Cooling apparatus for portable computer

The present application claims, under 35 U.S.C. § 119, the priority benefit of Korean Patent Application No. P03-080761 filed Nov. 14, 2003, and Korean Patent Application No. P03-085656 filed Nov. 28, 2003. The entire contents of each of these applications are herein filly incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a portable computer, and more particularly, to a cooling apparatus for use in a portable computer for releasing heat generated in the portable computer to the outside.

2. Description of the Related Art

Portable computers are devices, including notebook computers, tablet computers and the like, which can be used while users carry them. In the present invention, a notebook computer is used as an example of the portable computer.

<figref idref="DRAWINGS">FIG. 10</figref> shows a perspective view of an external appearance of a general notebook computer. As shown in this figure, the notebook computer <b>1</b> is mainly composed of a main body <b>3</b> and a display unit <b>5</b>. The display unit <b>5</b> generally includes a display <b>6</b> made of a liquid crystal panel and is connected to a rear end of the main body <b>3</b> so as to come into close contact with or to be unfolded from a top surface of the main body <b>3</b>. Both the main body <b>3</b> and the display unit <b>5</b> generally have a flat hexahedral shape.

A keyboard <b>7</b> is provided on the top surface of the main body <b>3</b>. A vent <b>9</b> for releasing heat generated in the main body to the outside is formed at one side of the main body <b>3</b>. That is, an air stream containing the heat generated in the main body <b>3</b> is discharged to the outside through the vent <b>9</b>.

As illustrated in <figref idref="DRAWINGS">FIG. 11</figref>, a main board <b>10</b> is installed within the main body <b>3</b>. A microprocessor (CPU) <b>11</b> is mounted onto the main board <b>10</b>. The microprocessor <b>11</b> controls the processing works such as command analysis, data operation and data comparison. A cooling fan unit <b>12</b> is installed within the main body <b>3</b> to release heat generated in the microprocessor <b>11</b> to the outside. The cooling fan unit <b>12</b> creates an air stream by using a cooling fan <b>14</b> installed in a fan housing <b>13</b>. The fan housing <b>13</b> is in thermal contact with the microprocessor <b>11</b>, and the air stream created by the cooling fan <b>14</b> flows toward the vent <b>9</b> along one side of the fan housing <b>13</b>.

A cooling fin unit <b>15</b> is installed between the vent <b>9</b> and the fan housing <b>13</b>. The cooling fin unit <b>15</b> is configured to allow the air stream to pass therethrough. Further, a heat pipe <b>16</b> is used to transfer the heat generated from the microprocessor <b>11</b> to the cooling fin unit <b>15</b>. The heat pipe <b>16</b> extends from one side of the fan housing <b>13</b> installed on the microprocessor <b>11</b> to the cooling fin unit <b>15</b>.

Furthermore, a plurality of chips <b>18</b> are mounted onto the main board <b>10</b>. To easily release the heat generated from the chips <b>18</b>, a cooling plate <b>19</b> is installed to come into thermal contact with the chips <b>18</b>. The cooling plate <b>19</b> may be made of an aluminum or copper plate and serves to receive heat generated in the chips through heat conduction and to release the received heat to the outside.

However, the aforementioned prior art has the following problems:

The system for cooling the interior of the main body <b>3</b> has been heretofore focused onto the microprocessor <b>11</b>. However, the heat generated in the chips <b>18</b> has become considerable, as the performance of the notebook computer is improved.

Therefore, if the release of heat generated from the chips <b>18</b> depends only on the heat conduction through the cooling plate <b>19</b>, the heat release performance of the main body <b>3</b> is greatly reduced and the surface temperature of the main body <b>3</b> is thus excessively increased. <figref idref="DRAWINGS">FIG. 12</figref> shows the heat release performance of various component parts, installed within the main body <b>3</b>, when the main body <b>3</b> is cooled using a conventional cooling mode. In this graph, bars, indicated by dotted lines, represent prescribed values, whereas bars, indicated by solid lines, represent actually measured values.

SUMMARY OF THE INVENTION

Accordingly, the present invention is conceived to solve one or more of the aforementioned problems in the related art. An object of the present invention is to provide a cooling apparatus for more smoothly releasing heat generated in a main body of a portable computer to the outside.

According to an aspect of the present invention for achieving the object, there is provided a cooling apparatus for a portable computer, comprising a main body which includes a main board installed in an internal space thereof A vent allows air to flow between the internal space and the outside. A cooling fan unit includes a cooling fan provided in a fan housing, and is installed in the main body for creating an air stream to release heat generated in the main body to the outside through the vent. A first heat pipe transfers heat generated in a first heat source on the main board to a path for the air stream. A second heat pipe transfers heat generated in a second heat source on the main board to the path for the air stream. An air supply means transfers a portion of the air stream to the interior of the main body.

Preferably, the fan housing of the cooling fan unit includes at least one outlet through which the air stream created by the cooling fan is discharged. The outlet is provided with a cooling fin unit which is thermally connected to the heat pipes to transfer the heat generated in the heat sources to the air stream.

In one embodiment, the first and second heat pipes are thermally connected to the cooling fin units provided at the separate outlets, respectively.

In another embodiment, the first and second heat pipes are thermally connected to the cooling fin unit provided at a single outlet.

In yet another embodiment, the first and second heat pipes are integrally formed with each other at their ends that come into contact with the cooling fin unit.

Preferably, the first heat source is a microprocessor and the air supply means supplies air to the microprocessor.

According to another aspect of the present invention, there is provided a cooling apparatus for a portable computer, comprising a main body which includes a main board installed in an internal space thereof. A vent allows air to flow between the internal space and the outside. A cooling fan unit includes a cooling fan provided in a fan housing, and is installed in the main body for creating an air stream to release heat generated in the main body to the outside through the vent. A first heat pipe transfers heat generated in a first heat source, which is installed on the main board, to a path of the air stream and is thermally connected to the cooling fan unit. A second heat pipe transfers heat generated in a second heat source on the main board to the path of the air stream and includes an end installed to face the cooling fan in a radial direction of the cooling fan of the cooling fan unit.

Preferably, the cooling fan unit comprises a fan housing including an outlet which is open toward the vent. A cooling fan is installed in the fan housing for causing air to be introduced from the outside of the fan housing and to be discharged to the outlet. A cooling fin unit is provided at an outlet side of the cooling fan for performing heat exchange with the air stream discharged through the outlet. A heat source connection extends along a side of the fan housing and is thermally connected to the first heat source.

Preferably, a fan seating space in which the cooling fan is seated, is formed in the fan housing. A portion of the second heat pipe is seated in a seating slot formed on the fan housing and exposed toward the fan seating space in a radial direction of the cooling fan.

Preferably, the other end of the second heat pipe is connected to a cooling plate that is thermally connected to the second heat source on the main board.

Also preferably, the first heat source is a microprocessor and the air supply means supplies air to the microprocessor.

According to the cooling apparatus for a portable computer of the present invention, there is an advantage in that heat generated not only from the microprocessor of the portable computer, but also from several other heat sources on the main board, can be effectively released to the outside.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

<figref idref="DRAWINGS">FIG. 1</figref> is a plan view showing a portable computer with a first embodiment of a cooling apparatus, according to the present invention;

<figref idref="DRAWINGS">FIG. 2</figref><i>a </i>is a schematic perspective view showing the cooling apparatus of <figref idref="DRAWINGS">FIG. 1</figref>;

<figref idref="DRAWINGS">FIG. 2</figref><i>b </i>is a schematic perspective view showing a modified cooling apparatus, according to the present invention;

<figref idref="DRAWINGS">FIG. 3</figref> is a plan view showing the configuration of a second embodiment of a cooling apparatus, according to the present invention;

<figref idref="DRAWINGS">FIG. 4</figref> is a schematic perspective view showing the cooling apparatus of <figref idref="DRAWINGS">FIG. 3</figref>;

<figref idref="DRAWINGS">FIG. 5</figref> is a plan view showing the configuration of a third embodiment of a cooling apparatus, according to the present invention;

<figref idref="DRAWINGS">FIG. 6</figref> is a plan view showing the configuration of a fourth embodiment if a cooling apparatus, according to the present invention;

<figref idref="DRAWINGS">FIG. 7</figref> is a cross sectional view of a cooling fan unit of the fourth embodiment of the present invention;

<figref idref="DRAWINGS">FIG. 8</figref> is a partial perspective view showing the cooling fan unit of the fourth embodiment of the present invention;

<figref idref="DRAWINGS">FIG. 9</figref> is a graph illustrating a cooling result of the fourth embodiment of the present invention;

<figref idref="DRAWINGS">FIG. 10</figref> is a perspective view of a portable computer, in accordance with the related art;

<figref idref="DRAWINGS">FIG. 11</figref> is a plan view showing an internal cooling apparatus of the portable computer of <figref idref="DRAWINGS">FIG. 10</figref>; and

<figref idref="DRAWINGS">FIG. 12</figref> is a graph illustrating a cooling result of the related art cooling apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of a cooling structure for a portable computer according to the present invention will be described in detail with reference to the accompanying drawings.

<figref idref="DRAWINGS">FIG. 1</figref> shows a plan view of the interior of a main body of the portable computer to which a first embodiment of a cooling structure of the present invention is applied, <figref idref="DRAWINGS">FIG. 2</figref><i>a </i>shows a schematic perspective view of the cooling apparatus of the first embodiment according to the present invention, and <figref idref="DRAWINGS">FIG. 2</figref><i>b </i>is a schematic perspective view showing a modified example of the first embodiment according to the present invention.

As shown in these figures, a predetermined internal space <b>30</b>′ is defined within a main body <b>30</b> of the portable computer. Vents <b>31</b> and <b>31</b>′ are formed at sides of the main body <b>30</b>. In this embodiment, the vents <b>31</b> and <b>31</b>′ are formed at a corner of the main body <b>30</b> to be adjacent to each other. The vents <b>31</b> and <b>31</b>′ allow the internal space <b>30</b>′ to communicate with the outside of the main body <b>30</b> such that an air stream can be created in the main body. A main board <b>32</b> is intalled within the internal space <b>30</b>′ of the main body <b>30</b>. Various kinds of component parts of the portable computer are also mounted onto the main board <b>32</b>.

Further, a cooling fan unit <b>35</b> is installed within the internal space <b>30</b>′. The cooling fan unit <b>35</b> is provided at a position corresponding to the vents <b>31</b> and <b>31</b>′. The cooling fan unit <b>35</b> is composed of a fan housing <b>36</b> and a cooling fan <b>38</b>, and a fan seating space <b>36</b>′ is also formed in the fan housing <b>36</b>.

The fan seating space <b>36</b>′ communicates with the outside through an inlet <b>36</b><i>i </i>formed in the fan housing <b>36</b>. The inlets <b>36</b><i>i </i>may be formed on top and bottom surfaces of the fan housing <b>36</b>. In this embodiment, the inlet <b>36</b><i>i </i>is formed at only the top surface of the fan housing <b>36</b>. First and second outlets <b>36</b><i>e </i>and <b>36</b><i>e</i>′ are formed at sides of the fan housing <b>36</b> corresponding to the vents <b>31</b> and <b>31</b>′.

In the meantime, an air supply port <b>37</b> is formed in the fan housing <b>36</b>. The air supply port <b>37</b> serves to transfer relatively low temperature air toward a microprocessor <b>52</b> to be explained later and allows the fan seating space <b>36</b>′ in the fan housing <b>36</b> to communicate with the outside of the fan housing <b>36</b>. The air supply port <b>37</b> is formed to be open toward the microprocessor <b>52</b>.

The cooling fan <b>38</b> creates an air stream for cooling the internal space of the main body and is seated into the fan seating space <b>36</b>′. The cooling fan <b>38</b> causes air to be introduced into the inlet <b>36</b><i>i </i>and creates an air stream to be discharged toward the outlets <b>36</b><i>e </i>and <b>36</b><i>e</i>′ and the air supply port <b>37</b>.

First and second cooling fin units <b>40</b> and <b>40</b>′ are installed at positions corresponding to the outlets <b>36</b><i>e </i>and <b>36</b><i>e</i>′. The cooling fin units <b>40</b> and <b>40</b>′ are formed such that the air can pass through the interior of the cooling fin units. The cooling fin units <b>40</b> and <b>40</b>′ are positioned between the outlets <b>36</b><i>e </i>and <b>36</b><i>e</i>′ and the vents <b>31</b> and <b>31</b>′, respectively, so that the air discharged from the outlets <b>36</b><i>e </i>and <b>36</b><i>e</i>′ flows into the vents <b>31</b> and <b>31</b>′ to perform desired heat exchange.

Furthermore, a first heat pipe <b>50</b> is installed to be thermally connected to the cooling fin unit <b>40</b>. The first heat pipe <b>50</b> is configured in such a manner that its one end is installed along the cooling fin unit <b>40</b> and the other end extends from the cooling fin unit <b>40</b> at a desired length. The first heat pipe <b>50</b> serves to transfer heat from a relatively high temperature point to a relatively low temperature point. Here, the heat pipe serves to transfer heat from one end to the other end while working fluid filled in the heat pipe, goes through a phase change due to the heat applied thereto.

The first heat pipe <b>50</b> extends up to the microprocessor <b>52</b> installed on the main board <b>32</b>. That is, the other end of the first heat pipe <b>50</b> is thermally connected to the microprocessor <b>52</b>. At least one power control chip <b>54</b> is mounted onto the main board <b>32</b> at a position adjacent to the microprocessor <b>52</b>. In this embodiment, power control chips <b>54</b> are mounted at a position close to the air supply port <b>37</b> whereas the microprocessor <b>52</b> is positioned opposite to the air supply port <b>37</b>. Therefore, the air discharged from the air supply port <b>37</b> passes sequentially by the power control chips <b>54</b> and the microprocessor <b>52</b>, so as to cool them.

A second heat pipe <b>60</b> is thermally connected to the cooling fin unit <b>40</b>′, installed at the outlet <b>36</b><i>e</i>′ of the fan housing <b>36</b>. The second heat pipe <b>60</b> is configured in such a manner that one end is installed along a top surface of the cooling fin unit <b>40</b>′ and the other end extends from the cooling fin unit <b>40</b>′ at a desired length.

The extended end of the second heat pipe <b>60</b> is thermally connected to a main chipset <b>62</b> and a graphic chipset <b>64</b>, which are mounted onto the main board <b>32</b>. In this embodiment, the second heat pipe <b>60</b> is sequentially connected to the main chipset <b>62</b> and the graphic chipset <b>64</b>.

As shown in <figref idref="DRAWINGS">FIG. 2</figref><i>b</i>, however, the second heat pipe <b>60</b> may be thermally connected to an additional cooling plate <b>66</b> that comes into simultaneous contact with top surfaces of the main chipset <b>62</b> and the graphic chipset <b>64</b>.

Next a second embodiment of the present invention is described with reference to <figref idref="DRAWINGS">FIGS. 3 and 4</figref>. In this embodiment, reference numerals with <b>100</b> added thereto are used to designate the components similar to those of the first embodiment, for the sake of explanation.

A predetermined internal space <b>130</b>′ is defined within a main body <b>130</b> of the portable computer. A vent <b>131</b> is formed at a side of the main body <b>130</b>. In this embodiment, the vent <b>131</b> is formed at a corner of the main body <b>130</b>. The vent <b>131</b> allows the internal space <b>130</b>′ to communicate with the outside of the main body <b>130</b> such that an air stream can be created in the main body. A main board <b>132</b> is installed within the internal space <b>130</b>′ of the main body <b>130</b>. Various kinds of component parts of the portable computer are also mounted onto the main board <b>132</b>.

Further, a cooling fan unit <b>135</b> is installed within the internal space <b>130</b>′. The cooling fan unit <b>135</b> is provided at a position corresponding to the vent <b>131</b>. The cooling fan unit <b>135</b> is composed of a fan housing <b>136</b> and a cooling fan <b>138</b>, and a fan seating space <b>136</b>′ is also formed in the fan housing <b>136</b>.

The fan seating space <b>136</b>′ communicates with the outside through an inlet <b>136</b><i>i </i>formed in the fan housing <b>136</b>. The inlet <b>136</b><i>i </i>may be formed on top and bottom surfaces of the fan housing <b>136</b>. In this embodiment, the inlet <b>136</b><i>i </i>is formed at only the top surface of the fan housing <b>136</b>. An outlet <b>136</b><i>e </i>is formed at a side of the fan housing <b>136</b> corresponding to the vent <b>131</b>.

In the meantime, an air supply port <b>137</b> is formed in the fan housing <b>136</b>. The air supply port <b>137</b> serves to transfer relatively low temperature air toward a microprocessor <b>152</b> to be explained later and allows the fan seating space <b>136</b>′ in the fan housing <b>136</b> to communicate with the outside of the fan housing <b>136</b>. The air supply port <b>137</b> is formed to be open toward the microprocessor <b>152</b> and power control chips <b>154</b>.

The cooling fan <b>138</b> creates an air stream for cooling the internal space of the main body and is seated into the fan seating space <b>136</b>′. The cooling fan <b>138</b> causes air to be introduced into the inlet <b>136</b><i>i </i>and creates an air stream to be discharged toward the outlet <b>136</b><i>e </i>and air supply port <b>137</b>.

A cooling fin unit <b>140</b> is installed at a position corresponding to the outlet <b>136</b><i>e</i>. The cooling fin unit <b>140</b> is formed such that the air can pass through the interior of the cooling fin unit. The cooling fin unit <b>140</b> is positioned between the outlet <b>136</b><i>e </i>and the vent <b>131</b>, so that the air discharged from the outlet <b>136</b><i>e </i>flows into the vent <b>131</b> to perform desired heat exchange.

Furthermore, a first heat pipe <b>150</b> is installed to be thermally connected to the cooling fin unit <b>140</b>. The first heat pipe <b>150</b> is configured in such a manner that one end is installed along the cooling fin unit <b>140</b> and the other end extends from the cooling fin unit <b>140</b> at a desired length. The first heat pipe <b>150</b> serves to transfer heat from a relatively high temperature point to a relatively low temperature point.

The first heat pipe <b>150</b> extends up to the microprocessor <b>152</b> installed on the main board <b>132</b>. That is, the other end of the first heat pipe <b>150</b> is thermally connected to the microprocessor <b>152</b>. At least one power control chip <b>154</b> is mounted onto the main board <b>132</b> at a position adjacent to the microprocessor <b>152</b>. In this embodiment, the microprocessor <b>152</b> and the power control chips <b>154</b> are mounted in parallel at a position close to the air supply port <b>137</b>.

A second heat pipe <b>160</b> is also thermally connected to the cooling fin unit <b>140</b> installed at the outlet <b>136</b><i>e </i>of the fan housing <b>136</b>. The second heat pipe <b>160</b> is configured in such a manner that its one end is installed in parallel with the first heat pipe <b>150</b> along a top surface of the cooling fin unit <b>140</b> and the other end extends from the cooling fin unit <b>140</b> at a desired length.

The extended end of the second heat pipe <b>160</b> is thermally connected to a main chipset <b>162</b> and a graphic chipset <b>164</b>, which are mounted onto the main board <b>132</b>. In this embodiment, the second heat pipe <b>160</b> is sequentially connected to the main chipset <b>162</b> and the graphic chipset <b>164</b>. However, the second heat pipe <b>160</b> may be thermally connected to an additional cooling plate that comes into simultaneous contact with top surfaces of the main chipset <b>162</b> and the graphic chipset <b>164</b>.

Next, a third embodiment of the present invention is described with reference to <figref idref="DRAWINGS">FIG. 5</figref>. In this embodiment, reference numerals with <b>200</b> added thereto are used to designate the components similar to those of the first embodiment, for the sake of explanation. One configuration of the third embodiment will be hereinafter explained.

In this embodiment, a single cooling fin unit <b>240</b> is installed between a cooling fan unit <b>235</b> and a vent <b>231</b>. A first end <b>251</b> of the cooling fin unit <b>240</b> is connected to a heat pipe <b>250</b>. The first end <b>251</b> of the heat pipe <b>250</b> is branched off into a second end <b>251</b><i>a </i>and a third end <b>251</b><i>b </i>at a position beyond the cooling fin unit <b>240</b>.

The first end <b>251</b> is thermally connected to the heat pipe <b>250</b>, whereas the second end <b>251</b><i>a </i>is thermally connected to a microprocessor <b>252</b>. Further, the third end <b>251</b><i>b </i>is thermally connected to a main chipset <b>262</b> and a graphic chipset <b>264</b>. That is, in this embodiment, a single heat pipe <b>250</b> can transfer heat generated in the microprocessor <b>252</b> and in the main chipset <b>262</b> and the graphic chipset <b>264</b> to the cooling fin unit <b>240</b>.

It is shown in this figure that the third end <b>251</b><i>b </i>is sequentially connected to the main chipset <b>262</b> and the graphic chipset <b>264</b>. However, this embodiment may be configured in such a manner that the third end <b>251</b><i>b </i>is thermally connected to an additional cooling plate that comes into simultaneous contact with top surfaces of the main chipset <b>262</b> and the graphic chipset <b>264</b>.

FIGS. <b>6</b> to <b>8</b> show the configuration of a fourth embodiment of the present invention. As shown in these figures, a predetermined internal space <b>330</b>′ is defined within a main body <b>330</b> of the portable computer. A vent <b>331</b> is formed on at least one side of the main body <b>330</b>. The vent <b>331</b> allows the internal space <b>330</b>′ to communicate with the outside of the main body <b>330</b> such that an air stream can be created in the main body <b>330</b>.

A main board <b>332</b> is installed within the internal space <b>330</b>′ of the main body <b>130</b>. Various kinds of component parts of the portable computer are mounted onto the main board <b>332</b>. First of all, a microprocessor <b>333</b> is installed on the main board <b>332</b>. The microprocessor <b>333</b> is a key component of the portable computer and controls the processing works such as command analysis, data operation and data comparison. In operation, the microprocessor <b>333</b> produces a great deal of heat.

Further, a cooling fan unit <b>335</b> for releasing heat generated in the main body <b>330</b> is provided within the internal space <b>330</b>′ of the main body <b>330</b>. It is preferred that the cooling fan unit <b>335</b> be installed at a position corresponding to the vent <b>331</b>.

The cooling fan unit <b>335</b> includes a fan housing <b>336</b> in which a fan seating space <b>336</b>′ is formed. To communicate the fan seating space <b>337</b> with the outside, an inlet <b>337</b><i>i </i>is formed on a top surface of the fan housing <b>336</b>. The inlet <b>337</b><i>i </i>becomes a passage, through which air is introduced from the internal space <b>330</b>′ into the fan seating space <b>337</b>. At one side of the fan housing <b>336</b> is formed an outlet <b>337</b><i>e </i>corresponding to a passage through which air is discharged from the fan seating space <b>337</b> to the outside of the fan housing <b>336</b>. The outlet <b>337</b><i>e </i>is formed to open toward the vent <b>331</b>.

A seating slot <b>337</b>′ is formed in the fan housing <b>336</b> to be open toward the interior of the fan seating space <b>337</b>. The seating slot <b>337</b>′ is formed at portions in the fan housing outwardly beyond a cooling fan <b>340</b> installed within the fan seating space <b>337</b> except portions where the outlet <b>337</b><i>e </i>and a heat source connection <b>338</b>, to be explained later, are formed. An end of a second heat pipe <b>345</b> to be explained later is positioned in the seating slot <b>337</b>′.

The heat source connection <b>338</b> is formed to extend along one side of the fan housing <b>336</b>. The heat source connection <b>338</b> is thermally connected to the microprocessor <b>333</b> to transfer heat generated in the microprocessor <b>333</b> to the fan housing <b>336</b>. Therefore, the heat source connection <b>338</b> extends from the fan housing <b>336</b> in a direction in which the microprocessor <b>333</b> is installed. Further, it is preferred that the fan housing <b>336</b> and the heat source connection <b>338</b> be made of a good heat transfer material.

The cooling fan <b>340</b> is installed within the fan seating space <b>337</b> of the fan housing <b>336</b>. The cooling fan <b>340</b> causes air to be introduced through the inlet <b>337</b><i>i </i>and then to be discharged into the fan seating space <b>337</b> in a centrifugal direction. Then, the air discharged as such is further discharged from the fan seating space <b>337</b> through the outlet <b>337</b><i>e. </i>

A cooling fin unit <b>342</b> is installed on the outlet <b>337</b><i>e </i>of the fan housing <b>336</b>. The cooling fin unit <b>342</b> is made of a good heat transfer material and also configured to allow air to pass therethrough. Therefore, the cooling fan unit <b>342</b> causes the outlet <b>337</b><i>e </i>and the vent <b>331</b> to communicate with each other and allows the air stream created by the cooling fan <b>340</b> to be discharged through the vent <b>331</b>.

As mentioned above, one end of the second heat pipe <b>345</b> is positioned in the seating slot <b>337</b>′ of the fan housing <b>336</b>. As well shown in <figref idref="DRAWINGS">FIGS. 7 and 8</figref>, a portion of the second heat pipe <b>345</b> is exposed into the fan seating space <b>337</b>. That is, a certain length of the second heat pipe <b>345</b> is exposed toward the fan seating space <b>337</b> in a radial direction of the cooling fan <b>340</b> such that the air discharged from the cooling fan <b>340</b> can be brought into contact with the exposed portion of the second heat pipe <b>345</b>.

The second heat pipe <b>345</b> extends from the cooling fan unit <b>335</b> to another heat source, i.e. a chip <b>347</b>, installed on the main board <b>332</b> and transfers heat generated in the chip <b>347</b> to the cooling fan unit <b>335</b>. A main chipset, a graphic chipset and the like are an example of the chip <b>347</b>. A cooling plate <b>350</b> is used such that the heat generated in the chip(s) <b>347</b> can be effectively released by using the second heat pipe <b>345</b>. The cooling plate <b>350</b> is thermally connected to the plurality of chips <b>347</b> and absorbs the heat generated in the chips <b>347</b>. It is preferred that the cooling plate <b>350</b> be made of aluminum or copper.

Hereinafter, the operation of the cooling structure for the portable computer according to the present invention will be described in detail.

The cooling operation performed in the first embodiment of the cooling structure shown in <figref idref="DRAWINGS">FIGS. 1 and 2</figref> is first explained. To release heat generated due to the operation of the portable computer, the cooling fan <b>38</b> is driven. As the cooling fan <b>38</b> is driven, air, in the internal space <b>30</b>′ of the main body <b>30</b>, flows into the cooling fan <b>38</b> through the inlet <b>36</b><i>i. </i>

The air introduced into the cooling fan <b>38</b> is discharged in an outward radial direction from the cooling fan <b>38</b> and delivered into the first and second outlets <b>36</b><i>e </i>and <b>36</b><i>e</i>′. Then, the desired heat exchange is performed between the air delivered into the first outlet <b>36</b><i>e </i>and the first cooling fin unit <b>40</b> while the air passes through the first cooling fin unit <b>40</b>. At this time, heat transferred form the microprocessor <b>52</b> through the first heat pipe <b>50</b> is transferred to the air passing through the first cooling fin unit <b>40</b>. The heated air is then discharged to the outside of the main body <b>30</b> through the vent <b>31</b>.

Further, a portion of the air discharged from the cooling fan <b>38</b> is discharged from the fan housing <b>36</b> through the second outlet <b>36</b><i>e</i>′. Then, the desired heat exchange is performed between the discharged air and the second cooling fin unit <b>40</b>′ while the air passes through the second cooling fin unit <b>40</b>′. At this time, heat transferred from the main chipset <b>62</b> and the graphic chipset <b>64</b> through the second heat pipe <b>60</b> is transferred to the air passing through the second cooling fin unit <b>40</b>′. The heated air is then discharged to the outside of the main body <b>30</b> through the vent <b>31</b>′.

Furthermore, air passing through the air supply port <b>37</b> from the cooling fan <b>38</b> is delivered toward the power control chip <b>54</b> and the microprocessor <b>52</b> and releases heat generated therein. Arrows shown in <figref idref="DRAWINGS">FIG. 2</figref><i>a </i>denote such air flow in this embodiment of the present invention.

Next, the cooling operation in the second embodiment is explained with reference to <figref idref="DRAWINGS">FIGS. 3 and 4</figref>. In this embodiment, only a single outlet <b>136</b><i>e </i>is formed in the fan housing <b>136</b> of the cooling fan unit <b>135</b> and the heat transferred through the first and second heat pipes <b>150</b> and <b>160</b> is transferred to the air passing through the cooling fin unit <b>140</b> provided close to the outlet <b>136</b><i>e. </i>

If the cooling fan <b>138</b> is driven, air is delivered from the outside of the fan housing <b>136</b> to the cooling fan <b>138</b> through the inlet <b>136</b><i>i</i>. The air delivered into the cooling fan <b>138</b> is discharged in an outward radial direction from the cooling fan <b>138</b> and delivered into the outlet <b>136</b><i>e</i>. Then, the desired heat exchange is performed between the air delivered into the outlet <b>136</b><i>e </i>and the cooling fin unit <b>140</b> while the air passes through the cooling fin unit <b>140</b>. At this time, heat transferred from the microprocessor <b>152</b> and the chipsets <b>162</b> and <b>164</b> through the first and second heat pipes <b>150</b> and <b>160</b> is transferred to the air passing through the cooling fin unit <b>140</b>.

Further, air passed through the air supply port <b>137</b> from the cooling fan <b>138</b> is delivered toward the power control chip <b>154</b> and the microprocessor <b>152</b> and releases heat generated therein.

When comparing a case where only a single outlet <b>136</b><i>e </i>is formed in the fan housing <b>136</b> with a case where two outlets <b>136</b><i>e </i>and <b>136</b><i>e</i>′ are formed in the fan housing <b>136</b>, pressure loss of the air stream in the former case is lower than that in the latter case, whereas flow loss in the former case is greater than that in the latter case. In other words, the latter case is advantageous in view of the flow rate even though its pressure loss is relatively large.

The air flow in the third embodiment shown in <figref idref="DRAWINGS">FIG. 3</figref> is the same as that in the second embodiment. However, the third embodiment is different from the second embodiment in that it employs only a single heat pipe <b>250</b> when transferring heat to the cooling fin unit <b>240</b>. That is, Heat generated in the microprocessor <b>252</b> is transferred from the second end <b>251</b><i>a </i>to the first end <b>251</b> of the heat pipe <b>250</b>, and heat generated in the main chipset <b>262</b> or graphic chipset <b>264</b> is transferred from the third end <b>251</b><i>b </i>to the first end <b>251</b> of the heat pipe <b>250</b>.

The heat transferred to the first end <b>251</b> of the heat pipe <b>250</b> is again transferred to an air stream created by the cooling fan unit <b>235</b> and then released to the outside through the vent <b>231</b>.

In such a case, in order to perform the desired heat exchange, only a single heat pipe <b>250</b> is used and only the first end <b>251</b> of the heat pipe is brought into thermal contact with the cooling fin unit <b>240</b>. Therefore, an area occupied by the heat pipe <b>250</b> and cooling fin unit <b>240</b> in the internal space <b>230</b>′ can be minimized.

Finally, the operation of the fourth embodiment of the present invention is described. In this embodiment, when the computer is operated, the cooling fan unit <b>335</b> creates an air stream to release heat generated in the main body <b>330</b> to the outside.

That is, as the cooling fan <b>340</b> is rotated, air in the internal space <b>330</b>′ of the main body <b>330</b> is introduced into the cooling fan <b>340</b> through the inlet <b>337</b><i>i</i>. The air introduced into the cooling fan <b>340</b> is discharged to the fan seating space <b>337</b> and then to the outlet <b>337</b><i>e </i>in an outward radial direction of the cooling fan <b>340</b>, due to the rotation of the cooling fan. At this time, the desired heat exchange is performed between the air discharged to the outlet <b>337</b><i>e </i>and the cooling fin unit <b>342</b> while the air passes through the cooling fin unit <b>342</b>. Then, the air passed through the cooling fin unit <b>342</b> is discharged to the outside of the main body <b>330</b> via the vent <b>331</b>.

It is now explained how the heat generated in the microprocessor <b>333</b> and the chip(s) <b>347</b> is released to the outside due to the creation of the air stream. The heat generated in the microprocessor is transferred to the cooling fan unit <b>335</b> through the heat source connection <b>338</b> and the first heat pipe <b>343</b>. A portion of the heat transferred through the heat source connection <b>338</b> is transferred to the cooling fan unit <b>335</b> and then released, by causing the air stream created by the cooling fan <b>340</b> to be brought into contact with inner surfaces of the fan seating space <b>337</b>.

In addition, the first heat pipe <b>343</b> transfers heat generated in the microprocessor <b>333</b> to the cooling fin unit <b>342</b>. The heat transferred to the cooling fin unit <b>342</b> is transferred to the air discharged from the fan seating space <b>337</b> through the outlet <b>337</b><i>e </i>when the air passes through the cooling fin unit <b>342</b>.

Furthermore, heat generated in the chip(s) <b>347</b> is conducted to the cooling plate <b>350</b>. The heat conducted to the cooling plate <b>350</b> is also transferred to the cooling fan unit <b>335</b> through the second heat pipe <b>345</b>. The heat transferred from the cooling plate <b>350</b> to the second heat pipe <b>345</b> is also transferred to the air stream created by the cooling fan <b>340</b> through a portion of the second heat pipe <b>345</b> that is seated in the seating slot <b>337</b>′ of the fan housing <b>336</b> and exposed toward the fan seating space <b>337</b>.

A portion of the second heat pipe <b>345</b> is exposed into the fan seating space <b>337</b> in a radial direction of the cooling fan <b>340</b>, such that the air stream created by the cooling fan <b>340</b> can be brought into direct contact with the exposed portion of the second heat pipe <b>345</b> to perform the desired heat exchange therebetween.

Meanwhile, <figref idref="DRAWINGS">FIG. 9</figref> is a graph illustrating the cooling performance of the preferred embodiments of the present invention. In <figref idref="DRAWINGS">FIG. 9</figref>, bars indicated by dotted lines represent prescribed values, whereas bars indicated by solid lines represent actually measured values. As seen from this figure, the cooling performance of the chips <b>347</b>, as well as the microprocessor <b>333</b>, is further improved as compared with the related art cooling structure. In particular, it can be understood that the temperature of a DDR cover is lowered below its relevant prescribed value. This means that the total cooling performance of the main body <b>330</b> was improved because the cooling structure of the present invention has been employed.

According to the cooling structure for the portable computer of the present invention as described above in detail, the following advantages can be obtained.

According to the present invention, a single cooling fan unit can release heat generated in a plurality of the chipsets, as well as the microprocessor, to the outside of the portable computer. Therefore, since the heat generated in the main body of the portable computer can be effectively released, there is an advantage in that the total cooling performance of the portable computer is improved. Furthermore, the internal space of the main body can be efficiently utilized and the thermal management for the portable computer can also be efficiently made.

The scope of the present invention is not limited by the illustrated embodiment but defined by the appended claims. It will be apparent that those skilled in the art can make various modifications and changes within the scope of the invention defined by the claims.