ELECTRONIC APPARATUS

According to one embodiment, an electronic apparatus includes a housing, a fan, and an AC adapter. The fan is accommodated in the housing and has a fan casing at least a portion of which is made of metal. The AC adapter is removably accommodated in the housing and also thermally connected to the fan casing by being brought in contact with the portion of the fan casing in the housing.

DETAILED DESCRIPTION

Various embodiments will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment, an electronic apparatus includes a housing, a fan, and an AC adapter as an example of the heating module. The fan is accommodated in the housing and has a fan casing at least a portion of which is made of metal. The AC adapter is removably accommodated in the housing and also thermally connected to the fan casing by being brought in contact with the portion of the fan casing in the housing.

First Embodiment

The first embodiment will be described below with reference toFIGS. 1 to 5.

FIGS. 1 to 3disclose a portable computer1as an example of an electronic apparatus. The portable computer1includes a computer main body2and a display3. The computer main body2has a first housing4. The first housing4has a rectangular box shape including a bottom wall5, a front wall6, left and right sidewalls7a,7b, a rear wall8, and a top wall9. The front wall6, the sidewalls7a,7b, and the rear wall8are examples of a circumferential wall and connect a circumference of the bottom wall5and a circumference of the top wall9. A keyboard10is provided in the top wall9of the first housing4.

The display3includes a second housing11and a liquid crystal display apparatus12accommodated in the second housing11. The second housing11is rotatably supported via hinge fittings in a rear end portion of the first housing4. The liquid crystal display apparatus12has a screen12athat displays information like images. The screen12ais exposed in the front of the second housing11.

As shown inFIG. 3, a motherboard15, a battery pack16, a centrifugal fan17, and an AC adapter18are accommodated inside the first housing4.

The motherboard15is supported on the bottom wall5of the first housing4so as to be positioned in the rear half of the first housing4. A plurality of circuit components19like a semiconductor package and connectors and a CPU20are mounted on the motherboard15. The CPU20is an example of a heating component and is thermally connected to a heat sink22via a heat pipe21. The heat pipe21transfers heat of the CPU20to the heat sink22. The heat sink22is arranged in the rear end portion of the first housing4and faces a plurality of exhaust ports23opened in the rear wall8.

The battery pack16is supported on the bottom wall5of the first housing4so as to be positioned in the front half of the first housing4. The battery pack16is electrically connected to the motherboard15.

The centrifugal fan17is an element blowing a cooling air on the heat sink22and is fixed onto the bottom wall5by a publicly known method like screwing. As shown inFIG. 5, the centrifugal fan17includes a fan casing25and an impeller26. The fan casing25has a flat box shape and is formed from a metal material, for example, a steel plate or aluminum alloy. The fan casing25has a first end plate27, a second end plate28, and a side plate29.

The first end plate27and the second end plate28are arranged in parallel in the thickness direction of the fan casing25with a space therebetween. The first end plate27is an element constituting the bottom of the fan casing25. The second end plate28is an element constituting the ceiling of the fan casing25. The side plate29connects a circumference of the first end plate27and a circumference of the second end plate28. The side plate29has a pair of linear portions30a,30b. The linear portions30a,30bare arranged in parallel with a space therebetween.

The impeller26is interposed between the first end plate27and the second end plate28and also surrounded by the side plate29. Further, the impeller26is supported by the second end plate28via a fan motor31.

As shown inFIG. 5, a first inlet port32is formed in the first end plate27as the bottom of the fan casing25. The first inlet port32is opposed to the lower end of the impeller26and also connected to an air supply opening33opened in the bottom wall5of the first housing4.

A second inlet port34is formed in the second end plate28as the ceiling of the fan casing25. The second inlet port34is opposed to the upper end of the impeller26and also opened to the inside of the first housing4.

An exhaust port35is formed between the linear portions30a,30bof the side plate29of the fan casing25. The exhaust port35has a horizontal opening shape and is opposed to an outer circumferential portion of the impeller26. Further, the exhaust port35is opposed to the heat sink22inside the first housing4.

When the impeller26of the centrifugal fan17rotates, the air outside the first housing4is drawn into a rotation center portion of the impeller26through the air supply opening33and the first inlet port32. Further, the air inside the first housing4is drawn into the rotation center portion of the impeller26through the second inlet port34. The drawn air is discharged into the fan casing25from the outer circumferential portion of the impeller26as a cooling air.

As a result, a cooling air of predetermined pressure is discharged from the exhaust port35toward the heat sink22. The discharged cooling air passes through the heat sink22before being exhausted out of the portable computer1from the exhaust ports23of the first housing4.

Therefore, heat of the CPU20transferred to the heat sink22is released out of the first housing4by heat exchange with the cooling air.

The AC adapter18is an example of the heating module and transforms commercial AC power into suitable DC power adjusted to the portable computer1and outputs the transformed power. As shown inFIG. 5, the AC adapter18includes a case40made of synthetic resin and a switching regulator circuit module41accommodated in the case40.

The case40is configured by combining a lower case40aand an upper case40b. The case40in the present embodiment is formed in a flat rectangular box shape having a front face42, a rear face43, and an undersurface44.

The circuit module41includes a printed wiring board45and various circuit components46mounted on the printed wiring board45. A power cord48having a power plug47is connected to an input terminal of the circuit module41. The power cord48is led out of the AC adapter18from the front face42of the case40. Further, an output plug49is arranged at an output terminal of the circuit module41. The output plug49exposed to the outside of the AC adapter18from the rear face43of the case40.

According to the present embodiment, the circuit components43of the circuit module41include a power semiconductor device used for power control. For the AC adapter18for a portable computer, a power semiconductor device of, for example, a few tens of V of withstand voltage and a few hundred KHz of switching frequency is demanded. Thus, in the present embodiment, a power semiconductor device made of gallium nitride (GaN) as a next-generation power semiconductor device is used.

GaN has characteristics, for example, the breakdown voltage and band gap are large when compared with silicon, the thermal conductivity is high, and the electron saturation speed is fast. Thus, when compared with a power semiconductor device made of silicon, a power semiconductor device made of GaN can perform a faster switching operation and has greater heat resistance.

More specifically, a power semiconductor device made of GaN can perform switching at a speed several times faster than a power semiconductor device made of silicon. With an increasing switching frequency, an element constituting a power converter such as an inductor can be made smaller.

In addition, a power semiconductor device made of GaN can operate even in a high-temperature environment of 200° C. or more, which is considered to be the upper limit of operation of a power semiconductor device made of silicon. Accordingly, a mechanism to cool a power converter can be made smaller or omitted.

As a result, the AC adapter18using a power semiconductor device made of GaN can be made smaller to a size allowing the AC adapter18to be accommodated inside the first housing4.

The Such being the case, in the portable computer1in the present embodiment, as shown inFIGS. 1 to 5, an adapter receptacle51that accommodates the AC adapter18is provided inside the first housing4. The adapter receptacle51is positioned at a left end in the rear end portion of the first housing4and is adjacent to the centrifugal fan17.

The adapter receptacle51includes a pair of guide walls52a,52band a top wall53. The guide walls52a,52bare raised from the bottom wall5of the first housing4. The guide walls52a,52bextend linearly in a width direction of the first housing4from a left sidewall7aof the first housing4and are arranged in parallel in the depth direction of the first housing4with a space therebetween. Tips of the guide walls52a,52bpositioned on the opposite side of the sidewall7areach immediately before the one linear portion30aof the fan casing25.

The top wall53connects upper ends of the guide walls52a,52b. The top wall53is opposed to the bottom wall5of the first housing4. Thus, the adapter receptacle51is surrounded by the bottom wall5of the first housing4, the guide walls52a,52b, the top wall53, and the one linear portion30aof the fan casing25.

In other words, the adapter receptacle51is partitioned so as to be an independent closed space inside the first housing4and also has an opening54at a termination positioned on the opposite side of the sidewall7a. The opening54is blocked by the one linear portion30aof the fan casing25.

Further, the first housing4has an insertion opening55to insert the AC adapter18into the adapter receptacle51or remove the AC adapter18therefrom. The insertion opening55is formed in the left sidewall7aof the first housing4. The insertion opening55has a horizontal opening shape matching the case40of the AC adapter18and also is opposed to the one linear portion30aof the fan casing25.

As shown inFIGS. 4 and 5, the fan casing25has a heat receiving unit56extended toward the adapter receptacle51. The heat receiving unit56is an element integrally formed in the first end plate27made of metal and constitutes a portion of the fan casing25. The heat receiving unit56is formed in a flat plate shape and stacked on the bottom wall5of the first housing4to be the bottom of the adapter receptacle51.

As shown inFIG. 4, the AC adapter18is removably inserted into the adapter receptacle51from the insertion opening55in a posture in which the output plug49is leading. More specifically, when the AC adapter18is inserted through the insertion opening55, the case40of the AC adapter18is slidably sandwiched between the guide walls52a,52bof the adapter receptacle51and also slidably sandwiched between the top wall53of the adapter receptacle51and the heat receiving unit56of the fan casing25.

Thus, the AC adapter18is inserted into the adapter receptacle51while the insertion direction thereof is guided by the guide walls52a,52b, the top wall53, and the heat receiving unit56. At this point, the undersurface44as a portion of the surface of the case40is totally in contact with the heat receiving unit56extended from the fan casing25.

When the AC adapter18is inserted into the adapter receptacle51up to a position where the front face42of the case40of the AC adapter18blocks the insertion opening55, the rear face43of the case40hits stoppers57projecting into the adapter receptacle51from the guide walls52a,52b. Accordingly, the insertion position of the AC adapter18is determined and also the output plug49of the AC adapter18is connected to a connector58arranged at the termination of the adapter receptacle51. As a result, a transition to a state in which the AC adapter18and the portable computer1are electrically connected occurs.

When the AC adapter18is removably inserted into the adapter receptacle51, it is desirable to install a lock mechanism that locks the AC adapter18in a fixed position for the adapter receptacle51. When the AC adapter18is inserted into the fixed position of the adapter receptacle51, the lock mechanism is caught by the case40of the AC adapter18so that the AC adapter18is held in the adapter receptacle51in a way that prevents the AC adapter18from dropping off.

According to the first embodiment, when the AC adapter18is accommodated in the adapter receptacle51of the first housing4, the undersurface44of the case40of the AC adapter18is totally in contact with the heat receiving unit56extended from the fan casing25. Through this contact, the AC adapter18is thermally connected to the heat receiving unit56to be a portion of the fan casing25.

Therefore, heat generated when the AC adapter18converts AC into DC is conducted to the heat receiving unit56from the case40of the AC adapter18and also diffused to the fan casing25via the heat receiving unit56. The heat of the AC adapter18diffused to the fan casing25is released out of the first housing4by heat exchange with a cooling air flowing inside the fan casing25.

Therefore, heat dissipation properties of the AC adapter18accommodated in the adapter receptacle51of the first housing4can be enhanced so that a temperature rise inside the first housing4can be prevented.

Further, the centrifugal fan17is an existing element that forcibly cools the CPU20and thus, a dedicated cooling element that promotes heat dissipation properties of the AC adapter18is not needed. Therefore, increasing complexity of the configuration of the portable computer1can be avoided and also the configuration is advantageous to maintain compactness of the portable computer1.

In addition, the adapter receptacle51into which the AC adapter18is inserted is an independent closed space inside the first housing4. Thus, heat of the AC adapter18is not released directly into the first housing4and also in this respect, the configuration is advantageous to prevent a rise of the internal temperature of the first housing4.

Furthermore, even if a conductive component, for example, a metal clip slips into the adapter receptacle51from the insertion opening55while the AC adapter18is removed from the adapter receptacle51, the conductive component remains in the adapter receptacle51. Thus, the conductive component can be prevented from entering the inside of the first housing4where circuit elements like the motherboard15are contained.

Further, the heat receiving unit56of the fan casing25is in contact with the undersurface44of the case40of the AC adapter18and receives heat of the AC adapter18in a position that is different from the location where the output plug49of the AC adapter18is connected to the connector58. Therefore, the heat receiving unit56made of metal does not interfere with the output plug49.

In the first embodiment, all of the first end plate27, the second end plate28, and the side plate29constituting the fan casing25are made of metal. However, for example, only the first end plate27where the heat receiving unit56is provided may be made of metal and the second end plate28and the side plate29may be made of synthetic resin.

Further, the insertion opening55through which the AC adapter18is inserted or removed may be covered with a cover that can be removed or opened/closed.

In addition, the heating module is not limited to the AC adapter. For example, an additional memory having a plurality of semiconductor packages that generate heat is also included in the heating module.

Second Embodiment

The second embodiment is different from the first embodiment in a configuration of a case40of an AC adapter18and a heat receiving unit56of a fan casing25. The other configuration of a portable computer1is the same as in the first embodiment. Thus, in the second embodiment, the same reference numerals are attached to the same structural elements as those in the first embodiment and the description thereof is thereby omitted.

As shown inFIGS. 6 and 7, a plurality of heights61is provided in the heat receiving unit56of the fan casing25. The heights61extend straight along the insertion direction of the AC adapter18and are arranged in parallel with a space therebetween in the depth direction of a first housing4.

According to the present embodiment, the height61has an angular shape projecting from the heat receiving unit56toward an adapter receptacle51while having substantially the same thickness as the heat receiving unit56. Thus, when the heat receiving unit56is viewed from the direction of a bottom wall5of the first housing4, a plurality of groove portions62is formed in positions corresponding to the heights61of the heating portion. One end of the groove portion62is open toward the termination of the adapter receptacle51. The other end of the groove portion62is open toward an insertion opening55of the first housing4.

A plurality of recesses63corresponding to the heights61is formed in a lower case40bof the AC adapter18. The recesses63extend straight along the insertion direction of the AC adapter18and are arranged in parallel with a space therebetween in a direction perpendicular to the insertion direction of the AC adapter18.

When the AC adapter18is inserted into the adapter receptacle51through the insertion opening55of the first housing4, an undersurface44of the case40of the AC adapter18is slidably comes into contact with the heat receiving unit56of the fan casing25. In addition, the heights61of the heat receiving unit56are slidably engaged with the recesses63of the case40and so the surface of the height61is totally in contact with the inner surface of the recesses63.

According to the second embodiment, the heights61of the heat receiving unit56and the recesses63of the case40are in contact like being engaged with each other while the AC adapter18is accommodated in the adapter receptacle51. Thus, the contact area between the AC adapter18and the heat receiving unit56increases when compared with the first embodiment so that heat of the AC adapter18can efficiently be conducted to the heating receiving unit56.

Therefore, heat dissipation properties of the AC adapter18accommodated in the adapter receptacle51can adequately be secured so that a temperature rise inside the first housing4can be prevented.

In the second embodiment, the heights61are provided in the heat receiving unit56and also the recesses63are provided in the case40of the AC adapter18. However, the relationship between the heights61and the recesses63are not limited the above relationship and, for example, the recesses63may be provided in the heat receiving unit56and the heights61may be provided in the case40of the AC adapter18.

Further, the shapes of the heights61and the recesses63are not limited to those in the second embodiment. For example, many waveform irregularities may be provided in each of the heat receiving unit56and the case40of the AC adapter18to cause irregularities of the heat receiving unit56and irregularities of the case40to engage with each other.

Third Embodiment

The third embodiment is different from the second embodiment in that a portion of a cooling air discharged from a centrifugal fan17is guided to an adapter receptacle51. The other configuration of a portable computer1is the same as in the second embodiment. Thus, in the third embodiment, the same reference numerals are attached to the same structural elements as those in the second embodiment and the description thereof is thereby omitted.

As shown inFIG. 8, a space71is formed between a rear face43of a case40of an AC adapter18and one linear portion30aof a fan casing25. An air outlet72is formed in the one linear portion30aof the fan casing25facing the space71. The air outlet72is positioned between an outer circumferential portion of an impeller26and an exhaust port35. Further, the air outlet72is open to the space71and also opposed to the rear face43of the case40.

Further, as shown inFIG. 10, groove portions62of a heat receiving unit56constitute a plurality of first air courses73in cooperation with a bottom wall5of a first housing4. The first air courses73extend straight along the insertion direction of the AC adapter18. An upstream end of the first air course73is open to the space71via one end of the groove portion62. A downstream end of the first air course73is open to an insertion opening55of the first housing4via the other end of the groove portion62.

According to the third embodiment, a portion of the cooling air discharged from an outer circumferential portion of an impeller26into the fan casing25is discharged, as indicated by arrows inFIGS. 8 and 9, into the space71from the air outlet72. The cooling air discharged into the space71is directly blown against the rear face43of the case40of the AC adapter18to forcibly cool the AC adapter18.

Further, the cooling air discharged into the space71flows into the first air courses73from one end of the groove portions62of the heat receiving unit56. The air having flown into the first air courses73flows along the first air courses73and also cools the heat receiving unit56forcibly in the course of the flow. The cooling air having cooled the heat receiving unit56is discharged out of the first housing4after passing through the insertion opening55from the other end of the groove portion62.

According to the third embodiment, the AC adapter18in the adapter receptacle51can forcibly be cooled by using the cooling air discharged into the space71from the air outlet72of the fan casing25. In addition, the cooling air flows along the first air courses73formed between the heat receiving unit56of the fan casing25and the bottom wall5of the first housing4and so the heat receiving unit56receiving heat from the AC adapter18can forcibly be cooled.

As a result, heat dissipation properties of the AC adapter18accommodated in the adapter receptacle51can be enhanced still further.

In addition, the cooling air having cooled the AC adapter18and the heat receiving unit56is discharged out of the first housing4from the insertion opening55. The flow of the cooling air in the adapter receptacle51is thereby made smooth, preventing a local build-up of heat inside the first housing4.

Fourth Embodiment

The fourth embodiment is different from the third embodiment in that an undersurface44of a case40of an AC adapter18is flat. The other configuration is the same as in the third embodiment.

As shown inFIG. 11, the flat undersurface44of the case40is in surface contact with tip surfaces of heights61of a heat receiving unit56while the AC adapter18is accommodated in the adapter receptacle51. Thus, the undersurface44of the case40is a distance corresponding to the height of the height61away from the surface of the heat receiving unit56. Thus, a plurality of second air courses81partitioned by the heights61is formed between the undersurface44of the case40and the surface of the heat receiving unit56.

The second air courses81extend straight along the heights61. The upstream end of the second air course81is open to a space71. Further, the downstream end of the second air course81is open to an insertion opening55.

According to the fourth embodiment, a cooling air discharged into the space71from an the air outlet72of a fan casing25flows into both of first air courses73and the second air course81. The cooling air flowing into the first air courses73cools, like in the third embodiment, the heat receiving unit56forcibly.

The cooling air flowing into the second air courses81flows along the heat receiving unit56and the undersurface44of the case40. The cooling air having cooled the heat receiving unit56and the case40is discharged out of a first housing4from the insertion opening55.

According to the fourth embodiment, the AC adapter18inside the adapter receptacle51can directly be cooled by the cooling air flowing through the second air courses81. In addition, the heat receiving unit56is in contact with the cooling air flowing through both of the first air courses73and the second air course81and thus, the heat receiving unit56can efficiently be cooled.

Therefore, heat dissipation properties of the AC adapter18accommodated in the adapter receptacle51are enhanced still further.

Fifth Embodiment

The fifth embodiment is different from the first embodiment in that heat of an AC adapter18is actively transferred to a fan casing25. The other configuration of a portable computer1is the same as in the first embodiment. Thus, in the fifth embodiment, the same reference numerals are attached to the same structural elements as those in the first embodiment and the description thereof is thereby omitted.

As shown inFIGS. 12 and 13, a heat pipe91is integrally incorporated in an area from a heat receiving unit56up to a first end plate27of the fan casing25. The heat pipe91includes a flat container92filled with a working fluid. The container92has a heat receiving edge93and a heat radiating edge94.

The heat receiving edge93of the container92extends straight along the insertion direction of the AC adapter18. The heat receiving edge93is thermally connected to the heat receiving unit56by being embedded in a groove95provided in the heat receiving unit56. Thus, the heat receiving edge93of the container92is positioned in the same plane as the heat receiving unit56without projecting from the heat receiving unit56of the fan casing25.

The heat radiating edge94of the container92is thermally connected to the first end plate27of the fan casing25. The heat radiating edge94is exposed to a flowing course of a cooling air from an impeller26toward an exhaust port35.

According to the fifth embodiment, as shown inFIG. 13, an undersurface44of a case40of the AC adapter18is in contact with both of the heat receiving unit56and the heat receiving edge93of the heat pipe91while the AC adapter18is accommodated in an adapter receptacle51.

Thus, heat of the AC adapter18is directly conducted to the heat receiving edge93of the heat pipe91from the AC adapter18and also conducted to the heat receiving edge93of the heat pipe91indirectly from the heat receiving unit56of the fan casing25.

The working fluid returned to the heat receiving edge93is heated by the heat conduction to become a vapor. The vapor flows from the heat receiving edge93toward the heat radiating edge94and also condenses at the heat radiating edge94. Heat released by the condensation is diffused to the fan casing25by heat conduction to the first end plate27. The heat of the AC adapter18diffused to the fan casing25is released out of a first housing4by heat exchange with a cooling air flowing inside the fan casing25.

The working fluid liquefied at the heat radiating edge94is returned to the heat receiving edge93by a capillary force to receive heat of the AC adapter18again. By repeated evaporation and condensation of the working fluid described above, heat of the AC adapter18is transferred to the fan casing25.

According to the fifth embodiment, by using the heat pipe91at the same time, heat of the AC adapter18can efficiently be released out of the first housing4, enhancing heat dissipation properties of the AC adapter18.

Sixth Embodiment

FIG. 14discloses the sixth embodiment related to the fifth embodiment.

In the sixth embodiment, a heat receiving edge93of a heat pipe91is fixed onto a heat receiving unit56without being embedded in the heat receiving unit56of a fan casing25. The heat receiving edge93extends straight along the insertion direction of an AC adapter18.

On the other hand, a recess98is formed in an undersurface44of a case40of the AC adapter18. The recess98is an element into which the heat receiving edge93of the heat pipe91is slidably inserted and extends straight along the insertion direction of the AC adapter18. Further, the recess98extends along the entire length of the undersurface44of the case40and is open to each of a corner defined by the undersurface44of the case40and a front face42and a corner defined by the undersurface44of the case40and a rear face43.

According to the sixth embodiment, when the AC adapter18is inserted into an adapter receptacle51through an insertion opening55, the heat receiving edge93of the heat pipe91enters the recess98of the case40to thermally connect to the AC adapter18.

Thus, like in the fifth embodiment, heat of the AC adapter18can actively be transferred to the fan casing25by using the heat pipe91so that heat dissipation properties of the AC adapter18can be enhanced.

In addition, in the sixth embodiment, the heat receiving edge93of the heat pipe91projecting above the heat receiving unit56extends straight in the insertion direction of the AC adapter18. Therefore, when the AC adapter18is inserted into for removed from the adapter receptacle51, the heat receiving edge93of the heat pipe91can be used as a guide rail.

Seventh Embodiment

The seventh embodiment is different from the first embodiment in a configuration in which an AC adapter18and a portable computer1are electrically connected and a configuration that enhances heat dissipation properties of the AC adapter18. The other configuration of the portable computer1is the same as in the first embodiment. Thus, in the seventh embodiment, the same reference numerals are attached to the same structural elements as those in the first embodiment and the description thereof is thereby omitted.

As shown inFIG. 16, a heat pipe100is arranged extending between a centrifugal fan17and an adapter receptacle51. The heat pipe100includes a container101filled with a working fluid. The container101is formed from a straight round pipe. The container101includes a heat radiating edge102and a heat receiving edge103.

The heat radiating edge102is introduced into a fan casing25by passing through a linear portion30aof the fan casing25. The heat radiating edge102is thermally connected onto a first end plate27of the fan casing25between an impeller26and an exhaust port35.

The heat receiving edge103is projected from the fan casing25toward the adapter receptacle51. The heat receiving edge103extends along the insertion direction of the AC adapter18inside the adapter receptacle51and the tip thereof reaches the vicinity of an insertion opening55.

In addition, the heat receiving edge103is away from an inner surface of the adapter receptacle51and a heat receiving unit56of the fan casing25. Thus, the heat receiving edge103is maintained in a floating state inside the adapter receptacle51.

Further, a power supply connector104is arranged inside a first housing4. The power supply connector104is exposed to the outside of the first housing4in a position adjacent to the insertion opening55of the adapter receptacle51.

On the other hand, a case40of the AC adapter18has an insertion path105. The insertion path105is an element into which the heat receiving edge103of the heat pipe100is removably inserted when the AC adapter18is inserted into the adapter receptacle51through the insertion opening55.

The insertion path105passes through the case40in a straight line along the insertion direction of the AC adapter18and also is isolated from the inside of the case40via a cylindrical partition wall106integrated with the case40. The insertion path105has a first opening105aopen to the front face42of the case40and a second opening105bopen to the rear face43of the case40.

Further, a first insertion hole107aadjacent to the first opening105ais provided in the front face42of the case40. Similarly, a second insertion hole107badjacent to the second opening105bis provided in the rear face43of the case40.

When the AC adapter18is inserted into the adapter receptacle51through the insertion opening55of the first housing4, the heat receiving edge103of the heat pipe100enters the insertion path105through the second opening105b. While the AC adapter18is accommodated in a fixed position of the adapter receptacle51, the heat receiving edge103of the heat pipe100is in contact with the inner surface of the partition wall106defining the insertion path105along the entire length thereof. Through this contact, the AC adapter18is thermally connected to the heat receiving edge103of the heat pipe100.

The AC adapter18in the present embodiment includes an output connector110so as to be usable even when removed from the adapter receptacle51. The output connector110is connected to the output terminal of a circuit module41and is exposed to the outside of the AC adapter18through the first insertion hole107aformed in the front face42of the case40.

The output connector110can be connected to the portable computer1via a removable output cable111. The output cable111has a first output plug112and a second output plug113.

The first output plug112is provided at one end of the output cable111. The first output plug112has a plug body115made of synthetic resin from which a pin terminal114projects. The pin terminal114can selectively be inserted into the first insertion hole107aor the second insertion hole107bof the AC adapter18and can also be connected to the output connector110via the first insertion hole107a.

The second output plug113is provided at the other end of the output cable111. A pin terminal116held by the second output plug113can be connected to the power supply connector104of the first housing4.

A cover portion118is integrally formed in the plug body115of the first output plug112. The cover portion118is projected from the plug body115along the front face42or the rear face43of the case40and has a projection119fitted into the first opening105aor the second opening105bof the insertion path105.

The projection119blocks the first opening105aby being fitted into the first opening105aof the insertion path105when the pin terminal114of the first output plug112is connected to the output connector110via the first insertion hole107a. Further, the projection119blocks the second opening105bby being fitted into the second opening105bof the insertion path105when the pin terminal114of the first output plug112is inserted into the second insertion hole107b.

In the present embodiment, the first output plug112is inserted into the second insertion hole107bwhen the AC adapter18is removed from the adapter receptacle51. Accordingly, the output cable111is held by the AC adapter18and also the second opening105bof the insertion path105is closed by the projection119of the plug body115.

When the AC adapter18is accommodated in the adapter receptacle51and used, as shown inFIG. 16, the pin terminal114of the first output plug112is pulled out of the second insertion hole107bof the case40. Accordingly, the projection119of the plug body115is removed from the second opening105bof the insertion path105to unblock the second opening105b.

Thereafter, like in the first embodiment, the AC adapter18is inserted into the adapter receptacle51through the insertion opening55. The AC adapter18is inserted into the adapter receptacle51while the insertion direction thereof is guided by guide walls52a,52b, a top wall53, and the heat receiving unit56. At this point, an undersurface44of the case40is totally in contact with the heat receiving unit56of the fan casing25. Further, as shown inFIG. 17, the heat receiving edge103of the heat pipe100is inserted into the insertion path105from the second opening105b.

When the rear face43of the case40hits stoppers57of the guide walls52a,52b, the output plug49of the AC adapter18is connected to a connector58of the adapter receptacle51. In addition, the heat receiving edge103of the heat pipe100is in contact with the inner surface of the partition wall106of the insertion path105along the entire length thereof. Accordingly, the AC adapter18is thermally connected to the fan casing25via the heat pipe100.

According to the seventh embodiment, while the AC adapter18is accommodated in the adapter receptacle51, heat emitted from the AC adapter18is conducted from the AC adapter18to the heat receiving unit56and also diffused by heat conduction from the heat receiving unit56to the fan casing25. The heat of the AC adapter18diffused to the fan casing25is released out of the first housing4by heat exchange with a cooling air flowing inside the fan casing25.

In addition, the heat receiving edge103of the heat pipe100is plugged in the insertion path105of the AC adapter18and thus, heat of the AC adapter18is directly conducted to the heat receiving edge103of the heat pipe100. As a result, heat of the AC adapter18is actively transferred to the fan casing25by the operation of a working fluid with which the heat pipe100is filled. The heat of the AC adapter18diffused to the fan casing25is released out of the first housing4by heat exchange with a cooling air flowing inside the fan casing25.

Therefore, heat dissipation properties of the AC adapter18accommodated in the adapter receptacle51of the first housing4can be enhanced so that a temperature rise inside the first housing4can be prevented.

In the seventh embodiment, the portable computer can be used even when the AC adapter18is removed from the adapter receptacle51by using the output cable111.FIG. 18shows a state in which the AC adapter18removed out of the adapter receptacle51and the portable computer1are connected by the output cable111.

As shown inFIG. 18, the first output plug112of the output cable111is connected to the output connector110of the AC adapter18by inserting the pin terminal114into the first insertion hole107aof the case40.

At this point, the first opening105ais closed by the cover portion118of the plug body115being overlaid with the front face42of the case40and the projection119projected from the cover portion118being fitted into the first opening105aof the insertion path105.

The second output plug113of the output cable111is connected to the power supply connector104of the first housing4.

While the AC adapter18is removed out of the adapter receptacle51, it is desirable to cover the insertion opening55with a cover to prevent dust or foreign matter from entering the adapter receptacle51through the insertion opening55.

In the seventh embodiment, the heat receiving edge103of the heat pipe100passes through the case40of the AC adapter18, but the embodiment is not limited to the above example. For example, a groove along the insertion direction of the AC adapter18may be formed in the side face of the case40so that the heat receiving edge103of the heat pipe100is plugged in.

Further, the heat pipe may be omitted so that heat of the AC adapter18is dissipated to the fan casing25only by heat conduction from the AC adapter18to the fan casing25.

Eighth Embodiment

The eighth embodiment is different from the first embodiment in that an AC adapter18accommodated in an adapter receptacle51has an output cable200.

As shown inFIG. 19, a power supply connector104is arranged inside a first housing4. The power supply connector104is exposed to the outside of the first housing4in a position adjacent to an insertion opening55of the adapter receptacle51.

The output cable200of the AC adapter18is an element that transmits power transformed from AC to DC by the AC adapter18and is led to the outside of the AC adapter18from the front face42of the case40. An output plug202is provided at the tip of the output cable200. The output plug202has a pin terminal203. The pin terminal203can be connected to the power supply connector104from outside the first housing4.

According to the eighth embodiment, the AC adapter18has a power cord48for input and the output cable200for output. Thus, by connecting the output plug202of the output cable200to the power supply connector104of a portable computer1, the AC adapter18can be used even while the AC adapter18is removed out of the first housing4from the adapter receptacle51.

Ninth Embodiment

The ninth embodiment is different from the first embodiment in a configuration to conduct heat of an AC adapter18to a fan casing25. The other configuration of a portable computer1is the same as in the first embodiment. Thus, in the ninth embodiment, the same reference numerals are attached to the same structural elements as those in the first embodiment and the description thereof is thereby omitted.

As shown inFIGS. 20 and 21, one linear portion30aof a side plate29of the fan casing25closes the termination of an adapter receptacle51so as to be opposed to an insertion opening55. Further, the one linear portion30aextends in a direction perpendicular to the insertion direction of the AC adapter18inside a first housing4.

When the AC adapter18is inserted into the adapter receptacle51up to a position where a front face42of a case40of the AC adapter18blocks the insertion opening55, an output plug49of the AC adapter18is connected to a connector58arranged at the termination of the adapter receptacle51.

Further, a rear face43of the case40hits the one linear portion30aof the fan casing25. Accordingly, the insertion position of the AC adapter18is determined and also the rear face43of the case40is totally in contact with the one linear portion30a. Therefore, the AC adapter18is thermally connected to the one linear portion30aas a portion of the fan casing25.

According to the ninth embodiment, heat emitted from the AC adapter18is directly conducted from the AC adapter18to the side plate29of the fan casing25and also diffused to the fan casing25. The heat of the AC adapter18diffused to the fan casing25is released out of the first housing4by heat exchange with a cooling air flowing inside the fan casing25.

Therefore, heat dissipation properties of the AC adapter18accommodated in the adapter receptacle51of the first housing4can be secured so that a temperature rise inside the first housing4can be prevented.

In the ninth embodiment, irregularities may be formed in each of the rear face43of the case40and the one linear portion30aof the fan casing25to cause irregularities of the rear face43and irregularities of the linear portion30ato engage with each other.

According to the above configuration, a contact area of the AC adapter18and the fan casing25can be increased so that heat of the AC adapter18can efficiently be conducted to the fan casing25.

Further, a heat pipe may be arranged extending between the adapter receptacle51and the fan casing25to actively transfer heat of the AC adapter18accommodated in the adapter receptacle51to the fan casing25via the heat pipe.