the y-axis and the z-axis whose positive direction is the right direction of the imaging device 101 .

This imaging device 101 is mounted on a vehicle with the positive direction of the x-axis aligned with the direction of travel of the vehicle and the negative direction of the y-axis aligned with the downward direction of the vehicle, and continuously captures images of the direction of travel of the vehicle. It is a device that recognizes the position and speed of objects (other vehicles, pedestrians, etc.) in the direction in which the vehicle is traveling, based on changes in images over time.

The imaging apparatus 101 shown in FIGS. 1 and 2 has an imaging element 2 mounted inside a metal (for example, aluminum die-cast) housing 1 having open bottom and back surfaces and heat radiation fins on the top surface. This is a monocular image pickup device in which a circuit board 3 and a circuit board 11a on which a plurality of circuit elements 6 (61 to 65) are mounted are accommodated, and a lens 4 projects forward from the top of a housing 1. It is assumed that the imaging element 2, the imaging substrate 3, and the lens 4 are integrated as an imaging module 5 using a holder (not shown). Further, the circuit board 11a is provided with a plurality of board fixing portions 12 (12a to 12c) for fixing the circuit board 11a to the housing 1. As shown in FIG. In the board fixing portion 12, for example, the circuit board 11a may be fixed to the housing 1 using screws, or the circuit board 11a may be fixed to the housing 1 using an adhesive. Further, housing fixing portions 7 (7a to 7c) used when fixing the housing 1 to a vehicle are provided on the front surface and rear portions of the left and right sides of the housing 1. As shown in FIG.

Here, the circuit elements 6 mounted on the circuit board 11a are, for example, the following. The first circuit element 61 is an FPGA (Field Programmable Gate Array) that processes the image signal output by the imaging device 2 , and is a circuit element that generates a large amount of heat and requires heat conduction to the housing 1 .
The second circuit element 62 is a circuit element such as a memory used for temporarily storing data. The third circuit element 63 is a circuit element that performs various signal processing such as an MPU (Micro Processing Unit). The fourth circuit element 64 is a large circuit element such as a capacitor. The fifth circuit element 65 is a relatively small circuit element such as a power supply circuit. Note that the plurality of circuit elements 6 are not limited to these examples, and some may be omitted or other types of circuit elements may be added.

The bottom and back openings of the housing 1 are closed with a cover (not shown) such as an aluminum plate with wiring holes after the imaging module 5 and the circuit board 11a are mounted. Therefore, the circuit board 11a of the imaging device 101 and the ECU (Electronic Control Unit) of the vehicle can be electrically connected through the wiring hole of the cover, and the output of the circuit board 11a can be reflected in the vehicle control by the ECU. can be done.

In recent years, there has been a demand for further miniaturization of imaging devices, and in order to miniaturize imaging devices, it is important to reduce the size of the built-in circuit board. As a measure for miniaturizing the circuit board, there is a method of reducing the number of board fixing portions 12 in order to increase the board area (hereinafter referred to as the effective board area) on which the circuit element 6 can be mounted. If the number of board fixing portions 12 is reduced, the circuit board 11a can be miniaturized while maintaining the effective board area of the circuit board 11a. can also be made smaller. In particular, in the case of a monocular image pickup apparatus having a small circuit board 11a, such as the image pickup apparatus 101 of this embodiment, the board fixing portion 12 occupies a large area ratio of the circuit board 11a. very effective for

A problem when the number of board fixing portions 12 of the circuit board 11a is reduced is that the cantilever portion 13 of the circuit board 11a is likely to vibrate in a bending mode or the like. For example, in the case of the circuit board 11a in FIG. 2, the substantially

triangular cantilever portions

13R and 13L are formed outside the triangular region with the board fixing portions 12a to 12c as vertices. 13R and 13L may vibrate. When the

cantilever portions

13R and 13L vibrate, the vibrations are propagated to the imaging device 2, and disturbances corresponding to the vibrations are recorded in the continuously captured images. measurement accuracy is reduced. In recent years, as the image pickup device 101 has become more capable of widening the angle of view, improving accuracy, and responding to high speed, the allowable amount of vibration of the image pickup device 2 has become smaller. getting stronger.

Further, if stress is repeatedly applied to the circuit element 6 mounted on the circuit board 11a due to the vibration of the

cantilever portions

13R and 13L, disconnection may occur in the solder portion or the like. Therefore, it is necessary to reduce vibrations at the

cantilever portions

13R and 13L of the circuit board 11a also from the viewpoint of preventing disconnection.

<Circuit board 11X of imaging device 100X of comparative example>
Here, using the see-through perspective view of FIG. 3 and the vibration mode simulation diagram of FIG. 4, the principle of vibration generation of the

cantilever portions

13R and 13L in the circuit board 11X built in the imaging device 100X of the comparative example will be described. do. 1 and 2 will not be redundantly explained below.

In many conventional imaging devices (not shown), the circuit board is fixed to the housing by means of board fixing portions 12 provided at the four corners of the circuit board. On the other hand, in the circuit board 11X of the comparative example shown in FIG. 3, the circuit board 11X is fixed to the housing 1 using three board fixing portions 12a to 12c.
As described above, in the circuit board 11X of the comparative example, the effective board area can be expanded by the amount corresponding to the reduction of one board fixing portion 12 compared to the conventional one, so that the circuit area can be reduced by the expansion of the effective board area. .

Since products such as imaging devices are often designed to be left-right symmetrical, in this comparative example, the board fixing portion 12a at the front center of the circuit board 11X and the board fixing portion 12b at the rear right end follow the conventional design policy. By symmetrically arranging the board fixing portion 12c at the rear left end, an isosceles triangular area having each vertex is formed on the circuit board 11X. When such a circuit board 11X is used, the

cantilever portions

13R and 13L having the same shape and having the same shape outside the area of the isosceles triangle resonate in the vibration mode of the same frequency, as shown in the vibration mode simulation diagram of FIG. , the amplitude of each vibration may increase. Then, when the large vibration of the

cantilever portions

13R and 13L is transmitted to the image pickup device 2 and the image pickup position change corresponding to the vibration is reflected in each image continuously picked up by the image pickup device 2, the object calculated based on the continuously picked-up images Since errors occur in the position, distance, and speed of the object, the measurement accuracy of the imaging device is degraded.

In addition, the resonance of the

cantilever parts

13R and 13L as shown in FIG. 4 repeatedly applies a large strain to the circuit elements mounted on the circuit board 11X, and there is a possibility that disconnection may occur in the solder part or the like.

In order to solve these problems, it is generally effective to provide an anti-vibration member to prevent the circuit board 11X from vibrating. This leads to an increase in the number of parts and complication of the manufacturing process. In addition, if the imaging device is provided with a vibration isolating member, the position and speed of the object are recognized based on the difference in the image due to time taken from the front side, especially when moving at high speed. The image difference is 0.1 degrees or less when converted to an angle, and the vibration mode of the anti-vibration member causes a positional shift in the image, which causes an error in calculating the speed and position of the object. A structure in which members are provided is not desirable. In addition, maintaining the mounting position of the vehicle body and the sensor is very important from the viewpoint of maintaining measurement accuracy. Normally, the vehicle body and the sensor are firmly fixed, so the vibration of the vehicle body is transmitted directly to the imaging device. . Therefore, the resonance mode of the circuit board, which is a component in the image pickup apparatus, is transmitted to the sensor through the housing and the like, causing a positional shift in the image, and an error in speed and position.

<Circuit board 11a of imaging device 101 of the present embodiment>
In order to solve the problems caused by the configuration of the comparative example as described above, in the circuit board 11a of the present embodiment, the board fixing portion 12a arranged at the front center in the comparative example shown in FIG. Moved slightly to the right. As a result, since the cantilever portion 13R and the cantilever portion 13R can be made asymmetrical, the frequency of the vibration mode of the cantilever portion 13R (natural frequency f _R ) and the frequency of the vibration mode of the cantilever portion 13L (natural frequency f _L ) can be different. Although the substrate fixing portion 12a is arranged on the right side in FIG. 5, it may be arranged on the left side.

When the natural frequencies f _R and f _L of the

cantilever portions

13R and 13L are made different, as shown in FIG. On the other hand, in the circuit board 11a of this embodiment, the double root state is eliminated, and the vibration amplitude of the vibration mode is reduced in both the

cantilever portions

13R and 13L. As a result, vibration conduction from the

cantilever portions

13R and 13L to the imaging element 2 is reduced. In addition, in the circuit board 11a of this embodiment, two

board fixing portions

12b and 12c are provided on the imaging element 2 side to increase the distance from the imaging element 2 to the

cantilever portions

13R and 13L. Also, the vibration conduction from the

cantilever portions

13R and 13L to the imaging element 2 is reduced. As described above, in the image pickup apparatus 101 of the present embodiment, by reducing the vibration conduction from the

cantilever portions

13R and 13L to the image pickup element 2, the position and velocity of the object can be obtained from the images continuously picked up by the image pickup element 2. etc. can be measured with high accuracy.

In addition, by suppressing the vibration of the

cantilever portions

13R and 13L, repeated strain applied to the circuit element 6 mounted on the circuit board 11a is also reduced, and disconnection of the solder portion around the circuit element 6 can be suppressed. can.

Furthermore, by reducing the number of board fixing portions 12, the effective board area of the circuit board 11a can be expanded. A reduction in size and weight of the device 101 can be realized.

At that time, considering vibration damping and the like, in order to prevent the vibration modes of the

cantilever portions

13R and 13L from overlapping, the difference between the natural frequencies f _R and f _L should generally be set to about 20 to 30 Hz. However, more specifically, the substrate fixing portion 12a may be arranged at a position where the natural frequencies f _R and f _L satisfy the relationships of Equations (1) and (2). The position of the board fixing portion 12a that satisfies the relationships of

Formulas

1 and 2 cannot be generalized because it is influenced by the rigidity of the circuit board 11a and the arrangement of the circuit elements 6 on the circuit board 11a. It is a position shifted by 10 to 20% with respect to the width from the widthwise center of the circuit board 11a, or a position shifted by about 5 to 10mm in the widthwise direction from the widthwise center of the circuit board 11a.

Since the center of gravity of the vehicle body is a neutral position with respect to disturbances (vibrations) from the vehicle body, if the imaging device 101 is installed at the center of gravity of the vehicle body, the external force applied to the imaging device 101 can be reduced and reliability can be improved. High recognition results can be output.

Therefore, in order to secure the field of view of the image pickup device 101 appropriately and attach the image pickup device 101 so as to be close to the center of gravity of the vehicle body, the image pickup device 101 is arranged at a position extending horizontally forward from the center of the weight of the vehicle body. is desirable. In the case of a typical four-wheeled motor vehicle, this is near the front grille, and in the case of a typical two-wheeled motor vehicle, it is between the headlights and the front wheels.

As described above, according to the image pickup apparatus of this embodiment, even with a structure in which fastening points and anti-vibration members are reduced, vibration of the circuit board in the image pickup apparatus and vibration transmitted to sensors such as image pickup elements Vibration can be reduced together. As a result, it is possible to reduce the optical axis vibration of the imaging device due to the vibration of the vehicle. In addition, it is possible to provide an imaging device in which the possibility of disconnection of circuit elements is low. Furthermore, since the number of fastening parts and vibration-proof members can be reduced, the effective area of the circuit board can be increased, and as a result, it is possible to provide an imaging device that achieves reduction in size and weight.

Next, with reference to FIG. 7, the imaging device 102 according to Example 2 of the present invention will be described. Note that the description of the points in common with the first embodiment will be omitted.

FIG. 7 is an explanatory diagram of the board fixing portion 12 of the imaging device 102 according to this embodiment. In the circuit board 11a of Example 1, in order to obtain the desired natural frequencies f _R and f _L that satisfy

Equations

1 and 2, the position of the board fixing portion 12a is moved rightward (or leftward) by a predetermined amount. In the circuit board 11b of this embodiment, the cantilever portions _13R and _13L have different areas in order to obtain desired natural frequencies fR and fL.

The natural frequencies f _R and f _L of the

cantilever portions

13R and 13L of the circuit board 11b of this embodiment are obtained from the rigidity and weight. Therefore, in the case of the circuit _board _11b having a uniform thickness, as shown in FIG. The frequencies f _R and f _L can be adjusted to a desired magnitude relationship. Specifically, the substrate fixing portion 12a may be arranged at the right-side position similar to that in FIG. The areas S _R and S _L may be varied by moving the substrate fixing portion 12b or the substrate fixing portion 12c toward the front or toward the center.

With such a configuration of this embodiment, the same effect as in the first embodiment can be obtained.

Next, with reference to FIG. 8, the imaging device 103 according to Example 3 of the present invention will be described. Note that the description of the points in common with the first embodiment will be omitted.

FIG. 8 is an explanatory diagram of the board fixing portion 12 of the imaging device 103 according to this embodiment. In the circuit board 11c of this embodiment, the cantilever portions _13R and _13L have different moments in order to obtain the desired natural frequencies fR and fL that satisfy the equations (1) and (2).

As shown in FIG. 8, the weights of the

cantilever portions

13R and 13L are m _R and m _L , respectively, and the distance from the straight line connecting the substrate fixing portions 12 to the center of gravity of the

cantilever portions

13R and 13L is L _R . , _LL , the moment MR of the cantilever 13R is calculated by _mR × _LR , and the moment _ML of the cantilever _13L is calculated by _mL × _LL . When the magnitude relationship of these moments is changed, the magnitude relationship of the natural frequencies f _R and f _L also changes _. By adjusting m _L , the natural frequencies f _R and f _L can be adjusted to a desired magnitude relationship. The weights m _R and m _L of the

cantilever portions

13R and 13L may be adjusted by providing either a weight or a reinforcing plate to the cantilever portion 13 .

Next, with reference to FIG. 9, an imaging device 104 according to Embodiment 4 of the present invention will be described. Note that the description of the points in common with the first embodiment will be omitted.

FIG. 9 is an explanatory diagram of the board fixing portion 12 of the imaging device 104 according to this embodiment. In the circuit board 11a of the first embodiment, the arrangement of the circuit elements 6 was not mentioned. , a relatively large circuit element 6 is arranged on the side connecting the substrate fixing portions 12 a to 12 c , and a relatively small circuit element 6 is arranged on the cantilever portion 13 .

Arranging the large circuit element 6 on the side connecting the board fixing portions 12a to 12c of the circuit board 11d reduces the number of electrical components because the side connecting the board fixing portions 12a to 12c is a portion of the circuit board with high rigidity. Vibration amplitude is reduced, and vibration to the imaging device 2 can be reduced. In particular, a large fourth circuit element 64 such as a capacitor is effective in reducing vibration because it tends to generate a moment and increases the vibration amplitude of the circuit board 11d.

Further, the heat conducting member connected to the housing 1 for heat dissipation of the fifth circuit element 65 (relatively small circuit element such as a power supply circuit) on the cantilever portion 13R is made of gel or rubber to heat dissipation. If it also has a damping function, the vibration amplitude of the circuit board 11d can be reduced, and the temperature rise of the circuit elements and the imaging element 2 can also be reduced. When the temperature of the circuit element 6 and the imaging element 2 increases, the noise component of the signal increases and the measurement accuracy decreases.
In particular, the number of pixels of the imaging device 2 increases as the angle of view of the imaging device 104 increases, and the number of pixels in the imaging device 2 increases, and the amount of heat (power consumption) in the imaging device 2 and the circuit elements 6 increases significantly. As a result, the temperature rise of the imaging element 2 and the circuit element 6 becomes a problem.

Next, with reference to FIG. 10, an imaging device 105 according to Example 5 of the present invention will be described. Note that the description of the points in common with the first embodiment will be omitted.

FIG. 10 is an explanatory diagram of the board fixing portion 12 of the imaging device 105 according to this embodiment. As shown in FIG. 10, the feature of the present embodiment is that consideration is given to vibration suppression when housing fixing portions 7a to 7c of the imaging device 105 are provided in the vicinity of the substrate fixing portions 12a to 12c.

Since the vibration mode of the housing 1 is a vibration mode with the housing fixing portions 7a to 7c as nodes, in the present embodiment, the housing fixing portions 7a to 7c and the substrate fixing portions 12a to 12c of the imaging device 105 are brought close to each other. By doing so, the polygonal region having the housing fixing portions 7a to 7c at each vertex and the polygonal region having the board fixing portions 12a to 12c at each vertex were made to overlap each other. By arranging the housing fixing part 7 and the board fixing part 12 in this way, the influence of the vibration mode of the housing 1 on the vibration mode of the circuit board 11e is suppressed, and the vibration caused by the housing 1 is suppressed. reduce the transmission to

According to this embodiment, in addition to the effect of the first embodiment, the effect of being able to suppress the influence of the vibration mode of the housing 1 is also obtained.

Next, with reference to FIG. 11, an imaging device 106 according to Example 6 of the present invention will be described. Note that the description of the points in common with the first embodiment will be omitted.

FIG. 11 is an explanatory diagram of the board fixing portion 12 of the imaging device 106 according to this embodiment. In the first embodiment, the board fixing portions 12 are provided at three locations on the circuit board 11a. It was a point. When adopting this configuration, the

substrate fixing portions

12a and 12b are provided so that the natural frequency f _R of the cantilever portion 13R on the image sensor 2 side is higher than the natural frequency f _L of the other cantilever portion 13L. In other words, the board fixing portion satisfies the relationship of _S _L >SR so that the areas S _R and S _L of the

cantilever portions

13R and 13L are smaller than the area S _R of the cantilever portion 13R on the image sensor 2 side. 12a and 12b are arranged.

Note that the housing 1 of the present embodiment is provided with a protrusion 8 for contacting the left end of the circuit board 11f. The projection 8 functions as a positioning pin for the circuit board 11f, and not only improves the mounting accuracy of the circuit board 11f, but also contributes to reducing the vibration amplitude of the

cantilever portions

13R and 13L. The same effect as the first embodiment can be obtained also by the configuration of .

Next, an imaging device 107 according to Embodiment 7 of the present invention will be described with reference to FIGS. Note that the description of the points in common with the first embodiment will be omitted.

FIG. 12 is a see-through perspective view of the imaging device 107 according to this embodiment. FIG. 13 is an explanatory diagram of the substrate fixing portion 12 of the imaging device 100Y of the comparative example. FIG. 14 is an explanatory diagram of the board fixing portion 12 of the imaging device 100Z of the comparative example. FIG. 15 is an explanatory diagram of the substrate fixing portion 12 of the imaging device 107 according to this embodiment.

As shown in FIG. 12, the imaging apparatus 107 of this embodiment includes a right imaging board 3R on which a right imaging element 2R is mounted, a left imaging board 3L on which a left imaging element 2L is mounted, and a plurality of circuit elements 6. It has a circuit board 11g, and a housing 1A that accommodates the right imaging board 3R, the left imaging board 3L, and the circuit board 11g. A plurality of circuit elements 6 are mounted on the circuit board 11g.

The right imaging element 2R is attached to the housing 1A as a set of a right imaging module 5R having a right imaging element holder (not shown) on which a right imaging substrate 3R and a right lens 4R are mounted. Similarly, the left imaging device 2L is attached to the housing 1A as a set of a right imaging module 5L having a second imaging device holder on which a left imaging substrate 3L and a left lens 4L are mounted. By attaching the cover to the housing 1A, the imaging device 107 is surrounded by the housing 1A and the cover. Enclosing the housing 1A with a metal such as aluminum die-cast and enclosing the cover with a metal such as an aluminum plate ensures dust resistance, countermeasures against electromagnetic fields, and improves heat dissipation. Electrical connection between the vehicle and the imaging device 107 is performed by connecting wiring to an internal electrical connector through an opening (not shown) in the rear surface of the housing 1A.

Here, in the imaging device 107 (stereo camera) of the present embodiment, the right imaging module 5R and the left imaging module 5L capture an image of the front, extract a feature point common to both images from a pair of image information, An integrated circuit performs a process of determining the number of pixels (parallax) in which the positions of the feature points are displaced between the pair of images, and calculates the distance. Therefore, if there is a deviation other than the original parallax between the pair of images, an error will occur in the distance measurement result. In addition, as the imaging device 107 has improved performance such as widening of the angle of view, high precision, and high-speed compatibility, the allowable amount of misalignment has become smaller, and it has become necessary to reduce the misalignment of the optical axis. As a cause of the deviation, there is an optical axis deviation due to thermal deformation caused by a difference in the amount of expansion of each component when the temperature rises due to sunlight, heat generation inside the device, or the like.

In many conventional imaging devices, the imaging module 5 is directly attached to the housing 1A, as shown in FIG. The circuit board 11Y is also attached to the housing 1A with screws or the like, and the housing 1A and the circuit board 11Y normally use materials having different coefficients of linear expansion. Assuming that the coefficient of linear expansion is larger than that of the circuit board 11Y, when the temperature of the imaging device 100Y rises, the expansion of the circuit board 11Y is smaller than the expansion of the housing 1A in the left-right (z-axis) direction. A force acts toward the center from the circuit board 11Y to the board fixing portions 12a to 12d, and the housing 1A is deformed. Therefore, the optical axis of each imaging module attached to the housing 1A is tilted. This inclination of the imaging module is called an optical axis deviation, and when the optical axis deviation occurs, the accuracy of measuring the distance and direction to the object decreases. In order to solve such a problem, it is preferable to flexibly fix the circuit board 11Y to the board fixing portions 12a to 12d of the circuit board 11Y with respect to the housing 1A with rubber or the like. Up.

On the other hand, as in the comparative example shown in FIG. 14, the positions of the board fixing portions 12a to 12d of the circuit board 11Z with respect to the housing 1A are fixed near the center between the right imaging element 2R and the left imaging element 2L (see FIG. 14). 14), the force acting from the circuit board 11Z toward the center is reduced, and the shift of the optical axis can be reduced.

However, in the configuration of the comparative example of FIG. 14, the

cantilever portions

13R and 13L outside the polygonal region having the substrate fixing portions 12a to 12d at the vertices are generated, and the disturbance such as vibration to the image pickup device 100Z is caused. The

cantilever portions

13R and 13L are likely to vibrate in a bending mode or the like, and the

cantilever portions

13R and 13L resonate as shown in the vibration mode on the lower side of FIG. When the vibration of the circuit board 11Z causes the vibration of the right imaging element 2R and the left imaging element 2L, a difference in the amount of vibration occurs in the image, resulting in a difference in distance and speed, resulting in a decrease in measurement accuracy. In addition, as the imaging apparatus 100Z has improved performance such as widening of the angle of view, high accuracy, and high-speed compatibility, the allowable amount of deviation against vibration has become smaller, and it has become necessary to reduce the vibration of the imaging apparatus 100Z.

In addition, the vibration of the

cantilever portions

13R and 13L repeatedly strains the circuit elements mounted on the circuit board 11Z, and there is a possibility that wire breakage may occur in the solder portions. Therefore, it became necessary to reduce the vibration of the circuit board 11Z as well. Providing a vibration-isolating member for general vibration prevention causes an increase in the size of the apparatus, an increase in the number of parts, and a complicated manufacturing process. In addition, if the device is provided with a vibration isolation member, the position and speed of the target object are recognized based on the difference in the image due to time taken from the front side, especially when moving at high speed. is 0.1 degrees or less when converted to an angle, and the vibration mode of the vibration isolation member causes positional deviation in the image, resulting in errors in speed and position. . From the viewpoint of measurement accuracy, it is very important to maintain the mounting position of the vehicle body and the sensor. Usually, the vehicle body and the sensor are firmly fixed, and the vibration of the vehicle body is transmitted to the imaging device. Therefore, a resonance mode of a circuit board or the like, which is a component in the apparatus, is transmitted to the sensor through the housing 1A or the like, which may cause positional deviation in the image and error in speed and position.

In order to solve such problems, in the circuit board 11g of the present embodiment, as shown in FIG. The natural frequencies of these

cantilever portions

13R and 13L are made different from each other. Alternatively, the length d _R of the cantilever portion of the cantilever portion 13R is made longer than the length dL of the cantilever portion of the cantilever portion _13L . Alternatively, the width w _R of the cantilever portion of the cantilever portion 13R is made longer than the width w _L of the cantilever portion of the cantilever portion 13L. Alternatively, the area of the cantilever portion of the cantilever portion 13R is made larger than the area of the cantilever portion of the cantilever portion 13L. Alternatively, it consists of the weight mm _R of the cantilever portion of the cantilever portion 13R and the distances L _R and L _L from the side connecting the plurality of adjacent substrate fixing portions 12a to 12d to the center of gravity of the

cantilever portions

13R and 13L. Moments MM _R and MM _L are made different for each cantilever portion 13 .

By making the natural frequency of each cantilever portion 13 of the circuit board 11g different as shown in the lower side of FIG. Since the overlapping root state in which the vibration modes match is eliminated, the vibration amplitude of the vibration modes becomes small, and the vibrations to the right imaging element 2R and the left imaging element 2L can be reduced. By reducing the vibration amplitude, the position and speed of the object can be measured with high precision, and repeated distortion of the circuit elements mounted on the circuit board 11g is also reduced. , the imaging device 107 . In addition, no additional parts such as rubber are required for fixing the circuit board 11g, and the imaging apparatus 107 is inexpensive and highly reliable with no optical axis deviation and high measurement accuracy.

Next, with reference to FIG. 16, an imaging device 108 according to embodiment 8 of the present invention will be described. Note that the description of the points in common with the seventh embodiment will be omitted.

FIG. 16 is an explanatory diagram of the board fixing portion 12 of the imaging device 108 according to this embodiment. In the circuit board 11h of the present embodiment, the

board fixing parts

12a and 12b are arranged with the front end separated by a distance La rightward from the center of the circuit board 11h in the left-right direction so that each cantilever part 13 has a different natural frequency. The

board fixing portions

12c and 12d are arranged at the front and rear ends of the circuit board 11h at a distance La from the center of the circuit board 11h in the left-right direction. In FIG. 16, the

board fixing parts

12a and 12b on the right side are arranged in the front and back direction, and the

board fixing parts

12c and 12d on the left side are arranged in the front and back direction. The substrate fixing portions 12 may be arranged in a trapezoidal shape so that the total distance between the left and right portions is different.

With the configuration of this embodiment, the same effects as those of the seventh embodiment can be obtained.

Next, with reference to FIG. 17, an imaging device 109 according to Example 9 of the present invention will be described. In addition, in the present embodiment, description of common points with the seventh embodiment will be omitted.

FIG. 17 is an explanatory diagram of the board fixing parts 12a to 12d of the imaging device 109 according to this embodiment. In the circuit board 11i of this embodiment as well, the board fixing parts 12a to 12d are arranged so that the

cantilever parts

13R and 13L have different natural frequencies. Specifically, the board fixing portion 12a is arranged at the front end position separated by a distance La rightward from the center in the left-right direction of the circuit board 11i, and the board fixing portion 12c is arranged at a distance Lb leftward from the center. placed in the front end position. Further, the board fixing portion 12b is arranged at the rear end position separated by the distance Lc in the right direction from the center in the left-right direction of the circuit board 11i, and after the board fixing portion 12d is separated from the center in the left direction by the distance Lc. placed at the end.

As a result, the difference in the natural frequencies of the

cantilever portions

13R and 13L of the circuit board 11i eliminates the overlapped state in which the two vibration modes coincide, the vibration amplitude of the vibration mode decreases, and the right imaging element 2R, Vibration to the left imaging element 2L can be reduced.

In the circuit board 11i of this embodiment, a female connector 66 for signal input/output and power supply is provided on the left side of the board fixing portion 12b on the right rear side. As a result, the board fixing portion 12a on the front right side and the female connector 66 are aligned in the inserting/removing direction of the male connector (not shown). Stress and strain are reduced, and damage such as cracks can be prevented.

It should be noted that the present invention is not limited to the above embodiments, and includes various modifications and combinations within the scope of the gist. Moreover, the present invention is not limited to those having all the configurations described in the above embodiments, and includes those having some of the configurations omitted.

100X to 100Z: imaging device of comparative example, 101 to 109: imaging device of the present invention, 1, 1A: housing, 2: imaging device, 2R: right imaging device, 2L: left imaging device, 3: imaging substrate, 3R Right imaging substrate 3L Left imaging substrate 4 Lens

4R Right lens

4L Left lens 5 Imaging module 5R Right imaging module 5L Left imaging module 6 Circuit element 61 Third 1 circuit element (FPGA) 62... 2nd circuit element (memory) 63... 3rd circuit element (MPU) 64... 4th circuit element (capacitor) 65... 5th circuit element (power supply circuit) 66... DESCRIPTION OF SYMBOLS Female connector 7...Case fixing part 8...Protrusion 11...Circuit board 12...Board fixing part 13...Cantilever part

Claims

An imaging device, a substrate for processing an image, and a housing in which the substrate is fixed by a plurality of substrate fixing portions,
The substrate has a plurality of cantilever portions that are regions outside a polygonal region having the substrate fixing portion at each vertex, and each of the cantilever portions has a different natural frequency. imaging device.
The imaging device according to claim 1,
The substrate is characterized in that the moment, which is the weight of the cantilever portion and the distance from the side connecting the plurality of adjacent substrate fixing portions to the center of gravity of the cantilever portion, differs for each of the cantilever portions. imaging device.
The imaging device according to claim 1,
The imaging device, wherein the substrate has different areas of the cantilever portions for each of the cantilever portions.
The imaging device according to claim 1,
The imaging device, wherein the width of each of the cantilever portions of the substrate is different for each cantilever portion.
The imaging device according to claim 1,
The imaging device, wherein the substrate has a different length of the cantilever portion for each cantilever portion.
The imaging device according to claim 1,
An image pickup apparatus, wherein the substrate has three substrate fixing portions, and the two substrate fixing portions are arranged on the image pickup element side.
The imaging device according to claim 1,
The imaging apparatus according to claim 1, wherein the substrate has an area of the cantilever portion on the imaging element side smaller than that of other cantilever portions.
The imaging device according to claim 1,
An image pickup apparatus, wherein circuit elements are arranged on a side of the substrate connecting the substrate fixing portions at the plurality of locations.
The imaging device according to claim 1,
The image pickup apparatus according to claim 1, wherein the substrate has a circuit element provided with a heat-conducting member on the cantilever portion.
The imaging device according to claim 1,
The housing has a housing fixing portion for fixing to the vehicle body,
An imaging device, wherein a polygonal area having the substrate fixing portion at each vertex and a polygonal area having the housing fixing portion at each vertex overlap each other.
The imaging device according to claim 1,
The board has a connector on the rear side,
The connector is arranged between the left and right board fixing parts on the rear side of the board and is aligned with one of the board fixing parts and the board fixing part on the front side of the board in the front-rear direction. An imaging device characterized by: