U.S. patent application number 10/671855 was filed with the patent office on 2005-08-11 for electronic apparatus including a circulation path for circulating cooling medium.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Hisano, Katsumi, Ishikawa, Kenichi.
Application Number | 20050174714 10/671855 |
Document ID | / |
Family ID | 18771406 |
Filed Date | 2005-08-11 |
United States Patent
Application |
20050174714 |
Kind Code |
A1 |
Ishikawa, Kenichi ; et
al. |
August 11, 2005 |
ELECTRONIC APPARATUS INCLUDING A CIRCULATION PATH FOR CIRCULATING
COOLING MEDIUM
Abstract
An electronic apparatus comprises a housing for accommodating a
heat generating component and a display unit supported by the
housing. A heat receiving head thermally connected to the heat
generating component is accommodated inside the housing. A heat
radiator is disposed in the display unit. A heat receiving head and
the heat radiator are connected to each other through a circulating
path for circulating cooling medium. The circulating path is
provided with an intermediate cooling unit. Before cooling medium
heated by heat transfer by the heat receiving head reaches the heat
radiator, the intermediate cooling unit forces cooling medium to be
cooled.
Inventors: |
Ishikawa, Kenichi;
(Hamura-shi, JP) ; Hisano, Katsumi; (Kashiwa-shi,
JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER
LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
|
Family ID: |
18771406 |
Appl. No.: |
10/671855 |
Filed: |
September 25, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10671855 |
Sep 25, 2003 |
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10298576 |
Nov 19, 2002 |
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6728102 |
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10298576 |
Nov 19, 2002 |
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09955091 |
Sep 19, 2001 |
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6510052 |
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Current U.S.
Class: |
361/103 |
Current CPC
Class: |
F28D 2021/0029 20130101;
G06F 1/203 20130101; F28D 1/0308 20130101 |
Class at
Publication: |
361/103 |
International
Class: |
H02H 005/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 21, 2000 |
JP |
2000-287691 |
Claims
1-20. (canceled)
21. An electronic apparatus comprising: a first housing including a
convex portion; a heat generating component housed in the first
housing; a second housing including a leg portion rotatably
supported by the convex portion; a heat receiving portion provided
in the first housing, and thermally connected to the heat
generating component; a heat radiating portion provided in the
second housing, and for radiating heat of the heat generating
component; and a circulation path circulating a cooling medium
between the heat receiving portion and the heat radiating portion,
and for transmitting the heat of the heat generating component
which is transmitted to the heat receiving portion, to the heat
radiating portion, wherein the circulation path extends between the
first housing and the second housing through an interior of the
convex portion and an interior of the leg portion, the leg portion
includes an opening at a part corresponding to the circulation path
for exposing the circulation path to the outside of the leg
portion, and the opening is covered with a removable lid.
22. An electronic apparatus according to claim 21, wherein the
second housing includes a rear face located at the rear of the heat
radiating portion, and a mounting port formed on the rear face, and
the mounting port has a size corresponding to a size of the heat
radiating portion and is continuous with the opening.
23. An electronic apparatus according to claim 21, further
comprising a pump for circulating the cooling medium between the
heat receiving portion and the heat radiating portion through the
circulation path.
24. An electronic apparatus comprising: a first housing including a
convex portion; a heat generating component housed in the first
housing; a second housing including a rear face, and a leg portion
rotatably supported by the convex portion; a heat receiving portion
provided in the first housing, and thermally connected to the heat
generating component; a heat radiating portion provided in the
second housing, and for radiating heat of the heat generating
component; and a circulation path for circulating a cooling medium
between the heat receiving portion and the heat radiating portion,
and for transmitting the heat of the heat generating component
which is transmitted to the heat receiving portion, to the heat
radiating portion, wherein the circulation path extends between the
first housing and the second housing through an interior of the
convex portion and an interior of the leg portion, the second
housing includes an opening in the rear face for exposing the
circulation path, and the opening is covered with a removable
lid.
25. An electronic apparatus according to claim 24, wherein the heat
radiating portion is supported by the second housing removably from
the rear face of the second housing.
26. An electronic apparatus according to claim 24, wherein the leg
portion includes a first leg and a second leg, the first and second
legs are apart from each other in a width direction of the second
housing, the circulation path includes a first path for guiding the
cooling medium heated at the heat receiving portion to the heat
radiating portion, and a second path for returning the cooling
medium cooled at the heat radiating portion to the heat receiving
portion, the first path extends inside the first leg, and the
second path extends inside the second leg.
27. An electronic apparatus according to claim 24, further
comprising a pump for circulating the cooling medium between the
heat receiving portion and the heat radiating portion through the
circulation path.
28. An electronic apparatus comprising: a first housing containing
a heat generating component; a second housing including a rear face
and rotatably supported by the first housing via a hinge; a heat
receiving portion provided in the first housing, and thermally
connected to the heat generating component; a heat radiating
portion provided in the second housing, and for radiating heat of
the heat generating component; and a circulation path extending
between the first housing and the second housing through the rear
of the hinge, the circulation path transmitting the heat of the
heat generating component which is transmitted to the heat
receiving portion, to the heat radiating portion by circulating a
cooling medium between the heat receiving portion and the heat
radiating portion, wherein the rear face of the second housing
includes an opening at a part corresponding to the circulation
path, and the opening is covered with a removable lid.
29. An electronic apparatus according to claim 28, wherein at least
a behind-the-hinge part of the circulation path is flexible.
30. An electronic apparatus according to claim 28, wherein the heat
radiating portion includes a thermally conductive heat radiating
plate, and a heat radiating path to which the cooling medium heated
at the heat receiving portion is guided, the rear face of the
second housing includes a mounting port at a part corresponding to
the heat radiating plate, and the mounting port is continuous with
the opening.
31. An electronic apparatus according to claim 30, wherein the heat
radiating plate is covered with a layer having a lower thermal
conductivity than the heat radiating plate, and the layer is
exposed to the outside of the second housing through the mounting
port.
32. An electronic apparatus according to claim 30, wherein the lid
includes a panel that covers the mounting port and the heat
radiating portion.
33. An electronic apparatus according to claim 28, further
comprising a pump for circulating the cooling medium between the
heat receiving portion and the heat radiating portion through the
circulation path.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No.
2000-287691, filed Sep. 21, 2000, the entire contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a cooling unit for forcing
a heat generating component like a semiconductor package to be
cooled with liquid-like cooling medium and an electronic apparatus
provided with the cooling unit, such as a portable computer.
[0004] 2. Description of the Related Art
[0005] An electronic apparatus like a portable computer has a micro
processing unit (MPU) for processing multi-media information such
as characters, voices and animation. This MPU tends to increase
generation of heat during its operation accompanied by currently
increased processing speed and multiple functions. Thus, in order
to ensure a stable operation of the MPU, it is necessary to
intensify heat radiation performance of this MPU.
[0006] Conventionally, a portable computer loaded with a MPU
generating a large amount of heat is equipped with an air-cooling
type cooling unit for forcing the MPU to be cooled. This cooling
unit has a heat sink thermally connected to the MPU and an electric
fan for supplying cooling air to this heat sink.
[0007] In this cooling unit, heat from the MPU is transmitted to
the heat sink and then discharged out of the computer through a
flow of cooling air. Therefore, because according to the
conventional cooling method, cooling air serves as a cooling medium
for depriving the MPU of heat, the cooling performance of the MPU
mostly depends on air feeding performance of the electric fan. If
the feeding amount of cooling air is increased to aim at
intensifying cooling performance of the MPU, the rotation amount of
the electric fan is increased, so that there is produced such a
problem that a large noise may be produced. Additionally, because
in the portable computer, a housing for incorporating the MPU and
electric fan is designed so thin in a compact body, it is difficult
to secure a space for accommodating a large electric fan having an
excellent air feeding performance and an ideal air feeding path
inside the housing.
[0008] In near future, it is expected that the processing speed of
the MPU for the portable computer will be further accelerated and
the MPU will become multi-functional, and accompanied by this
trend, the heat generation of the MPU increases tremendously. Thus,
the conventional forced air-cooling system has a fear that the
cooling capacity for the MPU becomes short or reaches its
limit.
[0009] As a means for improving this, for example, Jpn. Pat. Appln.
KOKAI Publication No. 7-142886 has disclosed so-called liquid
cooling system employing liquid having a higher specific heat than
air as heat transferring medium.
[0010] According to this new cooling system, a heat receiving
header connected to the MPU thermally is disposed inside the
housing and a heat radiating header is disposed inside the display
housing supported by this housing. The heat receiving header and
the heat radiating header are connected to each other through a
circulating pipe in which liquid-like cooling medium flows.
[0011] Because according to this cooling system, cooling medium
circulates between the heat receiving header and the heat radiating
header, heat from the MPU is transmitted to the heat receiving
header and after that, transferred to the heat radiating header via
the cooling medium. Heat transferred to the heat radiating header
is discharged to the atmosphere by diffusion by heat conduction to
the display housing. For the reason, the heat radiating header is
connected thermally to the display housing and the display housing
is composed of metallic material having excellent heat
conductivity.
[0012] Therefore, such liquid cooling system is capable of
transferring heat of the MPU more effectively than the conventional
forced air cooling system, thereby raising the cooling performance
of the MPU.
[0013] Meanwhile, heat of the MPU transferred from the heat
radiating header to the display housing is discharged to the
atmosphere from the surface of the display housing through natural
convection and heat radiation. Thus, as the amount of heat
transferred to the display housing increases, the surface
temperature of the display housing is raised. As a result, if user
happens to touch the surface of the display housing when
opening/closing the display housing or carrying the computer, he or
she may feel discomfort or heat.
[0014] Further, according to the liquid cooling system, a heat
radiating header inside the display housing is connected to a heat
receiving header inside the housing through a circulating pipe.
Thus, if a necessity of removing this display housing from the
housing occurs to carry out maintenance on the interior of the
display housing, the heat receiving header thermally connected to
the MPU needs to be removed from the housing temporarily.
[0015] However, disassembly of the periphery of such a precision
MPU not only leads to damage of the MPU but also may make
inappropriate the positional relationship between the heat
receiving header and the MPU upon installation of the heat
receiving header. Thus, this is unfavorable in terms of maintaining
reliability of thermal connection between the MPU and the heat
receiving header.
[0016] If the MPU is loaded on a place difficult to access like a
rear face of a circuit board, a troublesome work of disassembling
the housing and taking out the circuit board is required. This work
can be said to be inappropriate in viewpoint of operation
efficiency and therefore, there is a room for improvement at this
point.
BRIEF SUMMARY OF THE INVENTION
[0017] A first object of the present invention is to provide a
cooling unit and an electronic apparatus capable of preventing a
rise in temperature of the surface of a display unit.
[0018] A second object of the present invention is to provide an
electronic apparatus, which allows a second housing to be removed
from a first housing without releasing thermal connection between a
heat receiving portion and a heat generating component and which
can be disassembled/reassembled easily and maintain reliability of
heat conduction favorably.
[0019] In order to achieve the above-described first object,
according to a first aspect of the present invention, there is
provided a cooling unit for use in an electronic apparatus having a
computer main body containing a heat generating component and a
display unit supported by the computer main body, the cooling unit
comprising: a heat receiving portion thermally connected to the
heat generating component and accommodated in the computer main
body; a heat exchanging portion installed on the display unit;
circulating means for circulating cooling medium between the heat
receiving portion and the heat exchanging portion, the circulating
means having a pipe line for introducing cooling medium heated by
the heat receiving portion to the heat exchanging portion; and
intermediate cooling means installed in the pipe line, the
intermediate cooling means forcing the heated cooling medium
flowing from the heat receiving portion to the heat exchanging
portion to be cooled.
[0020] Further, in order to achieve the above-described first
object, according to a second aspect of the present invention,
there is provided an electronic apparatus comprising: a housing
containing a heat generating component; a display unit supported by
the housing; a heat receiving portion accommodated in the housing
and thermally connected to the heat generating component; a heat
exchanging portion installed on the display unit; circulating means
for circulating cooling medium between the heat receiving portion
and the heat exchanging portion, the circulating means being
disposed throughout the housing and the display unit and having a
pipe line for introducing cooling medium heated by the heat
receiving portion to the heat exchanging portion; and intermediate
cooling means installed in the pipe line of the circulating means,
the intermediate cooling means forcing the heated cooling medium
flowing from the heat receiving portion to the heat exchanging
portion to be cooled.
[0021] With such a structure, heat from the heat generating
component is transferred to the cooling medium by means of the heat
receiving portion. This heat is transmitted to the heat exchanging
portion through a flow of the cooling medium. The cooling medium
cooled by heat exchange by means of the heat exchanging portion is
returned to the heat receiving portion and receives heat from the
heat generating component again. By repeating such a cycle, heat
from the heat generating component is transmitted to the display
unit effectively and discharged to the atmosphere.
[0022] The cooling medium heated through heat conduction from the
heat receiving portion is cooled via the intermediate cooling means
before it reaches the heat exchanging portion. Thus, the
temperature of the cooling medium introduced by the heat exchanging
portion can be lowered. Thus, the rise in temperature of the
surface of the display unit can be suppressed despite discharging
heat from the heat generating component from the display unit, so
that a bad influence upon user using the electronic apparatus can
be reduced to such a level having no problem.
[0023] In order to achieve the above-described second object,
according to a third aspect of the present invention, there is
provided an electronic apparatus comprising: a first housing
containing a heat generating component; a second housing, the
second housing being journaled detachably on a rear end of the
first housing through a hinge device having a hinge shaft extending
in the width direction of the first housing and having a rear face
which is directed backward of the first housing when the second
housing is rotated to a posture in which it stands up from the rear
end of the first housing; a heat receiving portion accommodated
inside the first housing and thermally connected to the heat
generating component; a heat exchanging portion installed on the
second housing, the heat exchanging portion being capable of being
taken out of the rear face; and circulating means for circulating
the cooling medium between the heat receiving portion and the heat
exchanging portion, the circulating means comprising a first pipe
line for introducing cooling medium heated by the heat receiving
portion to the heat exchanging portion and a second pipe line for
introducing cooling medium cooled by heat exchange by means of the
heat exchanging portion to the heat receiving portion, the first
and second pipe lines being disposed throughout the inside of the
first housing and the inside of the second housing via backward of
the hinge shaft, the rear face of the second housing having at
least an opening portion at a position corresponding to the first
and second pipe lines, the opening portion being covered with a
removable lid.
[0024] With such a structure, heat from the heat generating
component is transferred to the cooling medium by means of the heat
receiving portion. This heat is transferred to the heat exchanging
portion through the cooling medium flowing through the first pipe
line. The cooling medium cooled by heat exchange by the heat
exchanging portion is returned to the heat receiving portion
through the second pipe line and receives heat from the heat
generating component again. By repeating such a cycle, heat from
the heat generating component is transmitted effectively to the
second housing and discharged thereof to the atmosphere.
[0025] In order to remove the second housing from the first
housing, first, the lid covering the opening portion of the second
housing is removed so as to expose the first and second pipe lines
introduced to the interior of the second housing through the
opening portion. Subsequently, the heat exchanging portion is taken
out in the direction of the rear face of the second housing and the
first and second pipe lines continuous to this heat exchanging
portion are taken out of the opening portion. Consequently, with
the first and second pipe lines connected to the heat exchanging
portion, this heat exchanging portion can be taken out of the
second housing. Finally, the hinge device is removed from the first
housing so as to separate the second housing from the first
housing.
[0026] In order to install the second housing onto the first
housing, the second housing is installed onto the first housing
through the hinge device. After that, the heat exchanging portion
is installed on the second housing in the direction of the rear
face of the second housing. Next, the first and second pipe lines
continuous to the heat exchanging portion are inserted into the
second housing through the opening portion and then this opening
portion is covered with the lid. As a result, the first housing and
the second housing are connected to each other and the installation
of the heat exchanging portion onto the second housing is
completed.
[0027] Consequently, when removing the second housing from the
first housing, it is not necessary to release thermal connection
between the heat receiving portion and the heat generating
component. Thus, a troublesome work of disassembling or
reassembling portions corresponding to the heat generating
component and heat receiving portion is not required, so that the
removal of the second housing is facilitated. Further, no
unreasonable force is applied to the heat generating component or
the positional relationship between the heat generating component
and the heat receiving portion is not changed, thereby making it
possible to maintain reliability of thermal connection between the
both.
[0028] In order to achieve the above-described second object,
according to a fourth aspect of the present invention, there is
provided an electronic apparatus comprising: a housing
accommodating a heat generating component and being capable of
being opened upward; a display unit supported by the housing; a
heat receiving portion accommodated in the housing and thermally
connected to the heat generating component; a heat exchanging
portion installed on the display unit; and circulating means for
circulating cooling medium between the heat receiving portion and
the heat exchanging portion, the circulating means comprising a
first pipe line for introducing cooling medium heated by the heat
receiving portion to the heat exchanging portion and a second pipe
line for introducing cooling medium cooled by heat exchange by
means of the heat exchanging portion to the heat receiving portion,
the first and second pipe lines being disposed throughout the
inside of the housing and the inside of the display unit and being
divided to upstream portions and downstream portions inside the
housing, the upstream portions and the downstream portions being
connected detachably through a joint, the joint having closing
means for closing the first and second pipe lines when the first
and second pipe lines are divided to the upstream portions and the
downstream portions.
[0029] With such a structure, heat from the heat generating
component is transferred to cooling medium by the heat receiving
portion. This heat is transmitted to the heat exchanging portion
through the cooling medium flowing through the first pipe line.
Cooling medium cooled by heat exchange by means of the heat
exchanging portion is returned to the heat receiving portion
through the second pipe line and receives heat from the heat
generating component again. By repeating such a cycle, heat from
the heat generating component is transmitted to the second housing
effectively and discharge thereof to the atmosphere.
[0030] In order to remove the second housing from the first
housing, the first housing is opened upward so as to expose the
first and second pipe lines introduced to the interior of the first
housing. Next, the first and second pipe lines extending throughout
the heat receiving portion and the heat exchanging portion are
divided inside the first housing. Consequently, when removing the
second housing having the heat exchanging portion from the first
housing, the first and second pipe lines make no obstacle and the
thermal connection between the heat receiving portion and the heat
generating component does not have to be released. As a result, a
troublesome work of disassembling/reassembling portions
corresponding to the heat generating component and heat receiving
portion is not required, so that the removal of the second housing
is facilitated. Further, no unreasonable force is applied to the
heat generating component or the positional relationship between
the heat generating component and the heat receiving portion is not
changed, so that reliability of thermal connection between the both
can be maintained.
[0031] Further, if the upstream portions and the downstream
portions of the first and second pipe lines are separated from each
other, the first and second pipe lines are automatically closed.
Therefore, no cooling medium leaks from the first and second pipe
lines and thus, no special work for sealing the first and second
pipe lines is required.
[0032] Additional objects and advantages of the invention will be
set forth in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0033] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiment of
the invention, and together with the general description given
above and the detailed description of the embodiment given below,
serve to explain the principles of the invention.
[0034] FIG. 1 is a perspective view of a portable computer
according to a first embodiment of the present invention;
[0035] FIG. 2 is a perspective view of a lid for covering an
opening portion in a display housing according to the first
embodiment of the present invention;
[0036] FIG. 3 is a sectional view of the portable computer having a
liquid-cooling type cooling unit according to the first embodiment
of the present invention;
[0037] FIG. 4 is a sectional view of the portable computer
indicating a second pipe line insertion path when the display unit
is rotated to its opening position in the first embodiment of the
present invention;
[0038] FIG. 5 is a sectional view of the portable computer
indicating a joint structure between the computer main body and the
display unit according to the first embodiment of the present
invention;
[0039] FIG. 6 is a sectional view of the portable computer
indicating the second pipe line insertion path when the display
unit is rotated to its closing position in the first embodiment of
the present invention;
[0040] FIG. 7 is a sectional view of the portable computer
indicating a state in which the lid thereof is removed from the
display housing in the first embodiment of the present
invention;
[0041] FIG. 8 is a sectional view showing a positional relationship
between a heat receiving head and a semiconductor package in the
first embodiment of the present invention;
[0042] FIG. 9 is a sectional view of the heat receiving head
indicating the structure of inside of a heat transmitting case in
the first embodiment of the present invention;
[0043] FIG. 10 is a sectional view of a heat radiator for use in
the first embodiment of the present invention;
[0044] FIG. 11 is a sectional view of an intermediate cooling unit
indicating the positional relationship between a refrigerant path
and a cooling air path in the first embodiment of the present
invention;
[0045] FIG. 12 is a flow chart showing electric fan control system
of the first embodiment of the present invention;
[0046] FIG. 13 is a sectional view of the portable computer
indicating a state in which the heat radiator is removed form the
display housing in the first embodiment of the present
invention;
[0047] FIG. 14 is a perspective view of the portable computer
according to a second embodiment of the present invention;
[0048] FIG. 15 is a perspective view of the portable computer
according to a third embodiment of the present invention;
[0049] FIG. 16 is a sectional view of the portable computer having
a liquid cooling type cooling unit according to a fourth embodiment
of the present invention;
[0050] FIG. 17 is a perspective view of a holder for maintaining an
interval between a first pipe line and a second pipe line constant
in the fourth embodiment of the present invention;
[0051] FIG. 18A is a sectional view of a joint indicating a state
in which a first joint portion and a second joint portion are
joined together in the fourth embodiment of the present invention;
and
[0052] FIG. 18B is a sectional view of the joint indicating a state
in which the first joint portion and the second joint portion are
separated from each other in the fourth embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0053] Hereinafter, the first embodiment of the present invention
applied to a portable computer will be described with reference to
FIGS. 1 to 13.
[0054] FIGS. 1 and 3 show a portable computer 1 which is an
electronic apparatus mentioned in this specification. The portable
computer 1 comprises a computer main body 2 and a display unit 3,
which is supported by this computer main body 2.
[0055] The computer main body 2 has a first housing 4 of synthetic
resin. The first housing 4 is a flat box comprising a bottom wall
4a, an upper wall 4b, right/left side walls 4c, a front wall 4d and
a rear wall 4e. The first housing 4 is composed of a base 5 having
the bottom wall 4a and a top cover 6 having the upper wall 4b. The
top cover 6 is installed detachably to the base 5. Thus, by
removing the top cover 6 from the base 5, the first housing 4 is
opened upward.
[0056] A hallow convex portion 8 protruded upward is formed at a
rear end portion of the upper wall 4b of the first housing 4. The
convex portion 8 is extended in the width direction of the first
housing 4 behind a keyboard 9. The convex portion 8 has display
supporting portions 10a and 10b on both ends thereof. The display
supporting portions 10a and 10b are constructed in the form of a
dent open continuously forward, upward and backward of the convex
portion 8. The bottom of each of the display supporting portions
10a and 10b is located downward of the upper wall 4b as shown in
FIG. 4.
[0057] As shown in FIGS. 3 and 4, a circuit board 11 is
accommodated inside the first housing 4. The circuit board 11 is
disposed in parallel to the bottom wall 4a of the first housing 4.
A semiconductor package 12 is installed at a left end portion of
the top face of the circuit board 11 as a heat generating
component.
[0058] The semiconductor package 12 composes a micro processing
unit (MPU), which serves as the center of the portable computer 1.
As shown in FIG. 8, the semiconductor package 12 includes a
rectangular base substrate 13 and an IC chip 14 soldered on the top
face of this base substrate 13. The base substrate 13 is soldered
to the top face of the circuit board 11 through plural soldering
balls 15. In this kind of the semiconductor package 12, its power
consumption during operation has been increased accompanied by
currently intensified processing speed and multiple functions, so
that heat generation from the IC chip 14 has become so large that
cooling of the chip is required.
[0059] As shown in FIGS. 1 and 3, the display unit 3 comprises a
display housing 17 serving as a second housing and a liquid crystal
display panel 18 accommodated in this display housing 17. The
display housing 17 is composed of, for example, synthetic resin
material and constructed in the form of a thin flat box having a
front face 20 in which an opening portion 19 is formed and a rear
face 21 opposing this front face 20. The liquid crystal display
panel 18 has a display screen (not shown) for displaying
information such as characters and pictures. This display screen is
exposed out of the display housing 17 through the opening portion
19.
[0060] The display housing 17 has a pair of leg portions 23a and
23b protruded from an end portion thereof. The leg portions 23a and
23b are hallow and apart from each other in the width direction of
the display housing 17. The leg portions 23a and 23b are introduced
to the display supporting portions 10a and 10b in the first housing
4.
[0061] The right leg portion 23a is supported by the first housing
4 via a hinge device 24. The hinge device 24 comprises a first
bracket 25, a second bracket 26 and a hinge shaft 27. As shown in
FIG. 5, the first bracket 25 is screwed to a top end of plural boss
portions 28 extended upward from the bottom wall 4a. A rear end
portion of the first bracket 25 is introduced to inside of the
convex portion 8 on the right side of the display supporting
portion 10a. As shown in FIG. 4, the second bracket 26 is screwed
to an inside face at the right end of the front face 20 of the
display housing 17. An end portion of the second bracket 26 is
introduced into inside of the right leg portion 23a. The hinge
shaft 27 is stretched between the rear end portion of the first
bracket 23a and the end portion of the second bracket 26 such that
it passes through a side face of the leg portion 23a and a side
face of the display supporting portion 10a. For the reason, the
hinge shaft 27 is disposed horizontally along the width direction
of the first housing 4 and the display housing 17.
[0062] An end portion of the hinge shaft 27 is rotatably coupled
with the rear end portion of the first bracket 25. The other end
portion of the hinge shaft 27 is fixed to the end portion of the
second bracket 26. A friction type brake mechanism (not shown)
employing, for example, a wave washer is built in a joint portion
between the hinge shaft 27 and the first bracket 25. This brake
mechanism limits a free rotation of the hinge shaft 27.
[0063] Thus, the display unit 3 is rotatable around the hinge shaft
27. If speaking more in detail, the display unit 3 is supported on
the first housing 4 rotatably with respect to the hinge shaft 27
from a closing position in which the same display unit 3 is tilted
down so as to cover the key board 9 to an opening position in which
it is raised so as to expose the key board 9 and the display
screen. When the display unit 3 is turned to the opening position,
the rear face 21 of the display housing 17 is directed rearward of
the portable computer 1.
[0064] As shown in FIG. 3, the portable computer 1 incorporates a
liquid cooling type cooling unit 30 for forcing the semiconductor
package 12 to be cooled. The cooling unit 30 comprises a heat
receiving head 31 as a heat receiving portion, a heat radiator 32
as a heat exchanging portion and a circulation path 33 as
circulating means.
[0065] As shown in FIGS. 8 and 9, the heat receiving head 31 is
accommodated in the first housing 4. This heat receiving head 31
has a heat transmitting case 34. The heat transmitting case 34 is
composed of metal material having an excellent thermal conductivity
like aluminum alloy. This heat transmitting case 34 is constructed
in the form of a thin flat box having a plane larger than the
semiconductor package 12.
[0066] The heat transmitting case 34 contains plural guide walls 35
inside. The guide walls 35 are disposed in parallel to each other
with an interval between one and another, so that the inside of the
heat transmitting case 34 is divided to plural refrigerant flow
paths 36. The heat transmitting case 34 has a refrigerant intake 37
and a refrigerant outlet 38. The refrigerant intake 37 is located
at an upstream end of the refrigerant flow paths 36. The
refrigerant outlet 38 is located at a downstream end of the
refrigerant flow paths 36.
[0067] The heat transmitting case 34 is supported on the top face
of the circuit board 11 via its four corner portions with screws
39. This heat transmitting case 34 opposes the circuit board 11
across the semiconductor package 12. A heat transmitting sheet 40
is disposed between the central portion on the bottom face of the
heat transmitting case 34 and the IC chip 14 of the semiconductor
package 12. The heat transmitting case 34 is pressed against the IC
chip 14 through a leaf spring 41 so that the heat transmitting
sheet 40 is sandwiched between the heat transmitting case 34 and
the IC chip 14. Thus, the heat transmitting case 34 is thermally in
contact with the IC chip 14 through the heat transmitting sheet
40.
[0068] As shown in FIGS. 3 and 4, the heat radiator 32 is
accommodated inside the display housing 17. The heat radiator 32
has the first and second heat radiating plates 43a and 43b. The
first and second heat radiating plates 43a and 43b are composed of
metal material having an excellent thermal conductivity like for
example aluminum alloy and have substantially the same size as the
liquid crystal display panel 18.
[0069] As shown in FIG. 10, the first heat radiating plate 43a and
the second heat radiating plate 43b are overlaid over each other.
The second heat radiating plate 43b has a concave portion 44, which
is open to a matching face with the first heat radiating plate 43a.
The concave portion 44 is formed meanderingly on substantially
entire surface of the second heat radiating plate 43b. The concave
portion 44 forms a radiated heat path 45 with the matching face
with the first heat radiating plate 43a. The radiated heat path 45
has a refrigerant intake 46 and a refrigerant outlet 47. The
refrigerant intake 46 is open to the left leg portion 23b inside
the display housing 17. The refrigerant outlet 47 is open to the
right leg portion 23a inside the display housing 17. Thus, the
refrigerant intake 46 and the refrigerant outlet 47 are apart from
each other in the width direction of the display housing 17.
[0070] The aforementioned circulation path 33 has a first pipe line
50 and a second pipe line 51. The first and second pipe lines 50
and 51 are composed of metallic pipe of, for example,
stainless.
[0071] The first pipe line 50 connects the refrigerant outlet 38 of
the heat receiving head 31 to the refrigerant intake 46 of the heat
radiator 32. The first pipe line 50 is extended toward the display
supporting portion 10b on the left inside the first housing 4.
After a front end of this first pipe line 50 passes through a front
face of the display supporting portion 10b and a front face of the
leg portion 23b on the left, it is introduced into the display
housing 17.
[0072] The second pipe line 51 connects the refrigerant intake 37
of the heat receiving head 31 to the refrigerant outlet 47 of the
heat radiator 32. After the second pipe line 51 is introduced to
the right side along the front wall 4d inside the first housing 4,
it is extended toward the display supporting portion 10a on the
right. After a front end of the second pipe line 51 passes through
a front face of the display supporting portion 10a and a front face
of the leg portion 23a on the right, it is introduced to the leg
portion 23b and then introduced into the display housing 17.
[0073] Therefore, the refrigerant flow paths 36 of the heat
receiving head 31 is connected to the radiated heat path 45 of the
heat radiator 32 through the first and second pipe lines 50 and 51.
The refrigerant flow path 36, the radiated heat path 45 and the
first/second pipe lines 50 and 51 are filled with liquid-like
cooling medium like water or fluorocarbon.
[0074] As shown in FIGS. 3 and 5, of the first and second pipe
lines 50 and 51, portions passing through the leg portions 23a and
23b of the display housing 17 are composed of an expandable bellows
pipe 52 having a flexibility. The bellows pipes 52 are curved in
the form of a circle around the hinge shaft 27 and disposed behind
this hinge shaft 27.
[0075] Thus, the bellows pipes 52 of the first and second pipe
lines 50 and 51 are deformable freely in a direction around the
hinge shaft 27. Consequently, the first and second pipe lines 50
and 51 are deformed smoothly following a rotation of the display
unit 3 when it is rotated from its closing position to its opening
position, so as to absorb a curve applied to the first and second
pipe lines 50 and 51 when the display unit 3 is rotated.
[0076] As shown in FIG. 1, the display housing 17 has a mounting
port 54, which is open in the rear face 21 thereof. The mounting
port 54 is located behind the liquid crystal display panel 18 and
has a size fitting to the heat radiator 32. The first heat
radiating plate 43a of the heat radiator 32 has a lower edge
portion adjacent the leg portions 23a and 23b of the display
housing 17 and an upper edge portion located on an opposite side to
this lower edge portion. A pair of fitting pawls 55a and 55b are
formed on the upper edge portion of the first heat radiating plate
43a. These fitting pawls 55a and 55b are apart from each other in
the width direction of the display housing 17.
[0077] The heat radiator 32 is fit to the mounting port 54 from the
rear face 21 of the display housing 17. Consequently, the fitting
pawls 55a and 55b of the heat radiator 32 are hooked on the opening
edge portion of the mounting port 54 detachably. Further, the first
and second heat radiating plates 43a and 43b are fixed to an inside
face of the display housing 17 through two positions on the lower
edge portion with screws 56. Thus, the heat radiator 32 is
maintained such that it is in contact with the inside face of the
display housing 17 so that it is thermally connected to the display
housing 17.
[0078] As shown in FIG. 4, an opposite surface to the second heat
radiating plate 43b of the first heat radiating plate 43a of the
heat radiator 32 is covered with protective layer 57. The
protective layer 57 is composed of synthetic resin having lower
thermal conductivity than the first and second heat radiating
plates 43a and 43b. This protective layer 57 is exposed out of the
display housing 17 through the mounting port 54 when the heat
radiator 32 is fixed to the display housing 17 and further, located
on the same plane as the rear face 21 of the display housing
17.
[0079] As shown in FIG. 1, the rear face 21 of the display housing
17 has a pair of opening portions 60a and 60b at positions
corresponding to the leg portions 23a and 23b. The opening portions
60a and 60b oppose the bellows pipes 52 in the first and second
pipe lines 50 and 51. Ends of the opening portions 60a and 60b
reach the front ends of the leg portions 23a and 23b while the
other ends of the opening portions 60a and 60b are continuous to
the mounting port 54. Thus, the opening portions 60a and 60b are
large enough to take out the bellows pipes 52.
[0080] The opening portions 60a and 60b are covered with lids 61 of
synthetic resin which can be removed. The lids 61 are fit to the
opening portions 60a and 60b so that the fitting pawl 62 of each
end thereof is hooked on the aforementioned heat radiator 32. The
other ends of the lids 61 are fixed to the front ends of the leg
portions 23a and 23b through a screw 63.
[0081] Thus, if engagement between the fitting pawl 62 and the heat
radiator 32 is released by removing the screw 63 as shown in FIG.
7, the lids 61 can be removed from the display housing 17 so as to
open the opening portions 60a and 60b. As a result, the bellows
pipes 52 inserted inside the leg portions 23a and 23b are exposed
toward the rear face 21 of the display housing 17 through the
opening portions 60a and 60b.
[0082] As shown in FIGS. 3, 11, the aforementioned cooling unit 30
is equipped with an intermediate cooling unit 70 as intermediate
cooling means. The intermediate cooling unit 70 is located halfway
of the first pipe line 50 and accommodated inside the first housing
4. The intermediate cooling unit 70 comprises a main body 71 and an
electric fan 90.
[0083] The main body 71 is composed of metallic material having an
excellent thermal conductivity like for example, aluminum alloy and
screwed to a top face on the left end portion of the circuit board
11. The main body 71 has a first concave portion 72, which is open
downward. The opening end of the first concave portion 72 is sealed
with a bottom plate 73. The bottom plate 73 forms a refrigerant
path 74 in cooperation with the first concave portion 72 and this
refrigerant path 74 is extended in the depth direction of the first
housing 4.
[0084] A pump 76 and an accumulator 77 are built in the main body
71 of the intermediate cooling unit 70 integratedly. A suction end
of the pump 76 is continuous to the refrigerant outlet 38 of the
heat receiving head 31 through an upstream portion of the first
pipe line 50. A discharge end of the pump 76 is continuous to the
refrigerant path 74 through the accumulator 77. This pump 76 is
driven at the same time when the portable computer 1 is powered on
and then pressurizes cooling medium and supplies to the accumulator
77.
[0085] As shown in FIG. 11, the accumulator 77 has a pressure
accumulating chamber 78 for accumulating cooling medium discharged
from the pump 76. The pressure accumulating chamber 78 is formed on
a side portion of the main body 71. Part of the peripheral wall of
this pressure accumulating chamber 78 is constructed of diaphragm
79 elastically deformable. If cooling medium discharged from the
pump 76 is supplied to the pressure accumulating chamber 78, the
diaphragm 79 is elastically deformed corresponding to a discharging
pressure of the cooling medium so that the capacity of the pressure
accumulating chamber 78 is changed. As a result, pulsation of the
cooling medium accompanied by driving of the pump 76 is absorbed so
as to adjust the discharging pressure of the cooling medium to a
constant level. This cooling medium is supplied to the refrigerant
path 74 through a communicating port 80 formed in the main body 71.
The refrigerant path 74 communicates with a refrigerant outlet 81
formed in the main body 71. The refrigerant outlet 81 is connected
to the refrigerant intake 46 of the heat radiator 32 through a
downstream portion of the first pipe line 50.
[0086] Therefore, cooling medium supplied to the refrigerant path
74 in the intermediate cooling unit 70 from the pump 76 is
introduced to the heat radiator 32 through the downstream portion
of the first pipe line 50. After this cooling medium flows through
the radiated heat path 45 in the heat radiator 32, it is introduced
to the heat receiving head 31 through the second pipe line 51 and
from here, it is returned to an absorption end of the pump 76
through the upperstream portion of the first pipe line 50. Thus,
the cooling medium is forced to circulate between the heat
receiving head 31 and the heat radiator 32.
[0087] As shown in FIG. 11, the main body 71 has a second concave
portion 83, which is open upward. The opening end of the second
concave portion 83 is sealed with a head plate 84. The head plate
84 forms a cooling air path 85 in cooperation with the second
concave portion 83. The cooling air path 85 adjoins the refrigerant
path 74 beyond the main body 71 and is thermally connected to this
refrigerant path 74. The cooling air path 85 is extended in the
width direction of the first housing 4. This cooling air path 85
has a cooling air outlet 86. The cooling air outlet 86 opposes an
exhaust port 87, which is open in the side wall 4c on the left side
of the first housing 4.
[0088] The main body 71 has a plurality of heat radiating fins 88
protruded from a bottom of the second concave portion 83. These
heat radiating fins 88 face the cooling air path 85 such that they
are extended linearly along the cooling air path 85.
[0089] As shown in FIG. 3, the aforementioned electric fan 90 is
built in the main body 71 integratedly. The electric fan 90 is
located on an opposite side to the cooling air outlet 86 of the
cooling air path 85 so as to feed cooling air through the cooling
air path 85. According to this embodiment, the electric fan 90 is
driven when the temperature of the semiconductor package 12 and the
temperature of the display housing 17 arrive at respective
predetermined values. Thus, the heat receiving head 31 thermally
connected to the semiconductor package 12 and the heat radiator 32
are equipped with temperature sensors 91a and 91b respectively. The
electric fan 90 is driven according to temperature signals from the
temperature sensors 91a and 91b.
[0090] Next, a cooling operation of the semiconductor package 12
will be described with reference to FIG. 12.
[0091] As shown in FIG. 12, power of the portable computer 1 is
turned on in step S1. Consequently, in step S2, the pump 76 of the
cooling unit 30 is driven so that circulation of the cooling medium
between the heat receiving head 31 and the heat radiator 32 is
started.
[0092] If the IC chip 14 of the semiconductor package 12 is heated
during an operation of the portable computer 1, heat of the IC chip
14 is transmitted to the heat transmitting case 34 of the heat
receiving head 31. Heat of the IC chip 14 transmitted to the heat
transmitting case 34 is transferred to cooling medium flowing
through the refrigerant flow paths 36. After heat exchange at the
heat receiving head 31, heated cooling medium is introduced to the
heat radiator 32 through the upstream portion of the first pipe
line 50, the refrigerant path 74 in the intermediate cooling unit
70 and the downstream portion of the first pipe line 50. Thus, heat
of the IC chip 14 is transferred to the heat radiator 32 through a
flow of the cooling medium.
[0093] The cooling medium introduced to the heat radiator 32 flows
through the meandering radiated heat path 45. In this flow process,
heat absorbed in the cooling medium is transmitted to the first and
second heat radiating plates 43a and 43b. Part of heat transmitted
to the first and second heat radiating plates 43a and 43b is
diffused by heat transfer to the display housing 17 so that it is
discharged into the atmosphere from the surface of the display
housing 17.
[0094] The protective layer 57 covering the first heat radiating
plate 43a is exposed out of the display housing 17 through the
mounting port 54 in the rear face 21 of the display housing 17.
Therefore, most of heat transmitted to the first heat radiating
plate 43a is discharged into the atmosphere from the surface of the
protective layer 57.
[0095] Cooling medium cooled by heat exchange by means of the heat
radiator 32 is returned to the absorbing end of the pump 76 through
the second pipe line 52. After this cooling medium is pressurized
by the pump 76, it is supplied to the refrigerant flow paths 36 of
the heat receiving head 31 through the accumulator 77.
[0096] While the portable computer 1 remains powered on, the
temperatures of the semiconductor package 12 and the display
housing 17 are monitored by the temperature sensors 91a and 91b.
Thus, as long as the portable computer 1 is powered on, in step S3,
the temperature of the semiconductor package 12 is being checked.
When the temperature of this semiconductor package 12 reaches a
predetermined level, the processing proceeds to step S4, in which
the electric fan 90 of the intermediate cooling unit 70 is
started.
[0097] If the electric fan 90 is driven, air inside the first
housing 4 is turned to cooling air and then fed to the cooling air
path 85. Because the cooling air path 85 is thermally connected to
the refrigerant path 74, part of heat in the cooling medium flowing
through this refrigerant path 74 is taken away by flow of cooling
air flowing through the cooling air path 85 and discharged out of
the first housing 4 through the exhaust port 87. Thus, the cooling
medium heated by the heat receiving head 31 is cooled before it
reaches the heat radiator 32, thereby the temperature of the
cooling medium fed to the heat radiator 32 being kept low.
[0098] Unless the temperature of the semiconductor package 12
checked in step S3 reaches the predetermined value, the processing
proceeds to step S5, in which the temperature of the display
housing 17 is checked. Because the pump 76 of the intermediate
cooling unit 70 continues to be driven as long as the portable
computer 1 remains powered on, the cooling medium continues to
transfer heat of the semiconductor package 12 to the display
housing 17. Thus, even if the temperature of the semiconductor
package 12 does not reach the predetermined value, when the
temperature of the display housing 17 reaches the predetermined
value, the processing proceeds to step S4, in which the electric
fan 90 is started.
[0099] Consequently, part of heat in the cooling medium flowing
through the refrigerant path 74 is taken away by a flow of cooling
air flowing through the cooling air path 85. As a result, the
temperature of cooling medium fed to the heat radiator 32 drops, so
that the amount of heat transferred from the heat radiator 32 to
the display housing 17 decreases.
[0100] After the driving of the electric fan 90 is started also,
the temperatures of the semiconductor package 12 and the display
housing 17 continue to be checked in steps S6, S7. Here, if it is
determined that the temperatures of the semiconductor package 12
and the display housing 17 are over the predetermined value, the
processing proceeds to step S8. In step S8, processing speed of the
semiconductor package 12 is reduced temporarily so as to reduce
power consumption of the semiconductor package 12 thereby
suppressing generation of heat in the IC chip 14.
[0101] According to such a portable computer 1, cooling medium is
forced to circulate between the heat receiving head 31 and the heat
radiator 32 so as to transfer heat of the semiconductor package 12
to the display housing 17 effectively and discharge it into the
atmosphere. Therefore, as compared to the conventional ordinary
forced air cooling system, heat radiation of the semiconductor
package 12 can be raised thereby making it possible to correspond
to increase of generation of heat reasonably.
[0102] Further, according to the above-described structure, the
cooling medium heated by the heat receiving head 31 is cooled
through the intermediate cooling unit 70 before it reaches the heat
radiator 32. Thus, the temperature of the cooling medium fed to the
heat radiator 32 can be lowered so that a rise of the surface
temperature of the display housing 17 receiving heat of the heat
radiator 32 can be suppressed. Thus, if an operator touch the
surface of the display housing 17 with his hand when for example,
adjusting the standing angle of the display unit 3 or carrying the
portable computer 1, he never feels a sudden of heat, thereby
making it possible to lower a thermal influence of the portable
computer 1 upon the human body during use.
[0103] At the same time when the portable computer 1 is powered on,
circulation of cooling medium is started so as to transfer heat of
the semiconductor package 12 to the heat radiator 32. Thus, at the
time of low/medium load in which the temperature of the
semiconductor package 12 is not raised so much, it is possible to
stop operation of the electric fan 90 or suppress the rotation
speed, thereby enabling a silent operation.
[0104] Further, because the pump 76 and the accumulator 77 are
built in the main body 71 of the intermediate cooling unit 70, a
structure containing a movable portion can be handled as a single
unit. Thus, incorporation of the cooling unit 30 into the first
housing 4 can be facilitated, thereby improving operation
efficiency of assembly of the portable computer 1.
[0105] Additionally, the first pipe line 50 for introducing cooling
medium heated by the heat receiving head 31 to the heat radiator 32
and the second pipe line 51 for returning cooling medium cooled by
the heat radiator 32 to the heat receiving head 31 are disposed on
the left and right leg portions 23a and 23b of the display housing
17. Thus, at portions where the first and second pipe lines 50 and
51 are stretched between the first housing 4 and the display
housing 17, these first and second pipe lines 50 and 51 can be kept
apart from each other so as to separate them thermally. Thus, it is
possible to prevent an undesired heat exchange between the first
pipe line 50 and the second pipe line 51, thereby raising heat
transfer efficiency from the heat receiving head 31 to the heat
radiator 32.
[0106] On the other hand, a procedure for removing the display unit
3 from the first housing 4 in the portable computer 1 having the
above-described structure will be described.
[0107] First, as shown in FIG. 6 the display unit 3 is rotated to
the closing position, so that the screws 63 which fix the lids 61
are exposed rearward of the display supporting portions 10a and
10b. Next, the screws 63 are loosened so as to release fixing of
the lids 61 with these screws 63. After that, engagement between
the fitting pawl 62 and the heat radiator 32 is released and the
lids 61 are removed from the display housing 17. Consequently, as
shown in FIG. 7, the opening portions 60a and 60b are opened so
that the bellows pipes 52 inserted inside the leg portions 23a and
23b are exposed toward the rear face 21 of the display housing 17
through the opening portions 60a and 60b.
[0108] Next, the screws. 56 which fix the first and second heat
radiating plates 43a and 43b to the display housing 17 are loosened
so as to release engagement between the heat radiator 32 and the
display housing 17. Subsequently, the fitting pawls 55a and 55b of
the heat radiator 32 are separated from the opening edge portion of
the mounting port 54 and then, this heat radiator 32 is taken out
in the direction of the rear face 21 of the display housing 17
through the mounting port 54. This procedure for taking out this
heat radiator 32 can be carried out irrespective of whether the
display unit 3 is rotated to its closing position or the opening
position.
[0109] Because the opening portions 60a and 60b are continuous to
the mounting port 54, the first and second pipe lines 50 and 51
continuous to this heat radiator 32 are pulled out of the opening
portions 60a and 60b rearward of the leg portions 23a and 23b at
the same time when the heat radiator 32 is taken out of the
mounting port 54. Because at this time, the second pipe line 51 is
disposed behind the hinge shaft 27, the hinge shaft 27 never
becomes an obstacle when taking the second pipe 51 out of the leg
portion 23a.
[0110] Thus, with the first and second pipe lines 50 and 51
connected to the heat radiator 32 as shown in FIG. 13, the heat
radiator 32 can be pulled out rearward of the display housing
17.
[0111] Next, by taking the top cover 6 of the first housing 4 out
of the base 5, the first bracket 25 of the hinge device 24 fixed to
this base 5 is exposed. Finally, the fixing between the first
bracket 25 and the boss portion 28 with the screws is released and
the display unit 3 is taken out upward of the base 5 together with
the hinge device 24. Thus, the display unit 3 and the computer main
body 2 can be separated from each other.
[0112] When mounting the display unit 3 onto the computer main body
2, the first bracket 25 of the hinge device 24 is screwed to the
boss portion 28 of the base 5 before the top cover 6 is mounted on
the base 5. After that, the top cover 6 is mounted on the base 5 so
as to cover the first bracket 25 with this top cover 6.
[0113] Next, the heat radiator 32 is fitted with the mounting port
54 in the rear face 21 of the display housing 17, so that the
fitting pawls 55a and 55b of the first heat radiating plate 43a are
hooked on the opening edge portion of the mounting port 54.
Further, the lower edge portions of the first and second heat
radiating plates 43a and 43b are fixed to the display housing 17
with the screws 56. Subsequently, the first and second pipe lines
50 and 51 continuous to the heat radiator 32 are inserted inside
the leg portions 23a and 23b through the opening portions 60a and
60b.
[0114] Finally, the lids 61 are fitted with the opening portions
60a and 60b and these lids 61 are fixed to the leg portions 23a and
23b with the screws 63. Consequently, the computer main body 2 and
the display unit 3 are coupled with each other rotatably, so that
the incorporation of the heat radiator 32 in the display housing 17
is completed.
[0115] With such a structure, the heat radiator 32 accommodated in
the display housing 17 can be taken out of the rear face 21 of the
display housing 17 together with the first and second pipe lines 50
and 51. Thus, with the heat radiator 32 taken out of the display
housing 17, the display unit 3 can be taken out of the first
housing 4 or installed to the first housing 4.
[0116] Therefore, when attaching/detaching the display unit 3
to/from the first housing 4, it is not necessary to release thermal
connection between the heat receiving head 31 and the semiconductor
package 12 or thermally connect again, so that the procedure for
disassembly/assembly of the thermally connecting portion between
the heat receiving head 31 and the semiconductor package 12 is not
required.
[0117] Thus, no unreasonable force is applied to the precision
semiconductor package 12 or the positional. relationship between
the semiconductor package 12 and the heat receiving head 31 is not
changed, so that reliability of heat conduction can be maintained
favorably.
[0118] Further, the bellows pipe 52 in the second pipe line 51 is
disposed behind the hinge shaft 27 inside the leg portion 23a.
Thus, the curvature of the bellows pipe 52 when the display unit 3
is rotated to the closing position can be suppressed to be small as
shown in FIG. 5. As a result, when the display unit 3 is rotated,
an unreasonable bending force is not applied to the bellows pipe 52
thereby improving the durability of the bellows pipe 52.
[0119] Meanwhile, according to the first embodiment, when the
temperature of the semiconductor package and the temperature of the
display housing reach their predetermined values, the electric fan
is started. However, the present invention is not restricted to
this. For example, it is permissible to adjust the air amount of
the cooling air or the flow amount of the cooling medium according
to a temperature signal outputted from the temperature sensor.
[0120] Further, the pump and accumulator do not always have to be
built together with the intermediate cooling unit and the pump and
accumulator may be installed halfway of the second pipe line.
Because with this structure, cooling medium cooled by the radiator
is introduced to the pump and accumulator, thermal influence upon
the pump and accumulator can be suppressed thereby improving the
reliability of the operation.
[0121] The present invention is not restricted to the
above-described first embodiment. A second embodiment of the
present invention shown in FIG. 14 will be described.
[0122] The second embodiment is different from the first embodiment
in that the lids 61 which cover the opening portions 60a and 60b in
the leg portions 23a and 23b are connected to each other through a
connecting panel 100. Other basic structure of the portable
computer 1 is the same as the first embodiment.
[0123] The connecting panel 100 is an elongated plate extending in
the width direction of the display housing 17. The connecting panel
100 is fitted detachably in an end portion adjacent the leg
portions 23a and 23b of the mounting port 54 of the display housing
17 and functions as a cover portion for covering this mounting port
54 partially. This connecting panel 100 is located on the same
plane as the rear face 21 of the display housing 17 and the
protective layer 57 of the heat radiator 32.
[0124] FIG. 15 shows a third embodiment of the present
invention.
[0125] This third embodiment is a further development of the second
embodiment. According to the third embodiment, a connecting panel
110 for connecting the lids 61 is large enough to cover the
mounting port 54 entirely. The connecting panel 110 is fit to the
mounting port 54 detachably such that it is overlaid on the first
heat radiating plate 43a of the heat radiator 32 supported by the
display housing 17. Thus, the first heat radiating plate 43a of the
heat radiator 32 is not equipped with any protective layer like
shown in the first embodiment and this connecting panel 110
functions a protective layer which covers the first heat radiating
plate 43a.
[0126] Further, FIGS. 16-18 show a fourth embodiment of the present
invention.
[0127] According to the fourth embodiment, the structure of a
cooling unit 120 for cooling mainly the semiconductor package 12 is
different from that of the first embodiment and other basic
structure of the portable computer 1 is the same as the first
embodiment. Thus, for the fourth embodiment, like reference
numerals are attached to the same component as the first embodiment
and a description thereof is omitted.
[0128] As shown in FIG. 16, the convex portion 8 located at the
rear end portion of the first housing 4 is so constructed that both
ends thereof are located inside in the width direction of the first
housing 4 with respect to the side wall 4c of the first housing 4.
At the rear end portion of the first housing 4 are formed a pair of
display supporting portions 121a and 121b which are specified by
both end faces of the convex portion 8 and a top face of the upper
wall 4b.
[0129] The leg portions 23a and 23b of the display housing 17 are
introduced to the display supporting portions 121a and 121b. These
leg portions 23a and 23b have side faces opposing both end faces of
the convex portion 8.
[0130] The hinge shaft 27 of the hinge device 24 is extended
horizontally such that it passes through the right end face of the
convex portion 8 and the right side face of the leg portion 23a.
The leg portion 23b located on the left opposite to the hinge
device 24 has a cylindrical guide 122 protruded from a side face
thereof toward the left end face of the convex portion 8. The guide
122 passes through the left end face of the convex portion 8
rotatably such that it is open inside the convex portion 8. Thus,
the inside of the first housing 4 and the inside of the display
housing 17 communicate with each other through the guide 122 and
the left leg portion 23b.
[0131] The cooling unit 120 for cooling the semiconductor package
12 comprises a heat receiving head 31 accommodated inside the first
housing 4, a heat radiator 123 accommodated inside the display
housing 17 and a circulating path 124 for connecting the heat
receiving head 31 and the heat radiator 123.
[0132] The heat radiator 123 has a flat heat radiating plate 125
and a meanderingly bent heat radiating pipe 126. The heat radiating
plate 125 is composed of, for example, metallic material having
excellent heat conductivity like aluminum alloy. The heat radiating
plate 125 is fixed to an inside face of the display housing 17
behind the liquid crystal display panel 18 with fixing means such
as screws, adhesive agent and the like, so that it is thermally
connected to the display housing 17.
[0133] The heat radiating pipe 126 is composed of aluminum alloy or
copper base metallic material having an excellent heat
conductivity. The heat radiating pipe 126 is fixed to the heat
radiating plate 125 by bonding or soldering means so that it is
thermally connected to this heat radiating plate 126. The heat
radiating pipe 126 is equipped with a refrigerant intake 127 and a
refrigerant outlet 128. The refrigerant intake 127 and the
refrigerant outlet 128 are located at the left end portion of the
heat radiator 123.
[0134] The circulating path 124 includes a first pipe line 130 and
a second pipe line 131. These pipe lines 130 and 131 are composed
of flexible material like silicone resin, for example. The first
pipe line 130 is intended for connecting the refrigerant outlet 38
of the heat receiving head 31 to the refrigerant intake 127 of the
heat radiating pipe 126. After introduced to the left end portion
of the convex portion 8 inside the first housing 4, this first pipe
line 130 is introduced into the display housing 17 through the
guide 122 and the inside of the leg portion 23b on the left. The
second pipe line 131 is intended for connecting the refrigerant
outlet 128 of the heat radiating pipe 126 to the refrigerant intake
37 of the heat receiving head 31. After introduced to the left end
portion of the convex portion 8 inside the first housing 4, the
second pipe line 131 is introduced to the inside of the display
housing 17 through the guide 122 and the leg portion 23b on the
left side.
[0135] Thus, the refrigerant flow paths 36 of the heat receiving
head 31 is connected to the heat radiating pipe 126 of the heat
radiator 123 through the first and second pipe lines 130 and 131.
The refrigerant flow paths 36, the heat radiating pipe 126 and the
first/second pipe lines 130 and 131 are filled with liquid-like
cooling medium.
[0136] A pump 132 is installed halfway of the second pipe line 131.
When the power of the portable computer 1 is turned on, the pump
132 is started so as to send out cooling medium to the heat
receiving head 31. As a result, the cooling medium is introduced to
the heat radiator 123 from the heat receiving head 31 through the
first pipe line 130 and after flowing through the heat radiating
pipe 126 in this heat radiator 132, returned to the pump 132
through the second pipe line 131.
[0137] As shown in FIG. 16, the first and second pipe lines 130 and
131 have intermediate portions 133a and 133b. The intermediate
portions 133a and 133b exist between the convex portion 8 and the
leg portion 23b of the display housing 17. The intermediate
portions 133a and 133b are extended horizontally along the axis X1
of the hinge shaft 27 such that they are disposed in parallel to
each other with a gap therebetween.
[0138] The intermediate portions 133a and 133b of the first and
second pipes 130 and 131 are provided with a holder 134 for keeping
constant the gap between these intermediate portions 133a and 133b.
The holder 134 is composed of material hard to transmit heat. As
shown in FIG. 17, the holder 134 has a first support pipe 135a and
a second support pipe 135b. The first support pipe 135a supports
the intermediate portion 133a of the first pipe line 130 rotatably
in an axial direction. The second support pipe 135b supports the
intermediate portion 133b of the second pipe line 131 rotatably in
an axial direction.
[0139] The first and second support pipes 135a and 135b are linked
through a pair of columns 136. The columns 136 are extended in the
diameter direction of the first and second support pipes 135a and
135b such that they are disposed between both end portions of these
support pipes 135a and 135b. Thus, the first and second support
pipes 135a and 135b are disposed in parallel to each other across a
heat insulating gap 137.
[0140] As shown in FIG. 16, the first and second pipe lines 130 and
131 are divided to upstream portions 130a and 131a and downstream
portions 130b and 131b inside the first housing 4. These upstream
portions 130a and 131a and the downstream portions 130b and 131b
are joined detachably through a joint 140. As shown in FIGS. 18A
and 18B, the joint 140 has a first joint portion 141 and a second
joint portion 142. The first joint portion 141 is connected to the
downstream portion 130b of the first pipe line 130 and the upstream
portion 131a of the second pipe line 131. The second pipe portion
142 is connected to the upstream portion 130a of the first pipe
line 130 and the downstream portion 131b of the second pipe line
131.
[0141] The first joint portion 141 has a hollow cylindrical body
145. A pair of refrigerant flow paths 146 are formed inside the
body 145. The refrigerant flow paths 146 are connected to the
downstream portion 130b of the first pipe line 130 and the upstream
portion 131a of the second pipe line 131. Each of the refrigerant
flow paths 146 has a valve hole 147 which is open to an end of the
body 145. A pair of pressing rods 148 protruding from the body 145
through an opening edge portion of the valve hole 147 are provided
at a front end of the body 145.
[0142] A ball-like valve body 149 is accommodated in each
refrigerant flow path 146 and used as a closing means. The valve
body 149 is supported by the body 145 and can approach and leaves
the valve hole 147, always pressed toward the valve hole 147 by a
spring 150. Thus, when the first joint portion 141 is separated
from the second joint portion 142, the valve body 149 remains in
firm contact with the opening edge portion of the valve hole 147,
closing the valve hole 147.
[0143] The second joint portion 142 has a hollow cylindrical body
152. A pair of refrigerant flow paths 153 are formed inside the
body 152. The refrigerant flow paths 153 are connected to the
upstream portion 130a of the first pipe line 130 and the downstream
portion 131b of the second pipe line 131. Each of the refrigerant
flow paths 153 has a fitting hole 154, which is open to a front end
of the body 152. The body 145 of the first joint portion 141
removably secured to the fitting hole 154 detachably.
[0144] As shown in FIG. 18B, a pressing protrusion 155 and a
partition wall 157 having a valve hole 156 are provided in the
middle part of the refrigerant flow path 153. The protrusion 155
extends toward the fitting hole 154. The partition wall 157 opposes
the fitting hole 154 across the pressing protrusion 155. A
ball-like valve body 158 is accommodated as a closing means between
the partition wall 157 and the other end of the refrigerant flow
path 153. The valve body 158 is supported by the body 152 and can
approach and leave the valve hole 156 and is always pressed toward
the valve hole 156 by a spring 159. Thus, while the first joint
portion 141 is separated from the second joint portion 142, the
valve body 158 remains in firm contact with the opening edge
portion of the valve body 156, closing the valve hole 156.
[0145] When as shown in FIG. 18A, the body 145 of the first joint
portion 141 is fit to the fitting holes 154 in the second joint
portion 142, the pressing protrusions 155 of the second joint
portion 142 enter the valve holes 147 in the first joint portion
141. The protrusions 155 strike the valve bodies 149. Consequently,
the valve bodies 149 are pushed and leave the opening edge portions
of the valve holes 147, in spite of the force of the springs 150.
The valve hole 147 are thereby opened.
[0146] At the same time, the pressing rods 148 of the body 145
passes over the periphery of the pressing protrusions 155 and enter
the valve holes 156 in the joint portion 142. The rods 148 strike
the valve bodies 158. As a result, the valve bodies 158 are pushed
and leave the opening edge portion of the valve holes 156, against
the force of the springs 159. The valve holes 156 are thereby
opened.
[0147] Since the first joint portion 141 is connect with the second
joint portion 142, the refrigerant flow paths 146 and 153
communicate with each other through the valve holes 147 and
156.
[0148] When the first joint portion 141 is separated from the
second joint portion 142 as shown in FIG. 18B, the valve bodies 149
are no longer pressed by the pressing protrusions 155. At the same
time, the valve bodies 158 are no longer pressed by the pressing
rods 148. Thus, the valve bodies 149 and 158 are pressed against
the opening edge portions of the valve holes 147 and 156 by the
springs 150 and 159. The bodies 149 and 158 seal the valve holes
147 and 156. Thus, the refrigerant
[0149] flow paths 146 and 153 continuous to the first and second
pipe lines 130 and 131 are automatically closed, thereby preventing
a leakage of the cooling medium.
[0150] If the IC chip 14 of the semiconductor package 12 is heated
in the portable computer 1 having such a structure, heat of the IC
chip 14 is transmitted to the heat transmitting case 34 of the heat
receiving head 31. Because the cooling medium is supplied to the
refrigerant flow paths 36 of this heat transmitting case 34, heat
transmitted to the heat transmitting case 34 is transferred to the
cooling medium flowing through the refrigerant flow paths 36 from
the heat transmitting case 34. After heated by heat exchange by
means of this heat receiving head 31, the cooling medium is
introduced to the heat radiator 123 of the display unit 3 through
the first pipe line 130, so that heat of the IC chip 14 is
transferred to the heat radiator 123 through a flow of the cooling
medium.
[0151] The cooling medium introduced to the heat radiator 123 flows
along the meandering heat radiating pipe 126. In this flow process,
heat absorbed in the cooling medium is transmitted to the heat
radiating pipe 126 and diffused by heat conductivity to the heat
radiating plate 125. Because the heat radiating plate 125 is
thermally connected to the display housing 17, heat transferred to
the heat radiating plate 125 is diffused by heat conductivity to
the display housing 17 and then, discharged into the atmosphere
from the surface of the display housing 17.
[0152] The cooling medium cooled by heat exchange by means of the
heat radiating pipe 126 is returned to the pump 132 through the
second pipe line 131 and after pressurized by this pump 132,
supplied to the heat receiving head 31.
[0153] The first pipe line 130 in which the cooling medium heated
by heat exchange by means of the heat receiving head 31 flows and
the second pipe line 131 in which the cooling medium cooled by heat
exchange by means of the heat radiator 123 extend between the first
housing 4 and the display housing 17. Then, the intermediate
portion 133a of the first pipe line 130 and the intermediate
portion 133b of the second pipe line 131 are held by the first and
second support pipes 135a and 135b in the holder 134. Consequently,
the gap between the first pipe line 130 and the second pipe line
131 is maintained constant and the gap between the first pipe line
130 and the second pipe line 131 is thermally shut down by the gap
137 between the first and second support pipe lines 135a and
135b.
[0154] Thus, although the first pipe line 130 in which the heated
cooling medium flows and the second pipe line 131 in which the
cooled cooling medium flows pass inside the guide 122 such that
they adjoin each other, a undesired heat exchange between the
adjacent pipe lines 130 and 131 can be prevented. Therefore,
transmission efficiency of heat from the heat receiving head 31 to
the heat radiator 123 can be raised, thereby maintaining heat
radiation performance of the semiconductor package 12.
[0155] On the other hand, a procedure for taking the display unit 3
out of the first housing 4 in the portable computer 1 having such a
structure will be described. First, the top cover 6 of the first
housing 4 is removed from the base 5 so as to expose the first and
second pipe lines 130 and 131 and the joint 140 accommodated in the
first housing 4.
[0156] Next, the first joint portion 141 and the second joint
portion 142 of the joint 140 are separated from each other and the
first and second pipe lines 130 and 131 are divided to the upstream
portions 130a and 131a and the downstream portions 130b and 131b
inside the first housing 4. Consequently, the circulating path 124
is divided between the first housing 4 and the display unit 3.
Thus, with the heat receiving head 31 remaining in the first
housing 4, the display unit 3 can be removed from the first housing
4 or can be installed onto the first housing 4.
[0157] For the reason, when attaching or detaching the display unit
3 to/from the first housing 4, it is not necessary to release
thermal connection between the heat receiving head 31 and the
semiconductor package 12 or thermally connect again, so that the
procedure for disassembly/assembly of the thermal connecting
portion between the heat receiving head 31 and the semiconductor
package 12 is not required. Therefore, no unreasonable force is
applied to the precision semiconductor package 12 and the
positional relationship between the semiconductor package 12 and
the heat receiving head 31 is not changed, thereby maintaining
reliability of heat transfer favorably.
[0158] Further, if the first joint portion 141 is separated from
the second joint portion 142, the valve holes 147 and 156 in the
respective joint portions 141 and 142 are automatically shut down
by the valve bodies 149, 158. Thus, a leakage of the cooling medium
can be prevented and any special procedure for sealing a dividing
portion between the first and second pipe lines 130 and 131 is not
required.
[0159] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *