Audio recording device, imaging device, control method, and program

Abstract

To drive a heat-dissipating fan at a speed suitable for voice recording.SOLUTION: A voice recording device includes a heat-dissipating fan. The voice recording device has acquiring means for acquiring a type of a microphone to be used for voice recording, control means for controlling the speed at which the fan is driven, and recording means for recording a voice acquired by the microphone to be used. The control means varies the rotation speed of the heat-dissipating fan according to the type of the microphone used as acquired by the acquiring means.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a voice recording device, an imaging device, a control method, and a program, and particularly relates to a voice recording technique in a device equipped with a heat dissipation fan (cooling fan).

Background Art

[0002] With the miniaturization and high performance of electronic devices, it is necessary to miniaturize and increase the density of various components including integrated circuits built into the devices. On the other hand, the high performance of the device requires an increase in the amount of calculation in the integrated circuit etc., and the amount of heat generated during its operation also increases. Therefore, in order to avoid malfunctions, functional degradation, or failures caused by temperature rise inside the device, heat conduction members such as heat dissipation fans and heat sinks are introduced into such electronic devices, and heat dissipation measures are taken.

[0003] By the way, when adopting a heat dissipation fan, particularly in an imaging device having a moving image shooting function, there was a risk that the driving sound of the heat dissipation fan would be collected by the microphone and recorded. Patent Document 1 discloses an imaging device that reduces the rotation speed of the heat dissipation fan when performing moving image shooting using a built-in microphone

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, reducing the rotation speed of the heat dissipation fan may lead to a reduction in function. Therefore, when using a built-in microphone as in Patent Document 1, the mode of uniformly reducing the rotation speed of the heat dissipation fan may cause constraints that the user does not desire, such as a shortening of the recordable time.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide an audio recording device, an imaging device, a control method, and a program that drive a cooling fan at a rotational speed suitable for audio recording. [Means for solving the problem]

[0007] To achieve the aforementioned objective, the present invention provides an audio recording device equipped with a cooling fan, comprising: an acquisition means for acquiring the type of microphone to be used for audio recording; a control means for controlling the rotational speed that drives the cooling fan; and a recording means for recording the audio acquired by the microphone used. The microphones used include built-in microphones within the audio recording device and non-built-in microphones not built into the audio recording device. The control means uses the microphone acquired by the acquisition means. If the microphone is not built-in, is it a non-built-in microphone mounted on the housing of the audio recording device? The system is characterized by varying the rotation speed of the cooling fan accordingly. [Effects of the Invention]

[0008] With this configuration, according to the present invention, it is possible to drive the cooling fan at a rotational speed suitable for audio recording. [Brief explanation of the drawing]

[0009] [Figure 1] Block diagram illustrating the functional configuration of a digital camera 100 according to embodiments and modifications of the present invention. [Figure 2] Perspective view of a digital camera 100 according to embodiments and modified examples of the present invention [Figure 3] Exploded perspective view of a digital camera 100 according to embodiments and modified examples of the present invention [Figure 4] Perspective view of duct 122 according to embodiments and modified examples of the present invention [Figure 5] Cross-sectional view of the internal structure of duct 122 according to embodiments and modified examples of the present invention. [Figure 6] This figure shows the relationship between the duct 122 and the main board 121 according to embodiments and modified examples of the present invention. [Figure 7] Exploded perspective view of the imaging unit 120 according to embodiments and modified examples of the present invention. [Figure 8]This figure shows the relationship between the imaging unit 120 and the internal fan 124 according to embodiments and modified examples of the present invention. [Figure 9] A flowchart illustrating the drive control process performed by the digital camera 100 according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] [Embodiment] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] One embodiment described below illustrates an example of applying the present invention to a digital camera capable of video recording, as an example of an audio recording device. However, the present invention is applicable to any device capable of recording audio. Furthermore, in this specification, "heat dissipation fan" includes a fan that generates airflow for cooling a predetermined heat-generating component, and fans provided for intake and exhaust to discharge the airflow to the outside of the housing. A heat dissipation fan is a component that can generate airflow that dissipates heat in a predetermined direction by pressurizing and pumping air through the rotation of a propeller (blade, wing) driven by a motor.

[0012] 《Configuration of 100 Digital Cameras》 The configuration of the digital camera 100 of this embodiment will be described below with reference to Figures 1 to 3. Figure 1 is a block diagram showing the functional configuration of the digital camera 100 according to an embodiment of the present invention. Figure 2(a) shows a front perspective view of the digital camera 100, and Figure 2(b) shows a rear perspective view of the digital camera 100. Figure 3 is an exploded perspective view of the main parts to explain the internal structure of the digital camera 100.

[0013] As shown in FIG. 3, the digital camera 100 has an exterior of the housing formed by a rear cover 101, a front base 104, a top cover 107, a bottom cover 108, and side covers 109. Inside the digital camera 100, an imaging unit 120, a main board 121, a duct 122, a shutter 410, and an EVF 451 are arranged. The grip portion 105 is integrally formed with the front base 104 and has a shape that is easy to hold with the right hand when the user holds the digital camera 100. The tripod socket 106 shown in FIG. 2(b) is a member for attaching the digital camera 100 to a tripod.

[0014] The main board 121 is provided with a control IC group 121a for controlling an imaging signal, a recording medium I / F 121b, and an external communication terminal 121c for connecting an external device (not shown) via a cable. The main board 121 may also be mounted with various other electronic components such as various ICs, chip resistors, chip capacitors, inductors, transistors, and interface connectors. The external communication terminal 121c is protected by a terminal cover 111 as shown in FIG. 2(a).

[0015] In FIG. 1, the shutter 410 is a focal plane shutter that can freely control the exposure time of the imaging element 161, and its control is performed by a system control unit 420 described later. The imaging element 161 has an imaging surface on which a subject image (optical image) that has passed through the lens 501 is formed, and is an imaging device that outputs an electrical signal (analog signal) corresponding to the optical image on the imaging surface by photoelectric conversion. The imaging element 161 may be, for example, a CCD (Charge Couple Device) or a CMOS (Complementary MOS) sensor. The imaging element 161 is included in the imaging unit 120.

[0016] The A / D converter 412 converts the analog signal output from the imaging device 161 into a digital signal. The image processing unit 413 performs predetermined pixel interpolation, resizing processes such as reduction, and color conversion processing on the digital signal from the A / D converter 412 or the digital signal from the memory control unit 422 described later, and generates image data. Based on the calculation result obtained by the image processing unit 413, the system control unit 420 controls the aperture position and the lens position. The image processing unit 413 further performs arithmetic processing using the image data, and performs TTL-based AWB (auto white balance) processing based on the obtained arithmetic result.

[0017] The system control unit 420 consists of at least one processor or circuit and controls the entire digital camera 100. The system control unit 420 realizes the operations of each block included in the digital camera 100 and the processing according to the present invention by expanding and executing the program recorded in the non-volatile memory 423 in the system memory 424.

[0018] The non-volatile memory 423 is an electrically erasable and recordable read-only storage device, and stores constants, programs, etc. for the operation of the system control unit 420. The system memory 424 is a storage means capable of reading and writing, in which constants, variables, programs read from the non-volatile memory 423, etc. for the operation of the system control unit 420 are stored.

[0019] The memory 421 temporarily records the digital signal obtained by the imaging device 161 and converted by the A / D converter 412 and the image data generated by the image processing unit 413. The memory 421 has a storage capacity sufficient to store a predetermined number of still images, a moving image for a predetermined time, and audio. The memory control unit 422 controls the transmission and reception of data controlled by the system control unit 420 to and from the A / D converter 412, the image processing unit 413, and the memory 421. The digital signal output from the A / D converter 412 is directly written into the memory 421 via the image processing unit 413 and the memory control unit 422, or via only the memory control unit 422. The memory 421 also serves as a memory for image display (video memory).

[0020] The system timer 425 is a timing unit that measures the time until it executes an auto power-off that turns off various display components (described later) to prevent battery drain when it determines that the user is not operating the digital camera 100, and also measures the exposure time.

[0021] These various blocks related to imaging are included in the control IC group 121a of the main board 121.

[0022] The power supply unit 430 consists of primary batteries such as alkaline batteries and lithium batteries, secondary batteries such as NiCd batteries, NiMH batteries and Li batteries, and an AC adapter. As shown in Figure 2(b), the batteries used in the power supply unit 430 are protected by a battery cover 108a provided on the bottom cover 108. The power control unit 431 consists of a circuit for detecting the power supply unit 430, which is the power source for driving the digital camera 100, a DC-DC converter, a switch circuit for switching the power supply destination, etc., and detects whether batteries are installed, the type of batteries, and the remaining battery level. Furthermore, the power control unit 431 controls the DC-DC converter based on the detection results and instructions from the system control unit 420, and supplies the necessary voltage to the power supply destination at the necessary timing.

[0023] The recording medium I / F121b is an interface to the recording medium 600. The recording medium 600 is a recording device that can be attached to and detached from the digital camera 100 and records captured images, such as an SD card, flash memory, or hard disk. In the digital camera 100, the recording medium I / F121b is provided with an opening, and recording to the recording medium 600 becomes possible when the recording medium 600 is inserted into this opening. This opening is protected by a recording medium cover 103, as shown in Figure 2(b).

[0024] The attitude detection unit 442 detects the attitude of the digital camera 100 relative to the direction of gravity. Based on the attitude detected by the attitude detection unit 442, the system control unit 420 can output orientation information indicating whether the image captured by the image sensor 161 was taken with the digital camera 100 held horizontally or horizontally. The system control unit 420 can also add the orientation information output by the attitude detection unit 442 to the image data. The attitude detection unit 442 may be, for example, an acceleration sensor or a gyro sensor. In an embodiment where an acceleration sensor and a gyro sensor are used as the attitude detection unit 442, it is also possible to detect the movement of the digital camera 100 (pan, tilt, lift, whether it is stationary or not, etc.).

[0025] The eyepiece section 443 is the part of the digital camera 100 where the user's (photographer's) eye (object) 700 approaches (eyepieces) the camera. The eyepiece detection unit 444 is a proximity or eyepiece detection sensor that detects when the eye 700 approaches (eyepieces) and moves away from (away from) the eyepiece section 443. The eyepiece detection unit 444 detects the eye 700 approaching the eyepiece section 443, for example, by detecting the presence or absence of light reception by the light-receiving part (not shown) of an infrared proximity sensor. After detecting eyepiece contact, the system control unit 420 determines that the eyepiece is in a contact state until eye-away is detected. After detecting eye-away, the system control unit 420 determines that the eyepiece is not in a contact state until eyepiece contact is detected again. Note that the infrared proximity sensor is just one example; the eyepiece detection unit 444 may use any other sensor that can detect the approach of an eye or object that can be considered as an eyepiece.

[0026] The rear display unit 450 and the EVF 451 receive and display digital signals and image data written to the memory 421 via the memory control unit 422. The rear display unit 450 is, for example, a liquid crystal panel, and displays information according to the signals from the memory control unit 422, allowing for previews of captured images and displays of various settings. The rear display unit 450 is a so-called vari-angle monitor that is rotatably mounted on the digital camera 100 and is stored in the display unit storage unit 102 as shown in Figure 2(b). The EVF 451 displays information according to the signals from the memory control unit 422 when an eyepiece is detected by the eyepiece detection unit 444. The analog signals obtained by imaging are A / D converted and recorded as digital signals in the memory 421, and live view display is realized by sequentially transferring these digital signals to the rear display unit 450 or the EVF 451 for display. The system control unit 420 switches the display (display state) / hidden (hidden state) of the rear display unit 450 and the EVF 451 according to the state detected by the eyepiece detection unit 444. Specifically, the system control unit 420 displays a digital signal on the rear display unit 450 and hides the EVF 451 when the eyepiece is not being used. Also, the system control unit 420 displays a digital signal on the EVF 451 and hides the rear display unit 450 when the eyepiece is being used.

[0027] The operation unit 460 consists of various operating components that receive operation input from the user. When the operation unit 460 detects an operation input made by the user, it outputs a control signal corresponding to that operation input to the system control unit 420. The operation unit 460 includes various operating components such as a mode switching switch 461, a shutter button 462, a first shutter switch 463, a second shutter switch 464, a touch panel 465, and a power switch 466. These operating components are mainly provided on the rear cover 101 and the top cover 107, as shown in Figures 2(a) and (b).

[0028] The mode switching switch 461 is an operating member for receiving a switch in the control mode of the system control unit 420. Depending on the state of the switch, the system control unit 420 switches its operation to one of the control modes, such as still image shooting mode or video shooting mode. Examples of shooting modes included in the still image shooting mode include auto shooting mode, auto scene detection mode, manual shooting mode, aperture priority mode (Av mode), shutter speed priority mode (Tv mode), and program AE mode (P mode). Similarly, the video shooting mode may also include multiple shooting modes.

[0029] The shutter button 462 is an operating component for receiving user instructions to prepare for shooting and to take a picture. The first shutter switch 463 turns ON when the shutter button 462 on the digital camera 100 is partially pressed (a shooting preparation instruction), generating the first shutter switch signal SW1. The first shutter switch signal SW1 causes the system control unit 420 to start shooting preparation operations such as AF (autofocus) processing, AE (automatic exposure) processing, and AWB (automatic white balance) processing. The second shutter switch 464 turns ON when the shutter button 462 is fully pressed (a shooting instruction), generating the second shutter switch signal SW2. The system control unit 420 controls the system control unit 420 to read the analog signal from the image sensor 161 and execute signal conversion processing in the A / D converter 412 and the image processing unit 413. Furthermore, the system control unit 420 executes shooting processing operations until the image data temporarily recorded in the memory 421 is written to the recording medium 600, which will be described later.

[0030] The touch panel 465 is an operating member that detects touch and drag operations performed by the user on the display surface of the rear display unit 450. In this embodiment, the touch panel 465 is configured as an integral part of the rear display unit 450.

[0031] The power switch 466 is an operating component that accepts the ON / OFF switching of the power supply. In response to the switching of the power switch 466, the power control unit 431 controls the power supply from the power supply unit 430.

[0032] As shown in Figure 2(a), the top cover 107 is provided with an accessory shoe 107a. The accessory shoe 107a is a part provided on the outer surface of the housing of the digital camera 100, on which external devices such as an external microphone can be attached. The accessory shoe 107a has electrical contacts, and when an external device having corresponding electrical contacts is attached, the external device and the digital camera 100 are electrically connected. Such external devices are provided with identification signals, and the digital camera 100 can identify the external device based on the identification signal. Devices that can be attached to the accessory shoe 107a include, for example, an external flash and an external microphone, and the user can attach and detach the desired device to the accessory shoe 107a. For example, when an external microphone 107c is attached, the audio signal acquired by the external microphone 107c can be recorded as the audio signal during video recording. The digital camera 100 is equipped with a built-in microphone 107b, and when the external microphone 107c is not connected, the audio signal recorded during video recording is acquired by the built-in microphone 107b.

[0033] In addition, a wireless microphone 107d can be connected to the digital camera 100 of this embodiment via a wireless communication interface 470. The wireless communication standard supported by the wireless communication interface 470 may be any standard, such as Bluetooth®. Devices connected via the wireless communication interface 470 can be identified by acquiring an identification signal during pairing, etc. When the wireless microphone 107d is connected, the audio signal acquired by the wireless microphone 107d via the wireless communication interface 470 can be recorded as the audio signal during video recording.

[0034] Thus, the digital camera 100 of this embodiment can use three types of microphones for audio recording during video recording: a built-in microphone 107b, an external microphone 107c, and a wireless microphone 107d. In the following description, to distinguish these microphones, the built-in microphone 107b may be referred to as the first microphone, the external microphone 107c as the second microphone, and the wireless microphone 107d as the third microphone.

[0035] Furthermore, the digital camera 100 of this embodiment has a duct fan 123 and an internal fan 124 as heat dissipation fans for dissipating (cooling) the internal heat source components. The duct fan 123 is a heat dissipation fan mainly for dissipating heat from the control IC group 121a of the main board 121, which is a heat source, and is located inside the duct 122. The duct 122 is configured by connecting the vent 110a provided in the rear cover 101 and the vent 110b provided in the side cover 109, as shown in Figures 2(a) and (b), and can be drawn in and out by driving the duct fan 123. That is, the duct 122 draws outside air from the digital camera 100 to the vicinity of the heat source such as the control IC group 121a by the duct fan 123, and generates airflow inside the duct 122. On the other hand, the internal fan 124 is a heat dissipation fan mainly for dissipating heat from the image sensor 161, which is a heat source, and is located near the imaging unit 120. Details regarding the cooling effect of these heat dissipation fans will be described later with reference to a separate diagram.

[0036] The lens unit 500 is a detachable interchangeable lens for the digital camera 100 and is mounted on the mount portion 112 of the digital camera 100. The mount portion 112 is configured such that when the lens unit 500 is mounted, the optical axis O of the lens unit 500 coincides with the center of the mount portion 112. The mount portion 112 is provided with a communication terminal 440, which contacts a lens communication terminal 506 provided on the lens unit 500 when the lens unit 500 is connected, thereby establishing an electrical connection between the digital camera 100 and the lens unit 500. This enables the system control unit 420, which controls the entire digital camera 100, to communicate with the lens system control circuit 505, which controls the entire lens unit 500.

[0037] The lens system control circuit 505 controls the position of the aperture 503 by the aperture drive circuit 504 and the focus state by the lens drive circuit 502. The lens drive circuit 502 controls the focus state by displacing the lens 501 in the direction of the optical axis O. The lens 501 guides the light reflected by the subject (subject light) to the image sensor 161. In the example in Figure 1, for simplicity, the lens 501 is shown as a single lens, but the lens 501 may be a lens group composed of multiple lenses.

[0038] Details of the heat dissipation process The following describes the details of the heat dissipation operation in the digital camera 100 of this embodiment.

[0039] <Around the duct fan> The control IC group 121a consumes a particularly large amount of power and generates a lot of heat within the digital camera 100. The control IC group 121a generates heat by performing various calculation processes during shooting, and its operation is restricted if it exceeds the guaranteed operating temperature. Therefore, shooting in the digital camera 100 stops when the control IC group 121a exceeds the guaranteed operating temperature, and the shooting time varies depending on the temperature state of the control IC group 121a. In other words, in order to maintain a long shooting time for the digital camera 100, it is necessary to dissipate / cool the heat source, the control IC group 121a, during its operation and control it so that it does not exceed the guaranteed operating temperature. For this reason, in the digital camera 100 of this embodiment, as shown in Figure 3, the duct 122 is located on the back of the main board 121 and is configured to be thermally connected to the control IC group 121a so that heat can be dissipated.

[0040] Figure 4(a) shows a front perspective view of duct 122, and Figure 4(b) shows a rear perspective view of duct 122. Figure 5 is a cross-sectional view of the internal structure of duct 122, corresponding to section AA in Figure 4(b).

[0041] The duct 122 is composed of a first duct section 130, a second duct section 131, and a third duct section 132.

[0042] The first duct section 130 is positioned approximately parallel to the optical axis O and is located below the EVF 451 in the display unit storage section 102. By positioning the first duct section 130 near the EVF 451, the contact area between the second duct section 131 (described later) and the control IC group 121a can be increased, which is advantageous from the viewpoint of heat dissipation.

[0043] The second duct section 131 is connected to the first duct section 130 and is formed to be approximately perpendicular to the optical axis O of the camera and located on the rear side of the imaging unit 120 and the control IC group 121a. The second duct section 131 is divided into a second front duct section 131a, which forms the surface facing the control IC group 121a, and a second rear duct section 131b, which forms the opposite side. The second duct recess 131c is a concave shape formed in the second duct section 131 and is provided on the surface facing the main board 121 so as not to overlap with the projection surface of the control IC group 121a. Due to this concave shape, the cross-sectional area of ​​the second duct section 131 is locally reduced, so that the airflow passing through the second duct section 131 flows mostly around the heat transfer member 150, which will be described later. This allows for efficient heat dissipation of the control IC group 121a. Because the second duct section 131 is located in a part other than the projection surface of the heat source, heat diffusion inside the digital camera 100 can be efficiently performed. Therefore, it is preferable to arrange a part of the duct 122, such as the second duct recess 131c, in the area other than the projection surface. Furthermore, utilizing the space created by this recess shape, a connector and FPC for connecting the imaging unit 120 and the main board 121 are arranged on the second duct recess 131c side of the main board 121.

[0044] The third duct section 132 is connected to the second duct section 131 and is formed to be located below the imaging unit 120 and the main substrate 121, approximately parallel to the optical axis O of the camera. The third duct section 132 is provided with a bottom duct cover 133, which is fixed to the third duct section 132 with an elastic member (not shown) in between.

[0045] The tripod mount section 140 is provided by cutting out a part of the third duct section 132. The tripod mount 106, which is positioned in the tripod mount section 140, is fastened to a highly rigid member. In this embodiment, the tripod mount section 140 is fastened to a front base 104 made of magnesium alloy. As a result, even if the digital camera 100 is subjected to a strong external force while attached to the tripod mount, the deformation of the entire camera can be suppressed by fastening it to a highly rigid member. In other words, by suppressing deformation around the imaging unit 120, the effect of strong forces on the captured image can be reduced. Furthermore, suppressing deformation of the entire digital camera 100 also suppresses deformation of the duct 122, which has the effect of preventing a decrease in heat transfer efficiency.

[0046] The first duct section 130 is provided with an air intake port 135, and the third duct section 132 is provided with an exhaust port 136. An elastic member (not shown) is provided between the air intake port 135 and the vent port 110a provided in the rear cover 101, thereby creating a sealed structure between the air intake port 135 and the vent port 110a. Similarly, an elastic member (not shown) is provided between the exhaust port 136 and the vent port 110b provided in the side cover 109, thereby creating a sealed structure between the exhaust port 136 and the vent port 110b. By creating such a sealed structure, the space between the vent port 110a and the vent port 110b is formed as a single sealed space, thus creating an airflow path and preventing water droplets, sand, etc. from entering the digital camera 100 from the outside.

[0047] Furthermore, in order to reduce pressure loss in the flow path within the duct 122, it is preferable that the cross-sectional areas of the flow paths of the first duct section 130, the second duct section 131, and the third duct section 132 be as equal as possible. Even if the cross-sectional area changes, each duct section is configured so that the change in cross-sectional area is kept to a minimum. The first duct section 130, the second duct section 131, and the third duct section 132 may be constructed by fastening separate parts together, or they may be a single integrated part made with a 3D printer or the like. Similarly, the connections between each duct section may be constructed by fastening, or each duct section may be integrally molded using a 3D printer or the like. In the case of fastening by fastening, it is desirable to maintain the airtightness of the duct 122 by inserting an elastic member (not shown) in between. The fastening method is not limited as long as it can create an airtight space, and any fastening method such as screws, adhesive, or crimping is acceptable as long as it achieves the purpose.

[0048] Furthermore, the materials of the first duct section 130, the second duct section 131, and the third duct section 132 are preferably made of materials with high thermal conductivity in order to efficiently transfer heat from the heat source. However, for the second rear duct section 131b, since its contribution to heat diffusion from the heat source is relatively small, a material with lower thermal conductivity than the second front duct section 131a may be used. Also, from the viewpoint of reducing the weight of the digital camera 100, a material with a low specific gravity is preferable. Furthermore, if the main material of the duct 122 is metal, it can be used as the ground housing of the digital camera 100, which is advantageous from the viewpoint of noise immunity. In this embodiment, the materials of the first duct section 130, the second front duct section 131a, and the third duct section 132 are made of aluminum, and the second rear duct section 131b is made of polycarbonate. Note that the second rear duct section 131b can be integrated with the rear cover 101 to reduce the thickness of the device in the rear direction. The second front duct section 131a is provided with a first fin section 141 consisting of multiple convex shapes on the side opposite to the main substrate 121. This increases the surface area of ​​the second duct section 131 and the heat exchange area with the air inside the duct, thereby improving cooling efficiency.

[0049] The duct fan 123 is a means of blowing air to create airflow within the duct 122 and is fixed to the third duct section 132 together with the bottom duct cover 133 by fixing screws 137. When the duct fan 123 is driven, air from outside the digital camera 100 flows into the duct 122 from the intake port 135 through the vent port 110a. The incoming air passes through the first fin section 141 in the second duct section 131 and then through the second fin section 142 in the third duct section 132. As the incoming air passes through the first fin section 141 and the second fin section 142, which are heated by the heat source, the fins are cooled and the heat source is cooled. After passing through the fins, the air is drawn into the duct fan 123 and discharged outside the digital camera 100 through the exhaust port 136 and the vent port 110b.

[0050] In this embodiment, the airflow is as described above, with air drawn in through vent 110a and discharged through vent 110b. This is to position the exhaust port 136 far from the user's face, etc. However, the arrangement is not limited to this as long as the desired cooling effect can be achieved. For example, the arrangement of the duct 122 and duct fan 123 may be changed so that air is drawn in through vent 110b and discharged through vent 110a.

[0051] Figure 6 shows a diagram illustrating the thermal connection between the duct 122 and the heat source (control IC group 121a). Figure 6 is an exploded perspective view showing the duct 122 and the control IC group 121a mounted on the main board 121.

[0052] The heat transfer member 150 is a thermally conductive rubber for thermally connecting the control IC group 121a and the second front duct section 131a. The heat generated in the control IC group 121a is transferred to the duct 122 via the heat transfer member 150. The heat transfer member 150 is in contact with the second duct section 131, and the aforementioned first fin section 141 is provided on the back side of its contact surface. Therefore, the heat from the control IC group 121a is efficiently exchanged with the air in the duct 122 by the first fin section 141, resulting in high cooling performance. In this embodiment, the heat transfer member 150 is described as thermally conductive rubber, but it is not limited to such materials as metal foil or heat pipes, as long as they have a higher thermal conductivity than materials such as resin and satisfy other mechanical and electrical performance requirements.

[0053] <Internal fan area> Similar to the control IC group 121a, the imaging unit 120 also generates heat during its operation. As shown in Figure 3, the internal fan 124 is positioned around the imaging unit 120 so that its airflow direction is perpendicular to the optical axis. By blowing air onto the back of the imaging unit 120, which is a heat source, the fan prevents the imaging unit 120 from becoming locally hot.

[0054] The internal fan 124 can cool both the imaging unit 120 and the main board 121 by positioning its air outlet 124a to blow air into the space between the imaging unit 120 and the main board 121. On the other hand, in a configuration that includes a movable part 160 for moving the imaging unit 120 for image stabilization, for example, there are fewer heat dissipation paths. For this reason, it is advantageous for the overall cooling of the digital camera 100 if the air outlet 124a of the internal fan 124 is positioned closer to the imaging unit 120 than to the main board 121.

[0055] Figure 7 shows an example of an exploded perspective view of the imaging unit 120 having a movable part 160. Figure 7(a) is an exploded front perspective view of the imaging unit 120, and Figure 7(b) is an exploded rear perspective view of the imaging unit 120.

[0056] The movable part 160 has a coil 162 on which a coil and a Hall element are arranged to move the image sensor 161, and is held by the sensor holder 163. In the example of Figure 7(a), the drive mechanism 164 holds three magnets 165, and the movable part 160 is attracted and held by the magnets 165. Between the movable part 160 and the drive mechanism 164, a ball (not shown) is placed in a ball holding part 163a provided on the sensor holder 163. The movement of the movable part 160 can be controlled by changing the amount of current supplied to the coil 162, and by moving the movable part in a direction that cancels out the shaking of the digital camera body 100, image stabilization can be achieved.

[0057] The image sensor 161 has a sensor chip (not shown) bonded to an imaging substrate 166 on which the imaging circuit is mounted, and is electrically connected to the imaging substrate 166 by wire bonding. The image sensor 161 and the sensor holder 163 are bonded and fixed together with adhesive. On the back surface of the surface on which the sensor chip is attached on the imaging substrate 166, components 166a of the imaging circuit, such as capacitors, resistors, and regulators, are mounted.

[0058] The electrical connection between the imaging unit 120 and the main board 121 is made using a flexible wiring board. The imaging signal flexible cable 167 is a wiring for communicating imaging signals output from the image sensor 161 and control signals necessary for driving the image sensor 161, and sends signals to the control IC group 121a on the main board 121. The imaging power supply flexible cable 168 supplies power to drive the image sensor 161. Inter-board connectors are used to connect the imaging board 166 to the imaging signal flexible cable 167 and the imaging power supply flexible cable 168.

[0059] Here, with reference to Figures 8(a) and (b), the movement of the movable part 160 of the imaging unit 120 and the positional relationship of the internal fan 124 will be explained. Figure 8(a) is a view of the internal fan 124 and imaging unit 120 from the rear, and Figure 8(b) is a schematic diagram of the internal fan 124 and imaging unit 120.

[0060] The movable part 160 is movable in a plane perpendicular to the optical axis O, and its range of movement is shown as 160a in Figure 8(b). Range 160b indicates the region where the movable part 160 is always present, regardless of its position within range 160a. The air outlet 124a of the internal fan 124 is directed to blow air into range 160b. More specifically, by positioning the internal fan 124 such that the airflow range indicated by L is included in range 160b, a cooling effect on the image sensor 161 can be obtained regardless of its position when moved by the drive mechanism 164. Furthermore, since the internal fan 124 does not physically contact the movable part 160, it does not interfere with the image stabilization function provided by the movable part 160.

[0061] As described above, the digital camera 100 of this embodiment incorporates a duct fan 123 and an internal fan 124, which helps to suppress the temperature rise of the control IC group 121a and the image sensor 161. As a result, the digital camera 100 is less likely to reach the operating temperature at which overheating limits its functionality. Analysis using FEM confirmed that, compared to a digital camera 100 without the duct fan 123 and internal fan 124, the temperature of the control IC group 121a and the image sensor 161 is reduced by 6°C or more.

[0062] In this embodiment, the internal fan 124 is described as being arranged so that its airflow direction is perpendicular to the optical axis O of the camera, but the present invention is not limited to this configuration. The arrangement of the internal fan 124 does not need to be perpendicular to the optical axis O of the camera, as long as the resulting airflow directly hits the imaging unit 120.

[0063] Furthermore, although this embodiment describes an example in which centrifugal fans are used for the duct fan 123 and the internal fan 124, the present invention is not limited to this. At least one of these heat dissipation fans may be other types of fans, such as axial fans.

[0064] 《Drive control during audio recording》 Incidentally, such cooling fans generate fan noise during operation, which can be recorded as background noise during video recording. Since the fan noise tends to increase in proportion to the rotation speed, the impact of the noise can be reduced by lowering the fan speed during video recording. However, lowering the fan speed reduces the cooling effect, which is a trade-off with the length of recording time.

[0065] On the other hand, the impact of rotational noise on the audio recorded during video shooting (hereinafter referred to as recorded audio) also differs depending on the microphone used to acquire the audio. For example, the impact of rotational noise differs between the built-in microphone 107b (first microphone) in the digital camera 100, the external microphone 107c (second microphone) attached to the accessory shoe 107a on the housing, and the wireless microphone 107d (third microphone) connected wirelessly. This is due to the different installation locations and propagation paths of the rotational noise for each. Generally, the built-in microphone 107b is more likely to pick up rotational noise than the external microphone 107c. Also, since the wireless microphone 107d tends to be used without being attached to the digital camera 100, the wireless microphone 107d is less likely to pick up rotational noise than the external microphone 107c.

[0066] Therefore, the rotation speed of the cooling fan that does not produce noise will differ depending on which microphone is used for audio recording during video recording. In the digital camera 100 of this embodiment, the rotation speed of the cooling fan during video recording is controlled according to the type of microphone used for audio recording. More specifically, the system control unit 420 controls the cooling fan to operate at a rotation speed that does not produce rotation noise for each microphone, depending on whether the microphone used for audio recording during video recording is the first microphone, the second microphone, or the third microphone.

[0067] <Drive control processing> The following describes the specific process of controlling the drive of the cooling fan, which is performed when shooting video in the digital camera 100 of this embodiment, using the flowchart in Figure 9. The process corresponding to the flowchart can be realized by the system control unit 420 reading the corresponding processing program stored in, for example, the non-volatile memory 423, loading it into the system memory 424, and executing it. This drive control process will be described as being started, for example, when an operation input related to a shooting start instruction is detected in video shooting mode.

[0068] In this explanation of the drive control process, we will describe, as an example, the drive control in which the system control unit 420 controls the rotation speed of the duct fan 123 in order to reduce the rotation noise of the duct fan 123 that may be transmitted to the microphone through the vents 110a and 110b. However, it will be easily understood that the implementation of the present invention is not limited to the duct fan 123, but can also be applied to an internal fan 124 used as a heat dissipation fan, or to a configuration in which both the duct fan 123 and the internal fan 124 are used.

[0069] At the start of the drive control process, since audio recording related to video shooting has not yet begun, the duct fan 123 is controlled to operate at a predetermined normal rotation speed (reference rotation speed). Here, the reference rotation speed is described as being higher than any of the first, second, and third rotation speeds described later, but it may also be set arbitrarily by the user.

[0070] In S901, the system control unit 420 determines whether the microphone used for audio recording during video recording is the first microphone, i.e., the built-in microphone 107b. The information about the microphone to be used is set before the operation input related to the start of recording is made and is stored, for example, in the memory 421. This setting may be made based on operation input by the user, or it may be changed in response to the attachment of an external microphone 107c to the accessory shoe 107a or the connection of a wireless microphone 107d. If the system control unit 420 determines that the microphone used for audio recording is the first microphone, it moves the process to S902; if it determines that it is not the first microphone, i.e., a non-built-in microphone, it moves the process to S903.

[0071] In S902, the system control unit 420 drives the duct fan 123 by changing the rotational speed from the reference rotational speed to a first rotational speed. Here, the first rotational speed is the lowest rotational speed among the first to third rotational speeds. The first rotational speed may be a value predetermined based on actual measurements, for example, as the upper limit of the rotational speed at which the rotational noise of the duct fan 123 is considered to have no effect on the audio recorded by the built-in microphone 107b.

[0072] On the other hand, if the system control unit 420 determines in S901 that the microphone used for audio recording is not the first microphone, then in S903, the system control unit 420 determines whether the microphone used for audio recording during video recording is the second microphone, i.e., the external microphone 107c. This determination is made based on whether the microphone to be used is the external microphone 107c connected via the electrical contacts of the accessory shoe 107a, or the wireless microphone 107d connected wirelessly via the wireless communication I / F 470. If the system control unit 420 determines that the microphone used for audio recording is the second microphone, the process moves to S904. If the system control unit 420 determines that the microphone used for audio recording is not the second microphone, i.e., the third microphone (wireless microphone 107d), the process moves to S905.

[0073] In S904, the system control unit 420 drives the duct fan 123 by changing the rotational speed from the reference rotational speed to a second rotational speed. Here, the second rotational speed is higher than the first rotational speed and lower than the third rotational speed. The second rotational speed may be a value predetermined based on actual measurements, for example, as the upper limit of the rotational speed at which the rotational noise of the duct fan 123 is considered to have no effect on the audio recorded by the external microphone 107c. Here, since the external microphone 107c that can be attached to the accessory shoe 107a may be sold by various manufacturers, the second rotational speed may differ depending on the type of external microphone 107c used. The type of external microphone 107c used can be identified based on the identification signal received from the external microphone 107c via the electrical contacts of the accessory shoe 107a. In this case, for example, the non-volatile memory 423 stores information (management table) of the upper limit rotation speed that is considered not to affect audio recording for each type of external microphone 107c, and the system control unit 420 only needs to determine a second rotation speed according to the type of external microphone 107c that is installed.

[0074] On the other hand, if in S903 it is determined that the microphone used for audio recording is not the second microphone, the system control unit 420 changes the rotation speed from the reference rotation speed to the third rotation speed in S905 and drives the duct fan 123. Here, the third rotation speed is the highest rotation speed among the first to third rotation speeds. The third rotation speed may be a value predetermined based on actual measurements, for example, as the upper limit of the rotation speed at which the rotation noise of the duct fan 123 is considered to have no effect on the audio recorded by the wireless microphone 107d, similar to the first and second rotation speeds. Alternatively, the wireless microphone 107d may be considered not to be attached to the housing of the digital camera 100, but for example, to the photographer or subject, and the third rotation speed may be the same value as the reference rotation speed or the maximum rotation speed that can be set for the duct fan 123. In other words, unlike the built-in microphone 107b and the external microphone 107c, when using the wireless microphone 107d, which is used separately from the digital camera 100, for audio recording, the duct fan 123 can be operated at a rotational speed that does not require consideration of rotational noise generation.

[0075] After the rotation speed of the duct fan 123 is controlled according to the microphone being used, the system control unit 420 starts processing related to video recording and audio recording in S906. Although the management table has been described as storing information on the rotation speed at which the duct fan 123 is driven during audio recording for each type of external microphone 107c, it may also be configured to store information on the first and third rotation speeds.

[0076] In S907, the system control unit 420 determines whether or not an operation input related to the instruction to end shooting has been made. If the system control unit 420 determines that an operation input related to the instruction to end shooting has been made, it moves the process to S908; otherwise, it repeats the process in this step.

[0077] At S908, the system control unit 420 stops the processing related to video recording and audio recording, returns the rotation speed to the reference rotation speed, drives the duct fan 123, and completes this drive control process.

[0078] In this way, the audio recording device of this embodiment can drive the cooling fan at a suitable rotational speed while ensuring the cooling effect of the heat-generating part, thereby enabling audio recording.

[0079] In the above-described drive control process, the rotation speed of the duct fan 123 was controlled according to the type of microphone used for audio recording. However, when applying the present invention to the control of the rotation speed of the internal fan 124, for example, it can be done as follows. When shooting video with audio recording, the system control unit 420 drives the internal fan 124 by changing the rotation speed from a reference rotation speed provided for the internal fan 124 to a rotation speed corresponding to the type of microphone used. At this time, the relationship between the rotation speed applied when the microphone used is the first microphone, the rotation speed applied when the microphone is the second microphone, and the rotation speed applied when the microphone is the third microphone is the same as in the case of the duct fan 123. That is, the relationship that rotation speed applied when the microphone is the first microphone < rotation speed applied when the microphone is the second microphone < rotation speed applied when the microphone is the third microphone is maintained. Furthermore, since the rotation sound of the duct fan 123 and the rotation sound of the internal fan 124 differ in volume and propagation path to the microphone, these rotation speeds do not need to be the same as those applied to the duct fan 123, and their relative magnitudes are not limited. Furthermore, information on the various rotational speeds related to the internal fan 124 may be stored in the non-volatile memory 423 in the same manner as the duct fan 123, in the form of a management table.

[0080] [Example 1] In the embodiments described above, it was assumed that information on the rotation speed of the cooling fan when using the external microphone 107c is pre-stored in the management table, but the implementation of the present invention is not limited to this. That is, it is not necessary for the management table to pre-store information on the rotation speed appropriate for audio recording, assuming the connection of all types of external microphones 107c. For example, when an external microphone 107c with an identification signal for which there is no information in the management table is connected, the external microphone 107c may be calibrated, and new information may be added to the management table based on the result.

[0081] Calibration can be performed, for example, by following the procedure below. The system control unit 420 first drives the duct fan 123 while changing its rotation speed from the minimum to the maximum, and records audio using the connected external microphone 107c. Then, the system control unit 420 performs frequency analysis on the recorded audio and identifies the rotation speed at which the audio level of a predetermined frequency of the rotation sound of the duct fan 123 does not exceed a threshold (the rotation speed at which the rotation sound is considered to have no effect on audio recording), and stores it in a management table in association with an identification signal. In this way, thereafter, when the external microphone 107c is connected, the duct fan 123 can be driven at an appropriate rotation speed when shooting video.

[0082] [Differentiation 2] In the embodiments described above, it was explained that a second rotation speed is defined in the management table for each type of external microphone 107c used for audio recording. However, the implementation of the present invention is not limited to this. Each external microphone 107c may have different characteristics, and a second rotation speed may be defined for each of these characteristics.

[0083] Microphones have characteristics such as directionality, and the influence of the cooling fan's rotation noise on audio recording differs depending on whether or not they are directive, and the degree of directivity. In other words, a unidirectional external microphone 107c, which is configured to easily capture sound from a specific direction, is less likely to pick up the cooling fan's rotation noise than an omnidirectional external microphone 107c which has no directionality. That is, when using the latter external microphone 107c, the influence of the cooling fan's rotation noise on audio recording is less than when using the former external microphone 107c. For this reason, the system control unit 420 should control the cooling fan to drive at a higher second rotation speed when a highly directive external microphone 107c is used than when a less directive external microphone 107c is used.

[0084] Therefore, the management table may store information on the rotational speed (second rotational speed) that drives the cooling fan for each directivity of the external microphone 107c. Alternatively, since some external microphones 107c have switchable directivity, the management table may store information on the rotational speed that drives the cooling fan for each combination of the type of external microphone 107c and the directivity in which it operates.

[0085] [Difference 3] In the above-described modification 2, an embodiment in which the second rotation speed is varied according to the characteristics of the external microphone 107c was explained. However, the implementation of the present invention is not limited to this, and can be applied as long as the rotation speed of the cooling fan is varied according to the characteristics of the microphone used for audio recording. That is, the present invention may be applied, for example, to a digital camera 100 equipped with a plurality of built-in microphones with different directivity, in which case the first rotation speed may be varied depending on which built-in microphone is used. It goes without saying that such control may also be performed for a third microphone, for example.

[0086] [Differentiation Example 4] In the embodiments described above, the third microphone was assumed to be a wireless microphone 107d, but the invention is not limited to this. That is, the third microphone does not have to be a microphone mounted inside or on the housing of the digital camera 100, and may be, for example, a microphone connected via a wired connection through an external communication terminal 121c, or an electrically unconnected microphone that records audio in synchronization with video recording in another device.

[0087] [Difference 5] In the embodiments described above, a method for controlling the rotational speed of the cooling fan depending on whether the first microphone, the second microphone, or the third microphone is used has been explained, but the implementation of the present invention is not limited thereto. Video recording is not limited to recording with sound, and in cases where there is no sound recording, the cooling fan may be controlled to be driven at a rotational speed higher than the first and second rotational speeds, such as the reference rotational speed.

[0088] [Modification 6] The embodiments and modifications described above illustrate the application of the present invention to an imaging device (digital camera 100) capable of recording video with audio recording. However, the implementation of the present invention is not limited to this. The present invention can be applied to any audio recording device equipped with a cooling fan, and an imaging function is not essential.

[0089] [Other embodiments] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0090] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0091] 100: Digital camera, 107a: Accessory shoe, 107b: Built-in microphone, 107c: External microphone, 107d: Wireless microphone, 110a: Vent, 110b: Vent, 122: Duct, 123: Duct fan, 124: Internal fan, 135: Intake, 136: Exhaust, 420: System control unit, 423: Non-volatile memory, 424: System memory

Claims

1. An audio recording device equipped with a cooling fan, A means for obtaining the type of microphone to be used for audio recording, Control means for controlling the rotational speed that drives the heat dissipation fan, A recording means for recording sound acquired by the microphone used, It has, The microphone used includes a built-in microphone in the audio recording device and a non-built-in microphone not built into the audio recording device. The control means, when the microphone to be used, as acquired by the acquisition means, is a non-built-in microphone, adjusts the rotation speed of the cooling fan depending on whether the microphone to be used is a non-built-in microphone mounted on the housing of the audio recording device. A voice recording device characterized by the following features.

2. The microphones used include microphones with different directivity, The control means adjusts the rotation speed of the cooling fan according to the directivity of the microphone being used. The audio recording device according to feature 1.

3. The microphones used include microphones that can be configured with different directivity settings. The control means adjusts the rotation speed of the cooling fan according to the directivity set for the microphone being used. The audio recording device according to feature 1.

4. The control means controls the rotation speed of the cooling fan to a higher value when the microphone used is a first directional microphone than when a second directional microphone with lower directivity than the first directional microphone is used for voice recording. The audio recording device according to feature 2 or 3.

5. The control means, when the microphone to be used is the non-built-in microphone, The rotation speed of the cooling fan is controlled to a higher value than when the built-in microphone is used for voice recording. Depending on the type of non-built-in microphone, the rotation speed of the cooling fan is further varied. The audio recording device according to any one of claims 1 to 4.

6. The control means controls the rotation speed of the cooling fan to a higher value than when the microphone used is a non-built-in microphone that is not mounted in the housing of the audio recording device, compared to when the non-built-in microphone mounted in the housing of the audio recording device is used for audio recording. The audio recording device according to any one of claims 1 to 5.

7. The control means determines whether the non-built-in microphone is mounted on the housing of the audio recording device based on whether the non-built-in microphone is electrically connected via electrical contacts provided on the housing of the audio recording device. The audio recording device according to any one of claims 1 to 6.

8. The control means determines that the non-built-in microphone is a wirelessly connected microphone and is not mounted in the housing of the audio recording device. The audio recording device according to any one of claims 1 to 7.

9. For each of the aforementioned types of microphones used, the system further includes a management means for managing information on rotational speeds at which the audio level of a predetermined frequency generated when the cooling fan is driven does not exceed a threshold. The control means drives the cooling fan at a rotation speed controlled by the management means for the type of microphone being used. The audio recording device according to any one of claims 1 to 8.

10. An imaging device capable of recording video, Imaging means, A sound recording device according to any one of claims 1 to 9, An imaging device characterized by having the following features.

11. A control method for an audio recording device equipped with a cooling fan, The acquisition process involves obtaining the type of microphone to be used for audio recording, A control step for controlling the rotational speed that drives the heat dissipation fan, A recording step of recording the sound acquired by the microphone used, It has, The microphone used includes a built-in microphone in the audio recording device and a non-built-in microphone not built into the audio recording device. In the control step described above, if the microphone to be used is the non-built-in microphone, the rotation speed of the cooling fan is controlled to differ depending on whether the microphone to be used is the non-built-in microphone mounted on the housing of the audio recording device. A control method characterized by the following:

12. A program for causing a computer equipped with a cooling fan to function as a control means for the audio recording device described in any one of claims 1 to 9.

Images