JP2013125894A - Electronic apparatus and battery for electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the rise of the internal temperature of an electronic apparatus over a long period of time using a heat storage material.SOLUTION: A loading part installed in a body 1 of an electronic apparatus is insertably/removably filled with heat storage materials 5 and 21. During filling, heat emitted from heating elements 3 and 4 in the electronic apparatus are absorbed into the heat storage materials 21 and 5, respectively, and the temperature rise of the heating elements is suppressed. When the heat storage effect of the heat storage materials is weakened, the heat storage materials are removed and replaced with new ones.

Description

  The present invention relates to an electronic device such as a digital camera and a battery for the electronic device.

  In digital cameras, a latent heat storage material is disposed in the vicinity of the image sensor, and heat generated from the image sensor is stored in the latent heat storage material by phase change, thereby suppressing temperature rise around the image sensor ( For example, see Patent Document 1).

JP 2009-60469A

  However, there is a limit to heat storage by phase change, and the latent heat storage material may not be able to suppress the temperature rise when the phase change is completed. Therefore, it may be difficult to suppress the temperature rise with a structure in which the latent heat storage material is simply disposed in the vicinity of the heating element (such as an image sensor).

An electronic apparatus according to the present invention includes a heating element in a main body, and includes a loading unit in which a heat storage material for heat removal of the heating element is detachably loaded, and the heat storage material loaded in the loading unit is It is characterized in that the heat of the heating element can be absorbed.
A battery according to the present invention is detachably loaded in an electronic device including a heating element in a main body, and includes a power feeding mechanism for feeding power to the electronic device when loaded, and heat generated in the electronic device when loaded. And a heat storage material that absorbs the heat of the body.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the raise of the internal temperature of an electronic device over a long time using a thermal storage material.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which looked at the digital camera in one Embodiment of this invention from the front. FIG. 2 is a schematic control block diagram of the digital camera. The figure explaining the effect | action of a latent heat storage material. The figure which shows the heat removal mechanism of an image pick-up element. The figure which shows the heat removal mechanism of ASIC using a thermal storage battery. The figure which shows the heat removal mechanism of ASIC which used the thermal storage card | curd. The figure which shows the other heat removal mechanism of ASIC which used the thermal storage card | curd.

An embodiment when the present invention is applied to a digital camera will be described with reference to the drawings.
In FIG. 1, a photographic lens 2 is provided on the front side of the camera body 1 on the right side in the drawing, and a subject light beam transmitted through the photographic lens 2 is guided to an image sensor (photoelectric conversion element) 3 disposed in the camera body 1. It is burned. Reference numeral 4 denotes an ASIC, which will be described later, and reference numeral 5 denotes a heat storage battery.

  As shown in the block diagram of FIG. 2, the photoelectric conversion output of the image sensor 3 is converted into a digital signal by the A / D converter 11, and then input to an ASIC (Application Specific Integrated Circuit) 4 in the CPU 16. Image processing is performed. The ASIC 4 is a chip that performs image processing, image compression / expansion, recording, monitor output, and the like, and is arranged on the left side of the camera body 1 as shown in FIG.

  The camera body 1 includes a liquid crystal monitor 12 capable of displaying an image, a recording medium interface (IF) for inserting and removing a recording medium such as a memory card, a temperature sensor 14 for detecting the temperature of the image sensor 3 or the surrounding temperature, and an ASIC 4. The temperature sensor 15 for detecting the temperature of the ambient temperature or the ambient temperature, a CPU 16, and an alarm device 17 are provided. FIG. 2 shows the recording medium 13 after being inserted into the recording medium IF. Note that members and circuits irrelevant to the present invention are not shown.

  In recent years, in digital cameras, the amount of information processing has increased with the increase in pixels and performance, and the processing speed has also been increased. For this reason, the amount of heat generated by the image sensor 3 and the ASIC 4 is increased, and the importance of heat countermeasures is increasing. Use of heat storage material is effective for heat countermeasures. In particular, the latent heat storage material uses heat absorption during the phase change of the material (here, solid phase → liquid phase), efficiently absorbs heat from the image sensor 3 and the ASIC 4, and dramatically increases their temperature rise. It is possible to delay.

  The inventor conducted an experiment for measuring a temporal temperature change of the image sensor 3 when a latent heat storage material is used. The latent heat storage material used is a sodium acetate-based latent heat storage material having a phase change temperature (melting point) of 55 ° C., a density of 1.45 × 10 −3 g / mm 3, and a latent heat of about 150 J / g during the phase change. This was placed on the back of the image sensor 3 of the camera, and moving images were continuously photographed at an ambient temperature of 40 ° C., and the time required for the temperature of the image sensor 3 to exceed 60 ° C. was measured. 60 ° C. is a temperature that hinders the operation of electronic equipment. As a result of the measurement, the time required for the temperature of the image sensor 3 to exceed 60 ° C. was about 35 minutes. FIG. 3 shows temporal changes in the temperature of the image sensor 3 when a latent heat storage material is used. The temperature of the image sensor 3 is constant due to the phase change of the latent heat storage material from time t1 to time t2, and exceeds the phase change temperature (melting point) T of the latent heat storage material when the phase change is completed.

  On the other hand, when a moving image was continuously shot under the same conditions without using a latent heat storage material, the time required for the temperature of the image sensor 3 to exceed 60 ° C. was about 20 minutes. As described above, it was found that the use of the latent heat storage material can increase the camera operation time at 60 ° C. or less, which is convenient for the operation of the electronic equipment, by 15 minutes, and by about 75%.

  However, simply placing the latent heat storage material in the vicinity of the image sensor 3 and the ASIC 4 causes the temperature to rise again after the phase change is completed, so that the temperature rise cannot be suppressed thereafter. For example, in the camera of Patent Document 1, the temperature of the latent heat storage material is measured, and when the temperature rises, measures such as limiting the period of the operation clock of the image sensor 3 or operating the cooling fan are taken. . That is, in Patent Document 1, in spite of the use of a latent heat storage material, it is necessary to take measures such as reducing the camera function or operating another cooling device in order to prevent the influence of heat.

Therefore, in this embodiment, the latent heat storage material can be used by being exchanged.
In FIG. 1, a card-type latent heat storage material 21 is used as a latent heat storage material, and a latent heat storage material is filled in a thin plate-like case (hereinafter referred to as a heat storage card). As the latent heat storage material, paraffin-based, sodium acetate-based, sodium sulfate-based and the like can be used, and those having a phase change temperature (melting point) of 55 ° C to 65 ° C are preferable. For example, when a latent heat storage material is used for an element such as the imaging element 3 or the ASIC 4 that is ideally operated at 60 ° C. or less, a latent heat storage material having a melting point of about 55 ° C. may be used. Since the normal paraffin that can be used as a latent heat storage material has a melting point that varies depending on the number of carbon atoms, an ideal paraffin can be selected.

  The shape of the heat storage card 21 is substantially the same as that of a memory card for image recording. Therefore, the heat storage card 21 can be inserted into and removed from the camera body 1 using a mechanism similar to a conventional recording medium insertion / removal mechanism. In the example of FIG. 1, since the image sensor 3 is located on the right side of the camera body 1, the insertion / removal opening (slit shape) of the heat storage card 21 is provided on the right side surface of the body 1. The card insertion slot may be opened and closed with a door.

FIG. 4 is a perspective view showing a heat removal structure of the image sensor 3 by the heat storage card 21.
The image pickup device 3 is mounted on the mounting surface of the image pickup substrate 31 (the surface facing the front of the camera), and accommodates the heat storage card 21 on the surface opposite to the mounting surface of the image pickup substrate 31 via the thermal coupling material 32. A slot 33 is disposed. The slot 33 is made of a material having high thermal conductivity such as copper or aluminum in order to have a function of thermal diffusion. The arrangement position of the slot 33 is a position corresponding to the mounting position of the image sensor 3 (behind the image sensor 3). The heat storage card 21 inserted into the slot 33 is configured such that the surface thereof entirely contacts the inner surface of the slot 33. The thermal coupling material 32 plays a role of increasing the adhesion between the substrate 31 and the slot 33 and decreasing the thermal resistance. The heat transfer efficiency from the image sensor 3 to the heat storage card 21 can be maximized by the action of the thermal coupling material 32 and the slot 33 having high thermal diffusivity.

  On the other hand, a battery (hereinafter referred to as a heat storage battery) 5 incorporating a latent heat storage material is used for heat removal of the ASIC 4. The heat storage battery 5 is configured by, for example, incorporating a circuit and a battery cell necessary for supplying power to each part of the camera in a resin cover, and further filling a latent heat storage material similar to the heat storage card 21 described above. . The battery chamber in which the heat storage battery 5 is loaded is provided in the grip part on the left side of the camera, like the battery chamber of many digital cameras.

FIG. 5 shows a heat removal structure of the ASIC 4 by the heat storage battery 5.
The ASIC 4 is mounted on the back surface (surface facing the rear of the camera) of the substrate 41 disposed in front of the battery chamber. A thermal diffusion plate 43 is closely attached to the top surface of the ASIC 4 via a thermal coupling material 42. The thermal diffusion plate 43 is made of a material having high thermal conductivity such as copper or aluminum in order to improve thermal diffusibility. One surface (surface with the largest area) of the heat storage battery 5 loaded in the battery chamber is in surface contact with the heat diffusion plate 43 throughout. Further, the thermal coupling material 42 plays a role of increasing the adhesion between the ASIC 4 and the thermal diffusion plate 43 and decreasing the thermal resistance. By the action of the thermal coupling material 42 and the heat diffusion plate 43, the efficiency of heat transfer from the ASIC 4 to the heat storage battery 5 can be maximized.

  The heat storage card 21 and the heat storage battery 5 (both in a solid state) are loaded into the camera body 1 and the power is turned on. When the imaging is repeated, the heat generation amount of the image sensor 3 and the ASIC 4 increases. In particular, when the high-speed continuous shooting or moving image shooting is performed for a long time, the heat generation amount also increases. The heat generated from the image pickup device 3 is efficiently transferred to the heat storage card 21 through the image pickup substrate 31, the thermal coupling material 32, and the slot 33 shown in FIG. Thereby, the temperature rise of the image sensor 3 is suppressed. For example, when the heat storage card 21 having a phase change temperature of 55 ° C. is used, the temperature of the image sensor 3 is kept below 60 ° C. until the phase change is completed.

  When the phase change is completed, the temperature of the image pickup device 3 rises. However, if the heat storage card 21 is taken out from the camera body 1 before reaching 60 ° C. and replaced with another heat storage card (solid phase state) 21, the temperature continues to be less than 60 ° C. Can be maintained. On the other hand, since the latent heat storage material of the extracted heat storage card 21 is solidified at room temperature, it is naturally returned to a reusable state by cooling at room temperature for a predetermined time.

  On the other hand, the heat generated from the ASIC 4 is efficiently transferred to the heat storage battery 5 via the thermal coupling material 42 and the heat diffusion plate 43 shown in FIG. 5 and absorbed and stored in the latent heat storage material in the heat storage battery 5. As a result, the temperature rise of the ASIC 4 is suppressed. For example, when the heat storage battery 5 filled with a latent heat storage material having a phase change temperature of 55 ° C. is used, the temperature of the ASIC 4 is kept below 60 ° C. until the phase change is completed. It is. When the phase change is completed, the temperature of the ASIC 4 rises. However, if the ASIC 4 is replaced with another heat storage battery 5 before reaching 60 ° C., the temperature remains below 60 ° C.

  Thus, in this embodiment, since the latent heat storage material (heat storage card 21 and the heat storage battery 5) for heat removal of the image sensor 3 and the ASIC 4 is configured to be replaceable, a plurality of (at least two) heat storage cards are previously stored. By possessing the heat storage battery 21 and the heat storage battery 5 respectively, it is possible to suppress a rise in the temperature of the image pickup device 3 and the ASIC 4 with virtually no time limit and to avoid a high temperature state in which the internal temperature of the camera body 1 causes a problem. Therefore, even if the camera body 1 is used relatively frequently, such as continuously performing high-speed continuous shooting and moving image shooting, it does not suffer from adverse effects such as image quality degradation due to thermal noise caused by high temperature conditions. Further, it is not necessary to reduce the operation clock of each element, and other cooling mechanisms such as a cooling fan are unnecessary.

  Further, since the heat storage card 21 and the heat storage battery 5 can be replaced in a very simple and short time as in the case of the conventional recording medium and battery replacement, the interruption time of the shooting due to the replacement can be shortened, and the photographer can change the replacement itself. I don't feel stress. Moreover, the enlargement of a camera can be suppressed by using a thin plate-like latent heat storage material (heat storage card 21). In addition, those using the heat storage battery 5 do not require a new heat storage material loading section, and are advantageous in reducing the size and cost of the camera.

  By the way, although the photographer may appropriately determine the replacement timing of the latent heat storage material in consideration of the usage status and usage time of the camera, the camera may have a function of notifying the replacement timing. For example, as shown in the block diagram of FIG. 2, the temperatures of the image sensor 3 and the ASIC 4 (or their ambient temperatures) are detected by temperature sensors 14 and 15, respectively. When the output of the temperature sensor 14 is equal to or greater than a predetermined value, the CPU 16 displays a message or the like for prompting the replacement of the heat storage card 21 on the liquid crystal monitor 12. Further, the CPU 16 displays a message or the like on the liquid crystal monitor 12 urging replacement of the heat storage battery 5 when the output of the temperature sensor 15 is a predetermined value or more. The predetermined value is a value slightly lower than the upper limit of the temperature at which the device malfunctions due to temperature rise. According to this, the latent heat storage material can be always exchanged at an appropriate timing, and it is not exchanged when it should be exchanged or when it is not necessary to exchange. In addition, you may prompt replacement | exchange of a latent heat storage material with the dedicated alarm device 17 (LED, a buzzer, a sound generator, etc.).

6 and 7 show two examples using the heat storage card 61 instead of the heat storage battery 5 for heat removal of the ASIC 4.
FIG. 6 shows an example in which the heat storage card 61 is brought into surface contact with the heat diffusion plate 53. FIG. 7 shows an example in which the heat storage card 61 is accommodated in the slot 54.
6 and 7, 61 is a heat storage card, 51 is a substrate on which the ASIC 4 is mounted, 52 is a thermal coupling material, 53 is a heat diffusion plate, and 54 is a slot in which the heat storage card 61 is loaded. The material and action are the same as those of the members of the same name described above. The insertion / removal port of the heat storage card 61 is provided, for example, on the bottom surface of the camera body 1. When heat is removed using the heat storage card 61, a battery that supplies power to each part of the camera is loaded into the camera body 1.

  In addition, you may comprise so that the latent heat storage material (heat storage card | curd 21, heat storage battery 5, etc.) with which it was loaded may contact directly with heat generating bodies, such as the image pick-up element 3 and ASIC4. In the above description, both the heat removal mechanism of the image sensor 3 and the ASIC 4 are shown, but only one of the heat removal mechanisms may be mounted. In addition, the heating element to be subjected to heat removal may be other than the above, and the present invention can also be applied to electronic devices other than digital cameras. For example, if the device has a projector (such as a small projector device or a camera with a built-in projector), the configuration of the present invention can be applied to heat removal from a high-intensity LED or the like that is a projector light source. Other heat removal targets include a memory and a DC / DC converter.

  Moreover, although the example using a latent heat storage material was shown, the sensible heat storage material using materials (glass, plastic, rubber, aluminum, etc.) with a large specific heat may be used, and a latent heat storage material and a sensible heat storage material are combined suitably. It may be used. Moreover, the shape of the heat storage material to be used is not limited to the above, and for example, a block-shaped heat storage material may be used.

DESCRIPTION OF SYMBOLS 1 Camera body 2 Shooting lens 3 Image sensor 4 ASIC
5 Thermal storage battery 12 Liquid crystal monitor 14, 15 Temperature sensor 16 CPU
17 Alarm 21, 61 Thermal storage card 31, 41, 51 Substrate 32, 42, 52 Thermal coupling material 33, 54 Slot 43, 53 Thermal diffusion plate

Claims (13)

An electronic device including a heating element in the body,
A loading section in which a heat storage material for heat removal of the heating element is detachably loaded;
An electronic apparatus, wherein the heat storage material loaded in the loading section is configured to be able to absorb the heat of the heating element.   The electronic apparatus according to claim 1, wherein the heat storage material loaded in the loading unit is configured to directly or indirectly contact the heating element.   The electronic apparatus according to claim 2, further comprising a heat transfer mechanism that transfers heat of the heating element to the heat storage material loaded.   The electronic apparatus according to claim 3, wherein the heat transfer mechanism includes a heat diffusion member that diffuses heat of the heating element and transfers the heat to the heat storage material.   The electronic apparatus according to claim 4, wherein the heat transfer mechanism further includes a coupling material for improving adhesion between the heat diffusing member and the heating element.   The temperature sensor which detects the said heat generating body or its ambient temperature, and the alerting | reporting means which urges | exchanges the said thermal storage material when the detected temperature becomes more than predetermined temperature, The further any one of Claims 1-5 characterized by the above-mentioned. Item 1. An electronic device according to item 1.   The electronic apparatus according to claim 1, wherein the heat storage agent has a thin plate shape.   The electronic device according to claim 1, wherein the heat storage material is incorporated in a battery for supplying power to the electronic device, and the loading unit is a battery chamber.   The electronic apparatus according to claim 1, wherein the heat storage material is a latent heat storage material.   The electronic device according to claim 9, wherein the phase change temperature of the latent heat storage material from a solid phase to a liquid phase is 55 degrees or more and 65 degrees or less.   The electronic device according to claim 1, wherein the heating element is an image sensor that receives a light beam from a subject and converts the light beam into an electrical image signal.   The electronic device according to claim 1, wherein the heating element is a control element that performs image processing on an image signal. A battery detachably loaded in an electronic device including a heating element in the body,
A battery for an electronic device, comprising: a power supply mechanism for supplying power to the electronic device at the time of loading; and a heat storage material that absorbs heat of the heating element provided in the electronic device at the time of loading.

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