JP2015126128A - Electronic apparatus having forced air cooling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that since a plurality of centrifugal fans are arranged vertically, exhaust air from a centrifugal fan strikes another centrifugal fan, and a configuration for avoiding that problem by bending the exhaust gas steeply has a high draft resistance and a low exhaust efficiency.SOLUTION: An electronic apparatus includes at least centrifugal fans 1 and 2, where the centrifugal fan 2 is arranged side by side in the rotary circumferential direction of the centrifugal fan 1, and when arranging the centrifugal fan 2 in the exhaust direction of the centrifugal fan 1, the centrifugal fan 1 is tilted by the thickness of the centrifugal fan 2 or more.

Description

  The present invention relates to an electronic device having a forced air cooling function.

  In recent years, as the market demands electronic devices with smaller size and higher functionality (increasing power consumption), the temperature of electronic devices has increased, and thermal runaway due to exceeding the guaranteed temperature of ICs such as microcomputers has become a problem in recent years. It has become.

  In order to cool the heat source for the above problem, forced air cooling using a fan (fan function unit), particularly a centrifugal fan with high static pressure, is generally used, and a plurality of centrifugal fans are often used ( Patent Document 1).

JP 2009-147243

  However, in the heat dissipation using forced air cooling described in Patent Document 1, since a plurality of centrifugal fans are arranged vertically, the exhaust of the centrifugal fan hits another centrifugal fan. In order to avoid this, the exhaust gas is sharply bent by a duct, but there is a problem that the ventilation resistance is high and the exhaust efficiency is lowered.

In the case where at least the centrifugal fan 1 and the centrifugal fan 2 are provided, the centrifugal fans 2 are arranged side by side in the rotational circumferential direction of the centrifugal fan 1, and the centrifugal fan 2 in the exhaust direction of the centrifugal fan 1 is disposed.
The electronic device according to claim 1, wherein the centrifugal fan 1 is disposed at an angle more than the thickness of the centrifugal fan 2.

In an electronic device having a duct,
An electronic device, wherein a space is arranged on an inlet side of the centrifugal fan, which is formed obliquely with respect to the centrifugal fan.

  As described above, according to the present invention, it is possible to provide an electronic device with good exhaust efficiency while reducing the height direction of the electronic device.

Block diagram of imaging device External view of imaging device (Part 1) External view of imaging device (part 2) External view of main unit 200 (Part 1) External view of main unit 200 (Part 2) External view of main unit 200 (Part 3) External view of main unit 200 (Part 4) External view of main unit 200 (Part 5) External view of main unit 200 (Part 6) The figure which showed a mode that the exterior part was removed from the main-body part 200 (the 1) The figure which showed a mode that the exterior part was removed from the main-body part 200 (the 2) The figure which showed a mode that the exterior part was removed from the main-body part 200 (the 2) Structure around the image sensor (part 1) Structure around the image sensor (Part 2) Diagram showing mechanical connection between heat sink 510 and heat sink / duct a302 (Part 1) Diagram showing mechanical connection between heat sink 510 and heat sink / duct a302 (Part 2) Diagram showing mechanical connection between heat sink 510 and heat sink / duct a302 (Part 3) Diagram showing mechanical connection between heat sink 510 and heat sink / duct a302 (Part 4) Diagram showing the structure around the main board (Part 1) Diagram showing the structure around the main board (Part 2) Diagram showing the structure around the main board (Part 3) Diagram showing structure around main board (Part 4) Diagram showing structure around main board (Part 5) Diagram showing the structure around the main board (No. 6) Diagram showing the structure around the main board (No. 7) Diagram showing the structure around the main board (No. 8) Control flow of the present embodiment (part 1) Control flow of this embodiment (part 2)

<First Embodiment>
1 General Description Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiment, an example in which the present invention is applied to an imaging apparatus having an external power supply unit will be described.

1-1 System Block Diagram FIG. 1 is a block diagram illustrating functions of an imaging apparatus according to an embodiment of the present invention.

(Description of block diagram, operation)
The control unit 101 is a block that controls the operation of each block included in the imaging apparatus. For example, the control unit 101 reads out each block operation program of the imaging apparatus stored in the ROM 102, develops it in a RAM (not shown), and executes it to control the operation of the block. A ROM 102 is a rewritable nonvolatile storage memory, and in addition to an operation program for each block of the imaging apparatus, for example, setting values such as parameters necessary for the operation of each block, and data such as a GUI displayed on the image display unit 108 Remember. Since the control unit 101 consumes a large amount of power and generates a lot of heat, the control unit 101 may fall into an uncontrollable state if the guaranteed temperature is exceeded.

  The operation input unit 103 is an input interface provided in the imaging apparatus, such as a trigger switch or a mode switch. For example, when an operation input is performed by the user, the input operation content is transmitted to the control unit.

  The imaging unit 104 is an imaging element such as a CCD or CMOS sensor, for example, photoelectrically converts a subject image formed on the imaging element by an optical system, and transmits the obtained analog image signal to the A / D conversion unit. . The A / D conversion unit 105 applies A / D conversion processing to the input analog image signal, and transmits the obtained digital image to the image processing unit 106. Due to the characteristics of the imaging unit 104, the imaging image quality may deteriorate when the guaranteed temperature is exceeded. In addition, for example, when the imaging apparatus is in the recording mode, the A / D conversion unit can sequentially output the obtained digital image to the image display unit 108, and the image display unit can function as an electronic viewfinder or an LCD monitor. It is.

  The image processing unit 106 applies various image processing and enlargement / reduction processing to the input digital image. When recording processing is performed, the image processing unit sequentially stores digital images to which various types of processing are applied, for example, in a RAM, and the moving image data of the obtained image group is a frame rate including a shooting time and a frame rate at the time of imaging. Along with the information, it is encoded into moving picture data in the AVCHD format. In addition, the image processing unit reads encoded moving image data recorded on a recording medium 107 described later under the control of the control unit, decodes it, and outputs it to the image display unit. Further, the image processing unit applies various image processing and enlargement / reduction processing to the moving image data and the GUI data stored in the ROM, synthesizes them, and outputs them to the image display unit. Since the image processing unit 108 consumes a large amount of power and generates a large amount of heat, it may fall into an uncontrollable state when the guaranteed temperature is exceeded.

  The recording medium 107 is a recording area for recording the recorded moving image data. For example, the recording medium 107 is a recording device such as a built-in memory included in the imaging device or a memory card or HDD that is detachably connected to the imaging device. The image display unit 108 is a display device included in an imaging device such as a small LCD, and is used for reproducing captured images and moving image data recorded on the recording medium 107.

  The wireless transmission / reception unit 109 includes an antenna for wireless transmission / reception. When wireless transmission is performed, the recorded moving image data, still image data, or captured data stored in the recording medium 107 is subjected to processing for wireless transmission / reception and transmitted from the antenna. When wireless reception is performed, the transmitted data is processed and output to the image display unit 108. At this time, the wireless transmission / reception unit 109 becomes a high heat generation unit. The power supply unit 110 converts the power obtained from the external power supply unit 111 into a predetermined voltage and supplies it to each block. The optical system 112 has a function of forming an optical image on the photographing unit 104.

  The air blowing unit 113 is a device for circulating air to cool the device, for example, a cooling device incorporated in the device so as not to overheat. In this embodiment, the air blowing unit 113 will be described using a fan. There are centrifugal fans and axial fans depending on the shape and function. The fan is activated in response to a signal from the control unit 101, detects the number of rotations of the fan blades, and feeds back to the control unit 101 to control the number of rotations. In the present embodiment, description will be made using a centrifugal fan.

  The temperature detection unit 114 detects the temperature and transmits temperature information to the control unit 101. In this embodiment, a thermistor is arranged on a substrate in the vicinity of a location where the guaranteed temperature of the imaging unit 104, the image processing unit 106, etc. is low or high, and the temperature is detected, transmitted to the control unit 101, and stored in the ROM 102. The rotation speed of the fan is controlled according to the programmed program. This makes it possible to control the rotational speed of the fan based on the temperature. A main body 115 indicates a control range included in the main body.

1-2 Appearance Description FIG. 2 is an overall view of the present embodiment. 2A is a perspective view of the exterior portion R 203 side, and FIG. 2B is a perspective view of the exterior portion L 204 side. This embodiment is an imaging apparatus that can be used by a photographer using a tripod, a rig, or the like. The present embodiment includes a main body 200 and a removable lens 201. The main body unit 200 corresponds to the main body 115 shown in FIG. 1, and the lens unit 201 corresponds to the optical system 112 shown in FIG.

  The main body 200 includes an exterior part TOP 202, an exterior part R 203, an exterior part L 204, an exterior part rear 205, an exterior part bottom 206, an exterior part front 207, a major hook pin 208, an intake port 209, an operation button 210, an operation, and an image. The display panel 211, the media slot cover 212, the exhaust port 213, the cheese plate lower 214, the external terminal input / output 215, and the cheese plate upper 216 are configured. The cheese plate lower 214 and the cheese plate upper 216 have a large number of tripod female screw portions and have a function capable of attaching various accessories.

  In the present embodiment, the lens unit 201 has various input / output means similar to those used in a general interchangeable lens imaging apparatus, and is mechanically, optically, and electrically connected to the main body unit 200. The lens unit 201 can be replaced with a lens unit having different characteristics.

2 Explanation of Structure 2-1 Explanation of Heat Dissipation Structure FIG. 3 is an external view of the main body 200. 3A is a diagram showing the main body 200 in the exterior R 203 surface view, and FIG. 3B is a diagram showing the main body 200 in the exterior front 207 surface view. 3c is a sectional view A_A of FIG. 3a, FIG. 3d is a sectional view B_B of FIG. 3a, FIG. 3e is a sectional view C_C of FIG. 3a, and FIG. 3f is a sectional view D_D of FIG.

  A dotted arrow 301 described in FIG. 3 c indicates the flow of air passing through the main body 200. Air enters the main body 200 through the air inlet 209, passes through the heat sink / duct a 302 and the fan 303, and is discharged from the air outlet 213. In this process, heat is transferred from the heat sink / duct a 302 to the air, and the heat in the main body 200 is discharged to the outside. In this embodiment, the heat sink / duct was made of highly heat conductive aluminum die cast.

  Dotted arrows 310 and 311 described in FIG. 3d indicate the flow of air passing through the main body 200. Air enters the main body 200 through the air inlet 209, passes through the heat sink / duct b (305, 304) and the fans 306, 307, and is discharged from the air outlet 213. In this process, heat is transferred from the heat sink / duct to the air, and the heat in the main body 200 is discharged to the outside.

  Dotted arrows 312 and 313 shown in FIG. 3e indicate the flow of air that passes through the main body 200. Air enters the main body 200 through the air inlet 209, passes through the heat sink and ducts 308 and 309 and the fans 306 and 307, and is discharged from the air outlet 213. In this process, heat is transferred from the heat sink / duct to the air, and the heat in the main body 200 is discharged to the outside.

  FIG. 3f shows the state of heat transfer from the heat source to the heat sink / duct, and heat transfer from the heat sink / duct to the exterior portion TOP 202. Here, only the heat flow will be briefly described, and the detailed structure will be described later. The heat sources in this embodiment are the sensor and sensor board 314, the main board a 315, the main board b 316, the main board c 317, the card medium 321 and the board 320. All of the shapes are substantially plate shapes. These heat sources are arranged substantially in parallel. First, the heat on the left side of the sensor and sensor substrate 314 and the main substrate a 315 in the drawing is transferred to the heat sink / duct a 302 disposed therebetween. In the present embodiment, thermal connection is made by interposing a heat-dissipating rubber having functions of elasticity and high thermal conductivity between them.

  Here, it is not illustrated because it is complicated in the drawing. Further, the heat on the right side of the main board a 315 in the drawing and the heat on the left side of the main board b 316 in the drawing is transferred to the heat sink and duct b (305, 304) disposed between them. In the present embodiment, thermal connection is made by interposing a heat-dissipating rubber having functions of elasticity and high thermal conductivity between them. Here, it is not illustrated because it is complicated in the drawing.

  Further, heat on the right side of the main board b 316 in the drawing and the left side of the main board c 317 in the drawing is transferred to the heat sink / duct C (308, 309) disposed between them. In the present embodiment, thermal connection is made by interposing a heat-dissipating rubber having functions of elasticity and high thermal conductivity between them. Here, it is not illustrated because it is complicated in the drawing. Further, the heat on the right side surface of the main board c 317 in the drawing is transferred to the heat sink 318. In the present embodiment, thermal connection is made by interposing a heat-dissipating rubber having functions of elasticity and high thermal conductivity between them. Here, it is not illustrated because it is complicated in the drawing.

  In the following examples, “thermally connected” means heat connection by heat conduction by the heat-dissipating rubber or heat conduction by fastening screws or the like.

  The heat sink 318 is cooled by the wind generated by the internal circulation fan 319. In addition, the internal circulation fan 319 is disposed between the main board c 317 and the card medium 321, so that the card medium 321 and the board 320 are cooled at the same time. It is possible to Further, the heat sink and ducts 320, 305, 304, 308, and 309 are thermally connected to the exterior part TOP 202. In this embodiment, thermal connection is made by interposing a heat-dissipating rubber 322 having a function of elasticity and high thermal conductivity between them. The exterior part TOP202 is thermally connected to the other exterior part, exterior part R203, exterior part L204, exterior part rear 205, exterior part bottom 206, exterior part front 207, and can be naturally cooled using the surface of the body part 202. It has become. In this example, the exterior part TOP202, the exterior part R203, the exterior part L204, the exterior part rear 205, the exterior part bottom 206, and the exterior part front 207 were made of magnesium die cast having both high thermal conductivity and high strength. Other materials can be used as long as they have high thermal conductivity and strength to maintain the appearance.

  FIG. 4 shows a state in which the exterior part is removed from the main body part 200. FIG. 4A is a perspective view seen from the operation display panel 211 side. FIG. 4b is a perspective view seen from the opposite side. 4c is a side view of the operation display panel 211. FIG. FIG. 4d is a cross section E_E of FIG. 4c.

  A new heat sink / duct d 401 and heat sink / duct e 403 are arranged on both sides of the heat sink / duct a 302, the heat sink / duct b (305, 304), and the heat sink / duct c (308, 309) in the intake / exhaust direction shown in FIG. The heat sink and duct a 302, the heat sink and duct b (305, 304), and the heat sink and duct c (308, 309) are thermally connected. Further, the heat sink / duct d 401 on the air inlet side thermally connects the heat of the card medium 321 and the substrate 320 via the heat sink 404. FIG. 4 b shows the fans 306 and 307 attached to the heat sink / duct e 403.

2-2 Imaging Device Peripheral Structure FIG. 5 shows a structure around the imaging device. 5a is an integrated state, and FIG. 5b is an exploded perspective view. As shown in FIG. 5a, the outer frame 501 is mechanically and thermally connected to the heat sink / duct a 302 by fastening screws 502. In this embodiment, the heat sink / duct a 302 has an L shape. The outer frame 501 is made of magnesium alloy with high thermal conductivity and high strength, and the heat sink and duct are also made of aluminum die cast with high thermal conductivity and high strength, so the image sensor is very robust and protected from external forces It becomes. As shown in FIG. 5b, the lens mount portion 503, the heat insulating spring portion 504, the front base 506, the ND filter portion 507, the image sensor and substrate 508, the image sensor holder 509, the heat sink 510, the fan screw 511, and the image sensor screw 512 It is configured. As a mechanical structure, the front base 507 is elastically held on the outer frame 501 via a heat insulating spring portion 504.

  In this embodiment, the heat insulating spring portion 504 is made of a stainless spring material having a lower thermal conductivity than magnesium or aluminum. In the front base 507, a lens mount 503, an ND filter 507, an image sensor and substrate 508, an image sensor holder 509, and a heat sink 510 are mechanically held by screws. The fan 303 is fastened to the heat sink / duct a 302 by a fan screw 511. The heat insulating spring 504 is used in order to prevent the heat of the heat sink / duct a 302 from being transmitted to the image sensor and the substrate 508 via the outer frame 501 and the heat insulating spring 504 and the front base 506.

  The reason why the spring property is necessary is that the distance from the image sensor to the mount (flange back) does not shift when an external impact is applied to the outer frame 501. The heat sink 510 is thermally connected to the imaging element and the substrate 508 via a heat radiating rubber (not shown).

  FIG. 6 is a diagram showing the mechanical connection between the heat sink 510 and the heat sink / duct a302. FIG. 6A is a view in which the outer frame 501 and the heat sink / duct a 302 are removed from FIG. 5A. As described above, the unit in this state is elastically held with respect to the outer frame 501 and the heat sink / duct duct a 302.

  FIG. 6b is an exploded perspective view of the heat sink 510 and the heat sink / duct a 302, which is a frame-shaped elastic airtight member 601. As shown in FIG. 6b, the heat sink 510 and the heat sink / duct a 302 are elastically held and hermetically sealed by a frame-shaped elastic hermetic member 601. This makes it possible to minimize the stress applied to the heat sink 510 by the heat sink / duct a 302. Therefore, the distance (flange back) from the image sensor to the mount is difficult to shift. FIG. 6c is a diagram of FIG.

  FIG. 6d is a sectional view F_F of FIG. 6c. As shown in FIG. 6d, by disposing the fan 303 in a direction other than the retracting direction of the ND filter 507 and disposing the heat sink / duct a 302 therebetween, the heat sink / duct between the fan 303 and the imaging device / substrate 508 is disposed. a 302 can be placed.

(Description of ND filter)
The ND filter 507 used in the present embodiment is a turret type and is not shown, but a disk rotation shaft 507a exists at the center of the disk, and three ND filters are arranged around the rotation axis. . Therefore, the direction that is not the retracting direction of the ND filter 507 is only the downward direction on the drawing of FIG. 6d.

  With this configuration, the heat sink and duct a 302 is formed of a magnetic shielding material, or a magnetic shielding material sheet is pasted on the flat surface 602 immediately above the fan 303, so that noise due to magnetic fluctuations generated when the fan 303 rotates is imaged. The device and the substrate 508 are not affected. In the present embodiment, the anti-magnetic may be a material which is not only shielded by magnetism but also magnetically induced by inducing magnetic flux. With this configuration, functions of downsizing, forced air cooling of the image sensor, and magnetic noise prevention of the fan can be obtained. At this time, the fan 303 is not only disposed at a position where the ND filter 507 is not retracted, but also disposed in the circumferential direction as shown in FIG. Become. This can reduce the size. The flat surface 602 directly above the fan, which is a part of the heat sink / duct a 302, is inclined toward the mounting direction. Thereby, size reduction can be achieved without increasing ventilation resistance.

2-3 Main Board Peripheral Structure FIG. 7 shows a structure around the main board. 7a is a perspective view in an integrated state, FIG. 7b is an exploded perspective view of FIG. 7a, FIG. 7c is an exploded perspective view of a heat sink / duct b (305, 304), and FIG. 7d is a side view of the exterior portion R 203 of FIG. 7e is a side view of the exterior front 207 of FIG. 7a, FIG. 7f is a sectional view G_G of FIG. 7d, FIG. 7g is a sectional view H_H of FIG. 7d, and FIG. 7h is a sectional view I_I of FIG.

  The structure around the main substrate will be described with reference to FIG. The heat sink / duct a 302 is mechanically joined to and integrated with the centrifugal fan 303. The heat sink / duct a 302 has an L shape, and a centrifugal fan 303 is arranged on the short side of the L shape. Outside air is taken in from the air inlet 701 of the heat sink / duct, heat is transferred to the outside air taken in the heat sink / duct a 302, and exhausted through the centrifugal fan 303.

(Explanation of thermal connection)
The main board a 315 and the heat sink / duct a 302 are thermally connected via a heat radiating rubber (not shown) having elasticity and high thermal conductivity. The heat sink / duct b (305, 304) is thermally connected to the main boards a 315, 316 by the above-described heat radiation rubber (not shown). The heat sink / duct c (308, 309) is thermally connected to the main boards b 316, 317 by the above-described heat radiation rubber (not shown). The heat sink 318 is thermally connected to the main board c 317 by the above-described heat radiating rubber (not shown). The heat sink 318 is mechanically connected to the internal circulation fan 319 and is cooled by the wind generated by the internal circulation fan 319.

  The wind of the internal circulation fan 319 circulates in the main body 200 and has a function of equalizing the temperature inside the main body. The heat sink and duct a 302, the heat sink and duct b (305, 304), and the heat sink and duct c (308, 309) are thermally connected to the heat sink and duct d 401 and the heat sink and duct e 403. This has the effect of making the temperature of the heat sink / duct uniform.

  The effect when the temperature of the heat sink / duct is equalized is to reduce fan noise. This is because when the heat sink ticket duct is locally hot, it is necessary to set the rotational speed of the cooling fan high, and the overall noise is determined by the noise level of the fan.

(Explanation of electrical connection)
Further, the heat sink / duct a 302 is electrically connected to the ground of the main board a 315 and becomes a mechanical ground. The mechanical ground is a conductor having a large electric capacity, and the larger the electric capacity, the better the signal characteristics of the electric circuit.

  The heat sink / duct b (305, 304) is also electrically connected to the main boards a 315, 316 to form a mechanical ground. The heat sink / duct c (308, 309) is also electrically connected to the main board b 316, 317 and serves as a mechanical ground. The heat sink 318 is also electrically connected to the main board c 317 and serves as a mechanical ground.

  The heat sink and duct a 302, the heat sink and duct b (305, 304), and the heat sink and duct c (308, 309) are electrically connected to the heat sink and duct d 401 and the heat sink and duct e 403. This has the effect of providing a mechanical ground with a large electric capacity of the heat sink / duct.

  FIG. 7c is an exploded perspective view of the heat sink / duct b (304, 305). The heat sink / duct 305 includes a heat sink 705 having a fin shape similar to the fin heat sink 702 made of aluminum die casting. The heat sink / duct b 304 includes a heat sink 705 made in the same manner as the heat sink 703 having a fin shape made of aluminum die casting. The fins of the heat sinks 702 and 703 and the heat sink 705 are arranged to alternate with each other when integrated.

  A heat sink and duct b (305, 304) shown in FIG. The fins have a staggered shape, and the tips of the fins are not applied to the opposing heat sinks, but are arranged with gaps approximately the same as the gaps between the alternating fins. Accordingly, it is possible to reduce the ventilation resistance and increase the heat radiation efficiency without reducing the surface area of the heat radiation. In this embodiment, since the heat sinks 702, 703, and 705 are aluminum die casts, there is a problem that the pitch of the fins cannot be made so narrow in manufacturing. Fins can be placed at a pitch greater than the limit. Thereby, the heat radiation surface area increased and the heat radiation efficiency improved.

  The BtoB 704 that electrically connects the main board a 315 and the main board b 316 and the dotted arrows 310 and 311 indicating the ventilation direction shown in FIG. 7f are substantially parallel. BtoB707 and dotted arrows 312 and 313 shown in FIG. 7g have the same configuration. A heat sink / duct 305 and a heat sink / duct 304 are arranged on both sides of the BtoB 704. Further, the fan 306 is disposed obliquely so that the exhaust does not hit the fan 307.

  At this time, the fan 306 is disposed obliquely more than the thickness of the fan 307. As a result, the exhaust efficiency of the fan can be increased while reducing the height direction of the main body. Similarly, the fan 307 is also arranged obliquely in order to reduce the reduction in exhaust efficiency due to exhaust hitting the floor when the main body is arranged on the floor. By disposing the fan at an angle, no space is blocked in the spaces 705 and 706 on the inlet side of the fan that can be formed. As a result, wind bias and turbulent flow are less likely to occur, leading to a reduction in fan noise.

  In this embodiment, the centrifugal fan is used as the fan. Also, as shown in FIGS. 3d and 3e, the BtoBs 704 and 707 are arranged so as to overlap on the projection of the operation and image display panel 211 in the operation and image display panel 211 view. Thereby, even when the operation and the image display panel 211 and the BtoB connection are compatible, the reduction in the intake efficiency can be minimized. In addition, when the fan 306 and the fan 307 are arranged vertically, the operation between the fan 306 and the fan 307 is arranged on the operation and projection of the image display panel 211 (in operation and in the image display panel 211 view). Efficient exhaust is possible.

  BtoB707 and BtoB704 shown in FIG. 7h are arranged so as not to overlap with each other when viewed from the main substrate. As a result, a heat sink / duct can be placed behind BtoB, and the heat source behind BtoB can also be cooled. Here, the heat radiation rubber interposed between the main board and the heat sink / duct is not shown so as not to complicate the figure.

  FIG. 8 is a control flow of this embodiment. FIG. 8a is a control flow when selecting the low exterior temperature mode or the low noise mode. The user selects whether to use the low exterior temperature mode through the operation input unit 103 (s801). If YES, the fan speed becomes MAX (S802), and the internal heat is dissipated mainly by forced air cooling. When the user selects the low noise mode instead of the low exterior temperature mode (S801), the system shifts to fan OFF or fan low rotation (s803), and as shown in FIG. Dissipates internal heat. This control flow adjusts the strength of the wind by controlling the number of rotations of the fan, and makes it possible to select the low exterior temperature mode or the low noise mode.

  FIG. 8b shows that a temperature detection unit 114, for example, a thermistor, etc. is arranged near a location where temperature control is required, such as an exterior, an image sensor, or a main IC, or a location where there is a temperature correlation with the above location, and asymptotically approaches a desired temperature. It is a control flow. First, the allowable temperature (MAX) (S804), allowable temperature (MIN) (S805), and fan speed (S807) are input to the controller 101, and the controller 101 reads the measured temperature (S806) from the thermistor and measures it. It is determined whether the temperature (S806) is equal to or higher than the allowable temperature (MAX) (S804) (S808). If it is above, the fan rotation is set to the current rotation speed + the fan increase / decrease rotation speed (S807) determined above.

  Thereafter, it is determined whether or not the process ends (S813). If the process ends, the process ends (S814). Otherwise, the process returns to X ≧ A (S808) via WAIT (S812). If the measured temperature (S806) is lower than the allowable temperature (MAX) (S804), it is determined whether the measured temperature (S806) is lower than the allowable temperature (MIN) (S805) (S810). The number of rotations is the current number of rotations-fan increase / decrease rotation number (S807). Thereafter, it is determined whether or not the process ends (S813). If the process ends, the process ends (S814). Otherwise, the process returns to X ≧ A (S808) via WAIT (S812). If this is the case, the current status is maintained. Thereafter, it is determined whether or not the process ends (S813). If the process ends, the process ends (S814). Otherwise, the process returns to X ≧ A (S808) via WAIT (S812). Here, the time until the temperature change is stabilized after changing the number of fan rotations is assumed to be one minute, and WAIT (S812) is inserted in the control flow.

  As described above, according to the present invention, the following effects can be obtained.

  * It is possible to provide an imaging device that allows the user to select between a low noise mode and a low exterior temperature mode without causing thermal runaway, etc., and that allows quick mode switching.

  * It is possible to provide an electronic device that achieves both division of the board and forced air cooling without reducing the placement efficiency of the mounted components on the board and with less restrictions on the wiring in the board.

  * It is possible to provide an electronic device with good exhaust efficiency while reducing the height direction of the electronic device.

  * 1. 1. cooling of the image sensor and the main substrate; 2. Reduce the influence of fan-driven magnetism on the image sensor; It is possible to provide an electronic device that is compatible with miniaturization of the electronic device body.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

101 ... Control unit 102 ... ROM
103 Operation input unit 104 Imaging unit 105 A / D conversion unit 106 Image processing unit 107 Recording medium 108 Image display unit 109 Wireless transmission / reception unit 110 Power supply unit 111 External power supply unit 112 ... Optical system 113 ... Blower unit 114 ... Temperature detector

Claims (2)

In the case where at least the centrifugal fan 1 and the centrifugal fan 2 are provided, the centrifugal fans 2 are arranged side by side in the rotational circumferential direction of the centrifugal fan 1, and the centrifugal fan 2 in the exhaust direction of the centrifugal fan 1 is disposed.
The electronic device according to claim 1, wherein the centrifugal fan 1 is disposed at an angle more than the thickness of the centrifugal fan 2. The electronic device according to claim 1, wherein a space is arranged on an inlet side of the centrifugal fan, which is formed obliquely with respect to the centrifugal fan in the electronic device having a duct.