Imaging device

Abstract

This imaging device comprises a cooling fan and a resonator that are disposed in a housing. The resonator has a structure in which a narrow space having an opening is in communication with an expansion tube of which the outer shape is a non-spherical body having a planar region, and the resonator is disposed in a space common to the cooling fan in the housing.

Description

Imaging device

[0001] This technology relates to the technical field of imaging devices equipped with cooling fans.

[0002] Various imaging devices such as video cameras and still cameras have heat-generating components such as various substrates in addition to imaging elements such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor). It is necessary to suppress the temperature rise due to the heat generation of these heat-generating components to ensure an appropriate driving state.

[0003] Therefore, some imaging devices are provided with a cooling structure in which a cooling fan (sirocco fan) and a heat sink are arranged in the case body to suppress the temperature rise due to the heat generation of the heat-generating components.

[0004] Patent Document 1 below discloses an example of providing a silencing device using a Helmholtz resonator in a device equipped with a cooling fan.

[0005] Patent No. 4215790

[0006] By the way, in an imaging device having a cooling fan, there is a situation where it is desired to reduce the noise caused by the operation of the cooling fan and promote quiet operation. Especially in the case of an imaging device, since it is often held by the user and located near the user's head, the demand for quiet operation is strong. Therefore, for example, a method of arranging a Helmholtz resonator in the housing can be considered. However, it is necessary to thicken the housing of the imaging device due to the arrangement of the resonator, which impairs the usability of the imaging device 1. On the other hand, it is difficult to obtain a sufficient soundproofing effect with a small resonator.

[0007] Therefore, in the present disclosure, a configuration is proposed in which a silencing mechanism is mounted in an imaging device without thickening the housing, and an appropriate soundproofing effect can be obtained.

[0008] The imaging device according to this technology has a structure in which a cooling fan located inside the housing, a narrow space with an opening, and an expansion tube having a non-spherical external shape with a planar region are connected, and a resonator located inside the housing in a space shared with the cooling fan. By arranging the resonator having a narrow space and an expansion tube, resonance at specific frequencies is reduced. In this case, the external shape of the resonator is a non-spherical shape with a planar region.

[0009] This is a perspective view of the imaging device according to an embodiment of this technology. This is a perspective view of the imaging device according to the embodiment with the display unit and the like removed. This is a perspective view of the imaging device according to the embodiment viewed from the bottom. This is an exploded perspective view of the cooling structure according to the embodiment. This is a perspective view of the cooling structure according to the embodiment. This is an explanatory diagram of the arrangement of resonators in the cooling structure according to the embodiment. This is an explanatory diagram of the arrangement of resonators in the cooling structure according to the embodiment. This is an explanatory diagram of a resonator used as a comparative example. This is an explanatory diagram of the resonator according to the embodiment. This is an explanatory diagram of the frequency characteristics compared with and without a Helmholtz resonator. This is an explanatory diagram of the frequency characteristics due to the resonator according to the embodiment. This is an explanatory diagram of an example of the shape of with multiple resonators connected. This is an explanatory diagram of the flow path in the case of side intake according to the embodiment. This is an explanatory diagram of the flow path in the case of bottom intake according to the embodiment. This is an explanatory diagram of the flow path in the case of side intake according to the embodiment. This is an explanatory diagram of the flow path in the case of bottom intake according to the embodiment. This is an explanatory diagram of the effect of arranging multiple resonators according to the embodiment. This is an explanatory diagram of the frequency characteristics due to the arrangement of multiple resonators in the embodiment. This is an explanatory diagram of a modified sound-dampening structure in the embodiment. This is an explanatory diagram of the signal processing configuration of the imaging device in the embodiment.

[0010] The embodiments will be described below in the following order: <1. Cooling and noise reduction structure in the imaging device> <2. Resonator shape, arrangement, and number> <3. Signal processing configuration of the imaging device> <4. Summary and modified examples>

[0011] The embodiments described below apply the imaging device of this technology to a video camera. However, the scope of application of this technology is not limited to video cameras; it can be broadly applied to other imaging devices such as still cameras.

[0012] In the following explanation, directions (front, back, up, down, left, and right) are indicated from the perspective of the photographer. Therefore, the subject side (object side) is the front and the photographer side (image side) is the back.

[0013] The directions indicated below (front, back, up, down, left, and right) are for illustrative purposes only, and the implementation of this technology is not limited to these directions.

[0014] <1. Cooling and Noise Reduction Structure in Imaging Device> First, the general configuration of the imaging device 1 will be described (see Figures 1 to 4). The imaging device 1 has, for example, an outer casing 2 formed in a horizontal shape and various necessary parts arranged inside the outer casing 2.

[0015] The outer casing 2 has various operating parts 3 arranged on its top surface, rear surface, etc. Examples of operating parts 3 include a power button, a shutter button, a zoom knob, a mode switching knob, and so on.

[0016] A circular opening (not shown) is formed on the front of the outer casing 2, and the area around the opening is provided as a mount for attaching an interchangeable lens (not shown). An image sensor (not shown), such as a CCD or CMOS, is arranged inside the outer casing 2, and the image sensor is located behind the opening. An interchangeable lens (not shown) can be attached to and detached from the mount.

[0017] On the rear side of the outer casing 2, a display unit 4 having a liquid crystal display is connected to the outer casing 2 in a way that allows it to be opened and closed (rotatably connected) (see Figures 1 and 3).

[0018] A side panel 5 is attached to one side of the outer casing 2 (see Figures 1 to 3). A vertically elongated air outlet 5a is formed at the rear end of the side panel 5. The air outlet 5a is partitioned by a plurality of partitions 5b that are spaced apart vertically. A bottom panel 6 is attached to the lower end of the outer casing 2 (see Figure 3). A horizontally elongated intake hole 6a is formed in the bottom panel 6. The intake hole 6a is partitioned by a plurality of partitions 6b that are spaced apart horizontally.

[0019] Inside the outer casing 2 is a control board 7 that controls the entire imaging device 1 (see Figure 4). The control board 7 is formed, for example, in a horizontally elongated, roughly rectangular shape, and is positioned inside the outer casing 2 with its roughly rectangular surface facing the front-to-back direction at the rear end.

[0020] On the rear surface of the control board 7, for example, a first card slot 8 and a second card slot 9 are mounted side by side vertically (see Figures 2 and 4). The first card slot 8 and the second card slot 9 are mounted on the right end of the control board 7 and are located laterally to the display unit 4.

[0021] The control board 7 has a mechanism arrangement section 7a in the area where the first card slot 8 and the second card slot 9 are not mounted, and this mechanism arrangement section 7a is located in front of the display unit 4. Multiple electronic components, not shown, such as semiconductor packages that act as heat sources and resistors, are mounted on the mechanism arrangement section 7a.

[0022] Next, the cooling structure 10 will be described (see Figures 2, 4 to 7). The cooling structure 10 is located on the rear side of the mechanism arrangement section 7a of the control board 7 and includes a case body 11, a first heat sink 12, a second heat sink 13, and a cooling fan (centrifugal fan or sirocco fan) 14 (see Figures 4 and 5). The cooling structure 10, for example, the heat sinks 12, 13, and mounting plate 15 are made of a material with high heat dissipation properties, such as a metal material.

[0023] The case body 11 is formed, for example, in a horizontally elongated, roughly rectangular shape, and is constructed by connecting the mounting plate 15 and the cover 16 at the front and rear.

[0024] The mounting plate 15 is formed in a horizontally elongated rectangular shape facing in the front-to-back direction and corresponds to the front part of the case body 11.

[0025] The cover 16 is formed in a box shape with openings at the front and one side, and has a base surface portion 17 facing in the front-rear direction, an upper surface portion 18 protruding forward from the upper edge of the base surface portion 17, a first side surface portion 20 protruding forward from the right edge of the base surface portion 17, and a second side surface portion 21 protruding forward from the left edge of the base surface portion 17.

[0026] The base surface portion 17 corresponds to the rear surface portion of the case body 11. Therefore, the base surface portion 17 is formed to be approximately the same size and shape as the mounting plate 15. The lower side of the base surface portion 17 is open and serves as an air intake port 22.

[0027] The second side portion 21 has exhaust ports 24 that penetrate from left to right.

[0028] The first heat sink 12 has a plurality of first heat dissipation fins 12a arranged on the left and right sides, and is composed of, for example, a first portion 25 and a second portion 26, and is attached to the rear surface of the mounting plate 15. The first heat dissipation fins 12a are formed in a shape such as a plate extending in the vertical direction. The first portion 25 and the second portion 26 have the same size (height) in the front-to-back direction and the same size (length) in the vertical direction, for example. However, the height and length of the first portion 25 and the second portion 26 may be different. In addition, in the imaging device 1, only the first portion 25 may be provided as the first heat sink 12.

[0029] The first portion 25 is wider in the left-right direction than the second portion 26 and is attached to the lower end of the mounting plate 15, excluding the right end. The second portion 26 has fewer first heat dissipation fins 12a than the first heat sink 12 and is attached to the mounting plate 15 above the right end of the first portion 25.

[0030] The second heat sink 13 has a plurality of second heat dissipation fins 13a arranged on the left and right sides and is attached to the rear surface of the mounting plate 15. The second heat dissipation fins 13a are formed in a shape such as a plate extending in the vertical direction. Therefore, the first heat dissipation fins 12a of the first heat sink 12 and the second heat dissipation fins 13a of the second heat sink 13 are arranged in parallel.

[0031] The second heatsink 13 is taller than the first heatsink 12 and longer than the first heatsink 12 (see Figures 4 and 6). The second heatsink 13 is attached to the right end of the mounting plate 15, and for example, its lower end protrudes downward from the mounting plate 15. The length of the second heat dissipation fins 13a increases as it moves away from the first heatsink 12 in the left-right direction. Therefore, the upper end of the second heatsink 13 as a whole is inclined to displace downward as it approaches the first heatsink 12 in the left-right direction.

[0032] Furthermore, in the second heat sink 13, the lengths of the second heat dissipation fins 13a may be partially different.

[0033] The cooling fan 14 is formed in a thin, flat shape and has a housing 27 that functions as a case and predetermined parts arranged inside the housing 27. The housing 27 has a first surface 28 provided as the front surface, a second surface 29 provided as the rear surface, and a circumferential surface 30 corresponding to the outer periphery.

[0034] For example, a circular intake opening 31 is formed on the first surface portion 28.

[0035] The housing 27 is formed in a shape that opens to the left, and this left-side opening is formed as an exhaust port 32. A rotating blade 33 is arranged inside the housing 27, and the rotating blade 33 rotates around a pivot point of the rotation axis 33a. The axial direction of the rotation axis 33a is in the thickness direction. The intake opening 31 formed in the housing 27 is formed in a circular shape centered on the rotation axis 33a of the rotating blade 33.

[0036] The cooling fan 14 is mounted on the left side of the second heatsink 13, on the rear surface of the mounting plate 15 or on the front surface of the base surface 17 of the cover 16. When the cooling fan 14 is mounted on the mounting plate 15 or the cover 16, a part of the cooling fan 14 overlaps with at least a part of the first heatsink 12 from the rear (see Figure 7). Specifically, the outer part of the intake opening 31 of the cooling fan 14 overlaps with the part of the first part 25 excluding the right end and the part of the second part 26 excluding the right end. Therefore, the intake opening 31 of the cooling fan 14 does not overlap with the first heatsink 12.

[0037] Furthermore, at least a portion of the first heatsink 12 and a portion of the first surface 28 of the cooling fan 14 are positioned to face each other in the thickness direction.

[0038] Therefore, since at least a portion of the first heat sink 12 and a portion of the cooling fan 14 are positioned to overlap in the thickness direction, the external shape of the cooling structure 10 perpendicular to the thickness direction can be miniaturized.

[0039] Furthermore, since the second heatsink 13 is positioned outside the outer circumference of the cooling fan 14, and the first heatsink 12 is positioned outside the intake opening 31, both the first heatsink 12 and the second heatsink 13 are positioned outside the intake opening 31 of the cooling fan 14, ensuring high intake performance of cooling air by the cooling fan 14. In addition, since the second heatsink 13 does not overlap with the cooling fan 14 in the thickness direction, the height of the second heat dissipation fins 13a can be increased to enlarge the heat dissipation area and improve cooling efficiency.

[0040] As described above, with the first heat sink 12, the second heat sink 13, and the cooling fan 14 each positioned in their respective locations, the mounting plate 15 and the cover 16 are joined together to form the cooling structure 10 (see Figure 5).

[0041] The cooling structure 10 disposed on the rear surface side of the mechanism arrangement portion 7a on the control board 7 is positioned laterally of the first card slot 8 and the second card slot 9. Further, in the cooling structure 10, the first heat sink 12 and the second heat sink 13 are positioned directly above the intake port 22 in the case body 11. In the first heat sink 12, the first portion 25 is positioned closer to the intake port 22 and the second portion 26 is positioned on the opposite side of the intake port 22 sandwiching the first portion 25.

[0042] In a state where the cooling structure 10 is disposed on the rear surface side of the mechanism arrangement portion 7a, the cooling structure 10 is connected, for example, by a heat conductor such as a graphite sheet, a thin copper plate, a heat conduction sheet, etc., of which an imaging element or the like is not shown. Further, heat generating components such as electronic components mounted on the control board 7 are in a state of being in contact with or close to the mounting plate 15 of the case body 11. Incidentally, heat generating components such as electronic components mounted on the control board 7 may also be connected to the cooling structure 10 by a heat conductor such as a graphite sheet or a thin copper plate.

[0043] Therefore, heat generated in the heat generating components is made to be in a state of being able to be transmitted to the cooling structure 10 by the heat conductor. In the imaging device 1, in particular, the heat of the imaging element is mainly transmitted to the first heat sink 12, and the heat of the heat generating components mounted on the control board 7 is mainly transmitted to the second heat sink 13, and the first heat sink 12 mainly has a role of suppressing the temperature rise of the imaging element, and the second heat sink 13 mainly has a role of suppressing the temperature rise of the heat generating components mounted on the control board 7.

[0044] Incidentally, in the imaging device 1, for example, in addition to having a role of suppressing the temperature rise of the heat generating components mounted on the control board 7, the second heat sink 13 may also have a role of suppressing the temperature rise of the first card slot 8 and the second card slot 9.

[0045] Further, in the imaging device 1, at least a part of the heat generated in each of the above-described heat generating components may be transmitted to the outer casing 2 and also be released from the outer casing 2.

[0046] The flow path of the cooling air in this cooling structure 10 will be explained (see Figure 7). In the imaging device 1, as the rotating blades 33 of the cooling fan 14 rotate, air present outside the imaging device 1 is taken in as cooling air through the intake hole 6a of the lower panel 6 and into the intake port 22 of the case body 11.

[0047] A portion of the cooling air taken in through the intake port 22 passes between the multiple first heat dissipation fins 12a of the first heat sink 12 and is drawn into the cooling fan 14 through the intake opening 31. The flow path from the intake port 22 through the multiple first heat dissipation fins 12a to the intake opening 31 is called the first flow path S1. At this time, the heat transferred to the first heat sink 12 is released and heat exchange takes place with the cooling air passing through the first flow path S1.

[0048] A portion of the cooling air taken in from the intake port 22 passes between the multiple second heat dissipation fins 13a of the second heat sink 13 to the upper part of the internal space of the case body 11, and then flows around to the rear side of the cooling fan 14 from above and is sucked into the inside of the cooling fan 14 through the intake opening 31 (see Figures 6 and 7). The flow path from the intake port 22 through the multiple second heat dissipation fins 13a to the intake opening 31 is called the second flow path S2. At this time, the heat transferred to the second heat sink 13 is released and heat exchange takes place with the cooling air passing through the second flow path S2.

[0049] Thus, in the cooling structure 10, a first flow path S1 is formed within the internal space of the case body 11, passing from the intake port 22 through the first heat dissipation fin 12a to the intake opening 31, and a second flow path S2 is formed from the intake port 22 through the second heat dissipation fin 13a to the intake opening 31.

[0050] The cooling air, whose temperature has risen due to heat exchange as it passes through the first flow path S1 and the second flow path S2, passes through the inside of the cooling fan 14 and is blown out from the exhaust port 32, and is discharged to the outside of the imaging device 1 through the exhaust port 24 of the case body 11 and the outlet hole 5a of the side panel 5. As a result, the temperature rise of heat-generating components such as the image sensor and electronic components of the control board 7 is suppressed.

[0051] This cooling structure 10 has four Helmholtz resonators 40 placed in the space inside the case body 11 for noise reduction (see Figures 4, 6, and 7).

[0052] The resonator 40 is formed by an expansion tube 42 and a narrow space duct 43 that forms a narrow space 41. In this example, the expansion tube 42 is rectangular in shape. A rectangular tubular narrow space 41 is provided by the narrow space duct 43, which communicates with the expansion tube 42 and its internal space.

[0053] The four resonators 40 are positioned to partition the space between the first heat sink 12 and the second heat sink 13. As can be seen from the figure, the four resonators 40 are all positioned so as not to obstruct the airflow in the first flow path S1 and the second flow path S2.

[0054] Furthermore, of these four resonators 40, the two upper resonators 40 are positioned so that the narrow space duct 43 faces downwind of the second flow path S2. The two lower resonators 40 are positioned so that the narrow space duct 43 faces perpendicular to the first flow path S1. In addition, all four resonators 40 are positioned so as not to be in contact with the exhaust port 32. Furthermore, the three resonators 40 other than the lowest resonator 40 are positioned so as not to be in contact with the intake port 22.

[0055] The shape, arrangement, and number of resonators 40 shown in the figure are just examples, but below we will describe in detail a resonator 40 suitable as a sound-dampening structure for the cooling structure 10 in the imaging device 1.

[0056] <2. Resonator Shape, Arrangement, and Number> In the imaging device 1, a cooling structure 10 is provided due to the increase in heat generation resulting from improved functionality. However, in order to suppress the increase in noise, a sound-dampening structure is provided within the flow path, and a design that reduces noise is required. Furthermore, the sound-dampening structure should be made as small as possible to avoid increasing the overall size of the imaging device 1. In this case, a sound-dampening structure using a Helmholtz-type resonator 40 is realized with the following points in mind.

[0057] First, while noise reduction is possible by introducing the resonator 40, we want to avoid increasing the thickness of the imaging device 1's casing. If the resonator 40 is large, the thickness of the case body 11 will have to be increased, which will also increase the thickness of the outer casing 2, for example, in the front-to-back direction. We want to avoid this situation. On the other hand, if the resonator 40 is made smaller, the sound-dampening effect will be reduced. Therefore, we are considering how to ensure that sufficient sound-dampening effect in the target frequency band can be obtained even if the resonator 40 is small or thin.

[0058] Furthermore, as is known with Helmholtz resonators, we want to avoid having other resonances appear around the suppressed resonant frequency.

[0059] Furthermore, we want to avoid the resonator 40 obstructing the airflow and reducing heat dissipation performance. Therefore, the resonator 40 is positioned so as not to block the airflow path, thereby providing a sound-dampening effect.

[0060] Based on the above considerations, the sound-dampening mechanism in the imaging device 1 of this embodiment incorporates various improvements regarding the shape of the Helmholtz-type resonator 40, the position of the resonator 40 within the case body 11, and the arrangement of the multiple resonators 40. These will be explained in detail below.

[0061] First, let's discuss the shape of the resonator 40. A spherical shape is preferable to a rectangular parallelepiped for the expansion tube 42 of the resonator 40. However, in order to reduce the volume, a shape that allows for a large internal surface area is preferable. A spherical shape would increase the thickness in order to increase the surface area, which is disadvantageous for mounting on the imaging device 1.

[0062] Therefore, let's consider non-spherical shapes. A non-spherical shape is defined as a shape that has a planar region in at least its external shape. Here, a non-spherical shape means that the entire shape is not formed by curved surfaces. For example, cubes, rectangular prisms, or shapes like those shown in Figures 12 to 15, which will be described later, have planar regions that are not curved, and are therefore non-spherical as defined in this disclosure. The reason for providing a planar region is that the presence of this planar portion is advantageous for thinning the shape compared to a sphere, at least.

[0063] First, consider a rectangular (including cubic) expansion tube 42. Figure 8 shows a resonator 40Z as a comparative example, and Figure 9 shows a resonator 40 as an example of this embodiment. Figures 8, 9, and 12 to 15 are schematic models of Helmholtz resonators, representing their external shapes, but the sizes of the expansion tube 42 and the confined space 41 represent the sizes of their internal spaces. The volume of the expansion tube 42, the length of the confined space 41, and the cross-sectional area are determined according to the target resonance frequency and the desired sound dampening effect.

[0064] If the external shape of the expansion tube 42 is a cube, and considering sound dampening around 1.5 kHz, for example, the resonator 40Z shown in Figure 8 can be assumed. For example, the internal space of the expansion tube 42 will be a cube with sides of 15 mm, and the narrow space 41 will have a diameter of 4 mm and a length of 2.6 mm. Figure 10 shows the simulation results of the frequency characteristics with and without such a resonator 40Z. The dashed line represents the case when a Helmholtz resonator is not used in the imaging device 1, and the solid line represents the case when the resonator 40Z is used.

[0065] Without using a Helmholtz resonator, the cooling structure 10 described above shows a peak around 1.4 kHz, and it is desirable to silence this frequency band (1 kHz to 2 kHz). It can be seen that using the resonator 40Z provides a silencing effect in this frequency band. Helmholtz silencing works by placing a resonator with the same resonance frequency as the cooling structure 10 to be silenced, thereby generating sound pressure with opposite phase and canceling it out. This effect is shown in Figure 10. However, with Helmholtz silencing, the original resonance frequency is lowered, and its second-order resonance occurs at a higher frequency. In other words, as shown by the dashed line 100 in the figure, a peak appears as a side effect, and its harmonic peaks also appear. Furthermore, the size of the resonator 40Z in Figure 8 is extremely disadvantageous in meeting the requirement for thinning the imaging device 1, making it difficult to adopt in a small imaging device 1.

[0066] Therefore, in this embodiment, multiple small resonators 40 as shown in Figure 9 are arranged. For example, the volume of the expansion tube 42 of the resonator 40 is set to W = 8.5 mm, H = 5 mm, and D = 5.12 mm in the width direction W, height direction H, and depth direction D as seen in the figure. The narrow space 41 is a rectangular tube with a length of 1.6 mm and sides of 0.5 mm.

[0067] The relationship between each size and the resonant frequency is as follows (Equation 1).

[0068]

[0069] f is the resonant frequency, c is the speed of sound, S is the cross-sectional area of ​​the narrow space 41, V is the volume of the expansion tube 42, L is the length of the narrow space 41, and α is an open-end correction term set to 1.7√(s / π).

[0070] For example, Figure 11 shows the simulation results of the frequency characteristics when four such resonators 40 are arranged inside the case body 11 as shown in Figure 7. As can be seen by comparing Figures 10 and 11, the peak around 1.4 kHz is suppressed, and the low-frequency peaks and their harmonics, which were side effects, are also suppressed.

[0071] As is well known, a Helmholtz resonator 40 is provided with a narrow space duct 43 that forms a narrow space 41 with a small cross-sectional area in the space inside an expansion tube 42 which has a relatively large volume. When sound with a frequency matching the resonant frequency of the air spring vibration of such a structure passes through the narrow space 41 and is transmitted to the internal space of the expansion tube 42, a resonance phenomenon occurs, causing the air in the narrow space 41 to vibrate violently, and some of the sound energy is converted into thermal energy due to viscous loss, resulting in a sound absorption effect.

[0072] Here, the flow resistance of the narrow space 41 increases inversely proportional to the fourth power of its cross-sectional diameter. By reducing the cross-sectional diameter of the narrow space 41, heat dissipation due to wall viscous resistance can be generated, and the Q value of the resonance that occurs as a side effect can be suppressed. However, if the cross-sectional diameter is reduced, the size of the resonator 40, which resonates with the same noise as the cooling structure 10, becomes smaller, and the noise reduction and heat dissipation effects also decrease. Instead, the noise reduction effect can be made sufficient by increasing the number of resonators 40. The number of resonators 40 and the noise reduction effect will be described later in Figures 21 and 22.

[0073] The size of the resonator 40 in Figure 9 is just an example, but from a size standpoint, the narrow space 41 should be in the range of 1 mm square to 0.1 mm square. It may be smaller than 0.1 mm square, but from a productivity standpoint, it is better to set 0.1 mm square as the lower limit. The narrow space 41 may also be a circular cross-section with a diameter of 1 mm or less. The volume of the expansion tube 42 is approximately 250 mm³. ３ The following is preferable. As shown above (Equation 1), the setting of the frequency band to be silenced largely depends on the volume V of the expansion tube 42. However, by using a volume of this size (the volume of the external shape that achieves this volume), it is possible to make it a size suitable for mounting on a small imaging device 1. In the case of the size exemplified in Figure 9, the volume is 8.5 × 5 × 5.12 = 217.6 mm ３ That's how it is.

[0074] In the cooling structure 10 of the imaging device 1, the noise frequency range to be canceled is mainly in the 1 kHz to 2 kHz range. This range is sensitive to human hearing, and it is preferable to target this range for noise reduction. In that case, the volume of the expansion tube 42 is 250 mm³. ３ The following will be set, and the size of the narrow space 41 will be designed accordingly. This will allow the necessary sound-dampening effect to be obtained with a small resonator 40.

[0075] However, if the expansion tube 42 is made into a rectangular parallelepiped shape, for example as shown in Figure 9, further flattening can promote thinning, but beyond a certain degree of flatness, it will no longer be able to function as a resonator. Therefore, the shape is made flatter to suit the thinning of the imaging device 1, but not so flat that it becomes too flat.

[0076] For example, the expansion tube 42 is designed so that the ratio of the major axis to the minor axis in any two of the three directions—width (W), height (H), and depth (D)—is 2:1 or less. In other words, the major axis (longer size) is no more than twice the minor axis (shorter size). To put it another way, it has a flattened shape within the range where the major axis is no more than twice the minor axis. In the case of Figure 9, the ratio of the width (W) to the height (H) is 8.5:5, which is 2:1 or less (the major axis is no more than twice the minor axis).

[0077] In the size example shown in Figure 9, we considered W:H, but this can be thought of as the ratio of the size in the direction of thinning, and for example, W:D would also be acceptable. Also, here we use the terms width, height, and depth with the direction in which the narrow space duct 43 is formed as the front, but as shown in Figure 12, the narrow space 41 may also be provided on the side as shown in Figure 9. In this case, the major axis is considered as the depth direction size (D), and the minor axis is considered as the width direction size (W) or height direction size (H), and it is sufficient if D:W or D:H is 2:1 or less.

[0078] Figures 9 and 12 show the case where the expansion tube 42 has a rectangular parallelepiped shape, but many other shapes are possible. Figure 13 shows the expansion tube 42 with a curved side portion compared to Figure 9. Figure 14 shows an example of an expansion tube 42 made of a decahedron, which has more faces than a rectangular parallelepiped. Figure 15 shows a shape in which the top and bottom of a sphere are cut off, forming planar regions 50 above and below the sphere. Many other shapes are possible for the expansion tube 42, as shown above.

[0079] In particular, the expansion tubes 42 in Figures 9 and 12 to 15 have a flattened external shape, with a planar region 50 having at least a first plane and a second plane that is the back side of the first plane. Since the expansion tubes 42 in Figures 9 and 12 are rectangular parallelepipeds, they have six planar regions 50, and each plane has a plane that is the back side. Therefore, if there are two of the width, height, and depth dimensions, one short axis and one long axis, it will have a flattened shape.

[0080] In the case of the polyhedron shape in Figure 14, the surface on which the narrow space duct 43 is provided and the surface on the back of it form a pair of planar regions 50, and the shape is flattened because the depth direction size (D) is shorter than the width direction size (W). In the cases of Figures 13 and 15, there are planar regions 50, 50 that are in a front-back relationship. In the case of Figure 13, the shape is flattened because the depth direction size (D) is shorter than the width direction size (W). In the case of Figure 15, the shape is flattened because the height size (H) is shorter than the width size (W).

[0081] In both cases, the flattened shape allows for a thinner design, making it suitable for placement in narrow spaces, such as inside the case body 11.

[0082] Furthermore, as shown in the upper part of Figure 16, a configuration in which the expansion tubes 42 of multiple resonators 40 are connected is also conceivable. The upper example shows an example in which the expansion tubes 42 are connected so that they are aligned horizontally. The internal spaces are partitioned and independent of each other. The lower example of Figure 16 shows an example in which the expansion tubes 42 are connected so that they are offset horizontally. When arranging multiple resonators 40, they may be placed individually at separate locations, or multiple resonators 40 may be arranged connected as in the example of Figure 16.

[0083] The following points should be considered when determining the placement of the resonator 40: • The opening of the narrow space 41 should be placed within the flow path. • The expansion tube 42 should be approximately adjacent to the outer circumference of the cooling fan 14, excluding the exhaust port, or a baffle should be placed so that air does not directly hit the expansion tube 42. • It should be placed in a location that does not come into contact with the intake or exhaust ports.

[0084] Figures 17 to 20 schematically show the cooling structure 10 and then show examples of the placement of the resonator 40. Each figure shows the cooling fan 81, heat sink 82, intake port 83, and exhaust port 84 within the case body 80 that constitutes the cooling structure 10, and then shows examples of the placement of the resonator 40 within that structure. The illustrated case body 80 is a model corresponding to the case body 11 described in Figures 1 to 7, but it does not necessarily match the specific structural example of the case body 11. The arrows indicate the airflow path. Each figure also shows the case body 80 as viewed from the rear side (photographer side) of the imaging device 1 (rear view) and as viewed from the top side.

[0085] Figure 17 shows an example in which an air intake port 83 is provided on the side of the case body 80. Air flowing in from the air intake port 83 passes through the area of ​​the heat sink 82 as shown by the arrow and reaches the intake opening 81a of the cooling fan 81. In this case, two resonators 40 are positioned along the flow path. The cooling fan 81 is located on the exhaust port 84 side, and the heat sink 82 is located on the air intake port 83 side, with the resonators 40 positioned between the cooling fan 81 and the heat sink 82. As shown in the top view of the lower part of Figure 17, the resonators 40 and the cooling fan 81 are positioned close to one side in the front-to-back direction of the imaging device 1, and the resonators 40 do not protrude beyond the thickness direction of the cooling fan 81. This prevents the resonators 40 from blocking the flow path. In this case, since the airflow is relatively slow, the resonators 40 do not adversely affect the cooling function even with the arrangement shown in the figure.

[0086] Figure 18 shows an example in which air intake ports 83a and 83b are provided on the bottom surface of the case body 80. Air flowing in from air intake port 83a reaches the intake opening 81a of the cooling fan 81 via the heat sink 82a. Air flowing in from air intake port 83b also reaches the intake opening 81a of the cooling fan 81 via the heat sink 82b, around the top surface of the case body 80. Two resonators 40 are arranged parallel to these airflow paths. Because the resonators 40 are arranged parallel to the airflow paths, they do not create resistance to the airflow and do not adversely affect the cooling function.

[0087] Figure 19 shows an example in which three connected resonators 40 are arranged in the same case structure 80 as in Figure 17, as shown in the upper part of Figure 16. Figure 20 shows an example in which three connected resonators 40 are arranged in the same case structure 80 as in Figure 18, as shown in the upper part of Figure 16.

[0088] The examples in Figures 17 to 20 above all represent arrangements that allow the opening of the narrow space 41 of the resonator 40 to be placed within the flow path. Furthermore, the expansion tube 42 is positioned almost adjacent to the outer circumference of the cooling fan 81, excluding the exhaust port 84. It is also positioned so as not to be in contact with the intake port 83 (83a, 83b) or the exhaust port 84. These arrangements allow for efficient noise reduction of the sound generated by the operation of the cooling fan 81.

[0089] Furthermore, the heat sinks 82 (82a, 82b) act as baffles, preventing air from directly hitting the expansion tube 42. This also reduces the possibility of dust entering the resonator 40.

[0090] Each resonator 40 only needs to have its narrow space 41 (narrow space duct 43) oriented towards the space forming the flow path. For example, it may be approximately perpendicular to the flow path, or it may be oriented towards the upwind side of the flow path, or towards the downwind side. However, if the narrow space duct 43 is oriented towards the upwind side, the possibility of dust entering increases. Therefore, it is best to have it oriented in a direction ranging from approximately perpendicular to the flow path to the downwind side. Figure 7 shows an example where the narrow space duct 43 is oriented towards the downwind side.

[0091] The example shown in Figure 7 is an example in which four resonators 40 are arranged in a structure that draws in air from the bottom side of the case body 11, as shown in Figure 18. In this arrangement as well, the opening of the narrow space 41 of the resonators 40 is located within the flow path. The expansion tube 42 is also positioned almost adjacent to the outer circumference of the cooling fan 14, excluding the exhaust port. Furthermore, it is positioned in a location that does not come into contact with the intake port 22 or the exhaust port 32. Therefore, the arrangement of the resonators 40 as shown in Figure 7 can efficiently suppress the sound generated by the operation of the cooling fan 81.

[0092] In this embodiment, a small resonator 40, as shown in Figure 9, is placed inside the case body 11. A sound-dampening effect can be obtained with one or more resonators 40. However, the sound-dampening effect can be enhanced by arranging a larger number of resonators. This will be explained in Figures 21 and 22.

[0093] Figure 21 shows the differences in the number of resonators 40 when a cooling fan 14 is provided inside the case body 11 as a cooling structure 10 as shown in Figure 7. Specifically, it shows the cases when no resonators 40 are provided, when one resonator 40 is provided, and when two, three, and four resonators 40 are provided. The sound attenuation (dB) around 1.4 kHz is shown with the case when no resonators 40 are provided as the reference. Figure 22 shows the frequency characteristics FR1 to FR5 as simulation results for each of these cases. Characteristics FR1, FR2, FR3, FR4, and FR5 are the cases when the number of resonators 40 is 0, 1, 2, 3, and 4, respectively.

[0094] Figures 21 and 22 clearly show that a noise reduction effect is obtained by placing the resonators 40 compared to when they are not placed. It can also be seen that the noise reduction effect is improved by increasing the number of resonators 40. Based on these results, it can be expected that the noise reduction effect will be further improved by increasing the number of resonators 40, but from the standpoint of securing the flow path in the space of the case body 11 and maintaining the cooling function, about four is preferable.

[0095] Up to this point, we have shown a Helmholtz resonator 40 in which a narrow space 41 and an expansion tube 42 are connected. The state in which this is installed relative to the flow path 59 is shown in the upper part of Figure 23. In order to obtain a sound dampening effect similar to that of this resonator 40, a membrane structure can be used as a mass damper, as shown in the lower part of the resonator 40A. This structure forms a space as an expansion tube 42 relative to the flow path 59, and separates the expansion tube 42 and the flow path 59 with a membrane 45. A weight 46 is attached to the membrane 45. In this resonator 40A, by designing it so that resonance is obtained by the membrane 45, a sound dampening effect equivalent to that of the resonator 40 can be obtained.

[0096] <3. Signal Processing Configuration of the Imaging Device> The following describes an example of the signal processing configuration of the imaging device 1 (see Figure 24).

[0097] The imaging device 1 is equipped with a camera block 90 that performs imaging functions, and includes a camera signal processing unit 91 that performs signal processing such as analog-to-digital conversion of captured image signals, and an image processing unit 92 that performs recording and playback processing of image signals. The imaging device 1 also includes a display unit 93 (display unit 4) that displays captured images, a R / W (reader / writer) 94 that writes and reads image signals to and from memory 99, a CPU (Central Processing Unit) 95 that controls the entire imaging device 1, a lens drive control unit 96 that controls the driving of the lens located on the camera block 90, and an operation unit 97 (operation unit 3) that allows the user to perform various operations such as switches. The camera block 90 is, for example, an interchangeable lens.

[0098] The imaging device 1 is equipped with an image sensor 98, such as a CCD or CMOS, which converts the optical image captured by the camera block 90 into an electrical signal.

[0099] The camera signal processing unit 91 performs various signal processing on the output signal from the image sensor 98, including conversion to a digital signal, noise reduction, image quality correction, and conversion to luminance and chromatic difference signals.

[0100] The image processing unit 92 performs compression encoding, decompression and decoding of image signals based on a predetermined image data format, as well as conversion processing of data specifications such as resolution.

[0101] The display unit 93 has the function of displaying various data such as the user's operation status to the operation unit 97 and the captured images. Note that the imaging device 1 does not necessarily have to have a display unit 93; the captured image data may be sent to another display device and the image displayed thereon.

[0102] The R / W (reader / writer) 94 writes image data encoded by the image processing unit 92 to the memory 99 and reads image data recorded in the memory 99.

[0103] The CPU 95 functions as a control processing unit that controls each circuit block provided in the imaging device 1, and controls each circuit block based on instruction input signals from the operation unit 97, etc.

[0104] The lens drive control unit 96 controls the drive source that moves the lens based on the control signal from the CPU 95.

[0105] The control unit 97 outputs an instruction input signal to the CPU 95 in response to user operations.

[0106] The memory 99 is, for example, a semiconductor memory that can be attached to or removed from a slot connected to the R / W 94, or a semiconductor memory that is pre-installed inside the imaging device 1.

[0107] A fan drive unit 16, which includes a drive circuit for driving the motor of the cooling fan 14, is provided for the cooling fan 14. The CPU 95 controls the fan drive unit 16 when necessary to drive the cooling fan 14. The fan drive unit 16 may also be equipped with a temperature sensor for detecting the temperature inside the enclosure, and the CPU 95 may control the drive of the cooling fan 14 according to the temperature detected by the temperature sensor.

[0108] The operation of the imaging device 1 is described below. In the standby state for shooting, under the control of the CPU 95, the captured image signal is output to the display unit 93 via the camera signal processing unit 91 and displayed as a camera-through image. When an instruction input signal is received from the operation unit 97, the CPU 95 outputs a control signal to the lens drive control unit 96, and the lens is moved based on the control of the lens drive control unit 96.

[0109] When a shooting operation is performed in response to an instruction input signal from the control unit 97, the captured image signal is output from the camera signal processing unit 91 to the image processing unit 92, where it is compressed and encoded, and converted into digital data in a predetermined data format. The converted data is output to the R / W 94 and written to the memory 99.

[0110] When playing back image data recorded in memory 99, in response to an operation on the operation unit 97, predetermined image data is read from memory 99 by the R / W 94, and after decompression and decoding processing is performed by the image processing unit 92, a playback image signal is output to the display unit 93 and the playback image is displayed.

[0111] In this technology, "imaging" refers to a series of processes, some or all of them, from the photoelectric conversion process that converts the light captured by the image sensor 98 into an electrical signal, to the camera signal processing unit 91 that converts the output signal from the image sensor 98 into a digital signal, performs noise reduction, corrects image quality, and converts it into brightness and color difference signals, to the image processing unit 92 that performs compression encoding and decompression decoding of the image signal based on a predetermined image data format and conversion of data specifications such as resolution, and to the writing of the image signal to the memory 99 by the R / W 94.

[0112] In other words, "imaging" may refer only to the photoelectric conversion process that converts the light captured by the image sensor 98 into an electrical signal, or it may refer to the process from the photoelectric conversion process that converts the light captured by the image sensor 98 into an electrical signal to the conversion of the output signal from the image sensor 98 into a digital signal by the camera signal processing unit 91, noise reduction, image quality correction, conversion to brightness and color difference signals, etc., and then the image processing unit 9 This may refer to the compression coding, decompression and decoding processing of image signals based on a predetermined image data format by 2, and the conversion processing of data specifications such as resolution, or it may refer to the photoelectric conversion processing that converts the light captured by the image sensor 98 into an electrical signal, the conversion of the output signal from the image sensor 98 into a digital signal by the camera signal processing unit 91, noise reduction, image quality correction, conversion to brightness and color difference signals, and the compression coding, decompression and decoding processing of image signals based on a predetermined image data format by the image processing unit 92, and the conversion processing of data specifications such as resolution, or it may refer to the writing of the image signal to the memory 99 by R / W 94.

[0113] <4. Summary and Modifications> The above embodiments provide the following effects.

[0114] The imaging device 1 of this embodiment includes a cooling fan 14 and a resonator 40, which are located inside the housing, for example, inside the outer casing 2 and the case body 11. The resonator 40 has a structure in which a narrow space 41 with an opening and an expansion tube 42 whose outer shape is a non-spherical shape with a planar region are connected, and is located inside the housing in a space shared with the cooling fan 14 (see Figures 6 and 7, etc.). By making the expansion tube 42 an outer shape with a planar region 50 in at least a part of it, i.e., a non-spherical shape, a part with less thickness can be provided, which is advantageous for placement inside the imaging device 1. In other words, the Helmholtz resonator can be made thinner, and a design can be made that does not increase the thickness of the housing even when it is mounted in the imaging device 1.

[0115] In this embodiment, the resonator 40 is positioned within the space where an airflow path is formed via the cooling fan 14 within the housing, and is positioned in a manner that does not obstruct the airflow path. This allows the cooling effect to be maintained without the resonator 40 obstructing the airflow from the cooling fan 14, while also providing an appropriate sound-dampening effect. Not obstructing the airflow path can also be described as being positioned at a location with low airflow velocity. In other words, it is positioned anywhere other than the location with the highest airflow velocity when the cooling fan 14 is operating. Alternatively, a position where the airflow velocity is half or less compared to the location with the highest airflow velocity is more preferable. Furthermore, the resonator 40 is preferable in terms of sound-dampening effect when positioned at a location with high sound pressure. In other words, within the space inside the housing, locations with low airflow velocity or high sound pressure are suitable positions for the resonator 40, and a location with both low airflow velocity and high sound pressure is optimal.

[0116] In this embodiment, an example was given in which multiple resonators 40 are arranged within the space forming the cooling structure 10. By arranging multiple resonators 40, the sound-dampening effect can be improved. In other words, even if the resonators 40 are made small for mounting inside the outer casing 2 of the imaging device 1, particularly inside the case body 11, arranging multiple resonators will enable a sufficient sound-dampening effect to be achieved. As explained in Figure 22, even arranging just one small resonator 40 will provide a sound-dampening effect. For implementation purposes, the number of resonators should be determined according to the noise level and the noise reduction target.

[0117] In this embodiment, the expansion tube 42 is given an example in which the planar region 50 has an external shape having at least a first plane and a second plane that is the back side of the first plane, for example, a flattened external shape. By adopting a flattened external shape, the thickness is suppressed, which is advantageous for arranging the resonator while maintaining the thin housing of the imaging device 1.

[0118] In this embodiment, an example was given in which the expansion tube 42 is approximately rectangular in shape. By making it a rectangular parallelepiped, or hexahedron, it is easy to obtain a relatively large surface area inside the expansion tube without increasing the thickness. This makes it possible to make the external dimensions smaller or thinner relative to the target frequency band to be silenced compared to, for example, making the expansion tube a sphere. In practice, the expansion tube may be approximately rectangular in shape with rounded (chamfered) corners.

[0119] In this embodiment, some or all of the one or more resonators 40 are positioned within the housing so as not to be in contact with the air intake port 22 (or air intake port 83) and exhaust port 32 (or exhaust port 84) of the air passing through the cooling fan 14. An example of this arrangement is shown in Figures 17 to 20. In the case of the examples in Figures 17 to 20, the position "in contact" with the air intake port 83 and exhaust port 84 means a position in contact with the opening space of the air intake port 83 and exhaust port 84 in the case body 80, when the housing is considered as the case body 80. Therefore, a position "not in contact" refers to an arrangement position other than one in contact with the opening space. In other words, at least some of the resonators 40 are positioned in a location that is not near the opening space of the air intake port 83 and exhaust port 84. Figures 17 and 19 show an example in which all of the multiple resonators 40 are positioned so as not to be in contact with the air intake port 83 and exhaust port 84. Figures 18 and 20 also show examples where at least a portion of the multiple resonators 40 are positioned so as not to be in contact with the intake port 83 and exhaust port 84. The same applies to the case body 11 described in Figures 4 and 7, where a position not in contact with the intake port 22 and exhaust port 32 means a position other than one that is in contact with their opening spaces. In the example of Figure 7, a portion of the multiple resonators 40 (the three resonators 40 other than the bottommost resonator 40 in Figure 7) are positioned so as not to be in contact with the intake port 83 and exhaust port 84. Furthermore, when considering the outer casing 2 as the housing, the air intake is the intake hole 6a and the exhaust is the exhaust hole 5a. It is also possible for one or more of the resonators 40, or some or all of them, to be positioned so as not to be near the opening spaces of the intake hole 6a and the exhaust hole 5a. For example, the configurations in Figures 7 and 17 to 20 also fall under this category. With these structures, the sound-dampening effect can be obtained more internally within the space that forms the flow path. Furthermore, by arranging multiple resonators 40, some of the resonators 40 may be located near, for example, the air intake port 22. It is also preferable that some or all of the one or more resonators 40 are positioned so as not to be in contact with the air intake opening 31 or exhaust port 32 of the housing 27 of the cooling fan 14, which is configured as a housing.

[0120] In this embodiment, heat sinks 12 and 13 are positioned near the intake port 22, and the air that passes through the flow path formed by the heat sinks 12 and 13 is discharged from the exhaust port 32 via the cooling fan 14. The entire resonator 40 is positioned within the space that forms the flow path for the air that has passed through the heat sinks 12 and 13 to the cooling fan 14. The space that forms the flow path for the air that has passed through the heat sinks 12 and 13 to the cooling fan 14 is a suitable position as it does not come into contact with the intake port 22 and the exhaust port 32. In particular, positioning it on the outer periphery that is not on the exhaust port side of the cooling fan 14, that is, substantially adjacent to the side where air flows into the cooling fan 14, is preferable in terms of noise reduction. It should be noted that some of the multiple resonators 40 may be positioned in the above positions.

[0121] In the embodiment, it was stated that the resonator 40 is preferably positioned such that the opening of the narrow space 41 faces a direction ranging from perpendicular to the flow path to downwind when viewed from the position of the expansion tube 42. By not having the opening of the narrow space 41 face upstream of the flow path, dust can be less likely to enter the expansion tube 42.

[0122] In the embodiment, an example was described in which the flow path is formed within the space forming the cooling structure 10 such that the expansion tube 42 is positioned at a location other than the position where the airflow velocity is fastest when the cooling fan 14 is operating. For example, the heat sinks 12 and 13 form the flow path, and the heat sinks 12 and 13 act as baffles, preventing high-velocity airflow from directly hitting the expansion tube 42 of the resonator 40. With such a flow path configuration and resonator arrangement, it is possible to maintain the cooling function while making it difficult for dust to enter the expansion tube, which is suitable for maintaining the sound-dampening effect.

[0123] In the embodiment, an example was given in which the ratio of the major axis to the minor axis of the expansion tube 42 is 2:1 or less in any two of the three directions: width, height, and depth. The thickness of the expansion tube 42 can be suppressed by making it flat, for example, but if it is made too thin, it will not function as a resonator. For example, if the ratio of the major axis to the minor axis is 3:1, it will not function as a resonator. Therefore, for example, as shown in Figures 9 and 12 to 15, the ratio of the major axis to the minor axis is set to 2:1 or less. This makes it possible to make the resonator 40 thinner while maintaining its effective function. In this disclosure, the major axis and minor axis may mean the length of one side in a rectangle, or the diameter in a circle or ellipse.

[0124] In this embodiment, the narrow space 41 is a rectangular cross-section with sides ranging from 1 mm to 0.1 mm, and the volume of the expansion tube 42 is 250 mm³. ３ An example is given below. The size of the expansion tube 42 and narrow space 41 of the resonator 40 is designed according to the frequency band to be resonated. In the imaging device 1, the frequency band to which the sound-dampening effect is desired is from 1 kHz to 2 kHz. This is because it is a frequency band to which human hearing is sensitive. In that case, the above size is suitable.

[0125] In this embodiment, the case body 11, which includes a cooling fan 14 and a resonator 40, is built into the outer casing 2 of the imaging device 1. However, the unit including the cooling structure 10, as in this embodiment, may be separate from the imaging device 1. For example, the unit including the cooling structure 10 with the cooling fan 14, etc., may be formed as a cooling accessory for a camera and be detachable from the imaging device 1. For example, it may be possible to attach it to the rear surface of the outer casing 2 when the display unit 4 is open. Even in such a cooling accessory, using the resonator 40 of this embodiment makes it possible to make it thinner, and the overall thickness does not become too large when attached to the imaging device 1. Furthermore, an appropriate sound-dampening effect can be obtained.

[0126] Furthermore, the effects described herein are merely illustrative and not limited to those described herein, and other effects may also occur.

[0127] Furthermore, this technology can also be configured as follows: (1) An imaging device comprising a cooling fan arranged inside a housing, and a resonator arranged inside the housing in a space common to the cooling fan, wherein the structure has a narrow space with an opening and an expansion tube having a non-spherical external shape with a planar region in communication with each other. (2) The imaging device according to (1) above, wherein the resonator is arranged inside the housing in a space where an airflow path is formed via the cooling fan, and is arranged in a manner that does not obstruct the airflow path. (3) The imaging device according to (1) or (2) above, wherein a plurality of the resonators are arranged in the space. (4) The imaging device according to any one of (1) to (3) above, wherein the expansion tube has an external shape having at least a first plane and a second plane that is the back side of the first plane as the planar region. (5) The imaging device according to any one of (1) to (4) above, wherein the expansion tube has a substantially rectangular parallelepiped shape. (6) The imaging device according to any one of (1) to (5) above, wherein one or more of the resonators are positioned within the housing so as not to be in contact with the air intake and exhaust ports of the cooling fan. (7) The imaging device according to (6) above, wherein a heat sink is positioned near the air intake, and the air that has passed through the flow path formed by the heat sink is discharged from the exhaust port via the cooling fan, and one or more of the resonators are positioned within a space that forms a flow path for the air that has passed through the heat sink to reach the cooling fan. (8) The imaging device according to any one of (1) to (7) above, wherein the resonators are positioned such that the opening of the narrow space faces a direction within a range from perpendicular to the airflow path when viewed from the position of the expansion tube. (9) The imaging device according to any one of (1) to (8) above, wherein the flow path is formed within the space such that the expansion tube is positioned anywhere other than within the housing of the cooling fan where the airflow velocity is fastest when the cooling fan is operating. (10) The imaging apparatus according to any one of (1) to (9) above, wherein the ratio of the major axis to the minor axis of the expansion tube in any two of the three directions of width, height, and depth is 2:1 or less.(11) The narrow space is rectangular with sides of 1 mm to 0.1 mm in cross-section, and the volume of the expansion tube is 250 mm³. ３ The imaging device described in any of the above (1) to (10).

[0128] 1 Imaging device 10 Cooling structure 11 Case body 12 First heat sink 12a First heat dissipation fins 13 Second heat sink 13a Second heat dissipation fins 14 Cooling fan 22 Intake port 40 Resonator 41 Narrow space 42 Expansion tube 43 Narrow space duct 50 Planar area 80 Case body 81 Cooling fan 82 Heat sink 83 Intake port 84 Exhaust port

Claims

1. An imaging device comprising a cooling fan located inside a housing, and a resonator located within the same space as the cooling fan inside the housing, wherein the resonator has a structure in which a narrow space with an opening and an expansion tube having a non-spherical external shape with a planar region are connected, and the resonator is located within the same space as the cooling fan inside the housing.

2. The imaging apparatus according to claim 1, wherein the resonator is positioned within the housing in a space where an airflow path is formed via the cooling fan, and is positioned in a manner that does not obstruct the airflow path.

3. The imaging apparatus according to claim 1, wherein a plurality of the resonators are arranged in the space.

4. The imaging device according to claim 1, wherein the expansion tube has an external shape having at least a first plane and a second plane that is the back side of the first plane as the planar region.

5. The imaging device according to claim 1, wherein the expansion tube is substantially rectangular in shape.

6. The imaging apparatus according to claim 1, wherein one or more of the resonators are positioned within the housing so as not to be in contact with the air intake and exhaust ports for air passing through the cooling fan.

7. The imaging apparatus according to claim 6, wherein a heat sink is placed near the air intake port, and air passing through the flow path formed by the heat sink is discharged from the exhaust port via the cooling fan, and one or more of the resonators are placed in a space that forms a flow path for the air passing through the heat sink to the cooling fan.

8. The imaging apparatus according to claim 1, wherein the resonator is positioned such that the opening of the narrow space faces a direction within the range from perpendicular to the airflow path when viewed from the position of the expansion tube.

9. The imaging apparatus according to claim 1, wherein the flow path is formed such that, within the space, the expansion tube is positioned at a location other than the one where the airflow velocity is fastest when the cooling fan is operating, except within the housing of the cooling fan.

10. The imaging apparatus according to claim 1, wherein the ratio of the major axis to the minor axis of the expansion tube in any two of the three directions of width, height, and depth is 2:1 or less.

11. The narrow space has a rectangular cross-section with sides measuring 1 mm to 0.1 mm, and the volume of the expansion tube is 250 mm³. ３ The imaging apparatus according to claim 1, which is as follows:

Images