U.S. patent application number 11/797158 was filed with the patent office on 2008-01-24 for electronic device.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Takeshi Hongo.
Application Number | 20080019093 11/797158 |
Document ID | / |
Family ID | 38856869 |
Filed Date | 2008-01-24 |
United States Patent
Application |
20080019093 |
Kind Code |
A1 |
Hongo; Takeshi |
January 24, 2008 |
Electronic device
Abstract
According to one embodiment, an electronic device includes a
housing including an opening, a partition wall which partitions an
interior part of the housing into a first chamber and a second
chamber which is opened to the outside through the opening, first
and second heat generating parts mounted in the first chamber, a
first heat radiation member located in the second chamber, a heat
transfer member which transfers heat generated by the first heat
generating part, a cooling fan which draws outside air and exhausts
the air against the first heat radiation member, a second heat
radiation member which is exposed to the outside of the housing and
is thermally connected to the second heat generating part, and a
cover covering the opening and the second heat radiation member.
The cover forms a gap between the cover and the housing. The gap
communicates with the second chamber.
Inventors: |
Hongo; Takeshi;
(Sagamihara-shi, JP) |
Correspondence
Address: |
PILLSBURY WINTHROP SHAW PITTMAN, LLP
P.O. BOX 10500
MCLEAN
VA
22102
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
|
Family ID: |
38856869 |
Appl. No.: |
11/797158 |
Filed: |
May 1, 2007 |
Current U.S.
Class: |
361/693 |
Current CPC
Class: |
G06F 1/203 20130101 |
Class at
Publication: |
361/693 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2006 |
JP |
2006-152286 |
Claims
1. An electronic device comprising: a housing including an opening
and an exhaust hole; a partition wall which partitions an interior
part of the housing into a first chamber and a second chamber, the
second chamber communicating with the exhaust hole and being opened
to the outside of the housing through the opening; a first heat
generating part mounted in the first chamber of the housing; a
second heat generating part mounted in the first chamber of the
housing; a first heat radiation member located in the second
chamber of the housing; a heat transfer member provided to pass
through the partition wall, the heat transfer member transferring
heat generated by the first heat generating part to the first heat
radiation member; a cooling fan located in the second chamber, the
cooling fan drawing outside air through the opening of the housing
and exhausting the drawn outside air against the first heat
radiation member; a second heat radiation member which is exposed
to the outside of the housing and is thermally connected to the
second heat generating part; and a cover mounted on the housing to
cover the opening of the housing and the second heat radiation
member, the cover forming a gap between the cover and the housing,
the gap communicating with the second chamber through the opening,
and allowing the outside air to flow therethrough.
2. The electronic device according to claim 1, wherein the cover
includes an intake hole which allows the gap between the cover and
the housing to communicate with the outside of the electronic
device.
3. The electronic device according to claim 2, wherein the intake
hole of the cover is formed in a region of the cover, which is
different from a region of the cover corresponding in position to
the opening of the housing.
4. The electronic device according to claim 1, wherein the housing
includes another opening which communicates with the first chamber,
and the second heat radiation member is removably mounted on the
housing and closes the other opening of the housing.
5. The electronic device according to claim 4, further comprising a
sealing member which surrounds the other opening of the housing and
is interposed between the housing and the second heat radiation
member.
6. The electronic device according to claim 5, wherein a rib is
provided at the edge of the other opening of the housing, the rib
being raised toward the outside of the housing, and the sealing
member is compressed between the housing and the second heat
radiation member so as to wrap the top end of the rib.
7. The electronic device according to claim 5, further comprising:
a screw which fixes the second heat radiation member to the
housing, wherein the second heat radiation member includes a
through hole into which the screw is inserted in a region closer to
the edge of the second radiation member than a region contacting
the sealing member, and the housing includes a wall, and a screw
hole reaching the mid-point of the wall as viewed in thickness
direction thereof, corresponding in position to the through hole of
the second heat radiation member and receiving the screw.
8. The electronic device according to claim 1, further comprising a
sealing member provided in an areal region of the partition wall
through which the heat transfer member passes, the sealing member
liquid-tightly isolating the first chamber of the housing from the
second chamber thereof.
9. The electronic device according to claim 1, wherein the housing
is provided with a leg which protrudes toward the outside of the
electronic device compared with the cover, and the cover is mounted
on the lower surface of the housing.
10. The electronic device according to claim 9, wherein the cover
is provided with another leg which protrudes toward the outside of
the electronic device.
11. The electronic device according to claim 1, further comprising
a holding member interposed between the housing and the cover, the
holding member holding a gap formed between the housing and the
cover.
12. An electronic device comprising: a case; a first heat
generating part mounted in the case; a second heat generating part
mounted in the case; a first heat radiation member located outside
the case; a heat transfer member which transfers heat generated by
the first heat generating part to the first heat radiation member;
a cooling fan located outside the case, and including an intake
port and an exhaust port, the exhaust port corresponding in
position to the first heat radiation member; a second heat
radiation member which is exposed to the outside of the case and is
thermally connected to the second heat radiation part; and a cover
mounted on the case, the cover covering the first heat radiation
member, the cooling fan and the second heat radiation member, and
forming an air passage which allows a space of the vicinal portion
of the second heat radiation member to communicate with the intake
port of the cooling fan, between the cover and the housing.
13. The electronic device according to claim 12, wherein the case
has a wall, and the wall includes a hollow part which is hollow
toward the inside of the case and which receives the first heat
radiation member and the cooling fan.
14. The electronic device according to claim 13, wherein the wall
of the case includes an exhaust hole which allows the hollow part
to communicate with the outside of the electronic device, and the
cover includes an intake hole which allows the air passage to
communicate with the outside of the electronic device.
15. The electronic device according to claim 14, wherein the intake
hole of the cover is formed in a region which is different from a
region of the cover corresponding in position to the cooling fan.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2006-152286, filed
May 31, 2006, the entire contents of which are incorporated herein
by reference.
BACKGROUND
[0002] 1. Field
[0003] One embodiment of the invention relates to an electronic
device, for example, including heat generating parts mounted
thereon.
[0004] 2. Description of the Related Art
[0005] An electronic device such as, for example, a portable
computer contains heat generating parts mounted within a housing
thereof. Recently, heat generating parts, for example, a CPU,
exhibit a tendency wherein the amount of heat generated is
increasing. The same is also true for circuit parts such as memory
chips and north bridge circuits. Under these circumstances, there
is a strong demand of further enhancement of cooling efficiency in
electronic devices.
[0006] A display device provided with heat radiation parts is
disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-189453. In
the display device, a heat radiation member is provided on the rear
side of a case thereof, while being exposed to outside. The heat
radiation member is thermally connected to a liquid crystal display
unit within the case.
[0007] An electronic device provided with a waterproof and cooling
structure is disclosed in Jpn. Pat. Appln. KOKAI Publication No.
2004-119844. The electronic device includes a metal housing having
a heating component mounted therein, and a cover entirely covering
the metal housing. The cover has an intake port and an exhaust
port. An air passage whereby the intake port communicates with the
exhaust port is formed between the cover and the metal housing. A
fan is provided at the exhaust port of the housing.
[0008] The heat radiating member of the display device functions as
a heat sink exposed to the outside of the housing to thereby cool
the liquid crystal display unit. In other words, the heat radiating
member exhausts the heat generated by the liquid crystal display
unit to the outside of the housing by natural heat radiation. This
leaves room for improvement from the standpoint of cooling
efficiency.
[0009] In the cooling structure of the electronic device, the heat
from the heating component is radiated through the metal housing.
Even when a plurality of heating components having different
heating amounts are installed in the housing of the electronic
device, the heat from all the heating components is radiated
through the metal housing. This leaves room for improvement from
the standpoint of cooling efficiency.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] A general architecture that implements the various feature
of the invention will now be described with reference to the
drawings. The drawings and the associated descriptions are provided
to illustrate embodiments of the invention and not to limit the
scope of the invention.
[0011] FIG. 1 is an exemplary perspective view showing a portable
computer according to a first embodiment of the invention;
[0012] FIG. 2 is an exemplary cross-sectional view showing the
portable computer taken along line F2-F2 in FIG. 1;
[0013] FIG. 3 is an exemplary perspective view showing the portable
computer of the first embodiment;
[0014] FIG. 4 is an exemplary perspective view showing an interior
part of the portable computer of the first embodiment;
[0015] FIG. 5 is an exemplary cross-sectional view showing the
portable computer of the first embodiment;
[0016] FIG. 6 is an exemplary plan view showing the interior part
of the portable computer of the first embodiment;
[0017] FIG. 7 is an exemplary cross-sectional view showing the
periphery of a CPU taken along line F7-F7 in FIG. 6;
[0018] FIG. 8 is an exemplary cross-sectional view showing a
partition wall taken along line F8-F8 in FIG. 6;
[0019] FIG. 9 is an exemplary cross-sectional view showing a
sealing member shown in FIG. 8 when it is exploded;
[0020] FIG. 10 is an exemplary perspective view showing the
portable computer of the first embodiment when covers are
mounted;
[0021] FIG. 11 is an exemplary plan view showing a first cover
according to the first embodiment;
[0022] FIG. 12 is an exemplary plan view showing a second cover
according to first embodiment;
[0023] FIG. 13 is an exemplary plan view showing a third cover
according to first embodiment;
[0024] FIG. 14 is an exemplary cross-sectional view showing the
portable computer of the first embodiment with the covers mounted
thereon;
[0025] FIG. 15 is an exemplary cross-sectional view showing the
portable computer taken along line F15-F15 in FIG. 14;
[0026] FIG. 16 is an exemplary cross-sectional view showing the
portable computer taken along line F16-F16 in FIG. 14;
[0027] FIG. 17 is an exemplary perspective view showing the
portable computer of the first embodiment when the covers are
mounted;
[0028] FIG. 18 is an exemplary plan view showing the cover
according to the first embodiment;
[0029] FIG. 19 is an exemplary cross-sectional view showing air
flows in the portable computer of the first embodiment;
[0030] FIG. 20 is an exemplary cross-sectional view showing a
portable computer according to a second embodiment of the
invention; and
[0031] FIG. 21 is an exemplary perspective view showing the
portable computer according to the second embodiment.
DETAILED DESCRIPTION
[0032] Various embodiments according to the invention will be
described hereinafter with reference to the accompanying drawings.
In general, according to one embodiment of the invention, an
electronic device includes: a housing including an opening and an
exhaust hole; a partition wall which partitions an interior part of
the housing into a first chamber and a second chamber which
communicates with the exhaust hole and is opened to the outside of
the housing through the opening; first and second heat generating
parts mounted in the first chamber; a first heat radiation member
located in the second chamber; a heat transfer member which
transfers heat generated by the first heat generating part to the
first heat radiation member; a cooling fan which is located in the
second chamber and draws outside air through the opening and
exhausts the outside air against the first heat radiation member; a
second heat radiation member which is exposed to the outside of the
housing and is thermally connected to the second heat generating
part; and a cover mounted on the housing, the cover covering the
opening and the second heat radiation member. The cover forms a gap
between the cover and the housing. The gap communicates with the
second chamber through the opening and allows outside air to flow
therethrough.
[0033] Embodiments of the present invention will be described with
reference to the accompanying drawings. In the embodiments, the
invention is applied to a portable computer.
[0034] FIGS. 1 to 19 show a portable computer 1, which is an
electronic device according to a first embodiment of the present
invention. As shown in FIG. 1, the portable computer 1 has a main
body 2 and a display unit 3.
[0035] As shown FIGS. 2 and 3, the main body 2 includes a box-like
housing 6, and a cover 7 attached to the lower surface of the
housing 6. The housing 6 has an upper wall 6a, a sidewall 6b and a
lower wall 6c. By way of example, the upper wall 6a, the sidewall
6b and the lower wall 6c form an outer wall of the housing 6. A
keyboard 5 is supported on the upper wall 6a.
[0036] The display unit 3 includes a display housing 8 and a liquid
crystal display panel 9 housed in the display housing 8. The Liquid
crystal display panel 9 is provided with a display screen 9a. The
display screen 9a is exposed to the outside through an opening 8a
which is formed in the front side of the display housing 8.
[0037] The display unit 3 is supported on the rear end of the
housing 6 by means of a hinge device (not shown).
[0038] The display unit 3 may be hinged between a closed position
and an open position. When the display unit 3 is hinged toward the
closed position and reaches the closed position, it covers the
upper side of the upper wall 6a at the closed position. When the
display unit 3 is hinged upward from the closed position, the upper
wall 6a is exposed to outside.
[0039] As shown in FIG. 4, a cover mounting portion 11 to which the
cover 7 is mounted is formed on the lower wall 6c of the housing 6.
A configuration of the cover mounting portion 11 is substantially
the same as the external configuration of the cover 7. The cover
mounting portion 11 is depressed toward the inner side of the
housing 6 by a thickness of the cover 7 from the lower wall 6c
located out of the cover mounting portion 11.
[0040] As shown in FIGS. 2 and 5, the housing 6 is provided with a
partition wall 14, which partitions an interior space thereof into
a first chamber 12 and a second chamber 13. The partition wall 14
has a top wall 15 and a sidewall 16. As shown in FIG. 2, the top
wall 15 is positioned between the upper wall 6a and the lower wall
6c of the housing 6, and extends parallel to the upper wall 6a. One
end of the top wall 15 is continuous to the sidewall 6b of the
housing. The other end of the top wall 15 extends to the inside of
the housing 6. The sidewall 16 extends from the other end of the
top wall 15 toward the lower wall 6c of the housing 6, and is
continuous to the lower wall 6c located in the cover mounting
portion 11.
[0041] As shown in FIG. 5, the sidewall 16 has a first wall 16a, a
second wall 16b and a third wall 16c. The first wall 16a faces the
sidewall 6b of the housing, while being oblique to the latter. The
second and third walls 16b and 16c extend from both ends of the
first wall 16a toward the sidewall 6b of the housing, and are
continuous to the sidewall 6b. The partition wall 14 is integral
with the housing 6, for example.
[0042] With this structure, the first chamber 12 and the second
chamber 13 of the housing 6 are liquid-tightly isolated from each
other. The first chamber 12 is a closed space isolated from the
outside of the housing 6. The first chamber 12 occupies the most
part of the interior space of the housing 6. The second chamber 13
occupies a part of the right lower end of the interior part of the
housing.
[0043] As shown in FIGS. 2 and 4, the housing 6 has a first opening
18 communicating with the second chamber 13. The first opening 18
is formed by substantially entirely cutting out an areal portion of
the lower wall 6c of the housing corresponding to the second
chamber 13. The second chamber 13 is opened to the outside of the
housing 6 through the first opening 18. It is not essential to form
the first opening 18 over the entire area corresponding to the
second chamber 13. It suffices that the first opening 18 is formed
in at least a part of the area corresponding to the second chamber
13, and the second chamber 13 communicates with the outside of the
housing 6.
[0044] In other words, it can be said that the portable computer 1
is provided with a case 19 having the outer walls 6a, 6b and 6c and
a closed interior space. The lower wall 6c of the case 19 includes
a hollow part 20 being hollow toward the inside of the case 19.
That is, a part of the housing 6 including the first chamber 12
forms the case 19. The second chamber 13 one side of which is
opened through the first opening 18 forms the hollow part 20.
[0045] As shown in FIGS. 4 and 5, the housing 6 further includes
exhaust holes 22. The exhaust holes 22 are opened in a part of the
sidewall 6b of the housing which defines the second chamber 13. The
exhaust holes 22 communicate with the second chamber 13. Thus, the
hollow part 20 communicates with the outside of the portable
computer 1 through the exhaust holes 22.
[0046] As shown in FIGS. 2, 4 and 6, the second chamber 13 is
provided with a cooling fan 24 and a first heat radiation member
25. In other words, the cooling fan 24 and the first heat radiation
member 25 are housed in the hollow part 20 of the case 19. The
cooling fan 24 has an intake port 24a and an exhaust port 24b. The
intake port 24a is formed in the lower surface of the cooling fan
24, while facing the first opening 18 of the housing 6. The exhaust
port 24b faces the first heat radiation member 25.
[0047] The cooling fan 24 draws air (referred to as outside air)
from the outside of the housing 6 into the second chamber 13 of the
housing 6 through the first opening 18, and feeds the drawn air
into the cooling fan 24 through the intake port 24a. The cooling
fan 24 blows the drawn air against the first heat radiation member
25 through the exhaust port 24b.
[0048] The first heat radiation member 25 extends along the exhaust
holes 22 of the sidewall 6b. One example of the first heat
radiation member 25 is a heat radiation fin. The first heat
radiation member 25 contains a plurality of plate-shaped fin
elements 25a. The plate surfaces of those fin elements 25a are
arrayed in the air blowing direction of the cooling fan 24.
[0049] As shown in FIG. 4, a circuit board 31 and a hard disc drive
(HDD) 32 are located in the first chamber 12 of the housing 6. A
CPU 33 and a memory module 34 are mounted on the circuit board 31.
The CPU 33, the memory module 34 and the HDD 32 are arrayed, for
example, horizontally.
[0050] The CPU 33 is one example of a first heat generating part.
As shown in FIG. 7, the CPU 33 includes a base substrate 33a and an
IC chip 33b. The base substrate 33a is mounted on the circuit board
31. The IC chip 33b is mounted on the central part of the base
substrate 33a.
[0051] As shown in FIG. 4, the portable computer 1 includes a heat
pipe 36. The heat pipe 36 is one example of a heat transfer member.
The heat pipe 36 has a pipe-like container both ends of which are
closed. One form of the container is constructed such that a wick
is formed on the inner wall of the container, and a coolant fluid
is sealed into the container. When one end of the heat pipe 36 is
exposed to high temperature, part of the coolant fluid evaporates
to move to the other end. The coolant fluid, which has moved to the
other end and is now in a vaporized state, radiates heat and
condenses at the other end. The coolant fluid having condensed
returns to the end having been exposed to high temperature by
capillary action.
[0052] The heat pipe 36 has a first terminal 36a and a second
terminal 36b. The first terminal 36a of the heat pipe 36 is
thermally connected to the CPU 33. More specifically, as shown in
FIG. 7, the IC chip 33b of the CPU 33 is connected to a heat
receiving plate 37. The heat receiving plate 37 is made of a
material having high thermal conductivity, such as aluminum alloy
or copper alloy. The heat receiving plate 37 is rectangular in
shape, and its size is larger than the external dimension of the IC
chip 33b.
[0053] A heat transfer member 38 is interlayered between the heat
pipe 36 and the heat receiving plate 37. The heat transfer member
38 is a lamination of a plurality of heat transfer sheets made of,
for example, a silicone material. The heat transfer member 38 is
not limited to the heat transfer sheets, but may be silicone
grease, for example.
[0054] The heat pipe 36 is fixed to the circuit board 31 by means
of a fixing member 39. The fixing member 39 includes a cover part
39a and legs 39b. The cover part 39a is brought into contact with
the heat pipe 36. The legs 39b extend from both ends of the cover
part 39a toward the circuit board 31, and are screwed into the
circuit board 31. The fixing member 39 presses the heat pipe 36
against the CPU 33.
[0055] As shown in FIGS. 6 and 8, the heat pipe 36 passes through
the partition wall 14. A pair of cables 40a and 40b, which extend
from the cooling fan 24 toward the circuit board 31, likewise pass
through the partition wall 14.
[0056] As shown in FIG. 9, the first wall 16a of the partition wall
14 has a rectangular cutout part 16d. The cutout part 16d is formed
at an areal region of the partition wall 14 through which the heat
pipe 36 and the cables 40a and 40b pass, that is, at the region of
a path of the heat pipe 36 and the cables 40a and 40b. The cutout
part 16d is cut out to be larger than the cross-sectional areas of
the heat pipe 36 and the cables 40a and 40b.
[0057] A first sealing member 42 is fit to the cutout part 16d. The
first sealing member 42 serves as a part of the partition wall 14.
The first sealing member 42 is formed with rubber, for example. The
first sealing member 42 includes a pair of first and second members
42a and 42b, which are separable from each other.
[0058] The first member 42a has hollows which are deep enough to
receive, for example, the lower half parts of the heat pipe 36 and
the cables 40a and 40b. The second member 42b has hollows which are
deep enough to receive the upper half parts of the heat pipe 36 and
the cables 40a and 40b. The heat pipe 36 and the cables 40a and 40b
are sandwiched between the first and second members 42a and 42b,
whereby the vicinal portions of the heat pipe 36 and the cables 40a
and 40b are liquid-tight. The cutout part 16d of the partition wall
14 and the first sealing member 42 are also liquid-tight. Thus, the
first sealing member 42 liquid-tightly isolates the first chamber
12 from the second chamber 13 of the housing.
[0059] As shown in FIG. 6, the second terminal 36b of the heat pipe
36 extends into the second chamber 13 of the housing 6, and is
attached to the first heat radiation member 25. That is, the second
terminal 36b of the heat pipe 36 is thermally connected to the
first heat radiation member 25. The heat pipe 36 transfers the heat
generated by the CPU 33 to the first heat radiation member 25. The
cables 40a and 40b of the cooling fan 24 extend into the first
chamber 12 and are electrically connected to the circuit board
31.
[0060] As shown in FIG. 4, a memory slot 44 is mounted to the
circuit board 31. The memory module 34 is inserted into and removed
from the memory slot 44. The memory module 34 is one example of the
second heat generating part. The memory module 34 includes a child
board 45 and a plurality of memory chips 46, for example, mounted
on the child board 45. By inserting the child board 45 into the
memory slot 44, the memory chips 46 are electrically connected to
the circuit board 31.
[0061] The first and the second heat generating parts are not
limited to the CPU and the memory module, but may be a north
bridge, a graphics board, a PCI module or any other heat generating
part.
[0062] As shown in FIGS. 4 and 6, the cover mounting portion 11
includes second to fourth openings 51, 52 and 53 formed therein.
The second to fourth openings 51, 52 and 53 communicate with the
first chamber 12 of the housing 6. As shown in FIG. 6, the second
opening 51 is provided facing the CPU 33. The third opening 52 is
provided facing the memory module 34. The memory module 34 is
inserted into and removed from the memory slot 44 through the third
opening 52. The fourth opening 53 is provided facing the HDD 32.
The HDD 32 is attached to and detached from the inside of the
housing 6 through the fourth opening 53.
[0063] As shown in FIGS. 15 and 16, a rib 55 is raised toward the
outside of the housing 6 from the opening edges of the second to
fourth openings 51, 52 and 53. As shown in FIG. 6, the rib 55
surrounds entirely the second to fourth openings 51, 52 and 53.
[0064] As shown in FIG. 4, a plurality of bosses 56 are raised from
the cover mounting portion 11 toward the outside of the housing 6.
The bosses 56 are integral with the lower wall 6c. The bosses 56
are protruded toward the outside of the housing 6 to be much higher
than the rib 55. For example, two bosses 56 are located between the
second opening 51 and the second chamber 13. Four bosses 56 are
located around the third and fourth openings 52 and 53.
[0065] A screw hole 56a is formed in each boss 56. A female screw
is formed in the surface of the screw hole 56a. As shown in FIGS.
15 and 16, the screw hole 56a reaches the mid-point of the lower
wall 6c when viewed in the thickness direction thereof. In other
words, the screw hole 56a does not pass through the lower wall
6c.
[0066] A pair of recess parts 57a and 57b are formed in an area
between the second opening 51 and the third opening 52. Those
recess parts 57a and 57b are arrayed along the edge of the second
opening 51. The recess parts 57a and 57b are each slightly
depressed from the lower wall 6c of the housing 6 toward the inner
part of the housing 6.
[0067] As shown in FIG. 10, the portable computer 1 includes first
to third covers 61, 62 and 63. The first to third covers 61, 62 and
63 are each one form of an outer covering part of the housing.
Those covers 61, 62 and 63 are removably mounted to the housing 6.
The first cover 61 has a size larger than the second opening 51.
The first cover 61 is mounted on the housing 6 to close the second
opening 51. As shown in FIG. 15, the first cover 61 includes a flat
portion 65 which covers the second opening 51 and the boss 56, and
a bent portion 66 which is bent from the peripheral edge of the
flat part 65 toward the housing 6.
[0068] As shown in FIGS. 11 and 15, a second sealing member 71 is
attached to the rear side of the first cover 61. The second sealing
member 71 has a ring-like shape to be equivalent in configuration
to the opening edge of the second opening 51. The width of the
ring-like second sealing member 71 is larger than that of the rib
55.
[0069] When the first cover 61 is attached to the housing 6, the
second sealing member 71 surrounds the second opening 51 and is
interposed between the housing 6 and the first cover 61. To be more
specific, the second sealing member 71 comes in contact with the
protruded surface, the inner surface and the peripheral surface of
the rib 55, and is pressed in three directions so as to wrap the
top end part of the rib 55. As shown in FIG. 14, the second sealing
member 71 is interposed between the housing 6 and the first cover
61, so that the vicinal portion of the second opening 51 is
liquid-tight.
[0070] As shown in FIG. 11, screw holes 75 are formed in a region
of the first cover 61 closer to the peripheral edge thereof than a
region of the first cover 61 contacting the second sealing member
71. The screw holes 75 are through holes. The screw holes 75
correspond in position to the bosses 56 located around the second
opening 51.
[0071] The first cover 61 further includes a pair of claw parts 76a
and 76b. The claw parts 76a and 76b slightly extend downward from
the peripheral edge of the first cover 61, and also outward from
the housing 6. The claw parts 76a and 76b correspond in position to
the recess parts 57a and 57b, respectively. When the first cover 61
is attached to the housing 6, the claw parts 76a and 76b are placed
into the recess parts 57a and 57b, respectively.
[0072] As shown in FIGS. 12 and 15, the second cover 62 has a size
larger than the third opening 52. The second cover 62 is mounted to
the housing 6 to close the third opening 52. The second cover 62 is
made of a material of good thermal conductivity such as metal, and
is one example of a second heat radiation member. The second cover
62 is exposed to the outside of the housing 6.
[0073] A third sealing member 72 is mounted to the rear side of the
second cover 62. The third sealing member 72 has a ring-like shape
to be equivalent in configuration to the opening edge of the third
opening 52. The width of the ring-like third sealing member 72 is
larger than that of the rib 55. When the second cover 62 is mounted
on the housing 6, the third sealing member 72 surrounds the third
opening 52 and is interposed between the housing 6 and the second
cover 62. With the interposing of the third sealing member 72
between the housing 6 and the second cover 62, the vicinal portion
of the third opening 52 is liquid-tight. The third sealing member
72 is pressed in three directions so as to wrap the top end part of
the rib 55.
[0074] The screw holes 75 as through holes are formed in a region
of the second cover 62 closer to the peripheral edge thereof than a
region of the second cover 62 contacting the second sealing member
71. The screw holes 75 correspond in position to the screw holes
56a of the bosses 56 located around the third opening 52.
[0075] As shown in FIG. 15, a heat transfer member 81 is mounted on
the central part of the rear side of the second cover 62. The heat
transfer member 81 may be a lamination of heat transfer sheets, for
example. As shown in FIG. 15, when the second cover 62 is mounted
on the housing 6, the heat transfer member 81 is brought into
contact with the memory module 34. That is, the second cover 62 is
thermally connected to the memory module 34 through the heat
transfer member 81.
[0076] Further, as shown in FIG. 15, the second cover 62 is brought
into contact with the claw parts 76a and 76b of the first cover 61.
As a result, the first cover 61 cannot be removed till the second
cover 62 is removed. This structural feature prevents the user from
easily opening the first cover 61. Accordingly, the possibility
that the CPU 33 is erroneously exposed to the outside is
lessened.
[0077] As shown in FIGS. 13 and 16, the third cover 63 has a size
larger than the fourth opening 53. The third cover 63 is mounted on
the housing 6 to close the fourth opening 53. The third cover 63 is
made of a material of good thermal conductivity such as metal, and
is one form of a second heat radiation member.
[0078] A fourth sealing member 73 is mounted on the rear side of
the third cover 63. The fourth sealing member 73 has a ring-like
shape to be equivalent in configuration to the opening edge of the
fourth opening 53. The width of the ring-like fourth sealing member
73 is larger than that of the rib 55. When the third cover 63 is
mounted on the housing 6, the fourth sealing member 73 surrounds
the fourth opening 53 and is interposed between the housing 6 and
the third cover 63. With the interposing of the fourth sealing
member 73 between the housing 6 and the third cover 63, the vicinal
portion of the fourth opening 53 is liquid-tight. The fourth
sealing member 73 is pressed in three directions so as to wrap the
top end part of the rib 55. For example, sponge rubber may be used
for the second to fourth sealing members 71, 72 and 73.
[0079] The screw holes 75 as through holes are formed in a region
of the third cover 63 closer to the peripheral edge thereof than a
region of the third cover 63 contacting the third sealing member
72. The screw holes 75 correspond in position to the screw holes
56a of the bosses 56 located around the fourth opening 53.
[0080] A heat transfer member 82 is mounted to the central part of
the rear side of the third cover 63. One example of the heat
transfer member 82 is a lamination of heat transfer sheets. As
shown in FIG. 16, when the third cover 63 is mounted to the housing
6, the heat transfer member 82 is brought into contact with the HDD
32. That is, the third cover 63 is thermally connected to the HDD
32 through the heat transfer member 82.
[0081] As shown in FIGS. 15 and 16, screws 84 are respectively
inserted into the screw holes 75 formed in the first to third
covers 61, 62 and 63. The screws 84 having inserted into the screw
holes 75 are screwed into the screw hole 56a of the lower wall 6c
of the housing, respectively. As a result, the first to third
covers 61, 62 and 63 are fixed to the housing 6. The first to third
covers 61, 62 and 63 having been fixed to the housing 6 are exposed
to the outside of the housing 6.
[0082] As shown in FIG. 17, a size of the cover 7 is about half of
the lower wall 6c of the housing. The cover 7 is mounted on the
cover mounting portion 11, and entirely covers the first opening 18
communicating with the second chamber 13, and the first to third
covers 61, 62 and 63 mounted on the cover mounting portion 11. The
cover 7 covers also the first heat radiation member 25 and the
cooling fan 24.
[0083] As shown in FIG. 2, the cover 7 includes a center portion 7a
shaped like a flat plate, and a bent portion 7b bent from the
peripheral edge of the center portion 7a toward the housing 6.
Since the cover 7 has the bent portion 7b along the peripheral edge
of the center portion 7a, a gap S is formed between the center
portion 7a of the cover 7 and the housing 6 when the cover 7 is
mounted on the housing 6. The first to third covers 61, 62 and 63
are exposed to the gap S between the cover 7 and the housing 6.
[0084] The gap S between the cover 7 and the housing 6 communicates
with the first opening 18 and the second chamber 13 of the housing
6. The gap S functions as an air passage which allows the space
around the first to third covers 61, 62 and 63 to communicate with
the intake port 24a of the cooling fan 24, which is housed in the
second chamber 13. A distance between the housing 6 and the cover
7, which define the gap S, is, for example, 2.0 to 2.5 mm.
[0085] The cover 7 has a rear side 7c which faces the housing 6. As
shown in FIG. 18, a plurality of gap holding members 85 are
provided on the rear side 7c of the cover 7. As shown in FIG. 2,
each of the gap holding members 85 has substantially the same
thickness as the size of the gap S formed between the cover 7 and
the housing 6. The gap holding members 85 are interposed between
the cover 7 and the housing 6 to thereby maintain the gap S. The
gap holding members 85 may be formed with synthetic rubber, for
example.
[0086] The cover 7 includes a first region 7d arranged in
opposition to the first opening 18 and a second region 7e located
out of the first region 7d. That is, the first region 7d is
arranged opposed to the cooling fan 24. For example, a plurality of
intake holes 88 are formed in the second region 7e. The intake
holes 88 are formed in substantially the entire area of the second
region 7e. The intake holes 88 are arrayed in a lattice, for
example. The gap S between the cover 7 and the housing 6
communicates with the outside of the portable computer 1 through
the intake holes 88. With this structure, the outside air flows
between the cover 7 and the housing 6 through the intake holes 88.
The first to third covers 61, 62 and 63 are exposed to the open
air.
[0087] The cover 7 is mounted on the housing 6 by means of the
screws 84. As shown in FIG. 17, the screws 84 for fixing the cover
7 are also used for fixing the first to third covers 61, 62 and 63.
Accordingly, the first to third covers 61, 62 and 63 are fixed by
the screws 84 for fixing the cover 7.
[0088] A plurality of first legs 91 are formed at positions on the
lower wall 6c of the housing 6 which is located out of the cover
mounting portion 11. The first legs 91 protrude from the lower wall
6c of the housing to the outside of the portable computer 1
compared with the cover 7. Similarly, the cover 7 is provided with
a second leg 92. The second leg 92 protrudes from the lower side of
the cover 7 to the outside of the portable computer 1.
[0089] Now, operation of the portable computer 1 will be
described.
[0090] When the portable computer 1 is operated, the IC chip 33b of
the CPU 33 generates heat. Part of the heat generated by the CPU 33
is transferred to the first terminal 36a of the heat pipe 36
through the heat receiving plate 37 and the heat transfer member
38. The heat pipe 36 transfers heat at the first terminal 36a to
the second terminal 36b by use of vaporization heat. The heat
having reached the second terminal 36b of the heat pipe 36
propagates to the first heat radiation member 25. The cooling fan
24 blows air against the first heat radiation member 25. The air
blown from the cooling fan 24 takes the heat from the first heat
radiation member 25 and exhausts it to the outside of the housing 6
through the exhaust holes 22. Thus, the first heat radiation member
25 is forcibly cooled to promote heat radiation from the CPU
33.
[0091] Part of the heat generated by the memory module 34 and the
HDD 32 is transferred to the second or third cover 62 or 63 through
the heat transfer members 81 or 82 attached to the second or third
cover 62 or 63. The cooling fan 24, when driven to operate, draws
air from the second chamber 13 of the housing 6, and blows the
drawn air to the first heat radiation member 25. The air blown out
of the cooling fan 24 is exhausted to the outside of the housing 6
through the exhaust holes 22 of the sidewall 6b.
[0092] As shown in FIG. 19, when the cooling fan 24 continues its
operation, the cooling fan 24 draws air from the gap S between the
cover 7 and the housing 6 through the first opening 18. With the
operation of the cooling fan 24, cool outside air flows from the
outside of the portable computer 1 into the gap S between the cover
7 and the housing 6, through the intake holes 88. The outside air
having flowed into the gap S between the cover 7 and the housing 6
through the intake holes 88 flows toward the first opening 18 in
the gap S. At this time, the second cover 62 and the third cover 63
are exposed to the air flowing through the gap S between the cover
7 and the housing 6, and part of the heat of those covers 62 and 63
is absorbed into the flowing air. As a result, the cooling
operation of the memory module 34 and the HDD 32 is promoted.
[0093] The air absorbing the heat from the second cover 62 and the
third cover 63 flows into the second chamber 13 via the first
opening 18. The air having flowed into the second chamber 13 is
discharged, by the cooling fan 24, to the outside of the portable
computer 1 by way of the exhaust holes 22.
[0094] With such a construction of the portable computer 1, the
first and second heat generating parts are both cooled by the
cooling fan, so that the cooling efficiency of the heat generating
parts is enhanced. The CPU 33 of which the heating amount is
relatively large is efficiently heat radiated, by the heat pipe 36,
the first heat radiation member 25, and the cooling fan 24. The
memory module 34 and the HDD 32, which are smaller in heating
amount than the CPU 33 but their heat radiation is required, are
heat radiated since the second cover 62 and the third cover 63
serve as heat sinks. By supplying cool outside air to the space
around the second cover 62 and the third cover 63 by the cooling
fan 24, which is provided mainly for cooling the CPU 33, cooling of
the memory module 34 and the HDD 32 is promoted.
[0095] In other words, in the embodiment, a plurality of heat
generating parts having different heating amounts are associated
with a plurality of heat radiation paths, which are provided
depending on the heating amounts of the heat generating parts. The
heat radiation of those heat radiation paths is promoted by using
one cooling fan 24. This feature contributes to size and cost
reduction of the portable computer 1.
[0096] The intake holes 88 formed in the cover 7 provide easy
supply of the outside air to between the cover 7 and the housing 6.
In this sense, provision of those suction holes contributes to
enhancement of the cooling efficiency of the memory module 34 and
the HDD 32. Particularly, formation of the intake holes 88 at an
area in the second region 7e located out of the area just under the
cooling fan 24, brings about the following advantage. Even when a
liquid enters the gap S between the cover 7 and the housing 6
through the intake holes 88, there is less possibility that the
liquid will adhere to the cooling fan 24. This feature contributes
to enhancement of reliability of the portable computer 1.
[0097] Temperature of the second cover 62 and the third cover 63
will be high as a possibility. If the cover 7 is mounted so as to
cover the second cover 62 and the third cover 63, the possibility
of the user touching the second cover 62 and the third cover 63 is
lessened.
[0098] If the function of the second heat radiation member is given
to the second cover 62 and the third cover 63, which cover the
openings 52 and 53, by using metal for those covers, there is no
need of using an additional heat radiation member for cooling the
memory module 34 and the HDD 32.
[0099] With provision of the first legs 91 on the lower wall 6c, a
gap is formed between the cover 7 and a installation surface F such
as a desk top even when the lower wall 6c is placed on the
installation surface F. Outside air is drawn through the gap formed
between surface F and the cover 7. In this respect, formation of
the gap contributes to enhancement of the cooling efficiency of the
portable computer 1. Provision of the second leg 92 to the cover 7
makes formation of the gap between the cover 7 and the installation
surface F more reliable.
[0100] With provision of the gap holding members 85 interposed
between he housing 6 and the cover 7, the gap S between the housing
6 and the cover 7 is reliably held. This contributes to enhancement
of the cooling efficiency of the portable computer 1.
[0101] With provision of the first sealing member 42 surrounding
the heat pipe 36 on the partition wall 14, liquid-tight sealing is
secured between the first chamber 12 and the second chamber 13.
With this, the drip-proof of the portable computer 1 is
improved.
[0102] Use of the second sealing members 71, 72 and 73 which
surround the second to fourth openings 51, 52 and 53, and are
interposed between the covers 61, 62 and 63 and the housing 6,
makes the vicinity of the second to fourth openings 51, 52 and 53
liquid-tight. As a consequence, the drip-proof of the portable
computer 1 is improved. When the sealing members 71, 72 and 73 are
compressed so as to wrap the rib 55, the vicinal portions of the
second to fourth openings 51, 52 and 53 are made more liquid-tight.
This feature contributes to improvement of the drip-proof
performance of the portable computer 1.
[0103] Where the sealing member is placed around the opening of the
case, it would be possible to compress the sealing member by
fitting the cover covering the opening to the case. In the case of
this approach, the work of attaching and detaching the cover will
be complicated. In this connection, it is noted that according to
one aspect of the invention, there is provided a drip-proof
structure with improved assembling properties.
[0104] According to one aspect of the invention, there is provided
a drip-proof structure comprising: a housing including an opening;
a cover which covers the opening; a screw which fixes the cover to
the housing; and a sealing member interposed between the housing
and the cover, while surrounding the opening.
[0105] The cover includes a through hole into which the screw is
inserted, and which is located in a region of the cover closer to
the peripheral edge of the cover than a region of the cover
contacting the sealing member. The housing includes a screw hole
reaching the mid-point of a wall of the housing when viewed in the
thickness direction thereof, the screw hole corresponding in
position to the through hole of the cover, and the screw hole
receiving the screw. This drip-proof structure provides improved
assembling properties. A portable computer is one example of the
drip-proof structure.
[0106] More specifically, the covers 61 to 63 are fixed to the
housing 6 by means of screws. Therefore, the work of attaching and
detaching the covers 61 to 63 is improved. The screw holes 75 are
formed in the covers 61 to 63 for the purpose of securing the
covers 61 to 63 with screws. The screw holes 75 are located in a
region of the covers 61 to 63 closer to the peripheral edges
thereof than a region thereof contacting the sealing members 71 to
73. With this structural feature, for the possibility of a liquid,
which has entered between the covers 61 to 63 and the housing 6
through the screw holes 75, entering the openings 51 to 53 is
lessened. If the screw hole 56a does not pass through the outer
wall 6c, there is no danger of liquid entering the inside of the
housing 6 through the screw hole 56a. Consequently, the resultant
portable computer 1 is improved in drip-proof performance and
assembling properties.
[0107] A portable computer 101 as an electronic device according to
a second embodiment of the invention will be described with
reference to FIG. 20 and 21. Like reference numerals are used for
designating like or equivalent portions in the portable computer 1
of the first embodiment, and explanations thereof are omitted.
[0108] As shown in FIG. 20, the portable computer 101 includes a
CPU 33 installed in a housing 6. The CPU 33 is one example of a
first heat generating part. A heat transfer member 102 is mounted
on the rear side of a first cover 61. The heat transfer member 102
is in contact with a fixing member 39. The first cover 61 is made
of a material of good thermal conductivity such as metal, and
functions as one form of a second heat radiating member. The heat
transfer member 102 may be a lamination of heat transfer sheets,
for example. The first cover 61 is thermally connected to the CPU
33 through the heat transfer member 102.
[0109] Another heat transfer member 103 is interposed between a
memory module 34 and a circuit board 31. An example of the other
heat transfer member is a lamination of heat transfer sheets. The
memory module 34 is thermally connected to the circuit board 31
through the heat transfer member 103.
[0110] As shown in FIG. 21, the first to third covers 61, 62 and 63
are provided with heat radiation fins 104, respectively. The heat
radiation fins 104 may be pin-like members provided on the first
cover 61, or plate-like members provided on the second and third
covers 62 and 63. The heat radiation fins 104 are configured so as
to be directed along the air flow direction between the housing 6
and the cover 7.
[0111] In the portable computer 101 thus constructed, the cooling
fan 24 cools both the first and second heat generating parts,
whereby the cooling efficiency of the heat generating parts is
improved. As in the portable computer 1 of the first embodiment, a
plurality of heat generating parts having different heating amounts
are associated with a plurality of heat radiation paths, which are
provided depending on the heating amounts of the heat generating
parts. The heat radiation of those heat radiation paths is promoted
by using one cooling fan 24.
[0112] The portable computer 101 of the embodiment provides further
improvement of the cooling efficiency. For example, when the heat
transfer member 102 is interposed between the first cover 61 and
the CPU 33, the first cover 61 is thermally connected to the CPU
33. The first cover 61 exposed to between the cover 7 and the
housing 6 functions as a heat sink, thereby to promote the cooling
of the CPU 33.
[0113] For example, where the heat transfer member 103 is
interposed between the memory module 34 and the circuit board 31,
the memory module 34 is thermally connected to the circuit board
31. Part of the heat generated by the memory module 34 propagates
to the circuit board 31, and it is exhausted to outside through the
atmosphere in the housing 6 and the outer walls of the housing 6.
More specifically, if the heat transfer members 102 and 103 are
respectively provided between the first cover 61 and the CPU 33 and
between the memory module 34 and the circuit board 31, more
increased number of heat radiation passes are formed, leading to
enhancement of the cooling efficiency of the portable computer
1.
[0114] Additionally, when the first to third covers 61, 62 and 63
are provided with the heat radiation fins 104, the cooling
efficiency of those covers is further enhanced.
[0115] While the portable computers 1 and 101 according to the
first and second embodiments have been described, it is clear that
the present invention is not limited to these computers. The heat
transfer members 38, 81, 82, 102 and 103 may be formed with
silicone grease or any material having good thermal conductivity,
in place of the heat transfer sheet. It is not essential that the
first chamber 12 and the second chamber 13 are liquid-tightly
separated from each other. The second to fourth sealing members 71,
72 and 73 are also not essential from the standpoint of the cooling
efficiency enhancement. Further, it is not essential that the
intake holes 88 are formed in the cover 7. The intake holes may
take any shape if they are capable of drawing air, which is to be
fed to between the cover 7 and the housing 6. Locations of the
intake holes are not limited to the described ones if such a
condition is satisfied. It is clear that the invention may be
applied to various types of electronic devices, in addition to the
portable computer 1.
[0116] While certain embodiments of the inventions have been
described, these embodiments have been presented by way of example
only, and are not intended to limit the scope of the inventions.
Indeed, the novel methods and systems described herein may be
embodied in a variety of other forms; furthermore, various
omissions, substitutions and changes in the form of the methods and
systems described herein may be made without departing from the
spirit of the inventions. The accompanying claims and their
equivalents are intended to cover such forms or modifications as
would fall within the scope and spirit of the inventions.
* * * * *