JP2015012586A - Portable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable terminal comprising a heat dissipation structure which prevents a user from feeling heat when the user touches a casing of the portable terminal even in the case where high-temperature heat is generated within the portable terminal.SOLUTION: In a portable terminal 10 which generates heat, a heat dissipation member 2 is provided in a casing outer peripheral part 11 that is touched with fingers of a user. The casing outer peripheral part 11 is divided into a plurality of regions and a finger touch detection sensor 3 is provided. An annular channel 4 is brought into contact with the heat dissipation member 2, an internal channel 5 for transferring heat of a heating component 11 is connected at a position of a portion neighboring to the plurality of regions in the annular channel 4, and a magnetic fluid 6 is encapsulated in both the channels. In portions corresponding to the regions of the annular channel 4 and a plurality of portions of the internal channel 5, induction coils 7 are adjacently provided for inducing the magnetic fluid 6 to the neighboring portion in the case of operation. When operating the portable terminal 10, the magnetic fluid 6 is caused to flow from the internal channel 5 to the annular channel 4 in the region which is detected by the touch detection sensor 3 and is not touched with fingers, thereby preventing heat of the heating element 1 from being transferred to the fingers.

Description

  The present application relates to a portable terminal having a heat dissipation structure.

  In recent years, mobile terminals represented by smartphones are in the spread stage. In such a portable terminal, in addition to a telephone function and a mail function, multi-functionality and high performance are being promoted by connecting to the Internet and incorporating various applications. With the improvement in performance of mobile terminals, mobile terminals such as so-called dual-core and quad-core equipped with a plurality of computing units in one MPU (Micro-Processing Unit) have been developed. It is increasing.

  In addition to this, there have been appeared that dozens to dozens of arithmetic units of GPU (Graphic Processing Unit), which was another chip until now, are built in the MPU. Since such an MPU has high performance, the amount of heat generated is large, and in a small portable terminal that is difficult to mount, such as a cooling fan, how to dissipate heat generated by the MPU is becoming a serious problem. is there.

  In an electronic device, as a heat transfer device that cools a portion that generates heat, for example, there is a heat transfer device disclosed in Patent Document 1. In the heat transfer device disclosed in Patent Document 1, the working fluid is circulated through the annular flow path by the fluid driving device (pump), and the working fluid is cooled by the cooling means, and then the object to be cooled is cooled and returned to the pump. It has become.

JP 2003-232596 A

  However, the heat transfer device disclosed in Patent Document 1 has a problem that the facility scale is too large to be mounted on a portable terminal such as a smartphone. In addition, portable terminals that are widely used in Japan often have a waterproof function, and since portable terminals with a waterproof function are highly airtight, heat is easily generated inside the portable terminal, and outside air is introduced. There is a problem that heat cannot be dissipated. For this reason, in such portable terminals, the MPU or the battery, which is the largest heat source, may rise to a temperature exceeding the user's body temperature. It was a big issue. Therefore, there is a demand for a portable terminal that does not feel hot even when a user touches the casing even if high-temperature heat is generated inside the portable terminal.

  In one aspect, even when high temperature heat is generated inside the mobile terminal, the present application prevents the heat of the mobile terminal from being felt hot even when the user touches the casing of the mobile terminal by releasing the heat to the outside of the mobile terminal. An object of the present invention is to provide a portable terminal having a heat dissipation structure that can be used.

  According to one aspect of the embodiment, the portable terminal includes a heat generating component, and is provided inside the outer peripheral portion of the casing of the portable terminal where the user's fingers come into contact, and can be in contact with the outside air with a gap. A heat-dissipating member, a portion where the fingers on the outer periphery of the casing come into contact are divided into a plurality of regions, a contact detection sensor that detects contact / non-contact of the fingers provided in each divided region, and the inside of the heat-dissipating member Is connected to the inner part of the annular flow path corresponding to the position of the adjacent part of the plurality of regions, and transfers the heat of the heat generating part. Adjacent to the flow path, the magnetic fluid filled in the annular flow path and the internal flow path and capable of transferring heat, the portions corresponding to the plurality of regions of the annular flow path, and the multiple portions of the internal flow path, respectively Arranged to be able to operate independently and guides magnetic fluid to adjacent parts during operation An induction coil, a contact detection sensor, and a control circuit connected to each induction coil. The control circuit is configured to flow in an annular flow path in a non-contact region of a finger detected by the contact detection sensor during operation of the mobile terminal. A portable terminal is provided that operates an induction coil so that a magnetic fluid flows from a path.

(A) is the front view of the smart phone of one Example of the portable terminal of this application, (b) is the rear view of the smart phone shown in (a), (c) is the smart phone shown in (a), (b). It is a perspective view of the mesh-shaped grill used for an outer peripheral part. (A) is a layout view showing a first embodiment of the layout of the heat dissipating member, the annular flow path, the internal flow path, and the heat generating component provided inside the smartphone shown in FIG. It is sectional drawing in the AA line of the layout shown to a). It is a block circuit diagram which shows the connection of the contact detection sensor and induction coil which were provided in the inside of the smart phone shown to Fig.1 (a), and a control circuit. It is explanatory drawing explaining the state of the magnetic fluid enclosed inside the annular flow path and internal flow path shown to Fig.2 (a). FIG. 2A shows a second embodiment of the arrangement of the annular flow path and the internal flow path provided in the smartphone shown in FIG. 1A, and FIG. 1A shows the smartphone in a state where the rear cover is removed from the smartphone. The rear view, (b) is a layout diagram showing an example of the configuration of the annular flow path and the internal flow path disposed on the back side of the rear cover removed from the smartphone shown in (a). (A) is principal part sectional drawing which shows the thermal connection of the heat-emitting component and internal flow path in arrangement | positioning of the 2nd Example of the cyclic | annular flow path shown in FIG. 5 (a), (b), and an internal flow path, (B) is sectional drawing which shows the state from which the rear cover was removed from the state shown to (a). It is principal part sectional drawing which shows the structure of the deformation | transformation Example of the 2nd Example of the annular flow path and internal flow path which were shown to Fig.5 (a), (b). FIG. 6 is a layout diagram illustrating a third embodiment of the layout of the heat dissipating member, the annular flow path, the internal flow path, and the heat generating component provided inside the smartphone illustrated in FIG. (A) is a figure explaining the heat dissipation state when a smartphone, which is an example of a portable terminal of the present application, is held sideways with both hands, and (b) is a smartphone, which is an example of a portable terminal of the present application, in the vertical direction with one hand. It is a figure explaining the heat dissipation state when being held. (A) is an example of a magnetic fluid flow path by switching of the induction coil when the smartphone is held as shown in FIG. 9A, and a magnetic fluid flow path by switching of the induction coil when the smartphone is charging. FIG. 9B is an explanatory diagram showing an example of a magnetic fluid flow path by switching of an induction coil when the smartphone is held as shown in FIG. 9B. It is a flowchart which shows one Example of the procedure of the switching control of the induction coil by the control circuit at the time of charge and operation | movement of a smart phone.

  Hereinafter, embodiments of the present application will be described in detail based on specific examples with reference to the accompanying drawings.

  FIG. 1A shows a smartphone 10 as an example of the portable terminal of the present application as viewed from the front side, and FIG. 1B shows the smartphone 10 shown in FIG. It is a thing. On the front side of the main body housing 20 of the smartphone 10 shown in FIG. 1A, there are a display 22, a mouthpiece 23, a mouthpiece 24, a sub camera 25, and the like. Further, a main camera 26, a fingerprint sensor 27, and the like are provided on the back side of the main body side housing 20 shown in FIG. 1B, and a rear cover 21 is attached. Inside the main body side housing 20, a heat generating component such as an arithmetic unit (MPU) described later is provided.

  In the smartphone 10 of the present application, the casing outer peripheral portion 11 of the main body side housing 20 is divided into a plurality of areas, and whether or not the finger of the person (user) who operates the smartphone 10 touches the area for each divided area. A contact detection sensor for detecting this is disposed. In the present embodiment, the number of divisions of the housing outer peripheral portion 11 is 10, and when viewed from the front, three regions R1, R2, and R3 on the right side, three regions L1, L2, and L3 on the left side, and two regions T1 on the upper side. , T2 and two regions B1 and B2 on the lower side. Each region is provided with a mesh-like grill 8 provided with a plurality of fine holes for heat dissipation as shown in FIG. 1C to ensure air permeability.

  FIG. 2A shows a first embodiment of the arrangement of the heat radiating member 2, the annular flow path 4, the internal flow path 5 and the heat generating component 1 provided in the smartphone 10 shown in FIG. 1A. FIG. 2B is a cross-sectional view taken along line AA of the layout shown in FIG. An arithmetic component 1 such as an MPU is provided inside the main body side housing 20 of the smartphone 10, and the arithmetic component 1 becomes the heat generating component 1 in the smartphone 10. The arithmetic component and the heat generating component will be described with the same reference numeral 1. In the present application, the heat generated by the heat generating component 1 during the operation of the smartphone 10 is radiated to the outside of the smartphone 10 using the annular flow path 4, the internal flow path 5, and the heat radiating member 2.

  The heat radiating member 2 includes a right heat radiating member 2R provided on the right side of the smartphone 10, a left heat radiating member 2L provided on the left side, an upper heat radiating member 2T provided on the upper side, and a lower heat radiating member 2B provided on the lower side. The reference numeral 2 will be described as these representative numbers. The heat dissipating member 2 is provided inside the mesh-like grill 8 provided on the housing outer peripheral portion 11 of the smartphone 10 with a gap 12 therebetween. Although not shown in the figure, the mesh-like grill 8 side of the heat dissipating member 2 is provided with a plurality of metal parallel fins (layer fins) having high thermal conductivity, which are in contact with the outside air over a wide area. ing. In other words, the heat radiating member 2 serves as a heat sink. Such a heat sink is also called a micro heat sink. At this time, the surface of the heat radiating member 2 can be coated or coated with a coating agent for increasing the heat radiating efficiency.

  In the embodiment shown in FIG. 2A, the right heat radiating member 2R, the left heat radiating member 2L, the upper heat radiating member 2T, and the lower heat radiating member 2B are continuous on each side. However, the right heat radiating member 2R, the left heat radiating member 2L, the upper heat radiating member 2T, and the lower heat radiating member 2B are adjacent boundary portions of the regions R1 to R3, the regions L1 to L3, the regions T1 and T2, and the regions B1 and B2. You may divide | segment by space or may divide | segment and insert a heat insulation member. Implementation in which the right heat radiating member 2R, the left heat radiating member 2L, the upper heat radiating member 2T, and the lower heat radiating member 2B are divided into heat radiating members 2R1 to 2R3, 2L1 to 2L3, T1, T2, B1, and B2 by spaces at adjacent boundary portions. An example is shown in FIG.

  On the inner side of the right heat radiating member 2R, the left heat radiating member 2L, the upper heat radiating member 2T, and the lower heat radiating member 2B, a reflux circuit 4 adjacent to the heat radiating member 2 in a heat transfer state is provided. The reflux circuit 4 can be formed by a pipe along the inside of the heat radiating member 2. An internal flow path 5 for transferring heat generated by the heat generating component 1 is provided inside the reflux circuit 4. The internal channel 5 is arranged vertically and horizontally inside the annular channel 4, and is connected to the annular channel 4 at a portion corresponding to the position of the adjacent portion of the plurality of regions. In the embodiment shown in FIG. 2 (a), the internal flow path 5 includes a boundary between regions R1 and R2, a boundary between regions R2 and R3, a boundary between regions L1 and L2, a boundary between regions L2 and L3, and a region. It is connected to the boundary between T1 and T2 and the boundary between regions B1 and B2.

  In the embodiment shown in FIG. 2A, the annular flow path 4 and the internal flow path 5 are pipes having a rectangular cross section, and are formed of a metal having high thermal conductivity and no magnetism, such as aluminum or resin. Has been. And the induction coil 7 is provided in the part corresponding to each area | region of the annular flow path 4, and the part between the connection part to the annular flow path 4 of the internal flow path 5, and the cross | intersection part of the internal flow paths 5. It has been. In the present embodiment, the induction coil 7 is formed in a sheet shape by metal printing or etching. The sheet-like induction coil 7 is attached to the side surfaces of the annular flow path 4 and the internal flow path 5 or is arranged in the very vicinity. Each induction coil 7 is connected to the computing component 1, for example, and can be turned on / off independently by switching.

  A magnetic fluid is sealed in the annular flow path 4 and the internal flow path 5, and when the induction coil 7 is turned on, the magnetic fluid is attracted to the induction coil 7 and moved by the magnetic field of the induction coil 7 that is turned on. To do. Therefore, if the plurality of induction coils 7 are sequentially switched on, the magnetic fluid can be moved to any position inside the annular flow path 4 and the internal flow path 5.

  Here, with reference to FIG. 2B, the arrangement relationship among the heat radiating member 2, the annular flow path 4, the internal flow path 5, the induction coil 7 provided in the smartphone 10 and other components will be described. A display 22 using liquid crystal is disposed on the main body side housing 20 of the smartphone 10, and a circuit portion 33 is provided below the display 22. The aforementioned heat generating component is mounted on this circuit portion 33. And the internal flow path 5 is arrange | positioned under the circuit part 33, and the induction coil 7 is affixed on the lower side of the internal flow path 5 in the present Example. A battery 34 is provided below the internal flow path 5, and a rear cover 21 is provided outside the battery 34.

  On the other hand, the outer peripheral portion 11 of the smartphone 10 is provided with a water blocking wall 31 for preventing water from entering the inside of the main body side housing 20, and the internal flow path 5 penetrates the water blocking wall 31. It is connected to the annular flow path 4 provided outside the water blocking wall 31. A water sealing material 32 is provided at a portion where the internal flow path 5 penetrates the water blocking wall 31 to prevent water from entering the main body side housing 20. A mesh-shaped grill 8 is provided outside the water blocking wall 31, and the heat radiating member 2 and an annular channel 4 in contact with the heat radiating member 2 are provided in the space between the mesh-shaped grill 8 and the water blocking wall 31. ing. In this embodiment, the heat radiating member 2 is a heat sink having a plurality of fins 13, and performs heat exchange with the outside of the mesh-like grill 8 by the gaps 12 between the fins 13.

  FIG. 3 shows the connection between the contact detection sensor 3 and the induction coil 7 provided inside the smartphone 10 shown in FIG. 1A and the control circuit 15. In this embodiment, the control circuit 15 generates heat. It is provided inside the component 1. In this figure, illustration of the heat radiating member 2, the annular flow path 4 and the internal flow path 5 is omitted. One contact detection sensor 3 is provided in each of the above-described regions, and is connected to the control circuit 15 independently. The plurality of induction coils 7 are also independently connected to the control circuit 15. The contact detection sensor 3 can form the mesh-like grill 8 itself as a capacitive touch sensor. Further, the contact detection sensor 3 can be formed using a pressure sensor, an optical sensor using an optical fiber, or the like in addition to the capacitive touch sensor.

  FIG. 4 is an explanatory view for explaining the state of the magnetic fluid 6 sealed in the annular flow path 4 and the internal flow path 5 shown in FIG. The magnetic fluid 6 is not filled in the entire area inside the annular flow path 4 and the internal flow path 5 but is divided by the plurality of air filling areas 16 so that the inside of the annular flow path 4 and the internal flow path 5 is Is enclosed. This is because the magnetic fluid 6 does not move when the annular flow path 4 and the internal flow path 5 are filled with the magnetic fluid 6, and the magnetic fluid 6 is divided by the plurality of air-filled regions 16, thereby providing the magnetic fluid 6. Becomes easy to move. Instead of the air filling area 16, the magnetic fluid 6 may be divided into a plurality of parts using a non-magnetic fluid.

  FIGS. 5A and 5B show a second embodiment of the arrangement of the annular flow path 4 and the internal flow path 5 provided inside the smartphone 10 shown in FIG. 1A. 5A shows a state where the rear cover 21 is removed from the smartphone 10, and FIG. 5B shows the back side of the rear cover 21 removed from the smartphone 10 shown in FIG. 5A. It can be seen from the main body housing 20 with the rear cover 21 removed that a battery 34 and an antenna 36 are provided in addition to the main camera 26 and the fingerprint sensor 27. The battery 34 is detachably accommodated in a recess 35 provided in the main body side housing 20.

  In the second embodiment, as shown in FIG. 5 (b), waterproofing is provided on the back side of the rear cover 21 to prevent water from entering a battery attached to the annular flow path 4, the internal flow path 5, and the main body side housing 20. A packing 28 is provided. Further, holes 26H and 27H are provided for exposing the main camera 26, the fingerprint sensor 27 and the like provided in the main body side housing 20 from the rear cover 21.

  FIG. 6A shows the connection between the heat generating component 1 and the internal flow path 5 in the arrangement of the annular flow path 4 and the internal flow path 5 shown in FIGS. 5A and 5B in the second embodiment. FIG. 6B is a partial sectional view, and FIG. 6B shows a state where the rear cover 21 is removed from the state shown in FIG. First, the structure of the main body side housing 20 of the smartphone 10 and the structure of the rear cover 21 side will be described separately with reference to FIG.

  As shown in FIG.6 (b), the display 22 is arrange | positioned at the surface in the main body side housing | casing 20 of the smart phone 10, and there are two circuit parts 33A and 33B on the lower side. The heat generating component 1 is mounted on the upper circuit portion 33A. A main camera 26 and a fingerprint sensor 27 are mounted on the circuit portion 33B, and a battery 34 is built in the side of the main body side housing 20 far from the main camera 26. The outer peripheral portion 11 of the smartphone 10 is provided with a water stop wall 31 for preventing water from entering the inside of the main body side housing 20, and the water stop wall 31 extends to the lower side of the circuit portion 33B. Yes. The main camera 26 and the fingerprint sensor 27 pass through the water blocking wall 31 and are mounted on the circuit portion 33B, and waterproof packings 37 and 38 are provided at portions where the main camera 26 and the fingerprint sensor 27 pass through the water blocking wall 31, respectively. Is provided.

  Further, in the second embodiment, since the annular flow path 4 and the internal flow path 5 are provided in the rear cover 21, the heat generated by the heating element 1 is taken out by the heat transfer graphite sheet 40 as heat transfer means, It passes through the water blocking wall 31 and is drawn to the front side of the water blocking wall 31. The free end of the heat transfer graphite sheet 40 is fixed to the front side of the water blocking wall 31 with a silicon rubber sheet 41. A waterproof packing 39 for water stop is provided at a portion where the heat transfer graphite sheet 40 penetrates the water stop wall 31. The point that the heat radiating member 2 and the mesh-shaped grill 8 are provided on the outer peripheral portion 11 of the case of the smartphone 10 is the same as that of the first embodiment. Furthermore, a connector 41 that supplies power to the induction coil 7 provided on the rear cover 21 side is provided in a circuit portion 33B between the end of the water blocking wall 31 in the main body side housing 20 and the battery 34. .

  On the other hand, on the rear cover 21 side, an internal flow path 5 is provided inside the rear cover 21, and an induction coil 7 is attached to a main part of the internal flow path 5. Reference numeral 28 denotes a waterproof packing that protects the battery 34 from the ingress of water. Reference numeral 29 denotes a connector that supplies power to the induction coil 7 provided on the rear cover 21 side, and is connected to the connector 41 of the main body side housing 20. is there. An annular flow path 4 connected to the internal flow path 4 is provided on the side of the rear cover 21 close to the housing outer peripheral portion 11, and an induction coil 7 is attached to the side surface of the annular flow path 4. It has been. When the rear cover 21 is attached to the back surface of the main body side housing 20, the state shown in FIG.

  FIG. 7 shows the structure of a modified embodiment of the second embodiment in which the annular flow path 4 and the internal flow path 5 shown in FIGS. 5 (a) and 5 (b) are arranged on the rear cover 21. The modified embodiment differs from the second embodiment only in that a bare chip 30 is mounted on the rear cover 21 for controlling the induction coil 7 to be turned on / off. Therefore, the same components as those of the second embodiment shown in FIGS. 5A and 5B are denoted by the same reference numerals and the description thereof is omitted. When the bare chip 30 is mounted on the rear cover 21, the connectors 29 and 42 provided between the circuit portion 33 </ b> B and the rear cover 21 supply power to the induction coil 7 and are built in the bare chip 30 and the heat generating component 1. The control circuit 15 is also connected.

  The first embodiment in which the annular flow path 4 and the internal flow path 5 are disposed in the main body side housing 20 and the second embodiment in which the annular flow path 4 and the internal flow path 5 are disposed in the rear cover 21 have been described above. did. However, in these two embodiments, the internal flow path 5 has a boundary between the region L1 and the region T1, a boundary between the region R1 and the region T2, a boundary between the region L3 and the region B1, and a boundary between the region R3 and the region B2. Was not connected to. FIG. 8 shows a third embodiment of the arrangement of the heat radiating member 2, the annular flow path 4, the internal flow path 5, and the heat generating component 1 provided inside the smartphone 10 shown in FIG. 1 (a). . In the third embodiment, the internal flow path 5 is also provided at the boundary between the region L1 and the region T1, the boundary between the region R1 and the region T2, the boundary between the region L3 and the region B1, and the boundary between the region R3 and the region B2. It is connected. Since other configurations of the third embodiment are the same as those of the first and second embodiments, further description is omitted.

  FIGS. 9A and 9B show typical usage states of the smartphone 10. FIG. 9A shows a usage state in which the smartphone 10 is held sideways by both the left hand LH and the right hand RH. If FIG. 9A is a state in which the smartphone 10 shown in FIG. 2A is rotated 90 degrees to the right, at this time, only the region L2 and the region R2 are non-contact regions of the fingers. FIG. 9B shows a usage state in which the smartphone 10 is held in the vertical direction only by the left hand LH. If FIG.9 (b) is the same state as the smart phone 10 shown to Fig.2 (a), only area | region T1, T2 and area | region B1, B2 will be a non-contact area | region of a finger at this time. Therefore, when the smartphone 10 is in the use state as shown in FIG. 9A, heat is released from the regions L2 and R2, and when the smartphone 10 is in the use state as shown in FIG. , T2 and the areas B1 and B2, the user can feel no heat from the fingers.

  FIG. 10A shows an example of a magnetic fluid flow path by switching of the induction coil 7 when the smartphone 10 is held as shown in FIG. 9A. By sequentially switching the induction coil 7 on, the magnetic fluid in this example can be circulated so as to pass through the route indicated by the solid line in FIG. As a result, the heat generated in the heat generating component 1 is carried to the regions L2 and R2 only by the magnetic fluid and dissipated, so that the heat is not transmitted to other regions where the user's fingers come into contact, and the user feels the heat. Absent.

  Moreover, the route of the magnetic fluid shown by the broken line in FIG. 10A shows an example of the flow path of the magnetic fluid by switching of the induction coil 7 when the smartphone 10 is being charged. When the smartphone 10 is being charged, a heat generating component such as a battery may generate heat and the casing may become hot. In this case, if the user holds the smartphone 10 after completion of charging, the user still feels heat. Therefore, when the smartphone 10 is being charged, the induction coil 7 is controlled to be turned on and off, and the heated magnetic fluid is circulated through the annular flow path 4 to dissipate the heat, so that the case of the smartphone 10 being charged is Temperature rise can be suppressed.

  FIG. 10B shows an example of a magnetic fluid flow path by switching of the induction coil 7 when the smartphone 10 is held as shown in FIG. 9B. Here, it is assumed that the internal flow path 5 described in FIG. 8 is provided inside the smartphone 10. In this case, the magnetic fluid can be circulated through the route indicated by the solid line in FIG. 10B by sequentially switching on and turning on the induction coil 7. In this route, the magnetic fluid that has dissipated heat in the regions T1 and T2 passes through the region L2 and the region R2 of the annular channel 4 again after passing through the internal channel 5, but the magnetic fluid when passing through the regions L2 and R2 Since the temperature of the user is lowered, the user does not feel the heat. As a result, the heat generated in the heat generating component 1 is dissipated in the regions T1 and T2 and the regions B1 and B2 by the magnetic fluid, so that the high temperature heat is not transmitted to other regions where the user's fingers come into contact. I don't feel the heat. This route is an example, and it is possible to prevent the magnetic fluid from passing through the regions L2 and R2.

  FIG. 11 is a flowchart illustrating an example of the procedure of switching control of the induction coil performed by the control circuit when the smartphone 10 is charged and operated. The route through which the magnetic fluid described in FIGS. 10A and 10B flows is determined by the operation of this control circuit. The control circuit performs the operation shown in FIG. 11 at predetermined time intervals regardless of the state of the smartphone.

  In the control procedure of this embodiment, it is first determined in step 111 whether or not the smartphone is being charged. When the smartphone is being charged, the process proceeds to step 112, and an operation of switching the induction coil is performed so that the magnetic fluid that has passed through the heat source returns to the heat source through the annular flow path. This operation is repeated many times when the smartphone is being charged. On the other hand, if it is determined in step 111 that the smartphone is not being charged, the process proceeds to step 113, where it is determined whether the smartphone is powered on. If the smartphone is not charged and the power is off, no heat is generated from the smartphone, so this routine ends.

  On the other hand, if it is determined in step 113 that the power of the smartphone is on, the process proceeds to step 114, and the detection values of the contact detection sensors provided in the respective areas on the outer periphery of the housing of the smartphone are read. In the following step 115, the contact area (or non-contact area) of the user's finger with the smartphone is detected, and in the next step 116, it is determined whether or not the detected area is the same as the previous one. Immediately after the power of the smartphone is turned on, there is no previous value, so the determination is (NO), and the process proceeds to step 117. If the user does not change the way the smartphone is held after the smartphone is turned on, the determination in step 116 is (YES). However, if the user holds the smartphone, the determination in step 116 is (NO). The process proceeds to step 117.

  In step 117, the route of the magnetic fluid passing through the non-contact region of the user's finger through the internal flow path and the annular flow path from the heat source is calculated, and the process proceeds to step 118. In step 118, the induction coil is switched so that the magnetic fluid passes through the calculated route, and this routine ends. As a result, the magnetic fluid passes through the route described in FIGS. 10A and 10B, and heat generated inside the smartphone can be prevented from being transmitted to the finger of the user having the smartphone.

  In the embodiment described above, a smartphone has been described as an example of a mobile terminal. However, the mobile terminal is not limited to a smartphone, and includes a small portable electronic device such as a tablet or an ultra book.

  The present application has been described in detail with particular reference to preferred embodiments thereof. For easy understanding of the present application, specific forms of the present application are appended below.

(Appendix 1) A mobile terminal with a built-in heat generating component,
A heat dissipating member that is provided inside the outer peripheral part of the casing of the mobile terminal and that is in contact with the user's fingers, and that can come into contact with the outside air across a gap,
A contact detection sensor that detects a contact / non-contact of the fingers provided in each of the divided areas by dividing a portion of the outer periphery of the housing that is in contact with the fingers.
An annular flow path that is provided in a heat transfer state inside the heat radiating member and transfers heat of the heat generating component;
An internal flow path that is connected to an inner portion of the annular flow path corresponding to a position of an adjacent portion of the plurality of regions, and that transfers heat of the heat generating component;
A magnetic fluid filled in the annular channel and the inner channel and capable of transferring heat;
An induction coil that is arranged so as to be independently operable adjacent to each of the plurality of regions of the annular flow path and the plurality of parts of the internal flow path, and that guides the magnetic fluid to the adjacent parts during operation;
A control circuit connected to each contact detection sensor and each induction coil;
The control circuit operates the induction coil so that the magnetic fluid flows from the internal flow path to the annular flow path in the non-contact area of the finger detected by the contact detection sensor when the mobile terminal is operated. A portable terminal characterized in that
(Additional remark 2) The said heat radiating member is comprised with the heat sink provided with the metal several layer fin with high heat conductivity, The portable terminal of Additional remark 1 characterized by the above-mentioned.
(Supplementary note 3) The mobile terminal according to supplementary note 2, wherein the heat dissipation member is coated or painted to increase heat dissipation efficiency.
(Additional remark 4) The said thermal radiation member is independent for every said area | region, The portable terminal in any one of Additional remark 1 to 3 characterized by the above-mentioned.
(Supplementary Note 5) The portable terminal according to any one of Supplementary Notes 1 to 4, wherein a mesh-shaped grill is provided on the outer peripheral portion of the casing to ensure air permeability with the gap.

(Additional remark 6) The said cyclic | annular flow path and the said internal flow path are high heat conductivity, and are comprised with the metal or resin which does not have magnetism, The portable in any one of Additional remark 1 to 5 characterized by the above-mentioned. Terminal.
(Additional remark 7) The said magnetic fluid is divided | segmented by the several air filling area | region, and is filled with the inside of the said annular flow path and the said internal flow path, The portable in any one of Additional remark 1 to 6 characterized by the above-mentioned. Terminal.
(Additional remark 8) The said induction coil is formed in the sheet form by the metal printing or the etching, and is arrange | positioned on the said annular flow path and the said internal flow path, or any of the vicinity. The portable terminal in any one.
(Supplementary Note 9) The heat generated by the heat generating component is transferred to the internal flow path by a heat transfer sheet having one end in contact with the heat generating component and the other end in contact with the internal flow path. The mobile terminal according to any one of 1 to 8.
(Supplementary note 10) The mobile terminal according to any one of Supplementary notes 1 to 9, wherein the contact detection sensor is one of a capacitance type sensor, a pressure sensor type, and an optical sensor type.

(Additional remark 11) The housing | casing of the said portable terminal is equipped with the main body side housing which incorporates the said heat-emitting component, and the rear cover attached to this main body side housing from the back surface side,
The portable terminal according to any one of appendices 1 to 9, wherein the annular flow path, the internal flow path, and the induction coil are provided inside the rear cover.
(Supplementary note 12) The portable terminal according to any one of Supplementary notes 1 to 11, wherein the heat generating component is an arithmetic device, and the control circuit is included in the heat generating component.
(Additional remark 13) The said control circuit is provided in the said rear cover, The portable terminal of Additional remark 11 characterized by the above-mentioned.
(Supplementary Note 14) The control circuit circulates the magnetic fluid between the annular flow path in a predetermined region and the internal flow path connected thereto by sequentially switching the induction coil. The mobile terminal according to 12 or 13.
(Supplementary Note 15) When the portable terminal is not used and charged, the control circuit operates the induction coil so that the magnetic fluid circulates and flows from the internal flow path to an arbitrary annular flow path. The mobile terminal according to appendix 14, characterized by:

DESCRIPTION OF SYMBOLS 1 Heat generating component 2 Heat radiating member 3 Contact detection sensor 4 Annular flow path 5 Internal flow path 6 Magnetic fluid 7 Inductive coil 8 Mesh-like grill 10 Mobile terminal (smart phone)
11 Housing outer peripheral portion 15 Control circuit 20 Body side housing 21 Rear cover

Claims (5)

A portable terminal with a built-in heat generating component,
A heat dissipating member that is provided inside the outer peripheral part of the casing of the mobile terminal and that is in contact with the user's fingers, and that can come into contact with the outside air across a gap,
A contact detection sensor that detects a contact of the finger by being provided in each of the divided areas, and a portion of the outer periphery of the housing that is in contact with the finger is divided into a plurality of areas.
An annular channel that is provided in contact with the inside of the heat dissipation member and transfers heat of the heat generating component;
An internal flow path that is connected to an inner portion of the annular flow path corresponding to a position of an adjacent portion of the plurality of regions, and that transfers heat of the heat generating component;
A magnetic fluid filled in the annular channel and the inner channel and capable of transferring heat;
An induction coil that is arranged so as to be independently operable adjacent to each of the plurality of regions of the annular flow path and the plurality of parts of the internal flow path, and that guides the magnetic fluid to the adjacent parts during operation;
A control circuit connected to each contact detection sensor and each induction coil;
The control circuit causes the magnetic fluid to flow from the internal flow channel to the annular flow channel in the region around the housing where the finger is not in contact with the contact detection sensor during the operation of the mobile terminal. A portable terminal, wherein the induction coil is operated so as to flow.   The mobile terminal according to claim 1, wherein the magnetic fluid is divided into a plurality of air filling regions and filled in the annular flow path and the internal flow path.   3. The mobile phone according to claim 1, wherein the induction coil is formed in a sheet shape by metal printing or etching, and is disposed on or in the vicinity of the annular flow path and the internal flow path. Terminal. A housing of the mobile terminal is provided with a main body housing containing the heat generating component, and a rear cover attached to the main body housing from the back side;
The portable terminal according to any one of claims 1 to 3, wherein the annular flow path, the internal flow path, and the induction coil are provided inside the rear cover.   5. The control circuit according to claim 1, wherein the control circuit circulates the magnetic fluid between the annular flow path in a predetermined region and the magnetic fluid connected thereto by switching the induction coil in order. The portable terminal of any one of Claims.

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