Imaging device

Abstract

To provide an imaging device capable of reducing vibration of a circuit board in the imaging device and vibration to a sensor such as an image sensor even with a structure that reduces the number of fastening points and anti-vibration members while reducing the size.SOLUTION: The imaging device includes: an image sensor; a board that processes images; and a housing where the board is fixed by the board fixing part at multiple points. The board has multiple cantilevers that are the area outside a polygonal area with the board fixing points at each vertex, and the natural frequency of the cantilever is different in each cantilever.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] 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 an area ahead of the vehicle. [Background technology]

[0002] In recent years, in order to realize a safe and comfortable automobile society, vehicle driver assistance systems such as four-wheeled automobiles and motorcycles are increasingly being installed. Among these, development of systems that pursue safety, convenience, and comfort for drivers and passengers is progressing, such as collision damage mitigation braking devices that automatically decelerate before colliding with an obstacle, automatic distance control devices that automatically track the preceding vehicle while maintaining a substantially constant distance according to the speed, lane departure prevention devices, sign recognition, etc. Such systems use external recognition devices that recognize vehicles, pedestrians, etc. and measure the distance to the target object.

[0003] For imaging devices, which are a type of external recognition device, a clear field of view is essential to accurately recognize the outside world. Imaging devices are subjected to vibrations caused by the vehicle's running, which can affect the image sensor and cause the image to vibrate, making the recognition of the outside world unclear. Also, the vibrations of the device can affect the circuit board, causing repeated distortion of the circuit elements mounted on the circuit board and possibly causing breaks in the solder joints.

[0004] Here, Patent Document 1 is known as a conventional technique for preventing disconnection due to repeated strain applied to circuit elements of a circuit board in an environment where the circuit board is subjected to vibrations caused by running of a vehicle. For example, the abstract of this document describes the problem as "to prevent disconnection in electronic components without installing vibration-proof members in an electronic device including an electronic board on which electronic components having multiple terminals are mounted and a support for supporting the electronic board," and discloses an electronic device as a solution to this problem, in which "the electronic board 3 and the terminal block 2 are fastened together such that the vibration mode of the electronic board 3 during resonance is a vibration mode capable of preventing disconnection in the electronic components 3b." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-161547 A Summary of the Invention [Problem to be solved by the invention]

[0006] Specifically, as described in paragraph 0018 of the document, the electronic device of Patent Document 1 is a power conversion device mounted on a vehicle such as a hybrid vehicle or an electric vehicle, and supplies power to a drive motor. In this power conversion device, as illustrated in Figs. 1 and 3 of the document, many screws 4 are used to fix an electronic board 3 to a terminal block 2, and the number of fastening points P of the electronic board 3 is increased, so that the electronic board 3 is in a vibration mode that can be suppressed. For this reason, the power conversion device of Patent Document 1 has a structure in which the area of ​​the fastening parts occupying the area of ​​the electronic board is large, which results in an increase in the size of the electronic board, making it unsuitable for miniaturization. However, for an in-vehicle power conversion device for which miniaturization is not so strongly required, such an increase in the board area would not be considered a problem.

[0007] In contrast, there is a strong demand for miniaturization of imaging devices, which are often installed on the upper part of the inner surface of the windshield, so as not to obstruct the driver's field of vision as much as possible. Therefore, it is not desirable to directly apply the vibration mode suppression structure of Patent Document 1, which would result in an increase in the size of the electronic board and, ultimately, the size of the imaging device.

[0008] In addition, a structure in which an anti-vibration member is provided on an electronic board is known as a structure for suppressing vibration of the electronic board without using the vibration mode suppression structure of Patent Document 1. However, the addition of the anti-vibration member leads to an increase in the size of the imaging device, an increase in the number of parts, and a complicated manufacturing process.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an imaging device that reduces both the vibration of the circuit board within the imaging device and the vibration transmitted to sensors such as image sensors, even in a structure that reduces fastening points and vibration-proof members. [Means for solving the problem]

[0010] The present application includes multiple means for solving the above problem, and one example is a housing to which the substrate is fixed at multiple substrate fixing portions, the housing having an image sensor, a substrate for processing images, and the substrate having multiple cantilever portions which are areas outside a polygonal area having the substrate fixing portions at each vertex, and the natural frequency of each cantilever portion being different, thereby achieving the above object. Effect of the Invention

[0011] According to the imaging device of the present invention, even with a structure that reduces fastening points and vibration-proof members, it is possible to reduce both the vibration of the circuit board within the imaging device and the vibration transmitted to sensors such as imaging elements. As a result, it is possible to reduce the optical axis vibration of the imaging device caused by vehicle vibration, and therefore it is possible to provide an imaging device with high recognition accuracy and high reliability of the outside world. It is also possible to provide an imaging device with a low possibility of circuit element breakage. Furthermore, since it is possible to reduce the fastening parts and vibration-proof members, it is possible to increase the effective area of ​​the circuit board, and as a result, it is possible to provide an imaging device that is smaller and lighter in weight. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an external perspective view of an imaging apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of the imaging device according to the first embodiment. [Diagram 3] FIG. 13 is a perspective view of an imaging device of a comparative example. [Figure 4] 6A and 6B are diagrams illustrating vibration modes of a circuit board of an imaging device according to a comparative example. [Diagram 5] FIG. 3 is an explanatory diagram of a substrate fixing part of the imaging device according to the first embodiment. [Figure 6] 5A to 5C are diagrams illustrating the vibration reduction effect of the imaging apparatus according to the first embodiment. [Figure 7] FIG. 11 is an explanatory diagram of a substrate fixing part of the imaging device according to the second embodiment. [Figure 8] FIG. 11 is an explanatory diagram of a substrate fixing portion of the imaging device according to the third embodiment. [Figure 9] FIG. 13 is an explanatory diagram of a substrate fixing part of the imaging device according to the fourth embodiment. [Figure 10] FIG. 13 is an explanatory diagram of a substrate fixing part of the imaging device according to the fifth embodiment. [Figure 11] FIG. 13 is an explanatory diagram of a substrate fixing part of the imaging device according to the sixth embodiment. [Figure 12] FIG. 13 is a perspective view of an imaging device according to a seventh embodiment. [Figure 13] FIG. 4 is an explanatory diagram of a substrate fixing portion of an imaging device of a comparative example. [Figure 14] FIG. 4 is an explanatory diagram of a substrate fixing portion of an imaging device of a comparative example. [Figure 15] FIG. 23 is an explanatory diagram of a substrate fixing part of the imaging device according to the seventh embodiment. [Figure 16] FIG. 23 is an explanatory diagram of a substrate fixing part of the imaging device according to the eighth embodiment. [Figure 17] FIG. 13 is an explanatory diagram of a substrate fixing part of the imaging device according to the ninth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an imaging device according to the present invention will be described with reference to the drawings. Note that components with the same reference numerals have the same functions, and therefore, unless otherwise specified, duplicated description will be omitted. EXAMPLES

[0014] First Embodiment First, an imaging device 101 according to a first embodiment of the present invention will be described with reference to FIGS.

[0015] 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 two-wheeled motor vehicle, 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, an orthogonal coordinate system is set, which is made up of an x-axis whose positive direction is the optical axis direction (forward direction) of the imaging device 101, a y-axis whose positive direction is the upward direction of the imaging device 101, and a z-axis whose positive direction is the rightward direction of the imaging device 101.

[0016] This imaging device 101 is mounted on a vehicle with the positive direction of the x-axis aligned with the vehicle's traveling direction and the negative direction of the y-axis aligned with the downward direction of the vehicle, and by continuously capturing images in the direction of the vehicle's traveling, it recognizes the position and speed of objects (other vehicles, pedestrians, etc.) in the vehicle's traveling direction based on changes in the image over time.

[0017] The imaging device 101 shown in FIG. 1 and FIG. 2 is a monocular imaging device that houses an imaging board 3 with an imaging element 2 mounted thereon and a circuit board 11a with multiple circuit elements 6 (61-65) mounted thereon in a metal (e.g., aluminum die-cast) housing 1 with an open bottom and back and a heat dissipation fin on the top, and has a lens 4 protruding forward from the top of the housing 1. The imaging element 2, the imaging board 3, and the lens 4 are integrated as an imaging module 5 using a holder (not shown). The circuit board 11a is provided with multiple board fixing parts 12 (12a-12c) for fixing the circuit board 11a to the housing 1. The board fixing parts 12 may fix the circuit board 11a to the housing 1 using, for example, screws or adhesive. Furthermore, the front face and the rear parts of the left and right sides of the housing 1 are provided with housing fixing parts 7 (7a-7c) used when fixing the housing 1 to a vehicle.

[0018] Here, the circuit elements 6 mounted on the circuit board 11a are, for example, as follows. The first circuit element 61 is an FPGA (Field Programmable Gate Array) that processes the image signal output by the imaging element 2, and is a circuit element that generates a large amount of heat and requires thermal conduction to the case 1. The second circuit element 62 is a circuit element such as a memory used for temporary storage of data. The third circuit element 63 is a circuit element such as an MPU (Micro Processing Unit) that performs various types of signal processing. 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 multiple circuit elements 6 are not limited to these examples, and some may be omitted, or other types of circuit elements may be added.

[0019] After the imaging module 5 and the circuit board 11a are mounted, the openings on the bottom and back of the housing 1 are closed with a cover (not shown) such as an aluminum plate with wiring holes. Therefore, the circuit board 11a of the imaging device 101 and the vehicle's ECU (Electronic Control Unit) can be electrically connected via the wiring holes of the cover, and the output of the circuit board 11a can be reflected in vehicle control by the ECU.

[0020] In recent years, imaging devices have been required to be further miniaturized, and in order to miniaturize imaging devices, it is important to miniaturize the built-in circuit board. As a measure for miniaturizing the circuit board, there is a method of reducing the number of board fixing parts 12 in order to increase the board area on which the circuit elements 6 can be mounted (hereinafter referred to as the effective board area). By reducing the number of board fixing parts 12, the circuit board 11a can be miniaturized while maintaining the effective board area of ​​the circuit board 11a, so that the housing 1 covering the circuit board 11a and the entire imaging device 101 can be miniaturized. In particular, in the case of a monocular imaging device in which the area of ​​the circuit board 11a is small, such as the imaging device 101 of this embodiment, the area ratio of the board fixing parts 12 to the circuit board 11a is large, so reducing the number of board fixing parts 12 is very effective for miniaturization.

[0021] When the board fixing portion 12 of the circuit board 11a is reduced, a problem occurs in that vibrations such as bending mode are easily generated in the cantilever portion 13 of the circuit board 11a. For example, in the case of the circuit board 11a of FIG. 2, the cantilever portions 13R and 13L are formed in a substantially triangular shape outside the triangular region having the board fixing portions 12a to 12c as vertices, so that the cantilever portions 13R and 13L may vibrate due to vibrations caused by the running of the vehicle. When the cantilever portions 13R and 13L vibrate, the vibrations are propagated to the image pickup element 2, and disturbances equivalent to the vibrations are recorded in the continuously captured images, so that the measurement accuracy of the distance and speed of the object, which are the output of the image pickup device 101, decreases. In recent years, as the image pickup device 101 has become more highly functional, such as with a wider angle of view, higher accuracy, and higher speed, the vibration tolerance of the image pickup element 2 has become smaller, and therefore, the need to reduce the vibration of the image pickup device 101 has become stronger.

[0022] Furthermore, if repeated stress is applied to the circuit element 6 mounted on the circuit board 11a due to the vibration of the cantilevers 13R and 13L, there is a possibility that disconnection may occur in the soldered parts, etc. Therefore, from the viewpoint of preventing disconnection, it is necessary to reduce the vibration of the cantilevers 13R and 13L of the circuit board 11a.

[0023] <Circuit Board 11X of Imaging Device 100X of Comparative Example> Here, the principle of vibration generation of the cantilevers 13R and 13L in the circuit board 11X built into the imaging device 100X of the comparative example will be described with reference to the see-through perspective view of Fig. 3 and the vibration mode simulation diagram of Fig. 4. Note that, in the following, overlapping explanations of points common to Figs. 1 and 2 will be omitted.

[0024] In conventional imaging devices (not shown), the circuit board is often fixed to the housing by board fixing parts 12 provided at the four corners of the circuit board. In contrast, in a circuit board 11X of a comparative example shown in Fig. 3, the circuit board 11X is fixed to the housing 1 using board fixing parts 12a to 12c at three locations. In this way, in the circuit board 11X of the comparative example, the effective board area can be expanded by the amount of board fixing part 12 reduced by one location compared to the conventional example, and therefore the circuit area can be reduced by the amount of the expansion of the effective board area.

[0025] Since products such as imaging devices are often designed symmetrically, in this comparative example, following the conventional design policy, the board fixing part 12a at the front center of the circuit board 11X, the board fixing part 12b at the rear right end, and the board fixing part 12c at the rear left end are arranged symmetrically to form an isosceles triangular area with each of the vertices on the circuit board 11X. When such a circuit board 11X is used, the cantilevers 13R and 13L of the same shape outside the isosceles triangular area may resonate with multiple roots in a vibration mode of the same frequency, and the vibration amplitude of each may become large, as shown in the vibration mode simulation diagram of FIG. 4. Then, when the large vibration of the cantilevers 13R and 13L is transmitted to the imaging element 2 and the imaging position change equivalent to the vibration is reflected in each image continuously captured by the imaging element 2, an error occurs in the position, distance, and speed of the object calculated based on the continuously captured images, resulting in a decrease in the measurement accuracy of the imaging device.

[0026] Furthermore, the resonance of the cantilevers 13R and 13L as shown in FIG. 4 repeatedly applies large strain to the circuit elements mounted on the circuit board 11X, which may cause breaks in the soldered parts or the like.

[0027] In order to solve these problems, it is generally effective to provide a vibration-proofing member to prevent the circuit board 11X from vibrating. However, in this case, the addition of the vibration-proofing member leads to an increase in the size of the imaging device, an increase in the number of parts, and a complication of the manufacturing process. In addition, when the imaging device is provided with a vibration-proofing member, the image difference is converted to an angle of 0.1 degrees or less when recognizing a distant object, particularly when moving at high speed, because the front side is imaged and the position and speed of the object are recognized based on the difference in the image over time. In addition, the vibration mode of the vibration-proofing member causes a position shift in the image, which causes an error in the calculation of the speed and position of the object. From this viewpoint, too, a structure in which a vibration-proofing member is provided is undesirable. In addition, maintaining the mounting positions of the vehicle body and the sensor is very important from the viewpoint of maintaining the measurement accuracy, and since the vehicle body and the sensor are usually firmly fixed, the vibration of the vehicle body is directly transmitted to the imaging device. Therefore, the resonance mode of the circuit board, which is a component in the imaging device, is transmitted to the sensor through the housing, etc., causing a position shift in the image, which may cause errors in the speed and position.

[0028] <Circuit Board 11a of Imaging Device 101 of this Embodiment> In order to address the problems caused by the configuration of the comparative example as described above, in the circuit board 11a of this embodiment, the board fixing part 12a, which is located at the front center in the comparative example shown in Fig. 4, is moved slightly to the right of the center as shown in Fig. 5. As a result, the cantilever parts 13R and 13R can be made asymmetrical, so that the frequency of the vibration mode of the cantilever part 13R (natural frequency f R ) and the frequency of the vibration mode of the cantilever 13L (natural frequency f L 5, the substrate fixing portion 12a is disposed on the right side, but it may be disposed on the left side.

[0029] Natural frequency f of the cantilevers 13R and 13L R ,f L6, in the circuit board 11X of the comparative example, a double root state in which the two vibration modes coincide occurs, whereas in the circuit board 11a of the present embodiment, the double root state is eliminated, and the vibration amplitude of the vibration mode is reduced in both the cantilevers 13R and 13L. This reduces the vibration conduction from the cantilevers 13R and 13L to the imaging element 2. In addition, in the circuit board 11a of the present embodiment, the distance from the imaging element 2 to the cantilevers 13R and 13L is lengthened by providing two board fixing parts 12b and 12c on the imaging element 2 side, and this structure also reduces the vibration conduction from the cantilevers 13R and 13L to the imaging element 2. In this way, in the imaging device 101 of the present embodiment, the vibration conduction from the cantilevers 13R and 13L to the imaging element 2 is reduced, so that the position and speed of the object can be measured with high accuracy from the images continuously captured by the imaging element 2.

[0030] Furthermore, by suppressing the vibration of the cantilevers 13R and 13L, the repeated strain applied to the circuit element 6 mounted on the circuit board 11a is also reduced, and breakage of the soldered portion around the circuit element 6 can be suppressed.

[0031] Furthermore, by reducing the number of board fixing portions 12, the effective board area of ​​the circuit board 11a can be expanded. Therefore, if the number of circuit elements 6 mounted is the same, the circuit board 11a and the housing 1 can be made smaller, thereby enabling the imaging device 101 to be made smaller and lighter.

[0032] In this case, in consideration of vibration damping, in order to prevent the vibration mode of the cantilever portions 13R and 13L from becoming multiple roots, the natural frequency f R ,f L The difference between the natural frequency f and the natural frequency f should be set to about 20 to 30 Hz. R ,f LIt is sufficient to arrange substrate fixing portion 12a at a position that satisfies the relationship of formulas 1 and 2. Note that the position of substrate fixing portion 12a that satisfies the relationship of formulas 1 and 2 cannot be generally determined because it is affected by the rigidity of circuit substrate 11a and the arrangement of circuit elements 6 on circuit substrate 11a, but it is, for example, a position shifted by 10 to 20% in relation to the width from the center in the width direction of circuit substrate 11a, or a position shifted by about 5 to 10 mm in the width direction from the center in the width direction of circuit substrate 11a.

[0033]

number

[0034]

number

[0035] In addition, since the center of gravity of the vehicle body is a neutral position with respect to external 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 highly reliable recognition results can be output.

[0036] Therefore, in order to mount the imaging device 101 close to the center of gravity of the vehicle body while ensuring an appropriate field of view for the imaging device 101, it is desirable to place the imaging device 101 at a position extending horizontally forward from the center of gravity of the vehicle. This would be near the front grille in the case of a typical four-wheeled automobile, and between the headlight and the front wheel in the case of a typical two-wheeled automobile.

[0037] As described above, according to the imaging device of this embodiment, even with a structure that reduces fastening points and vibration-proof members, it is possible to reduce both the vibration of the circuit board in the imaging device and the vibration transmitted to sensors such as imaging elements. As a result, it is possible to reduce the optical axis vibration of the imaging device caused by vehicle vibration, and therefore it is possible to provide an imaging device with high recognition accuracy of the outside world and high reliability. It is also possible to provide an imaging device with a low possibility of circuit element breakage. Furthermore, since it is possible to reduce the fastening parts and vibration-proof members, it is possible to increase the effective area of ​​the circuit board, and as a result, it is possible to provide an imaging device that is smaller and lighter in weight. EXAMPLES

[0038] Second Embodiment Next, an imaging device 102 according to a second embodiment of the present invention will be described with reference to Fig. 7. Note that a description of points in common with the first embodiment will be omitted.

[0039] 7 is an explanatory diagram of the board fixing part 12 of the imaging device 102 according to the present embodiment. In the circuit board 11a of the first embodiment, the desired natural frequency f R ,f L In order to obtain the desired natural frequency f, the position of the board fixing part 12a is moved to the right (or left) by a predetermined amount. R ,f L In order to obtain this, the areas of the cantilevers 13R and 13L are made different.

[0040] The natural frequency f of the cantilever portions 13R and 13L of the circuit board 11b of this embodiment R ,f L Therefore, if the circuit board 11b has a uniform thickness, the area S of the cantilever portions 13R and 13L is R ,S L By providing the substrate fixing parts 12a to 12c so that the natural frequency f R ,f L Specifically, the substrate fixing portion 12a may be disposed at a position shifted to the right as in FIG. 5, or, although not shown, the substrate fixing portion 12a may be disposed at the center front as in FIG. 3, and the substrate fixing portion 12b or the substrate fixing portion 12c may be moved forward or toward the center to adjust the area S R ,S L may be different.

[0041] With such a configuration of this embodiment, it is possible to obtain the same effects as those of the first embodiment. EXAMPLES

[0042] Next, an imaging device 103 according to a third embodiment of the present invention will be described with reference to Fig. 8. Note that a description of points in common with the first embodiment will be omitted.

[0043] 8 is an explanatory diagram of the board fixing part 12 of the imaging device 103 according to this embodiment. In the circuit board 11c of this embodiment, the desired natural frequency f R ,f L In order to obtain this, the moments of the cantilevers 13R and 13L are made different.

[0044] As shown in FIG. 8, the weights of the cantilevers 13R and 13L are m R ,m L The distance from the line connecting the substrate fixing parts 12 to the center of gravity of the cantilever parts 13R and 13L is L R ,L L When this is the case, the moment M of the cantilever 13R is R m R ×L R The moment M of the cantilever 13L is calculated as L m L ×L L By changing the magnitude relationship of these moments, the natural frequency f R ,f L The magnitude relationship of the weights m of the cantilevers 13R and 13L also changes, so the position of the substrate fixing part 12 can be adjusted. R ,m L By adjusting the natural frequency f R ,f L The weights m of the cantilevers 13R and 13L can be adjusted to the desired magnitude relationship. R ,m L To adjust the height, a weight or a reinforcing plate may be provided on the cantilever portion 13.

[0045] With such a configuration of this embodiment, it is possible to obtain the same effects as those of the first embodiment. EXAMPLES

[0046] Next, an imaging device 104 according to a fourth embodiment of the present invention will be described with reference to Fig. 9. Note that a description of points in common with the first embodiment will be omitted.

[0047] 9 is an explanatory diagram of the board fixing part 12 of the imaging device 104 according to this embodiment. In the circuit board 11a of the embodiment 1, no mention was made of the arrangement of the circuit elements 6, but in the circuit board 11d of this embodiment, attention is paid to the size of each circuit element 6, and as shown in FIG. 9, a relatively large circuit element 6 is arranged on the side connecting the board fixing parts 12a to 12c, and a relatively small circuit element 6 is arranged on the cantilever part 13.

[0048] By arranging the large circuit element 6 on the side connecting the board fixing parts 12a to 12c of the circuit board 11d, the side connecting the board fixing parts 12a to 12c is a part of the circuit board with high rigidity, so that the vibration amplitude of the electrical components is reduced, and vibration to the imaging element 2 can be reduced. In particular, the large fourth circuit element 64 such as a capacitor is effective in reducing vibration because it is prone to generate a moment and increases the vibration amplitude of the circuit board 11d.

[0049] Furthermore, if the heat conductive member connected to the housing 1 for dissipating heat of the fifth circuit element 65 (a relatively small circuit element such as a power supply circuit) on the cantilever portion 13R is made gel-like or rubber-like and has both the functions of dissipating heat and attenuation, the vibration amplitude of the circuit board 11d can be reduced and the temperature rise of the circuit element and the image sensor 2 can also be reduced. If the temperature of the circuit element 6 or the image sensor 2 increases, the noise components of the signal increase and the measurement accuracy decreases, so it is necessary to reduce the temperature of the circuit element and the image sensor 2. In particular, as the image sensor 104 improves in performance, such as increasing the angle of view, high accuracy, and high speed, the number of pixels of the image sensor 2 increases, and the amount of heat (power consumption) of the image sensor 2 and the circuit element 6 increases significantly, and the temperature rise of the image sensor 2 and the circuit element 6 becomes an issue.

[0050] With such a configuration of this embodiment, it is possible to obtain the same effects as those of the first embodiment. EXAMPLES

[0051] Next, an imaging device 105 according to a fifth embodiment of the present invention will be described with reference to Fig. 10. Note that a description of points in common with the first embodiment will be omitted.

[0052] Fig. 10 is an explanatory diagram of the substrate fixing portion 12 of the imaging device 105 according to this embodiment. The feature of this embodiment is that, as shown in Fig. 10, consideration is given to vibration suppression when the housing fixing portions 7a to 7c of the imaging device 105 are provided near the substrate fixing portions 12a to 12c.

[0053] Since the vibration mode of the housing 1 is a vibration mode with the housing fixing parts 7a-7c as nodes, in this embodiment, the housing fixing parts 7a-7c and the board fixing parts 12a-12c of the imaging device 105 are brought close to each other so that a polygonal region having the housing fixing parts 7a-7c as vertices overlaps with a polygonal region having the board fixing parts 12a-12c as vertices. By arranging the housing fixing parts 7 and the board fixing parts 12 in this manner, the influence of the vibration mode of the housing 1 on the vibration mode of the circuit board 11e is suppressed, and the transmission of vibration caused by the housing 1 to the imaging element 2 is reduced.

[0054] According to this embodiment, in addition to the effects of the first embodiment, it is possible to obtain an effect that the influence of the vibration mode of the housing 1 can be suppressed. EXAMPLES

[0055] Sixth embodiment Next, an imaging device 106 according to a sixth embodiment of the present invention will be described with reference to Fig. 11. Note that a description of commonalities with the first embodiment will be omitted.

[0056] 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 positions on the circuit board 11a, but in this embodiment, in order to further increase the effective board area of ​​the circuit board 11f, the board fixing portions 12a and 12b of the circuit board 11f are provided at two positions. When this configuration is adopted, the natural frequency f R The natural frequency of the other cantilever 13L is f L In other words, the area S of the cantilever portions 13R and 13L isR ,S L The area S of the cantilever 13R on the imaging element 2 side is R So that S becomes smaller. L >S R The substrate fixing parts 12a and 12b are arranged so as to satisfy the relationship.

[0057] In addition, the housing 1 of this embodiment is provided with a protrusion 8 for abutting against the left end of the circuit board 11f. This protrusion 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, so that the configuration of this embodiment can also provide the same effects as those of the first embodiment. EXAMPLES

[0058] Seventh embodiment Next, an imaging device 107 according to a seventh embodiment of the present invention will be described with reference to Figs. 12 to 15. Note that a description of commonalities with the first embodiment will be omitted.

[0059] Fig. 12 is a perspective view of an imaging device 107 according to this embodiment. Fig. 13 is an explanatory diagram of a substrate fixing portion 12 of an imaging device 100Y of a comparative example. Fig. 14 is an explanatory diagram of a substrate fixing portion 12 of an imaging device 100Z of a comparative example. Fig. 15 is an explanatory diagram of a substrate fixing portion 12 of an imaging device 107 according to this embodiment.

[0060] 12, the imaging device 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, a circuit board 11g on which a plurality of circuit elements 6 are mounted, and a housing 1A that houses the right imaging board 3R, the left imaging board 3L, and the circuit board 11g inside. A plurality of circuit elements 6 are mounted on the circuit board 11g.

[0061] The right imaging element 2R is attached to the housing 1A as a set with a right imaging module 5R including a right imaging element holder (not shown) on which a right imaging board 3R and a right lens 4R are mounted. Similarly, the left imaging element 2L is attached to the housing 1A as a set with a right imaging module 5L including a second imaging element holder on which a left imaging board 3L and a left lens 4L are mounted. By attaching a cover to the housing 1A, the imaging device 107 is surrounded by the housing 1A and the cover. By surrounding the housing 1A with a metal such as aluminum die casting and the cover with a metal such as an aluminum plate, dustproofness is ensured, and electromagnetic field countermeasures and heat dissipation are also improved. The vehicle and the imaging device 107 are electrically connected by connecting wiring to an internal electrical connector through an opening (not shown) on the rear surface of the housing 1A.

[0062] Here, in the imaging device 107 (stereo camera) of this embodiment, the right imaging module 5R and the left imaging module 5L capture images of the front, extract feature points common to both images from the pair of image information, and perform a process of calculating the number of pixels (parallax) where the positions of the feature points are shifted between the pair of images in an integrated circuit to calculate the distance. Therefore, if there is a shift other than the original parallax between the pair of images, an error will occur in the distance measurement result. In addition, with the improvement in the performance of the imaging device 107, such as a wider angle of view, high accuracy, and high speed response, the allowable amount of shift is reduced, and it is necessary to reduce the optical axis shift. One of the causes of the shift is the optical axis shift due to thermal deformation caused by the difference in the amount of expansion of each part when the temperature rises due to sunlight or heat generation inside the device.

[0063] In many conventional imaging devices, as shown in FIG. 13, the imaging module 5 is directly attached to the housing 1A. The circuit board 11Y is also attached to the housing 1A by screws or the like. The housing 1A and the circuit board 11Y are usually made of materials with different linear expansion coefficients. If we assume that the linear expansion coefficient of the housing 1A is greater than that of the circuit board 11Y, the circuit board 11Y will expand less than the housing 1A in the left-right (z-axis) direction when the temperature of the imaging device 100Y rises, and a force acts from the circuit board 11Y toward the center of the housing 1A on the board fixing parts 12a-12d such as screws, causing the housing 1A to deform. As a result, the optical axis of each imaging module attached to the housing 1A is tilted. This tilt of the imaging module is called optical axis deviation, and if an optical axis deviation occurs, the measurement accuracy of the distance and direction to the object decreases. To address this issue, board fixing portions 12a to 12d of circuit board 11Y may be flexibly fixed to housing 1A using rubber or the like. However, this would increase the number of parts, complicating the manufacturing process and increasing costs.

[0064] On the other hand, as in the comparative example shown in FIG. 14, when the positions of the board fixing portions 12a-12d of the circuit board 11Z are fixed to the housing 1A toward the center between the right imaging element 2R and the left imaging element 2L (j in FIG. 14 is made smaller) to form a symmetrical configuration, the force acting from the circuit board 11Z toward the center is reduced, and the optical axis deviation can be reduced.

[0065] However, in the configuration of the comparative example of FIG. 14, the cantilevers 13R and 13L are outside the polygonal region having the board fixing parts 12a to 12d as vertices, and vibrations such as bending modes are easily generated in the cantilevers 13R and 13L in response to disturbances such as vibrations to the imaging device 100Z, and the cantilevers 13R and 13L resonate with multiple roots as in the vibration mode shown in the lower part of FIG. 14. When the vibrations of the circuit board 11Z are applied to the right imaging element 2R and the left imaging element 2L, a difference in the vibration amount occurs in the image, which results in a difference in distance and speed, resulting in a decrease in measurement accuracy. In addition, as the imaging device 100Z becomes more highly functional, such as with a wider angle of view, higher accuracy, and higher speed, the tolerance for deviations due to vibrations becomes smaller, and it becomes necessary to reduce the vibrations of the imaging device 100Z.

[0066] In addition, the vibration of the cantilever parts 13R and 13L may repeatedly apply strain to the circuit elements mounted on the circuit board 11Z, which may cause breakage in the soldered parts. Therefore, it has become necessary to reduce the vibration of the circuit board 11Z. Providing a vibration-proof member for general vibration prevention will lead to an increase in the size of the device, an increase in the number of parts, and a complication of the manufacturing process. In addition, when the device is provided with a vibration-proof member, the front side is imaged and the position and speed of the target object are recognized based on the difference in the image over time, and when recognizing a distant object, especially during high-speed movement, the difference in the image is converted to an angle of 0.1 degrees or less, and the vibration mode of the vibration-proof member causes a position shift in the image and causes errors in the speed and position, so it is not desirable to provide a vibration-proof member in the imaging device. From the viewpoint of measurement accuracy, it is very important to maintain the mounting positions of the vehicle body and the sensor, and usually the vehicle body and the sensor are firmly fixed, and the vibration of the vehicle body is transmitted to the imaging device. Therefore, the resonance mode of a circuit board or other component within the device may be transmitted to the sensor through the housing 1A or the like, causing a position shift in the image and resulting in errors in speed and position.

[0067] In order to solve this problem, in the circuit board 11g of this embodiment, as shown in FIG. 15, cantilever portions 13R and 13L are provided outside the polygonal region having the board fixing portions 12a to 12d as vertices, and the natural frequencies of the cantilever portions 13R and 13L are made different from each other. R The length of the cantilever part 13L is d L The width w of the cantilever portion 13R is longer than that of the cantilever portion 13R. R The width w of the cantilever part 13L L Or, 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. Or, the weight of the cantilever portion of the cantilever portion 13R is made larger than the area of ​​the cantilever portion of the cantilever portion 13L. R and the distance L from the side connecting the adjacent substrate fixing portions 12a to 12d to the center of gravity of the cantilever portions 13R and 13L. R ,L L and the moment MM R ,M.M. L was made different for each cantilever portion 13.

[0068] By using any of the methods, the natural frequency is made different for each cantilever 13 of the circuit board 11g, as in the vibration mode shown in the lower part of FIG. 15, and the double root state in which the two vibration modes coincide is eliminated, as shown in FIG. 6 of the first embodiment, so that the vibration amplitude of the vibration mode is reduced and the vibration to the right imaging element 2R and the left imaging element 2L can be reduced. By being able to reduce the vibration amplitude, the position and speed of the object can be recognized and measured with high accuracy, and the repeated strain of the circuit elements mounted on the circuit board 11g is also reduced, resulting in a highly reliable imaging device 107 with no breaks in the soldered parts, etc. Furthermore, no additional parts such as rubber are required to fix the circuit board 11g, and the imaging device 107 is inexpensive and highly reliable with no optical axis misalignment and high measurement accuracy. EXAMPLES

[0069] Next, an imaging device 108 according to an eighth embodiment of the present invention will be described with reference to Fig. 16. Note that a description of points in common with the seventh embodiment will be omitted.

[0070] 16 is an explanatory diagram of the board fixing portion 12 of the imaging device 108 according to the present embodiment. In the circuit board 11h of the present embodiment, the board fixing portions 12a and 12b are arranged at the front end and rear end positions separated by a distance La to the right from the center in the left-right direction of the circuit board 11h, and the board fixing portions 12c and 12d are arranged at the front end and rear end positions separated by a distance La to the left from the center in the left-right direction of the circuit board 11h, so that the natural frequency of each cantilever portion 13 is different. Note that in FIG. 16, the board fixing portions 12a and 12b on the right side are arranged in the front-rear direction, and the board fixing portions 12c and 12d on the left side are also arranged in the front-rear direction, but the distance from the center of each board fixing portion 12 may be made different, and the board fixing portions 12 may be arranged in a trapezoidal shape so that the total distance between the left and right sides is different.

[0071] The configuration of this embodiment can also provide the same effects as those of the seventh embodiment described above. EXAMPLES

[0072] Next, an imaging device 109 according to a ninth embodiment of the present invention will be described with reference to Fig. 17. Note that in this embodiment, a description of points common to the seventh embodiment will be omitted.

[0073] 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, the board fixing parts 12a to 12d are arranged so that the natural frequencies of the cantilevers 13R and 13L are different. Specifically, the board fixing part 12a is arranged at a front end position that is a distance La away from the center in the left-right direction of the circuit board 11i, and the board fixing part 12c is arranged at a front end position that is a distance Lb away from the center in the left-right direction. In addition, the board fixing part 12b is arranged at a rear end position that is a distance Lc away from the center in the left-right direction of the circuit board 11i, and the board fixing part 12d is arranged at a rear end position that is a distance Lc away from the center in the left-right direction.

[0074] As a result, since the natural frequencies of the cantilever portions 13R and 13L of the circuit board 11i are different, the double root state in which the two vibration modes coincide is eliminated, the vibration amplitude of the vibration mode is reduced, and the vibration to the right imaging element 2R and the left imaging element 2L can be reduced.

[0075] In the circuit board 11i of this embodiment, a female connector 66 for signal input / output, power supply, etc. is provided on the left side of the right rear board fixing portion 12b. As a result, the right front board fixing portion 12a and the female connector 66 are aligned in the insertion / removal direction of the male connector (not shown), so deformation of the circuit board 11i and the soldered portion when the connector is inserted or removed can be reduced, stress and distortion can be reduced, and damage such as cracks can be prevented.

[0076] The present invention is not limited to the above-mentioned embodiment, and includes various modifications and combinations within the scope of the gist of the present invention. Furthermore, the present invention is not limited to those having all the configurations described in the above-mentioned embodiment, and includes those in which some of the configurations are omitted. [Explanation of symbols]

[0077] 100X~100Z Comparative image pickup device 101-109 Imaging device of the present invention 1, 1A housing 2. Image sensor 2R Right image sensor 2L Left image sensor 3 Imaging Board 3R Right imaging board 3L Left imaging board 4 Lenses 4R Right lens 4L Left lens 5. Imaging module 5R Right imaging module 5L Left imaging module 6 Circuit Elements 61 First circuit element (FPGA) 62 Second circuit element (memory) 63 Third circuit element (MPU) 64 4th circuit element (capacitor) 65 5th circuit element (power supply circuit) 66 female connector 7 Housing fixing part 8 protrusions 11 Circuit Board 12 Board fixing part 13 Cantilever

Claims

1. An image sensor comprising: an image sensor; a substrate for processing images; and a housing to which the substrate is fixed at 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 as each vertex, and the natural frequency of each of the cantilever portions is different for each of the cantilever portions; The imaging device according to the present invention, wherein the cantilever portions of the substrate have different areas.

2. An image sensor comprising: an image sensor; a substrate for processing images; and a housing to which the substrate is fixed at 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 as each vertex, and the natural frequency of each of the cantilever portions is different for each of the cantilever portions; The imaging device according to the present invention, wherein the width of each of the cantilevers of the substrate is different.

3. An image pickup device comprising: an image pickup element; a substrate for processing images; and a housing to which the substrate is fixed by substrate fixing portions at a plurality of locations; the substrate has a plurality of cantilever portions that are regions outside a polygonal region having the substrate fixing portion as each vertex, and the natural frequency of each of the cantilever portions is different for each of the cantilever portions; The imaging device according to the present invention, wherein the length of each of the cantilevers of the substrate is different.

4. An image sensor comprising: an image sensor; a substrate for processing images; and a housing to which the substrate is fixed at 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 as each vertex, and the natural frequency of each of the cantilever portions is different for each of the cantilever portions; The imaging device according to the present invention is characterized in that the substrate has three substrate fixing portions, two of which are disposed on the imaging element side.

5. An image pickup device comprising: an image pickup element; a substrate for processing images; and a housing to which the substrate is fixed by substrate fixing portions at a plurality of locations; the substrate has a plurality of cantilever portions that are regions outside a polygonal region having the substrate fixing portion as each vertex, and the natural frequency of each of the cantilever portions is different for each of the cantilever portions; An imaging device according to claim 1, wherein the area of ​​the cantilever portion of the substrate on the imaging element side is smaller than the area of ​​the other cantilever portion.

6. An image pickup device comprising: an image pickup element; a substrate for processing images; and a housing to which the substrate is fixed by substrate fixing portions at a plurality of locations; the substrate has a plurality of cantilever portions that are regions outside a polygonal region having the substrate fixing portion as each vertex, and the natural frequency of each of the cantilever portions is different for each of the cantilever portions; The housing has a housing fixing portion for fixing to a vehicle body, An imaging device, characterized in that a polygonal region having the substrate fixing portion at each vertex and a polygonal region having the housing fixing portion at each vertex overlap each other.

7. The imaging device according to any one of claims 1 to 6, An imaging device characterized in that the moment formed by the weight of the cantilever and the distance from the edge connecting multiple adjacent substrate fixing portions to the center of gravity of the cantilever differs for each cantilever.

8. The imaging device according to any one of claims 1 to 6, The imaging device according to the present invention is characterized in that the substrate has a circuit element disposed on a side connecting the substrate fixing portions at the plurality of locations.

9. The imaging device according to any one of claims 1 to 6, The imaging device according to the present invention, wherein the substrate has a circuit element provided with a thermal conductive material disposed on the cantilever portion.

10. The imaging device according to any one of claims 1 to 6, The board has a connector on a rear side, An imaging device characterized in that the connector is positioned between the left and right board fixing portions on the rear side of the board, further from one of the board fixing portions, and in a position aligned in the front-to-back direction with the board fixing portion on the front side of the board.

Images