Imaging device

Abstract

To cool an imaging element sufficiently by an airflow from a fan and to prevent the adhesion of fine particles in the airflow to an imaging surface.SOLUTION: An imaging apparatus 100 has an imaging element 115 including an optical member 115d in front of an imaging surface. The imaging apparatus has a fan 130 inside the same that generates an airflow in one direction along a rear surface on the opposite side of the imaging element from the imaging surface and a first dividing member 201 that is provided downstream of the imaging element in the one direction and that divides an inner space of the imaging apparatus into a first space A in which the optical member and imaging surface are arranged and a second space B in which the fan is arranged and the air flows. A portion 201a1 of a first dividing member that divides the first space and the second space in an imaging optical axis direction is located on a back side of a foremost surface of the optical member and on a front side of a back surface of the imaging element.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an imaging device having an internal cooling fan. [Background technology]

[0002] Imaging devices such as digital still cameras and video cameras are equipped with imaging elements such as CMOS sensors and CCD sensors for capturing subject images, as well as electronic elements such as CPUs and ICs mounted on circuit boards, which generate heat. If the temperature of the imaging elements or electronic elements rises excessively, their performance may deteriorate or malfunction may occur, making it impossible to capture good images. Patent Documents 1 and 2 disclose imaging devices that forcibly cool the imaging elements using airflow from an internally located fan. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-34791 [Patent Document 2] Patent No. 5631116 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the imaging device of Patent Document 1, although a board on which heat-generating electronic elements are mounted is thermally connected to a duct that is a flow path for the airflow from the fan, the thermal connection with the imaging element is weak, resulting in low cooling efficiency for the imaging element. Furthermore, the imaging device of Patent Document 2 has an image stabilization function that moves the imaging element in a direction perpendicular to the optical axis, but because the components thermally connected to the imaging element are cooled by the airflow from the fan, the movement direction of the imaging element is limited.

[0005] On the other hand, when a fan is disposed inside the imaging device, it is also necessary to control the airflow so that fine particles (dust) floating on the airflow from the fan do not adhere to the imaging surface of the imaging element.

[0006] The present invention provides an imaging device that can sufficiently cool an imaging element using airflow from a fan and can also suppress adhesion of fine particles to the imaging surface. [Means for solving the problem]

[0007] An imaging device according to one aspect of the present invention includes an imaging element provided with an optical member in front of an imaging surface, the imaging device including a fan for generating a unidirectional airflow along a rear surface of the imaging element opposite to the imaging surface, and a first dividing member disposed downstream of the imaging element in the unidirectional airflow direction, the first dividing member dividing the interior space of the imaging device into a first space in which the optical member and the imaging surface are disposed and a second space in which the fan is disposed and through which air flows. , and a substrate on which electronic elements are mounted, which is located behind the image sensor. The portion of the first dividing member that divides the first space and the second space in the imaging optical axis direction is located behind the front surface of the optical member and in front of the rear surface of the imaging element. The outlet of the fan is located forward of the substrate in the imaging optical axis direction, air flows along the substrate in one direction, and a third space is formed between the substrate and an exterior member facing the substrate to return the air that has flowed through the second space to the intake port of the fan, and the flow resistance of the third space is smaller than the flow resistance of the second space between the imaging element and the substrate. It is characterized by: [Effects of the Invention]

[0008] According to the present invention, the imaging element can be sufficiently cooled by the airflow from the fan, and the adhesion of fine particles contained in the airflow to the optical members and the imaging surface can be suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an exploded perspective view of a digital camera according to a first embodiment. [Figure 2] FIG. 1 is an exploded perspective view of a main part of a digital camera according to a first embodiment. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 10 is a cross-sectional view of a digital camera according to a second embodiment. [Figure 6] FIG. 1 is a block diagram showing the internal configuration of a digital camera according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Example]

[0011] 6 shows the configuration of a digital camera (hereinafter simply referred to as camera) 100 as an imaging device according to a first embodiment of the present invention. A lens unit 500 including a lens 501 is detachably (replaceably) attached to the camera 100. Note that for simplicity, only one lens 501 is shown in the figure, but in reality, multiple lenses are provided.

[0012] In camera 100, shutter 410 is a focal plane shutter that controls the exposure time of image sensor 115, which will be described later, and its operation is controlled by camera control unit 420, which will be described later. Image sensor 115 is composed of a CCD sensor or CMOS sensor, and performs photoelectric conversion (captures) of a subject image (optical image) formed by light passing through lens 501, and outputs an image signal (analog signal). A / D converter 412 converts the analog image signal output from image sensor 115 into a digital image signal. The digital image signal is written to memory 421 via image processing unit 413 and memory control unit 422, which will be described later, or via memory control unit 422 alone.

[0013] The image processing unit 413 generates image data by performing image processing such as pixel interpolation, resizing, and color conversion on the digital imaging signal from the A / D converter 412 or the memory control unit 422. Furthermore, the image processing unit 413 also performs auto white balance processing based on the results of calculations using the image data.

[0014] The camera control unit 420 is configured by a computer including a processor such as a CPU and circuits, and controls the entire camera 100 and imaging lens 500 by executing a program recorded in the nonvolatile memory 423. For example, the camera control unit 420 controls the image sensor 115 and the shutter 410 in response to an imaging instruction from the user, and also performs autofocus control and aperture control based on image data generated by the image processing unit 413.

[0015] The memory 421 temporarily records the digital imaging signal output from the A / D converter 412 and image data generated by the image processing unit 413. The memory control unit 422 controls the exchange of data between the A / D converter 412, the image processing unit 413, and the memory 421. The nonvolatile memory 423 is an electrically erasable and recordable read-only memory, and stores constants, programs, etc. for the operation of the camera control unit 420. The system memory 424 is a readable and writable memory that stores constants, variables, and programs, etc. for the operation of the camera control unit 420 read from the nonvolatile memory 423.

[0016] The system timer 425 measures the time of no operation until the camera 100 is put into an auto power-off state to save power in order to prevent battery drain when the camera 100 is not being operated by the user, and the exposure time of the image sensor 115 by the shutter 410.

[0017] The power supply unit 430 is configured with a primary battery, a secondary battery, or an AC adapter. The power supply control unit 431 determines whether a battery is installed in the power supply unit 430, determines the type of the installed battery, and detects the remaining battery capacity, and further supplies the required voltage to the supply destination at the required timing.

[0018] The camera communication terminal 440 is electrically connected to a lens communication terminal 506 provided in the lens unit 500 , and enables communication between the camera control unit 420 and a lens control unit 505 in the lens unit 500 .

[0019] The recording medium I / F 441 is an interface with a recording medium 600 that is detachably attached to the camera 100. The recording medium 600 is a memory card, a FLASH (registered trademark) memory, a hard disk, etc., and records image data (still images and videos) generated by the image processing unit 413.

[0020] The shake detection unit 442 is configured with a gyro sensor or the like, and outputs a signal corresponding to the shake of the camera 100 due to hand shake or the like (hereinafter referred to as camera shake).

[0021] The A / D converter 412, image processing unit 413, camera control unit 420, memory 421, memory control unit 422, nonvolatile memory 423, system memory 424, system timer 425, and power supply control unit 431 are mounted on the main board 107 as a plurality of electronic elements such as a CPU, IC, memory chip, etc. In addition, a recording medium I / F 441 and a shake detection unit 442 are also mounted on the main board 107.

[0022] The aforementioned memory 421 also serves as a memory for image display (video memory). The digital imaging signals and image data written to the memory 421 are displayed as live view images and imaging confirmation images on a rear display unit 450 provided on the rear surface of the camera 100 and on an EVF display unit 451 arranged in the viewfinder via a memory control unit 422. The rear display unit 450 and the EVF display unit 451 are configured with display elements such as a liquid crystal panel or an organic EL panel.

[0023] The operation unit 460 is an input unit that accepts operations by the user and outputs a signal corresponding to the accepted operation to the camera control unit 420. The operation unit 460 includes various operation members such as a mode changeover switch 461, a first shutter switch 463 and a second shutter switch 464 linked to a shutter button 462, a touch panel 465, and a power switch 466. The mode changeover switch 461 is operated to switch between imaging modes such as still image capture and video capture. The shutter button 462 is operated by the user to issue an imaging preparation instruction and an imaging instruction. The first shutter switch 463 is turned ON when the shutter button 462 is pressed halfway, and outputs an SW1 signal to the camera control unit 420. The second shutter switch 464 is turned ON when the shutter button 462 is pressed all the way, and outputs an SW2 signal to the camera control unit 420. The camera control unit 420 executes image capture preparation operations (autofocus, autoexposure, autowhite balance, etc.) in response to the SW1 signal, and executes image capture processing for a still image to be recorded in response to the SW2 signal.

[0024] The operation unit 460 also includes a touch panel 465 provided on the rear display unit 450. A power switch 466 is operated to turn the power of the camera 100 on and off.

[0025] Fan 130 is provided to generate an air flow near imaging unit 106, which includes imaging element 115, which is a heat source, to cool imaging element 115. Camera control unit (control means) 420 controls the driving of fan 130 (rotation / stop and rotation speed).

[0026] In the lens unit 500 , a lens communication terminal 506 is a camera communication terminal that enables the lens unit 500 to communicate with the digital camera 100 .

[0027] In the lens unit 500, a lens control unit 505 receives a control instruction from the camera control unit 420 via communication and controls the position (aperture value) of the aperture 503 and the focus of the lens 501 via an aperture drive unit 504 and a lens drive unit 502.

[0028] 1 shows an exploded view of the camera 100 seen obliquely from the rear side. The camera 100 has a front base 102, a rear cover 101, a top cover 103, a bottom cover 104, and a side cover 105 as exterior members.

[0029] The front base 102 is made of magnesium die-cast or resin, and has a mount 102a fixed thereto to which the lens unit 500 is attached, as well as a grip portion for the user to hold the camera 100.

[0030] A plurality of operating members that can be operated by the user and an openable / closable rear display unit 450 are attached to the rear cover 101. Also attached to the rear cover 101 is a finder unit 109 having an EVF display unit 451 and an eyepiece 443 to which a user who views the EVF display unit 451 brings their eye 700 close as shown in FIG.

[0031] A plurality of operating members (such as a mode selector switch 461, a shutter button 462, and a power switch 466) that can be operated by the user are attached to the top cover 103. The bottom cover 104 has openings formed therein for exposing a battery cover that covers the opening of the battery chamber and a tripod mount that is fixed to the bottom surface of the front base 102. A terminal cover 105a is attached to the side cover 105 for protecting an external communication terminal 107c, which will be described later.

[0032] Inside these exterior members, there are arranged an imaging unit 106 having an imaging element 115 and an image shake correction mechanism, a main board 107, a shutter 108, and a chassis 110. The imaging unit 106 has a movable part 114 that can move the imaging element 115 in two directions that are perpendicular to the imaging optical axis (the optical axis of the lens unit 500) and perpendicular to each other, and a drive base (described later) that holds the movable part 114 so that it can move in the two directions.

[0033] The main board 107 is made up of a multi-layer board, and various electronic components including the above-mentioned electronic elements are mounted on both sides of the board. The main board 107 is fixed to the front base 102 and a metal chassis 110 with screws. Furthermore, the main board 107 is mounted with a recording medium connector 107b for storing an external recording medium and an external communication terminal 107c for connecting a cable for connecting to an external device.

[0034] Among the components of the camera 100, the image sensor 115 consumes particularly large amounts of power, generates a large amount of heat, and is prone to temperature rise. The imaging time of the camera 100 is limited in many cases by the guaranteed operating temperature of the image sensor 115, excluding the remaining battery charge. To maximize the imaging time, it is necessary to cool the image sensor 115 so that its temperature does not exceed the guaranteed operating temperature. The imaging unit 106, which includes the image sensor 115, is fixed to the front base 102 with screws, and heat from the imaging unit 106 is transferred to the front base 102.

[0035] The fan 130 is disposed near the imaging unit 106 and is oriented so that the air discharge direction is perpendicular to the imaging optical axis. The air from the fan 130 flows in one direction along the back surface of the imaging element 115, thereby effectively cooling the imaging element 115. In this embodiment, a centrifugal fan is used as the fan 130. However, other fans, such as an axial fan, may also be used. Furthermore, the orientation of the fan 130 is not limited to the above-described orientation, and it is sufficient that the airflow from the fan 130 is oriented so as to directly impinge on the imaging element 115, and the discharge direction does not have to be perpendicular to the imaging optical axis.

[0036] As described above, the multiple electronic elements 107a mounted on the main board 107 are also heat sources. Therefore, by arranging the fan 130 so as to circulate air between the imaging element 115 and the main board 107, a cooling effect can be obtained for the imaging element 115 and the multiple electronic elements 107a.

[0037] However, since the imaging unit 106, which has the movable part 114, has few heat dissipation paths, the cooling of the imaging element 115 can be performed more effectively by locating the outlet of the fan 130 closer to the imaging unit 106 than to the main board 107.

[0038] 2(a) and 2(b) show exploded views of the imaging unit 106 as viewed obliquely from the front and rear, respectively. The imaging unit 106 has a movable part 114 and a drive base (base member) 113. The movable part 114 is composed of an imaging element 115 and a sensor holder 117 that holds it. The imaging element 115 is configured by adhesively fixing a sensor chip having multiple pixels to an imaging substrate 115a, and electrically connecting electrodes of the sensor chip to an imaging circuit on the imaging substrate 115a by wire bonding. The imaging element 115 is fixed to the sensor holder 117 by adhesive. Sensor electronic elements 115b, such as capacitors, resistors, and regulators that constitute the imaging circuit, are mounted on the back surface (rear surface) of the imaging substrate 115a, opposite the surface on which the sensor chip is attached.

[0039] The sensor holder 117 is held by the drive base 113 so as to be movable in two directions (horizontal and vertical directions) that are perpendicular to the imaging optical axis and perpendicular to each other. Three coils 116 are fixed to the sensor holder 117. The drive base 113 holds three magnets 118 so as to face the three coils 116. The movable part 114 is attracted in the imaging optical axis direction (rearward) by the magnetic force of the magnets 118. Balls (not shown) held by ball holding parts 117a provided at multiple locations on the sensor holder 117 are disposed between the movable part 114 and the drive base 113. As a result, the movable part 114 is positioned relative to the drive base 113 in the imaging optical axis direction via the balls.

[0040] In the imaging unit 106 configured in this manner, the imaging element 115 can be moved in the two directions described above by controlling the energization of the three coils 116. The camera control unit 420 controls the energization of the coils 116 in accordance with the camera shake detected by the shake detection unit 442 so as to move the movable unit 114 in a direction that reduces (corrects) the image shake caused by the camera shake.

[0041] The imaging unit 106 and the main board 107 are electrically connected using an FPC. The imaging signal FPC 111 shown in Fig. 1 has wiring for transmitting imaging signals output from the imaging element 115 and control signals required to drive the imaging element 115, and these signals are sent to a camera control unit 420 on the main board 107. The imaging power supply FPC 112 shown in Fig. 1 has wiring for supplying power for driving the imaging element 115 from a power supply control unit 431 to the imaging element 115.

[0042] Next, a configuration for efficient cooling by the fan 130 will be described. As shown in FIGS. 3(a), (b), and 4(a), a first divided member 201 and a second divided member 202, which are dividing members (partition members) that divide the internal space of the camera 100, are arranged around the imaging unit 106 and the main board 107. FIGS. 3(a) and 3(b) show these members as viewed from the rear and side, respectively. A cross section of the first divided member 201 is shown so that the internal structure can be seen. FIG. 4(a) shows these members disassembled and viewed obliquely from the front.

[0043] The first divided member 201 is made up of a first airflow restriction section 201a and a third airflow restriction section 201b combined with the first airflow restriction section 201a. The first divided member 201 is disposed downstream (below in each drawing) of the imaging element 115 in one direction in which air flows along the back surface (rear surface) of the imaging element 115. In other words, the first divided member 201 is disposed on the opposite side of the imaging unit 106 from the fan 130 in an in-plane direction perpendicular to the imaging optical axis.

[0044] The second divided member 202 is composed of a second airflow restriction section 202a and a fourth airflow restriction section 202b, which are arranged in an area around the imaging unit 106 where the first divided member 201 is not arranged. Specifically, the second airflow restriction section 202a is arranged on the same side of the imaging unit 106 as the fan 130 (the upper side in each figure) in an in-plane direction perpendicular to the imaging optical axis. The fourth airflow restriction section 202b is arranged on the opposite side of the imaging unit 106 from the side cover 105, which is an exterior member, (the right side in FIG. 3(a) and the left side in FIG. 4(a)). The side cover 105 also serves as part of the second divided member.

[0045] As shown in FIG. 3(b), the first divided member 201 and the second divided member 202 are each arranged so that a narrow gap of approximately 1 mm or less is formed between them and the imaging unit 106 in the imaging optical axis direction. However, as shown in FIG. 3(a), when the gap is viewed from the imaging optical axis direction, a portion of each of the first divided member 201 and the second divided member 202 overlaps with the imaging unit 106 (drive base 113). This makes it difficult for some of the air flowing through the second space B to flow into the first space A through the gap. Furthermore, the gap between the bottom cover 104 and the side cover 105, which are exterior members, is also set to approximately 1 mm or less.

[0046] 3(b), the first dividing member 201 and the second dividing member 202 arranged in this manner can separate a first space A facing the imaging surface of the imaging element 115 from a second space B between the rear surface of the imaging element 115 (the surface on which the sensor electronics 115b is mounted) and the main board 107. The separation here means that it is sufficient to significantly prevent fine particles (dust) contained in the airflow from the fan 130 inside the camera 100 from entering the first space A from the second space B, but it is not necessary to completely prevent the entry of dust. Of course, the above-mentioned gap may be filled with an elastic member or the like to completely prevent the entry of dust.

[0047] It is desirable that neither first divided member 201 nor second divided member 202 have any holes through which air passes, but they may have small holes that allow only a small amount of air to pass through.

[0048] As shown in FIG. 3(b), the imaging element 115 includes a sensor chip 115c fixed to an imaging substrate 115a and an optical member 115d, such as an infrared cut filter, a low-pass filter, and a cover glass, that covers the light-receiving surface (imaging surface) of the sensor chip 115c. The first airflow restriction member 201a, located below the imaging unit 106, has an end 201a1 facing the imaging unit 106, which is located behind the front surface (foreground) of the optical member 115d and in front of the back surface of the imaging element 115 (imaging substrate 115a) in the imaging optical axis direction. That is, the end 201a1 is positioned so that the airflow hits the sensor electronic component 115b mounted on the back surface of the imaging substrate 115a. The end 201a1 is adjacent to the imaging unit 106 (movable portion 114) in a direction perpendicular to the imaging optical axis and separates the first space A from the second space B in the imaging optical axis direction.

[0049] As described above, first airflow restriction section 201a only needs to have a configuration that can separate first and second spaces A and B. That is, it is only necessary that the gap between imaging unit 106, bottom cover 104, and side cover 105 is narrow, and that at least a portion of the gap (for example, end 201a1) is positioned at the above-described position in the imaging optical axis direction. This makes it possible to prevent dust contained in the airflow from fan 130 from adhering to the surface of optical member 115d of imaging element 115, without increasing the size of camera 100.

[0050] 3(b), at least a portion (end 202a1 facing the imaging unit 106) of the second airflow restriction unit 202a arranged above the imaging unit 106 is arranged behind the light receiving surface of the sensor chip 115c in the imaging optical axis direction and in front of the outlet 131 of the fan 130. The end 202a1 is close to the imaging unit 106 (movable part 114) in a direction perpendicular to the imaging optical axis, and is a part that separates the first space and the second space in the imaging optical axis direction.

[0051] As shown in FIG. 4(b), the third airflow restriction section 201b has a recess 201c and a protrusion 201d that serve as guides for guiding the airflow (indicated by arrows in the figure) that is discharged from the fan 130 and passes through the second space B to cool the image sensor 115 and the main board 107. A collecting member 203 is provided on the bottom surface (bottom portion) of the recess 201c and on the ceiling surface (opposing portion) facing the protrusion 201d. The third airflow restriction section 201b also has an opening 201e that discharges air to the outside. The third airflow restriction section 201b and the first airflow restriction section 201a are fixed to each other so as to be integrated.

[0052] The fourth airflow restriction section 202b is disposed so that the gap between itself and the imaging section 106 and the gap between itself and the first divided member 201 are narrowed.

[0053] FIG. 3(b) shows the path along which air discharged from the fan 130 circulates within the camera 100. As indicated by the arrows in the figure, air discharged from the outlet 131 of the fan 130 passes through the second space B between the imaging unit 106 and the main board 107 and flows into the internal flow path within the first divided member 201, which is composed of the first and third airflow restriction sections 201a and 201b. The air that has passed through the internal flow path within the first divided member 201 flows through the opening 201e toward the rear side of the camera 100, opposite the imaging unit 106. The air then passes through the third space C between the main board 107 and the exterior member (the bottom, rear, and top covers 101, 104, and 103 are shown schematically in the figure), moves upward within the camera 100, and is drawn into the intake port of the fan 130. The flow path of the third space C is preferably configured appropriately to minimize resistance to the airflow passing therethrough. It is preferable that the flow path resistance of the third space C is smaller than the flow path resistance of the second space B at least.

[0054] A gap is provided between first and second airflow restriction sections 201a, 202a and movable section 114, corresponding to the range of movement of movable section 114 in the up-down direction. The size of this gap is preferably as small as possible, and it is desirable that the total cross-sectional area of ​​the gap is at least smaller than the minimum cross-sectional area of ​​the internal flow path within first divided member 201. This is because, by making the cross-sectional area of ​​the internal flow path within first divided member 201 larger, the flow path resistance becomes smaller than that of the gap, and air that flows out from the internal flow path through opening 201e can more easily flow rearward within camera 100. This makes it less likely that dust contained in the airflow will adhere to imaging element 115 on the front side.

[0055] The third airflow restriction section 201b and trapping member 203 shown in FIG. 4(b) will now be described in detail. The air that cools the image sensor 115 and main board 107 and then flows into the first divided member 201 flows into a recess 201c provided in the third airflow restriction section 201b, where some of the air stagnates. At this time, dust in the stagnant air falls toward the bottom of the recess 201c. A trapping member 203 is provided on this bottom. The trapping member 203 is a member that can trap dust, and is made of tape with an adhesive surface, an adhesive elastic member, or a porous member such as a sponge. In this way, the dust that falls to the bottom is collected.

[0056] The air flowing out of recess 201c then hits the slope of protrusion 201d and flows upward, hitting collection member 203 attached to the ceiling surface of third airflow restriction section 201b. At this time, dust in the air is collected by collection member 203. Collection member 203 may be attached anywhere on the inner surface of third airflow restriction section 201b. The air with reduced dust content flows out rearward through opening 201e of third airflow restriction section 201b.

[0057] As described above, in this embodiment, the first and second dividing members 201 and 202 make it difficult for the airflow from the fan 130 to flow into the first space A on the imaging surface side of the imaging element 115, and dust contained in the airflow on the second space B side is collected by the collecting member 203. This makes it possible to suppress adhesion of dust to the imaging surface of the imaging element 115 and the surface of the optical member 115d. [Example]

[0058] FIG. 5 shows a schematic cross section of the exterior members (front base 102 and bottom, rear and top covers 101, 104, 103), imaging unit 106, fan 130 and first divided member 201 of a camera 100' according to a second embodiment of the present invention.

[0059] The first divided member 201 is disposed so as to surround a front space (first space) M extending from the periphery of the optical member 115d of the imaging unit 106 to the front base 102. An end 201a1 of the first airflow restriction section 201a of the first divided member 201 that faces the imaging unit 106 is disposed rearward of the surface (frontmost surface) of the optical member 115d in the imaging optical axis direction and forward of the rear surface of the imaging element 115 (imaging board 115a) in the imaging optical axis direction. The end 201a1 separates the front space M from the remaining rear space (second space) U in the imaging optical axis direction. The end 201a1 is disposed so that the gap between the end 201a1 and the drive base 113 of the imaging unit 106 in the imaging optical axis direction is approximately 1 mm or less.

[0060] The rear space U faces the rear surface of the imaging element 115 (sensor electronics 115b) and the inner surfaces of the bottom, rear, and top covers 101, 104, and 103, and air discharged from the fan 130 circulates within this space.

[0061] In this embodiment, the first divided member 201 makes it difficult for the airflow from the fan 130 to flow into the front space M on the imaging surface side of the imaging element 115. This makes it possible to prevent dust contained in the airflow in the rear space B from adhering to the imaging surface of the imaging element 115 and the surface of the optical member 115d. This embodiment is particularly suitable for cameras that do not have a shutter.

[0062] The embodiments described above are merely representative examples, and various modifications and alterations are possible to each embodiment when implementing the present invention. [Explanation of symbols]

[0063] 100 digital cameras 106 Imaging unit 107 Main board 115 Image sensor 115a Imaging board 115c sensor chip 130 fans 201 First divided member 202 Second divided member 203 Collection material

Claims

1. An imaging device having an imaging element with an optical member in front of an imaging surface, a fan that generates a unidirectional air flow along a rear surface of the imaging element opposite to the imaging surface inside the imaging device; a first dividing member provided downstream of the imaging element in the one direction and dividing an internal space of the imaging device into a first space in which the optical member and the imaging surface are disposed and a second space in which the fan is disposed and through which the air flows; a substrate on which electronic elements are mounted, the substrate being disposed behind the imaging element; a portion of the first divided member that divides the first space and the second space in the imaging optical axis direction is located rearward of the forefront surface of the optical member and forward of the rear surface of the imaging element, an outlet of the fan is located forward of the substrate in the imaging optical axis direction, and the air flows along the substrate in the one direction; a third space is formed between the substrate and an exterior member facing the substrate to return the air that has flowed through the second space to an intake port of the fan, An imaging device, characterized in that the flow resistance of the third space is smaller than the flow resistance between the imaging element and the substrate in the second space.

2. a second dividing member that is disposed at a position different from the first dividing member inside the imaging device and divides the internal space into the first space and the second space; 2. The imaging device according to claim 1, wherein the portion of the second dividing member that separates the first space and the second space in the imaging optical axis direction is located behind the frontmost surface of the optical member and in front of the outlet of the fan.

3. the imaging element is held by a base member, 3. The imaging device according to claim 2, wherein the first and second divided members have portions that overlap the base member when viewed in the imaging optical axis direction.

4. 4. The imaging device according to claim 2, wherein at least a part of the second divided member is an exterior member of the imaging device.

5. 5. The imaging device according to claim 1, wherein a collecting member for collecting fine particles contained in the air flowing through the second space is provided in a portion of the first divided member facing the second space.

6. a recessed portion that retains at least a portion of the air flowing through the second space is provided in a portion of the first divided member that faces the second space, 6. The imaging device according to claim 5, wherein the collection member is disposed at the bottom of the recess.

7. a protrusion that changes the direction of the air flow in the second space is provided on a portion of the first divided member facing the second space, 6. The imaging device according to claim 5, wherein the collection member is provided at a position facing the protrusion.

8. the imaging element is movable in a direction perpendicular to the imaging optical axis direction, and a gap is provided between the first and second divided members and the imaging element according to a range of movement of the imaging element; the first dividing member has an internal flow path that allows the air that has flowed along the rear surface of the imaging element in the second space to pass into the third space, 5. The imaging device according to claim 2, wherein a total cross-sectional area of ​​the gaps is smaller than a minimum cross-sectional area of ​​the internal flow path.

Images