Heat dissipating device and portable electronic device using the same

A portable electronic device, which including a casing, a circuit board, a fan and a heat dissipating device, is disclosed. The circuit board is disposed in the casing and includes at least one electronic component thereon. The fan is disposed in the casing. The heat dissipating device is disposed in the casing and near the side of an air outlet of the fan. Gaps formed between the outer surfaces of the heat dissipating device and the inner surfaces of the casing as air flow channels. The portable electronic device isolates heat conducted to the casing of the portable electronic device via the gaps.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a heat dissipating device and, more particularly, to a heat dissipating device of a portable electronic device.

2. Related Art

Nowadays, computers are important in our life. Currently, a portable electronic device is characterized in light, thin and small, therefore it is widely used. However, the portable electronic device may have problems in heat dissipating.

Taking a notebook computer as an example,FIG. 1is a top view showing a conventional notebook computer land its heat dissipating fan12and the het dissipating fins13thereof. The conventional notebook computer1dissipates heat of the heat dissipating fins13by the heat dissipating fan12, disposed in a casing11of the conventional notebook computer1, and the heat dissipating fan12blows hot air out of the casing11. In consideration of the small size and the performance, the space for disposing the heat dissipating fan12becomes smaller. As a result, the heat dissipating fan12only can be disposed at a palm rest area14.

The heat dissipating fan12blows cool air into the heat dissipating fins13, the cool air brings heat from the heat dissipating fins13and blows out of the casing11(shown in arrows). However, the heat dissipating fan12blows the hot air from the heat dissipating fins13out of the casing11, resulting in temperature increasing around the casing.

SUMMARY OF THE INVENTION

A portable electronic device includes a casing, a circuit board, a fan and a heat dissipating device. The circuit board is disposed in the casing and includes at least one electronic component thereon. The fan is disposed in the casing. The heat dissipating device is disposed in the casing and at a side of an air outlet of the fan. Furthermore, a gap formed between the heat dissipating device and the casing for air flowing.

In an embodiment, the heat dissipating device includes an upper surface and a lower surface and the gap formed between the upper surface and the casing and between the lower surface and the casing, respectively.

In an embodiment, thickness of the fan is larger than that of the heat dissipating device.

In an embodiment, the casing includes at least one opening.

In an embodiment, the opening is disposed corresponding to the air outlet of the heat dissipating device.

In an embodiment, a space is formed between the opening and the air outlet of the heat dissipating device.

In an embodiment, the portable electronic device further includes a keyboard module disposed in the casing, and the fan and the heat dissipating device are disposed adjacent to one side of the keyboard module.

In an embodiment, the casing includes a plurality of air inlets formed at the side of the keyboard module opposite to the side of the fan and the heat dissipating device.

In an embodiment, a plurality of through holes are formed at the circuit board corresponding to the air inlets.

In an embodiment, the shape of the air inlets is the same as the shape of the through holes at the circuit board.

In an embodiment, the heat dissipating device includes a plurality of heat dissipating fins and at least one heat pipe.

In an embodiment, the electronic component includes one of a central processing unit (CPU), a chipset, a graphic processing unit (GPU), a video graphics array (VGA) and a memory.

In an embodiment, the fan further includes an upper cover and a lower cover, the height between the upper cover and the lower cover is larger than the height of the heat dissipating device, the heat dissipating device is disposed between the upper cover and the lower cover, and gaps are formed between the heat dissipating device and the upper cover and between the heat dissipating device and the lower cover, respectively.

In an embodiment, the fan further includes an upper cover, a lower cover, an upper block board connected to the upper cover and a lower block board connected to the lower cover, the height between the upper block board and the lower block board is larger than the height of the heat dissipating device, the heat dissipating device is disposed between the upper block board and the lower block board, and a gap formed between the heat dissipating device and the upper block board and formed between the heat dissipating device and the lower block board, respectively.

As stated above, in the portable electronic device as disclosed herein, air flow channels are formed via the gaps exist between the outer surface of the heat dissipating device and the inner surface of the casing, between the upper cover and the lower cover of the fan, or between the upper block board and the lower block board of the fan. Thus, the cool air from the fan flows through the air flow channel to isolate the heat of the heat dissipating device from contacting with the casing, so as to prevent heat of the heat dissipating device from conducting to the casing, and the user would not feel uncomfortable when he or she puts the hands at the casing. Furthermore, the cool air from the fan flows through the heat dissipating device, and takes the heat of the heat dissipating device away through the opening of the casing, so as to avoid temperature increasing on the casing or around the casing.

DETAILED DESCRIPTION OF THE INVENTION

A portable electronic device is illustrated with relating figures, and the same symbols denote the same components.

FIG. 2AandFIG. 2Bare top views and front views respectively showing a fan22and a heat dissipating device23of a portable electronic device2in an embodiment. Taking a notebook computer2as an example, it includes a casing21, a circuit board (not shown), a fan22and a heat dissipating device23. The circuit board is disposed in the casing21, and the electronic components such as a central processing unit (CPU), a chipset, a graphic processing unit (GPU), a video graphics array (VGA) and a memory is selectively disposed on the circuit board as requirement, which is not limited herein. The fan22and the heat dissipating device23are disposed in the casing21, and the heat dissipating device23is disposed at a side of an air outlet221of the fan22. Gaps G1and G2exist between the outer surface231,232of the heat dissipating device23and the inner surface211,212of the casing21, respectively.

InFIG. 2B, the gap G1exists between the upper surface231of the heat dissipating device23and the inner surface211of the casing21, and the gap G2exists between the lower surface232of the heat dissipating device23and the inner surface212of the casing21. That is, the gap G1forms an upper air flow channel, as indicated by an arrow A1, and the gap G2forms a lower air flow channel, as indicated by an arrow A2. The term “air flow channel” means a channel which air flows through. That is, the fan22blows cool air through the air flow channel to isolate the heat of the heat dissipating device23from contacting with the casing21, and thus the user would not feel uncomfortable when he or she puts the hands at the palm rest area24due to the temperature increasing of the casing21.

FIG. 3is a front view showing a fan21and a heat dissipating device33of a notebook computer3in an embodiment. Specifically, as showed inFIG. 2B, the two gaps G1and G2formed between the outer surface231,232of the heat dissipating device23and the inner surface211,212of the casing21, respectively, is not limited herein. As shown inFIG. 3, a gap G3also may be formed between the upper surface331of the heat dissipating device33and the inner surface211of the casing21, which is the upper air flow channel, so as to prevent the heat of the heat dissipating device33from conducting to the inner surface211of the casing21and avoid the temperature increasing of the casing21.

The heat dissipating device may include a plurality of heat dissipating fins and at least one heat pipe. Moreover, the thickness of the fan22may be larger than that of the heat dissipating device, that is, the height of the air outlet221of the fan22is larger than the height of the heat dissipating device. Thus, the cool air from the fan22can flow through the heat dissipating device, the upper air flow channel and the lower air flow channel.

FIG. 4Ais a front view showing a fan42and a heat dissipating device23of a notebook computer4in an embodiment. In this embodiment, the fan42includes an upper cover421and a lower cover422, and the height between the upper cover421and the lower cover422is larger than that of the heat dissipating device23. The upper cover421and the lower cover422cover the upper surface231and the lower surface232of the heat dissipating device23, respectively. That is, the heat dissipating device23is disposed between the upper cover421and the lower cover422. Gaps G4and G5are formed between the upper surface231and the lower surface232of the heat dissipating device23, and between the upper cover421and the lower cover422, respectively, to form the upper air flow channel and the lower air flow channel as shown as the arrows A1and A2.

FIG. 4Bis a front view showing a fan44and a heat dissipating device23of a notebook computer4in an embodiment. In this embodiment, the fan includes an upper cover441, a lower cover442, an upper block board443connected to the upper cover441and a lower block board444connected to the lower cover442, and the height between the upper block board443and the lower block board444is larger than that of the heat dissipating device23. The upper block board443and the lower block board444cover the upper surface231and the lower surface232of the heat dissipating device23, respectively. That is, the heat dissipating device23is disposed between the upper block board443and the lower block board444. Gap G4is formed between the upper surface231of the heat dissipating device23and the upper block board443as the upper air flow channel, and G5is formed between the outer surface232of the heat dissipating device23and the lower block board444as the lower air flow channel, showed as the arrows A1and A2.

FIG. 5is a front view showing a portable electronic device in an embodiment. The casing51of the notebook computer5includes at least one opening511corresponding to the air outlet233of the heat dissipating device23, and thus the hot air from the heat dissipating device23may be blown out through the air outlet233of the heat dissipating device23and the opening511. The opening511may be a hole or a slot, which is not limited herein. The shape of the hole or the slot can be adjusted according to requirements, which is not limited herein.

Moreover, a space S forms between the opening511and the air outlet233of the heat dissipating device23. In the space, cool air from the upper surface231(the upper air flow channel) and the lower surface232(the lower air flow channel) of the heat dissipating device23blows through the heat dissipating device23, and takes the heat of the heat dissipating device23away through the opening511of the casing51to decrease the temperature of the dissipated hot air.

FIG. 6A,FIG. 6BandFIG. 6Care sectional diagrams showing a portable electronic device in an embodiment. Taking the notebook computer6as an example, it further includes a keyboard module65disposed in the casing61, and the fan22and the heat dissipating device (not shown) are disposed adjacent to a side of the keyboard module65. Furthermore, the casing61may include a plurality of air inlets66formed at a side of the keyboard module65opposite to the fan22and the heat dissipating device23.

As shown inFIG. 6B, a plurality of through holes671are formed at the circuit board67corresponding to the air inlets66, and thus external air can flow through the air inlets66, the through holes671of the circuit board67and at least one electronic component672at the circuit board67to dissipate heat of the electronic component672. Moreover, the air inlets66may not correspond to the through hole671, as shown inFIG. 6C.

In an embodiment, the shape and the size of the air inlets66and the through holes671of the circuit board67may be the same or not, respectively.