U.S. patent application number 12/567274 was filed with the patent office on 2010-04-08 for cooling apparatus, electronic apparatus, and blower apparatus.
This patent application is currently assigned to SONY CORPORATION. Invention is credited to Tadaomi Fujieda, Toru Kimura, Takashi Mochida, Yuji Shishido.
Application Number | 20100084123 12/567274 |
Document ID | / |
Family ID | 42048515 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100084123 |
Kind Code |
A1 |
Shishido; Yuji ; et
al. |
April 8, 2010 |
COOLING APPARATUS, ELECTRONIC APPARATUS, AND BLOWER APPARATUS
Abstract
Disclosed is a cooling apparatus including a heat sink, a blower
mechanism, an opening member, and a movement mechanism. The blower
mechanism has a blower opening that has a predetermined area and is
opposed to the heat sink. The opening member has a first opening
that has an area smaller than the area of the blower opening. The
movement mechanism moves the opening member so that switching
between a first state and a second state is performed. The first
state is a state in which the first opening is disposed between the
blower opening and the heat sink, and the second state is a state
in which the first opening is removed from between the blower
opening and the heat sink.
Inventors: |
Shishido; Yuji; (Kanagawa,
JP) ; Mochida; Takashi; (Chiba, JP) ; Kimura;
Toru; (Tokyo, JP) ; Fujieda; Tadaomi; (Tokyo,
JP) |
Correspondence
Address: |
K&L Gates LLP
P. O. BOX 1135
CHICAGO
IL
60690
US
|
Assignee: |
SONY CORPORATION
Tokyo
JP
|
Family ID: |
42048515 |
Appl. No.: |
12/567274 |
Filed: |
September 25, 2009 |
Current U.S.
Class: |
165/200 ;
165/104.34; 165/122; 165/96 |
Current CPC
Class: |
G06F 1/203 20130101;
F04D 29/582 20130101; F04D 27/002 20130101 |
Class at
Publication: |
165/200 ;
165/104.34; 165/96; 165/122 |
International
Class: |
F28F 27/00 20060101
F28F027/00; F28D 15/00 20060101 F28D015/00; F28F 13/12 20060101
F28F013/12 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2008 |
JP |
P2008-246645 |
Jan 8, 2009 |
JP |
P2009-002337 |
Claims
1. A cooling apparatus, comprising: a heat sink; a blower mechanism
having a blower opening that has a predetermined area and is
opposed to the heat sink; an opening member having a first opening
that has an area smaller than the area of the blower opening; and a
movement mechanism to move the opening member to perform switching
between a first state and a second state, the first state being a
state in which the first opening is disposed between the blower
opening and the heat sink, the second state being a state in which
the first opening is removed from between the blower opening and
the heat sink.
2. The cooling apparatus according to claim 1, wherein the opening
member further has a second opening having an area equal to the
area of the blower opening, and wherein the second state is a state
in which the second opening is opposed to the blower opening.
3. The cooling apparatus according to claim 2, wherein the opening
member is a band-like member having a longitudinal direction,
wherein the first opening and the second opening are formed in the
band-like member in a line along the longitudinal direction of the
band-like member, and wherein the movement mechanism moves the
band-like member along the blower opening in the longitudinal
direction.
4. The cooling apparatus according to claim 3, wherein the movement
mechanism includes a first shaft connected to an end portion of the
band-like member and capable of rolling up and rolling out the
band-like member, a second shaft disposed so that the first shaft
and the second shaft sandwich the blower opening, connected to
another end portion of the band-like member, and capable of rolling
up and rolling out the band-like member, and a drive source to
rotate and drive the first shaft and the second shaft.
5. The cooling apparatus according to claim 3, wherein the
band-like member is annular, and wherein the movement mechanism
includes a plurality of shafts to support the band-like member
while rotating the band-like member around the blower mechanism
with the plurality of shafts being provided around the blower
mechanism, and a drive source to rotate and drive at least one of
the plurality of shafts.
6. The cooling apparatus according to claim 1, wherein the opening
member is a plate-like member having a longitudinal direction, and
wherein the movement mechanism moves the plate-like member along
the blower opening in the longitudinal direction.
7. The cooling apparatus according to claim 6, wherein the
plate-like member includes a rack gear in the longitudinal
direction, and wherein the movement mechanism includes a pinion
engaged with the rack gear, and a drive source to rotate and drive
the pinion.
8. The cooling apparatus according to claim 1, further comprising:
a control means for controlling a movement of the opening member by
the movement mechanism so that the second state is periodically
switched to the first state.
9. The cooling apparatus according to claim 8, wherein the blower
mechanism further includes a blade member that generates airflow
flown out from the blower opening by rotation thereof, and wherein
the control means controls the movement of the opening member so
that the second state is switched to the first state when one of
start and stop of the rotation of the blade member is
performed.
10. The cooling apparatus according to claim 8, wherein the blower
mechanism further includes the blade member that generates airflow
flown out from the blower opening by rotation thereof, the cooling
apparatus further comprising: a rotation counting means for
counting a number of rotations of the blade member; and a rotation
count judging means for judging whether the number of rotations
counted reaches a specified count, and wherein the control means
controls the movement of the opening member so that the second
state is switched to the first state when the number of rotations
reaches the specified count.
11. The cooling apparatus according to claim 8, further comprising:
a time counting means for counting a time period that elapses from
when the first state is switched to the second state; and a time
judging means for judging whether the time period counted reaches a
specified time period, wherein the control means controls the
movement of the opening member so that the second state is switched
to the first state when the time period reaches the specified time
period.
12. A cooling apparatus, comprising: a heat sink; a blower
mechanism having a blower opening that has a predetermined area and
is opposed to the heat sink; a rotary member including a shield
portion that limits the area of the blower opening, the rotary
member being rotatable and disposed between the heat sink and the
blower opening; and a rotary mechanism to rotate the rotary member
to perform switching between a first state and a second state, the
first state being a state in which the area of the blower opening
is limited by the shield portion, the second state being a state in
which the area of the blower opening is free of being limited by
the shield portion.
13. The cooling apparatus according to claim 12, wherein the blower
opening has a longitudinal direction, and wherein the rotary member
is rotatable about a shaft extended along the longitudinal
direction.
14. The cooling apparatus according to claim 13, wherein the rotary
member includes a first rotary member and a second rotary member
that are disposed while the blower opening being disposed
therebetween.
15. An electronic apparatus, comprising: a heat generation source;
and a cooling apparatus including a heat sink that radiates heat
transferred from the heat generation source, a blower mechanism
having a blower opening that has a predetermined area and is
opposed to the heat sink, an opening member having a first opening
that has an area smaller than the area of the blower opening, and a
movement mechanism to move the opening member to perform switching
between a first state and a second state, the first state being a
state in which the first opening is disposed between the blower
opening and the heat sink, the second state being a state in which
the first opening is removed from between the blower opening and
the heat sink.
16. An electronic apparatus, comprising: a heat generation source;
and a cooling apparatus including a heat sink that radiates heat
transferred from the heat generation source, a blower mechanism
having a blower opening that has a predetermined area and is
opposed to the heat sink, a rotary member that includes a shield
portion to limit the area of the blower opening and is rotatable
and disposed between the heat sink and the blower opening, and a
rotary mechanism to rotate the rotary member to perform switching
between a first state and a second state, the first state being a
state in which the area of the blower opening is limited by the
shield portion, the second state being a state in which the area of
the blower opening is free of being limited by the shield
portion.
17. A blower apparatus, comprising: a blower mechanism having a
blower opening that has a predetermined area; an opening member
having a first opening that has an area smaller than the area of
the blower opening; and a movement mechanism to move the opening
member to perform switching between a first state and a second
state, the first state being a state in which the first opening is
disposed in front of the blower opening, the second state being a
state in which the first opening is removed from the front of the
blower opening.
18. A blower apparatus, comprising: a blower mechanism having a
blower opening that has a predetermined area; a rotary member
including a shield portion that limits the area of the blower
opening, the rotary member being rotatable and disposed in front of
the blower opening; and a rotary mechanism to rotate the rotary
member to perform switching between a first state and a second
state, the first state being a state in which the area of the
blower opening is limited by the shield portion, the second state
being a state in which the area of the blower opening is free of
being limited by the shield portion.
19. A cooling apparatus, comprising: a heat sink having a surface
to which airflow is directed; a blade member to generate the
airflow to the surface; a flow path member to form a flow path
through which the airflow is guided from the blade member to the
heat sink; a limiting member capable of limiting the flow path; and
a drive mechanism to drive the limiting member so that switching
between a first state and a second state is performed, the first
state being a state in which the flow path is free of being limited
by the limiting member, the second state being a state in which the
flow path is limited by the limiting member to generate a vortex so
that the vortex is contacted with the surface.
20. The cooling apparatus according to claim 19, further
comprising: a control means for controlling the drive mechanism so
that the first state is periodically switched to the second
state.
21. The cooling apparatus according to claim 20, wherein the blade
member generates the airflow by rotation thereof, and wherein the
control means controls the drive mechanism so that the first state
is switched to the second state when the rotation of the blade
member is started.
22. The cooling apparatus according to claim 20, wherein the blade
member generates the airflow by rotation thereof, and wherein the
control means controls the drive mechanism so that the first state
is switched to the second state when the rotation of the blade
member is stopped.
23. The cooling apparatus according to claim 20, wherein the blade
member generates the airflow by rotation thereof, the cooling
apparatus further comprising: a rotation counting means for
counting a number of rotations of the blade member; and a rotation
count judging means for judging whether the number of rotations
counted reaches a specified count, and wherein the control means
controls the drive mechanism so that the first state is switched to
the second state when the number of rotations reaches the specified
count.
24. The cooling apparatus according to claim 20, further
comprising: a time counting means for counting a time period that
elapses from when the second state is switched to the first state;
and a time judging means for judging whether the time period
counted reaches a specified time period, wherein the control means
controls the drive mechanism so that the first state is switched to
the second state when the time period reaches the specified time
period.
25. An electronic apparatus, comprising: a heat generation source;
and a cooling apparatus including a heat sink that has a surface to
which airflow is directed and radiates heat transferred from the
heat generation source, a blade member to generate the airflow to
the surface, a flow path member to form a flow path through which
the airflow is guided from the blade member to the heat sink, a
limiting member capable of limiting the flow path, and a drive
mechanism to drive the limiting member so that switching between a
first state and a second state is performed, the first state being
a state in which the flow path is free of being limited by the
limiting member, the second state being a state in which the flow
path is limited by the limiting member to generate a vortex so that
the vortex is contacted with the surface.
26. A blower apparatus, comprising: a blade member to generate
airflow to a surface of a heat sink, the heat sink having the
surface to which the airflow is directed; a flow path member to
form a flow path through which the airflow is guided from the blade
member to the heat sink; a limiting member capable of limiting the
flow path; and a drive mechanism to drive the limiting member so
that switching between a first state and a second state is
performed, the first state being a state in which the flow path is
free of being limited by the limiting member, the second state
being a state in which the flow path is limited by the limiting
member to generate a vortex so that the vortex is contacted with
the surface.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application contains subject matter related to
that disclosed in Japanese Priority Patent Application JP
2008-246645 filed in the Japan Patent Office on Sep. 25, 2008 and
Japanese Priority Patent Application JP 2009-002337 filed in the
Japan Patent Office on Jan. 8, 2009, the entire contents of which
are hereby incorporated by reference.
BACKGROUND
[0002] The present invention relates to a blower apparatus that
generates airflow to a heat sink, a cooling apparatus including a
heat sink and a blower apparatus, and an electronic apparatus
equipped with a cooling apparatus.
[0003] In the past, with increase in performance of a PC (personal
computer), the amount of heat generated from a heat source such as
a CPU has problematically increased. To deal with this problem,
various techniques of radiating heat have been proposed or
produced. There has been known a heat radiation method in which
heat from a CPU is transferred to a heat sink including radiation
fins made of a metal such as aluminum and is radiated from the
radiation fins, thereby forcibly getting rid of warmed air around
the radiation fins by using a fan apparatus.
[0004] However, the fan apparatus takes in air around the fan
apparatus from an intake and blows the air to the radiation fins of
the heat sink. Therefore, the fan apparatus undesirably blows dirt
or dust contained in the air to the radiation fins together. As a
result, the dust adheres to gaps of the radiation fins and
accumulates thereon, which causes a problem of degrading a cooling
performance of the heat sink.
[0005] As a technique relating to the above problem, Japanese
Patent Application Laid-open No. 2005-321287 (paragraphs 0035,
0050, 0062, and 0063, and FIG. 1) (hereinafter, referred to as
Patent Document 1) discloses a cooling apparatus provided with a
trapezoidal heat sink having an incline portion on an end surface
on a side to which airflow generated by the rotation of a blade
portion is directed. To a duct that regulates airflow generated by
the blade portion into one direction, a dust outlet is provided in
addition to an intake and an outlet. The dust contained in the
airflow is transferred along the incline portion of the heat sink
and is put out to outside from the dust outlet provided to the
duct.
[0006] In addition, as a technique relating to the above problem,
Japanese Patent Application Laid-open No. 2008-159925 (paragraphs
0036, and 0042 to 0045, and FIGS. 3 and 4) (hereinafter, referred
to as Patent Document 2) discloses a cooling apparatus provided
with a heat sink including a first heat sink and a second heat sink
that are separately formed. The second heat sink which is provided
close to a blower opening of a cooling fan and to which dust easily
adheres is detachably incorporated in an electronic apparatus such
as a PC. A user detaches the second heat sink from the PC and
washes it, to remove the accumulated dust from the second heat
sink.
SUMMARY
[0007] However, the cooling apparatus disclosed in Patent Document
1 does not sufficiently overcome the above problem of removing the
dust, although the cooling apparatus can reduce the amount of dust
that adheres to the heat sink. With increasing utilization of the
PC, the dust accumulates between the radiation fins in the end.
[0008] On the other hand, in the cooling apparatus disclosed in
Patent Document 2, the second heat sink can be detached from the PC
and washed. However, in the cooling apparatus, the user has to
detach the second heat sink from the PC, which is a troublesome
task.
[0009] In view of the above-mentioned circumstances, it is
desirable to provide a blower apparatus capable of automatically
removing the dust that adheres to a heat sink, a cooling apparatus
including the blower apparatus and the heat sink, and an electronic
apparatus equipped with the cooling apparatus.
[0010] According to an embodiment, there is provided a cooling
apparatus including a heat sink, a blower mechanism, an opening
member, and a movement mechanism.
[0011] The blower mechanism has a blower opening that has a
predetermined area and is opposed to the heat sink.
[0012] The opening member has a first opening that has an area
smaller than the area of the blower opening.
[0013] The movement mechanism moves the opening member to perform
switching between a first state and a second state. The first state
is a state in which the first opening is disposed between the
blower opening and the heat sink, and the second state is a state
in which the first opening is removed from between the blower
opening and the heat sink.
[0014] In this embodiment, in the first state, the first opening of
the opening member is located between the blower opening and the
heat sink. Because the first opening has the area smaller than that
of the blower opening, the area of the blower opening can be
temporarily made smaller by using the first opening. As a result,
it is possible to locally increase a flow rate of airflow flown out
from the blower opening. Thus, the dust that adheres to and
accumulates on the heat sink can be removed (dust removal
mode).
[0015] On the other hand, in the second state, the first opening of
the opening member is not located between the blower opening and
the heat sink. Therefore, in the second state, the airflow is
directed to the heat sink from the entire blower opening, thereby
cooling the heat sink (cooling mode).
[0016] Further, in this embodiment, the first state (dust removal
mode) and the second mode (cooling mode) can be automatically
switched by the movement mechanism, with the result that a
troublesome task of detaching the heat sink from an electronic
apparatus such as a PC and washing it can be eliminated.
[0017] In the cooling apparatus, the opening member may further
have a second opening having an area approximately equal to the
area of the blower opening.
[0018] In this case, the second state may be a state in which the
second opening is opposed to the blower opening.
[0019] In this embodiment, in the second state, the second opening
having the area approximately equal to the area of the blower
opening is opposed to the blower opening. Through the second
opening, the airflow is directed to the heat sink from the entire
blower opening, thereby cooling the heat sink.
[0020] In the cooling apparatus, the opening member may be a
band-like member having a longitudinal direction.
[0021] In this case, the first opening and the second opening may
be formed in the band-like member in a line along the longitudinal
direction of the band-like member.
[0022] Further, in this case, the movement mechanism may move the
band-like member along the blower opening in the longitudinal
direction.
[0023] In this embodiment, the switching between the first state
and the second state is performed by moving the band-like member
having the first opening and the second opening in the longitudinal
direction of the band-like member. In this case, the band-like
member is moved along the blower opening, and therefore the first
opening and the second opening are also moved along the blower
opening. When the first opening is moved along the blower opening,
a position at which strong airflow is generated is moved along the
blower opening. As a result, the strong airflow can be directed to
the entire heat sink opposed to the blower opening, which can
remove the dust from the entire heat sink.
[0024] In the cooling apparatus, the movement mechanism may include
a first shaft, a second shaft, and a drive source.
[0025] The first shaft is connected to an end portion of the
band-like member and capable of rolling up and rolling out the
band-like member.
[0026] The second shaft is disposed so that the first shaft and the
second shaft sandwich the blower opening, connected to another end
portion of the band-like member, and capable of rolling up and
rolling out the band-like member.
[0027] The drive source rotates and drives the first shaft and the
second shaft.
[0028] In this embodiment, because the first shaft and the second
shaft can roll up and roll out the band-like member, it is possible
to reduce a space in which the band-like member is provided. As a
result, the cooling apparatus can be downsized.
[0029] In the cooling apparatus, the band-like member may be
annular.
[0030] In this case, the movement mechanism may include a plurality
of shafts and a drive source.
[0031] The plurality of shafts support the band-like member while
rotating the band-like member around the blower mechanism with the
plurality of shafts being provided around the blower mechanism.
[0032] The drive source rotates and drives at least one of the
plurality of shafts.
[0033] In this embodiment, because the band-like member rotates
around the blower mechanism, the space in which the band-like
member is provided can be reduced, with the result that the cooling
apparatus can be downsized.
[0034] In the cooling apparatus, the opening member may be a
plate-like member having a longitudinal direction.
[0035] In this case, the movement mechanism may move the plate-like
member along the blower opening in the longitudinal direction.
[0036] In this embodiment, the plate-like member having the first
opening is moved along the blower opening, and therefore the first
opening is also moved along the blower opening. When the first
opening is moved along the blower opening, a position at which
strong airflow is generated is moved along the blower opening. As a
result, the strong airflow can be directed to the entire heat sink
opposed to the blower opening, which can remove the dust from the
entire heat sink.
[0037] In the cooling apparatus, the plate-like member may include
a rack gear in the longitudinal direction.
[0038] In this case, the movement mechanism may include a pinion
and a drive source.
[0039] The pinion is engaged with the rack gear.
[0040] The drive source rotates and drives the pinion.
[0041] In this embodiment, with the use of the rack and pinion
mechanism, the plate-like member is linearly moved and the first
opening is moved between the heat sink and the blower opening. As a
result, the dust that adheres to and accumulates on the heat sink
can be removed with the simple structure.
[0042] In the cooling apparatus may further include a control
means.
[0043] The control means controls a movement of the opening member
by the movement mechanism so that the second state is periodically
switched to the first state.
[0044] In this embodiment, the second state (cooling mode) is
periodically switched to the first state (dust removal mode), with
the result that the dust can be removed from the heat sink before
the dust that adheres to the heat sink and accumulates thereon
causes clogging of radiation fins.
[0045] In the cooling apparatus, the blower mechanism may further
include a blade member that generates airflow flown out from the
blower opening by rotation thereof.
[0046] In this case, the control means may control the movement of
the opening member so that the second state is switched to the
first state when one of start and stop of the rotation of the blade
member is performed.
[0047] With this structure, the dust can be removed from the heat
sink before the dust that adheres to and accumulates on the heat
sink causes clogging of the radiation fins.
[0048] In the case where the blade member is provided to the
cooling apparatus, the cooling apparatus may further includes a
rotation counting means and a rotation count judging means.
[0049] The rotation counting means counts a number of rotations of
the blade member.
[0050] The rotation count judging means judges whether the number
of rotations counted reaches a specified count.
[0051] In this case, the control means may control the movement of
the opening member so that the second state is switched to the
first state when the number of rotations reaches the specified
count.
[0052] With this structure, the dust can be removed from the heat
sink before the dust that adheres to and accumulates on the heat
sink causes clogging of the radiation fins.
[0053] The cooling apparatus may further include a time counting
means and a time judging means.
[0054] The time counting means counts a time period that elapses
from when the first state is switched to the second state.
[0055] The time judging means judges whether the time period
counted reaches a specified time period.
[0056] In this case, the control means may control the movement of
the opening member so that the second state is switched to the
first state when the time period reaches the specified time
period.
[0057] With this structure, the dust can be removed from the heat
sink before the dust that adheres to and accumulates on the heat
sink causes clogging of the radiation fins.
[0058] According to another embodiment of the present invention,
there is provided a cooling apparatus including a heat sink, a
blower mechanism, a rotary member, and a rotary mechanism.
[0059] The blower mechanism has a blower opening that has a
predetermined area and is opposed to the heat sink.
[0060] The rotary member includes a shield portion and is rotatable
and disposed between the heat sink and the blower opening.
[0061] The shield portion limits the area of the blower
opening.
[0062] The rotary mechanism rotates the rotary member to perform
switching between a first state and a second state. The first state
is a state in which the area of the blower opening is limited by
the shield portion, and the second state is a state in which the
area of the blower opening is free of being limited by the shield
portion.
[0063] In this embodiment, in the first state, the area of the
blower opening is limited by the shield portion of the rotary
member. Accordingly, the area of the blower opening can be
temporarily made smaller. As a result, the flow rate of the airflow
flown out from the blower opening can be increased, which can
remove the dust that adheres to and accumulates on the heat sink
(dust removal mode).
[0064] On the other hand, in the second state, the area of the
blower opening is not limited by the shield portion of the rotary
member. Accordingly, in the second state, the airflow is directed
to the heat sink from the entire blower opening, thereby cooling
the heat sink (cooling mode).
[0065] Further, in this embodiment, the switching between the first
state (dust removal mode) and the second mode (cooling mode) can be
automatically performed by the rotary mechanism. Thus, it is
possible to eliminate the troublesome task of detaching the heat
sink from the electronic apparatus such as the PC and washing
it.
[0066] In the cooling apparatus, the blower opening may have a
longitudinal direction.
[0067] In this case, the rotary member may be rotatable about a
shaft extended along the longitudinal direction.
[0068] In this embodiment, because the rotary member is rotated
about the shaft extended along the longitudinal direction of the
blower opening, a distance between the blower opening and the heat
sink can be reduced as compared to a case where the rotary member
is rotated about a shaft extended along a short-side direction of
the blower opening. Thus, the cooling apparatus can be
downsized.
[0069] In the cooling apparatus, the rotary member may include a
first rotary member and a second rotary member that are disposed
while the blower opening being disposed therebetween.
[0070] With this structure, the distance between the blower opening
and the heat sink can b reduced, with the result that the cooling
apparatus can be downsized.
[0071] According to another embodiment of the present invention,
there is provided an electronic apparatus including a heat
generation source and a cooling apparatus.
[0072] The cooling apparatus includes a heat sink, a blower
mechanism, an opening member, and a movement mechanism.
[0073] The heat sink radiates heat transferred from the heat
generation source.
[0074] The blower mechanism has a blower opening that has a
predetermined area and is opposed to the heat sink.
[0075] The opening member has a first opening that has an area
smaller than the area of the blower opening.
[0076] The movement mechanism moves the opening member to perform
switching between a first state and a second state. The first state
is a state in which the first opening is disposed between the
blower opening and the heat sink, and the second state is a state
in which the first opening is removed from between the blower
opening and the heat sink.
[0077] According to another embodiment of the present invention,
there is provided an electronic apparatus including a heat
generation source and a cooling apparatus.
[0078] The cooling apparatus including a heat sink, a blower
mechanism, a rotary member, and a rotary mechanism.
[0079] The heat sink radiates heat transferred from the heat
generation source.
[0080] The blower mechanism has a blower opening that has a
predetermined area and is opposed to the heat sink.
[0081] The rotary member includes a shield portion and is rotatable
and disposed between the heat sink and the blower opening.
[0082] The shield portion limits the area of the blower
opening.
[0083] The rotary mechanism rotates the rotary member to perform
switching between a first state and a second state. The first state
is a state in which the area of the blower opening is limited by
the shield portion, and the second state is a state in which the
area of the blower opening is free of being limited by the shield
portion.
[0084] According to another embodiment of the present invention,
there is provided a blower apparatus including a blower mechanism,
an opening member, and a movement mechanism.
[0085] The blower mechanism has a blower opening that has a
predetermined area.
[0086] The opening member has a first opening that has an area
smaller than the area of the blower opening.
[0087] The movement mechanism moves the opening member to perform
switching between a first state and a second state. The first state
is a state in which the first opening is disposed in front of the
blower opening, and the second state is a state in which the first
opening is removed from the front of the blower opening.
[0088] According to another embodiment of the present invention,
there is provided a blower apparatus including a blower mechanism,
a rotary member, and a rotary mechanism.
[0089] The blower mechanism has a blower opening that has a
predetermined area.
[0090] The rotary member including a shield portion and is
rotatable and disposed in front of the blower opening.
[0091] The shield portion limits the area of the blower
opening.
[0092] The rotary mechanism rotates the rotary member to perform
switching between a first state and a second state. The first state
is a state in which the area of the blower opening is limited by
the shield portion, and the second state is a state in which the
area of the blower opening is free of being limited by the shield
portion.
[0093] According to another embodiment of the present invention,
there is provided a cooling apparatus including a heat sink, a
blade member, a flow path member, a limiting member, and a drive
mechanism.
[0094] The heat sink has a surface to which airflow is
directed.
[0095] The blade member generates the airflow to the surface.
[0096] The flow path member forms a flow path through which the
airflow is guided from the blade member to the heat sink.
[0097] The limiting member is capable of limiting the flow
path.
[0098] The drive mechanism drives the limiting member so that
switching between a first state and a second state is performed.
The first state is a state in which the flow path is free of being
limited by the limiting member, and the second state is a state in
which the flow path is limited by the limiting member to generate a
vortex so that the vortex is contacted with the surface.
[0099] In this embodiment, in the first state, the limiting member
does not limit the flow path, and the flow path is released. In
this case, the airflow generated by the blade member is directed to
the heat sink, thereby cooling the heat sink (cooling mode).
[0100] On the other hand, in the second state, the limiting member
limits the flow path. In this case, the airflow that passes through
the flow path is changed, thereby generating the vortex so as to be
contacted with the heat sink. The vortex blows away the dust that
adheres to and accumulates on the heat sink, with the result that
the dust can be removed therefrom (dust removal mode).
[0101] In addition, in this embodiment, it is possible to
automatically switch the first state (cooling mode) and the second
state (dust removal mode) by using the drive mechanism.
Accordingly, the troublesome task of detaching the heat sink from
the electronic apparatus such as the PC and washing it can be
eliminated.
[0102] The cooling apparatus may further include a control means
for controlling the drive mechanism so that the first state is
periodically switched to the second state.
[0103] In this embodiment, the first state (cooling mode) is
periodically switched to the second state (dust removal mode), with
the result that the dust can be removed from the heat sink before
the dust that adheres to the heat sink accumulates thereon and
causes clogging of the radiation fins.
[0104] In the cooling apparatus, the blade member may generate the
airflow by rotation thereof
[0105] In this case, the control means controls the drive mechanism
so that the first state is switched to the second state when the
rotation of the blade member is started.
[0106] With this structure, it is possible to remove the dust from
the heat sink before the dust that adheres to the heat sink
accumulates thereon and causes clogging of the radiation fins.
[0107] In the cooling apparatus, in the case where the blade member
generates the airflow by rotation thereof, the control means may
control the drive mechanism so that the first state is switched to
the second state when the rotation of the blade member is
stopped.
[0108] With this structure, it is possible to remove the dust from
the heat sink before the dust that adheres to the heat sink
accumulates thereon and causes clogging of the radiation fins.
[0109] In the case where the blade member generates the airflow by
rotation thereof in the cooling apparatus, the cooling apparatus
may further includes a rotation counting means and a rotation count
judging means.
[0110] The rotation counting means counts a number of rotations of
the blade member.
[0111] The rotation count judging means judges whether the number
of rotations counted reaches a specified count.
[0112] In this case, the control means may control the drive
mechanism so that the first state is switched to the second state
when the number of rotations reaches the specified count.
[0113] With this structure, it is possible to remove the dust from
the heat sink before the dust that adheres to the heat sink
accumulates thereon and causes clogging of the radiation fins.
[0114] The cooling apparatus may further include a time counting
means and a time judging means.
[0115] The time counting means counts a time period that elapses
from when the second state is switched to the first state.
[0116] The time judging means judges whether the time period
counted reaches a specified time period.
[0117] In this case, the control means may control the drive
mechanism so that the first state is switched to the second state
when the time period reaches the specified time period.
[0118] With this structure, it is possible to remove the dust from
the heat sink before the dust that adheres to the heat sink
accumulates thereon and causes clogging of the radiation fins.
[0119] According to another embodiment of the present invention,
there is provided an electronic apparatus including a heat
generation source and a cooling apparatus.
[0120] The cooling apparatus includes a heat sink, a blade member,
a flow path member, a limiting member, and a drive mechanism.
[0121] The heat sink has a surface to which airflow is directed and
radiates heat transferred from the heat generation source.
[0122] The blade member generates the airflow to the surface.
[0123] The flow path member forms a flow path through which the
airflow is guided from the blade member to the heat sink.
[0124] The limiting member is capable of limiting the flow
path.
[0125] The drive mechanism drives the limiting member so that
switching between a first state and a second state is performed.
The first state is a state in which the flow path is free of being
limited by the limiting member, and the second state is a state in
which the flow path is limited by the limiting member to generate a
vortex so that the vortex is contacted with the surface.
[0126] According to another embodiment, there is provided a blower
apparatus including a blade member, a flow path member, a limiting
member, and a drive mechanism.
[0127] The blade member generates airflow to a surface of a heat
sink having the surface to which the airflow is directed.
[0128] The flow path member forms a flow path through which the
airflow is guided from the blade member to the heat sink.
[0129] The limiting member is capable of limiting the flow
path.
[0130] The drive mechanism drives the limiting member so that
switching between a first state and a second state is performed.
The first state is a state in which the flow path is free of being
limited by the limiting member, and the second state is a state in
which the flow path is limited by the limiting member to generate a
vortex so that the vortex is contacted with the surface.
[0131] As described above, according to the embodiments of the
present invention, it is possible to provide the blower apparatus
capable of automatically removing the dust that adheres to the heat
sink, the cooling apparatus including the blower apparatus and the
heat sink, and the electronic apparatus equipped with the cooling
apparatus.
[0132] These and other objects, features and advantages of the
present invention will become more apparent in light of the
following detailed description of best mode embodiments thereof, as
illustrated in the accompanying drawings.
[0133] Additional features and advantages are described herein, and
will be apparent from the following Detailed Description and the
figures.
BRIEF DESCRIPTION OF THE FIGURES
[0134] FIG. 1 is a perspective view showing an electronic apparatus
equipped with a cooling apparatus according to a first
embodiment;
[0135] FIG. 2 is a perspective view of the cooling apparatus
according to the first embodiment;
[0136] FIG. 3 is a top plan view of the cooling apparatus according
to the first embodiment;
[0137] FIG. 4 is a diagram showing a position of an opening member
in a case where the opening member is not driven;
[0138] FIG. 5 are diagrams each showing a relative position of a
blower opening and the opening member (adjustment opening) in a
case where the opening member is driven;
[0139] FIG. 6 are diagrams each showing a relationship between
coordinates of positions in the blower opening and flow rates of
airflow flown out from the blower opening in a cooling mode and a
dust removal mode;
[0140] FIG. 7 is a perspective view of a cooling apparatus
according to a second embodiment;
[0141] FIG. 8 is a development view showing the opening member;
[0142] FIG. 9 are diagrams for explaining an operation of the
cooling apparatus according to the second embodiment when the
blower opening and the opening member are viewed from the front of
the blower opening;
[0143] FIG. 10 is a perspective view of a cooling apparatus
according to a third embodiment;
[0144] FIG. 11 is a development view showing the opening
member;
[0145] FIG. 12 are diagrams for explaining an operation of the
cooling apparatus according to the third embodiment when the blower
opening and the opening member are viewed from the front of the
blower opening;
[0146] FIG. 13 is an exploded perspective view of a cooling
apparatus according to a fourth embodiment;
[0147] FIG. 14 is a perspective view of the cooling apparatus 400
according to the fourth embodiment;
[0148] FIG. 15 are diagrams for explaining an operation of the
cooling apparatus according to the fourth embodiment when the
cooling apparatus is viewed from the side;
[0149] FIG. 16 are diagrams each showing a relationship between
coordinates of positions in the blower opening and flow rates of
airflow flown out from the blower opening in the cooling mode and
the dust removal mode;
[0150] FIG. 17 are diagrams for explaining an operation of a
cooling apparatus according to a modified example when the cooling
apparatus is viewed from the side;
[0151] FIG. 18 is a flowchart showing an operation in a first mode
regarding a mode switching timing;
[0152] FIG. 19 is a flowchart showing an operation in a second mode
regarding a mode switching timing;
[0153] FIG. 20 is a flowchart showing an operation in a third mode
regarding a mode switching timing;
[0154] FIG. 21 is a flowchart showing an operation in a fourth mode
regarding a mode switching timing;
[0155] FIG. 22 is a perspective view showing an electronic
apparatus equipped with a cooling apparatus according to a fifth
embodiment;
[0156] FIG. 23 is a perspective view showing the cooling apparatus
according to the fifth embodiment;
[0157] FIG. 24 is an exploded perspective view showing the cooling
apparatus according to the fifth embodiment;
[0158] FIG. 25 is a side cross-sectional view showing the cooling
apparatus according to the fifth embodiment;
[0159] FIG. 26 are schematic views for explaining operations of the
cooling apparatus according to the fifth embodiment;
[0160] FIG. 27 is a view showing a state in which dust is adhered
to a heat sink;
[0161] FIG. 28 is an enlarged view showing the heat sink to which
the dust is adhered;
[0162] FIG. 29 are views each showing a relationship between a
generation area of a secondary vortex and various parameters;
[0163] FIG. 30 is a diagram for explaining a relationship between
an expansion factor of flow path and a size of the secondary
vortex, and showing a schematic model of enlarged airflow;
[0164] FIG. 31 is a graph showing a relationship between a ratio
xR/b0 of a re-adhesion distance xR to a slit gap b0 and an
expansion ratio D/b0;
[0165] FIG. 32 is a view showing a test apparatus used for
evaluating dust removal performance;
[0166] FIG. 33 is a graph showing a comparison among flow path
resistances of the heat sink prior to a test, in a case where the
dust removal performance is provided, and in a case where the dust
removal performance is not provided;
[0167] FIG. 34 is a flowchart showing an operation in a fifth mode
regarding a mode switching timing;
[0168] FIG. 35 is a flowchart showing an operation in a sixth mode
regarding a mode switching timing;
[0169] FIG. 36 is a flowchart showing an operation in a seventh
mode regarding a mode switching timing; and
[0170] FIG. 37 is a flowchart showing an operation in an eighth
mode regarding a mode switching timing.
DETAILED DESCRIPTION
[0171] The present application will be described with reference to
the drawings according to an embodiment.
First Embodiment
[0172] FIG. 1 is a perspective view showing an electronic apparatus
equipped with a cooling apparatus according to this embodiment. It
should be noted that in the description of this embodiment, a
laptop PC is used as an example of the electronic apparatus
equipped with the cooling apparatus.
[0173] As shown in FIG. 1, a laptop PC 101 includes an upper casing
91, a lower casing 92, and a hinge portion 93 that rotatably
connects the upper casing 91 and the lower casing 92 with each
other. The upper casing 91 includes a display portion 94 such as a
liquid crystal display and an EL (electro-luminescence)
display.
[0174] The lower casing 92 includes a plurality of input keys 95
and a touch pad 96 on an upper surface 92a and includes an outlet
97 on a side surface 92b. Further, the lower casing 92 includes an
intake (not shown) on a bottom surface 93c, for example.
[0175] A cooling apparatus 100 is disposed so as to be close to the
outlet 97 in the lower casing 92.
[0176] FIG. 2 is a perspective view of the cooling apparatus
according to this embodiment, and FIG. 3 is a top plan view of the
cooling apparatus.
[0177] As shown in FIGS. 2 and 3, the cooling apparatus 100
according to this embodiment of the present invention includes a
centrifugal blower mechanism 10, a heat sink 20, and an opening
member 30 that is movable between a blower opening 4 and the heat
sink 20. The cooling apparatus 100 further includes a drive
mechanism 40 that drives the opening member 30. It should be noted
that in FIG. 1, the blower mechanism 10, the opening member 30, and
the heat sink 20 are more separate than they really are, for ease
of explanation of the structure of the cooling apparatus 100.
[0178] The blower mechanism 10 is a centrifugal blower mechanism,
and includes a fan case 1, a centrifugal blade member 2 that is
rotatable in the fan case 1, and a fan drive motor 5 that rotates
and drives the blade member 2.
[0179] The blade member 2 is capable of rotating about a shaft
extended in a z-axis direction and is subjected to counterclockwise
rotary drive by the rotation of the fan drive motor 5. The rotation
of the blade member 2 generates airflow to the heat sink 20.
[0180] The fan case 1 includes an upper intake 3 on an upper
surface 1a of the fan case 1 and a lower intake (not shown) on a
bottom surface 1c thereof. The upper intake 3 and the lower intake
are provided in the vicinity of the center of the upper surface 1a
and the bottom surface 1c of the fan case 1, respectively. Through
the upper intake 3 and the lower intake, air around the blower
mechanism 10 is taken in the fan case 1.
[0181] The fan case 1 further includes a blower opening (outlet) 4
on a side peripheral surface 1b. The blower opening 4 has a
rectangular shape that is long in one direction (x-axis direction).
Through the blower opening 4, airflow is delivered to the heat sink
20. In the following description, a length (x-axis direction) of
the blower opening 4 is represented by L1 and a height (z-axis
direction) thereof is represented by H1.
[0182] The heat sink 20 has a rectangular parallelepiped shape that
is long in one direction (x-axis direction), and includes a
plurality of radiation fins 21 and a support plate 22 that supports
the radiation fins 21 from below. The plurality of radiation fins
21 are aligned at predetermined intervals in a longitudinal
direction (x-axis direction) of the heat sink 20. Through the gaps
of the radiation fins 21, airflow generated by the blower mechanism
passes. The heat sink 20 is made of a metal such as aluminum and
copper, for example. However, the material of the heat sink 20 is
not particularly limited.
[0183] The heat sink 20 is thermally connected to a heat source
such as a CPU provided in the lower casing 92 of the laptop PC 101,
for example.
[0184] The heat sink 20 is disposed so as to face the blower
opening 4 and be close to the blower opening 4 (see, FIG. 3). A
length L2 and a height H2 of the heat sink 20 are almost the same
as the length L1 and the height H1 of the blower opening 4,
respectively.
[0185] The opening member 30 has a rectangular thin-plate shape
that is long in one direction (x-axis direction). For example, the
opening member 30 is made of a metal, a resin, or the like, but the
material thereof is not limited to those. A height H3 of the
opening member 30 is set to be almost the same as or slightly
larger than the height H1 of the blower opening 4, and a length L3
of the opening member 30 is set to be about twice the length L1 of
the blower opening 4.
[0186] In the vicinity of the center of the opening member 30, an
opening 31 (hereinafter, referred to as adjustment opening 31)
whose size is smaller than the area of the blower opening is
formed. Further, the opening member 30 is provided with a plurality
of rack gears 32 in the longitudinal direction (x-axis direction)
of the opening member 30.
[0187] The adjustment opening 31 has a rectangular shape, for
example, but the shape is not limited to this. The adjustment
opening 31 may have a circular, oval, or polygonal shape, for
example.
[0188] The drive mechanism 40 includes a pinion 41 and a motor 42.
The pinion 41 is engaged with the rack gears of the opening member
30. The motor 42 rotates and drives the pinion 41. The motor 42 may
be a typical motor, but when a stepper motor is used for the motor
42, the movement of the opening member 30 can be positively
controlled. The same holds true for motors used in the following
embodiments.
[0189] The opening member 30 is movable between the blower opening
4 and the heat sink 20 in the x-axis direction by being driven by
the drive mechanism 40. It is to be noted that the movement of the
opening member 30 may be controlled so that the opening member 30
moves in the x-axis direction by a guide (not shown).
[0190] (Description of Operation)
[0191] Next, a description will be given on an operation of the
cooling apparatus 100. FIG. 4 is a diagram showing a position of
the opening member 30 in a case where the opening member 30 is not
driven. Meanwhile, FIG. 5 are diagrams each showing a relative
position of the blower opening 4 and the opening member 30
(adjustment opening 31) in a case where the opening member 30 is
driven. It should be noted that FIG. 5 each show a state when the
blower opening 4 and the opening member (adjustment opening 31) are
viewed from a front side of the blower opening 4.
[0192] As shown in FIG. 4, normally, the opening member 30 is not
driven by the drive mechanism 40 and is stopped in a state where
the opening member 30 is not located between the blower opening 4
and the heat sink 20.
[0193] First, a description will be given on an operation of the
cooling apparatus 100 in a case where the opening member 30 is
stopped in the state of being not disposed between the blower
opening 4 and the heat sink 20.
[0194] When the blade member 2 is rotated, air in the lower casing
92 of the laptop PC 101 is taken in the fan case 1 through the
upper intake 3 and the lower intake.
[0195] The air taken in the fan case 1 is accelerated in a
centrifugal direction by the rotation of the blade member, flown
out from the blower opening 4, and directed to the heat sink 20. In
this case, the blower opening 4 is fully opened. Therefore, the
airflow from the blower opening 4 is entirely directed to a surface
20a (hereinafter, referred to as opposed surface 20a) of the heat
sink 20, which is opposed to the blower opening 4.
[0196] From the radiation fins 21, the heat sink 20 radiates heat
transferred from the heat generation source such as the CPU
provided to the laptop PC 101. Warmed air between the radiation
fins 21 is carried by the airflow from the blower opening 4 and
forcibly exhausted to the outside of the lower casing 92 through
the outlet 97 provided to the lower casing 92. As a result, the
heat generation source such as the CPU is cooled.
[0197] It should be noted that in this specification, the state
where the heat sink 20 is cooled with the blower opening 4 being
fully opened is referred to as a cooling mode.
[0198] Here, because air in the lower casing 92 taken therein from
the upper intake 3 and the lower intake of the blower mechanism 10
contains the dust, airflow delivered from the blower opening 4 also
contains the dust. Therefore, when the airflow is directed to the
heat sink 20, the dust is also directed to the heat sink 20 and
adheres thereto. In particular, the dust easily adheres to and
accumulates on the opposed surface 20a of the heat sink 20, which
is opposed to the blower opening 4.
[0199] If the cooling mode is maintained for a long time period,
the radiation fins 21 are clogged with the dust. As a result,
ventilation through the radiation fins is hindered, resulting in
reduction in the cooling performance of the cooling apparatus
100.
[0200] Next, an operation in a case where the opening member 30 is
driven will be described with reference to FIGS. 5A to 5I.
[0201] As shown in FIG. 5A, when the rotation of the motor 42 is
started and then the rotary drive of the pinion 41 is started, the
opening member 30 starts to move leftward. In this case, the
rotation movement of the pinion 41 by the rack gears 32 provided to
the opening member 30 causes a linear movement of the opening
member 30, and thus the opening member 30 is started to move
leftward.
[0202] It should be noted that timing at which the opening member
30 is driven will be described later in detail.
[0203] As shown in FIG. 5B, the opening member 30 goes between the
blower opening 4 and the heat sink 20 from an left end portion of
the opening member 30.
[0204] As shown in FIG. 5C, when the adjustment opening 31 is moved
to a position opposed to a right end portion of the blower opening
4 and disposed between the blower opening 4 and the heat sink 20,
the airflow is directed to the heat sink 20 through the adjustment
opening 31. At this time, an apparent area of the blower opening 4
is reduced by the adjustment opening 31, and therefore a flow rate
of the airflow directed to the heat sink is locally increased. As a
result, the dust that adheres to and accumulates on the gaps
between the radiation fins 21 of the heat sink 20 can be blown
away. The dust blown away is discharged to the outside of the
laptop PC 101 through the outlet 97 provided to the lower casing 92
of the laptop PC 101.
[0205] It should be noted that in this specification, the state
where the adjustment opening 31 is located between the blower
opening 4 and the heat sink 20 and strong airflow is directed to
the heat sink 20 through the adjustment opening is referred to as a
dust removal mode.
[0206] As shown in FIGS. 5D and 5E, even after the adjustment
opening 31 reaches the right end portion of the blower opening 4,
the leftward movement of the opening member 30 is continued until
the adjustment opening 31 gets to the position opposed to a left
end portion of the blower opening.
[0207] At this time, the adjustment opening 31 is moved from the
right end portion of the blower opening 4 to the left end portion
of the blower opening 4 between the blower opening 4 and the heat
sink 20. In this case, the adjustment opening 31 moves along the
blower opening 4 while directing the strong airflow to the heat
sink 20. Therefore, the entire opposed surface 20a of the heat sink
20 can receive the strong airflow. As a result, the dust that
adheres to the heat sink 20 can be removed from the entire heat
sink 20.
[0208] When the adjustment opening 31 gets to the left end portion
of the blower opening 4 (see, FIG. 5E), a reverse rotation of the
motor 42 is started, thereby starting a reverse rotation of the
pinion, with the result that the opening member 30 is started to
move rightward.
[0209] As shown in FIGS. 5F and 5G, the adjustment opening 31 is
moved from the left end portion of the blower opening 4 to the
right end portion thereof between the blower opening 4 and the heat
sink. That is, the adjustment opening 31 is moved in the reverse
direction to the direction in the above-described case, i.e., from
left end portion of the blower opening 4 to the right end portion
thereof, and the strong airflow is directed to the entire heat sink
20, thereby entirely removing the dust that adheres to the heat
sink 20.
[0210] As shown in FIG. 5H, even after the adjustment opening 31
reaches the right end portion of the blower opening 4, the opening
member 30 is continued to move in the positive x direction.
[0211] As shown in FIG. 5I, when the opening member 30 is moved to
a position at which the opening member 30 does not face the front
of the blower opening, the rotary drive of the pinion 41 by the
motor 42 is stopped, thereby stopping the movement of the opening
member 30. When the opening member 30 is moved to the position
shown in FIG. 5I, the airflow is directed to the heat sink 20 from
the entire blower opening 4, thereby cooling the heat sink 20 again
(cooling mode).
[0212] In the description with reference to FIGS. 5A to 5I, the
case where the opening member 30 is reciprocated between the blower
opening 4 and the heat sink 20 once is shown. But, the number of
the reciprocating movements is not limited to one, and the opening
member 30 may be reciprocated two or more times. With this
operation, the dust can be positively removed from the heat sink
20.
[0213] As described above, the cooling apparatus 100 according to
this embodiment can remove the dust from the heat sink 20 by moving
the opening member 30, and thus can prevent the radiation fins 21
from being clogged with the dust and prevent the cooling
performance of the cooling apparatus 100 from deteriorating.
[0214] In addition, the cooling apparatus 100 according to this
embodiment can automatically remove the dust that adheres to the
heat sink 20, and thus can eliminate the troublesome task of
detaching the heat sink 20 from the laptop PC 101 and washing the
heat sink 20.
[0215] Further, in this embodiment, the dust can be removed from
the heat sink 20 by directing the strong airflow thereto without
increasing the rotation speed of the blade member 2 of the blower
mechanism 10. Thus, an excessive increase of power consumption of
the cooling apparatus 100 can be suppressed. In addition, even when
the power of the fan drive motor 5 that rotates the blade member 2
is small and the strong airflow is difficult to be generated, the
dust can be removed from the heat sink 20 by directing the strong
airflow to the heat sink 20.
[0216] Next, a dust removal performance of the cooling apparatus
100 according to this embodiment will be described in more
detail.
[0217] In order to evaluate the dust removal performance, the
inventors of the present invention measured the flow rate of the
airflow directed from the blower opening 4 with the blower opening
4 being fully opened (in the cooling mode), and measured the flow
rate of the airflow in the case where the airflow is directed
through the adjustment opening 31 (in the dust removal mode).
[0218] For evaluation of the dust removal performance, the flow
rate of the airflow in the case where the blower opening 4 was
fully opened (in the cooling mode) and the flow rate of the airflow
in the case where the apparent area of the blower opening 4 was
made small by the adjustment opening 31 (in the dust removal mode)
were compared.
[0219] The length L1 and the height H1 of the airflow opening 4
used for the evaluation of the dust removal performance were set to
70 mm and 10 mm, respectively, and the width and the height of the
adjustment opening 31 were set to 10 mm and 10 mm, respectively.
Further, the length L2, the height H2, and the depth of the heat
sink 20 were set to 70 mm, 10 mm, and 18 mm, respectively, and the
intervals between the radiation fins 21 were set to 1 mm.
[0220] For the measurement of the flow rate of the airflow,
Climomaster Model 6542 (registered trademark) (hereinafter, simply
referred to as anemometer) manufactured by Kanomax Japan, Inc. was
used.
[0221] In the state where the blower opening 4 was fully opened,
the flow rate of the airflow in the cooling mode was measured at
distances of 10 mm, 15 mm, 20 mm, 25 mm, . . . 60 mm from the left
end portion of the blower opening 4. Specifically, the flow rate
was measured at each of the measurement positions (10, 15, . . .
60) in the blower opening 4 with an end portion of a probe provided
to the anemometer being set at the center of the blower opening 4
at each of the measurement positions (10, 15, . . . 60).
[0222] Meanwhile, in the dust removal mode, the adjustment opening
31 was opposed to each of the measurement positions (10, 15, . . .
60) in the blower opening 4 and the flow rate was measured at each
of the measurement positions (10, 15, . . . 60) with the end
portion of the probe of the anemometer being set at the center of
the adjustment opening 31.
[0223] FIG. 6A is a table showing a relationship between
coordinates of the positions in the blower opening 4 and the flow
rates of the airflow directed from the blower opening in the
cooling mode and the dust removal mode.
[0224] FIG. 6B is a graph of the relationship shown in FIG. 6A. In
FIG. 6B, a horizontal axis indicates the coordinates of the
positions (mm) in the blower opening 4 in the x-axis direction, and
a vertical axis indicates the flow rates (m/s) of the airflows of
directed from the blower opening 4.
[0225] In addition, in FIG. 6B, the graph indicated by the dashed
line and the square dots shows the relationship between the
positions in the blower opening 4 and the flow rates in the cooling
mode. On the other hand, in FIG. 6B, the graph indicated by the
solid line and the rhomboid dots shows the relationship between the
positions in the blower opening 4 and the flow rates in the dust
removal mode.
[0226] As shown in FIGS. 6A and 6B, the flow rates of the airflows
that passed through the adjustment opening 31 were significantly
increased as compared to the case where the blower opening 4 was
fully opened.
[0227] As a result of the measurement conducted by the inventors of
the present invention, it was found that when the flow rate of the
airflow was approximately 10 m/s, the dust that clogged the
radiation fins 21 was easily removed from between the radiation
fins. As shown in FIGS. 6A and 6B, in the dust removal mode, the
flow rate exceeded 10 m/s at each of the position coordinates (10,
15, . . . 60), and it was verified that the dust adhered to the
radiation fins was desirably removed.
[0228] In FIGS. 6A and 6B, particularly characteristically, as the
flow rate becomes lower in the case where the blower opening 4 is
fully opened, the flow rate of the airflow that passes through the
adjustment opening 31 becomes higher. This reveals that as the
position is more likely to get the dust because of the low flow
rate in the fully opened state of the blower opening, the dust can
be removed more strongly.
[0229] As described above, the fact that the flow rate of the
airflow that passes through the adjustment opening 31 becomes
higher as the flow rate becomes lower in the fully opened state of
the blower opening 4 is attributed to the fact that a pressure is
more increased as the flow rate becomes lower in the state where
the blower opening 4 is fully opened. Therefore, when the
pressurized airflow passes through the adjustment opening 31, the
flow rate becomes higher.
Second Embodiment
[0230] Next, a second embodiment of the present invention will be
described. It should be noted that in the description of the second
and subsequent embodiments, the members having the same structures
and functions as the first embodiment are denoted by the same
reference numerals or symbols, and their descriptions will be
omitted or simplified.
[0231] FIG. 7 is a perspective view showing a cooling apparatus 200
according to the second embodiment. It should be noted that a gap
between the blower opening 4 of the blower mechanism 10 and the
heat sink 20 is more separate than it really is, for ease of
explanation of the structure of the cooling apparatus 200.
[0232] As shown in FIG. 7, the cooling apparatus 200 according to
the second embodiment includes the blower mechanism 10 having the
blower opening 4 and the heat sink 20 disposed at a position
opposed to the blower opening 4. In addition, the cooling apparatus
200 further includes an opening member 50 having flexibility and
first and second storage portions 60 and 70 that are capable of
rolling up and storing the opening member 50 and rolling out the
opening member 50. The blower opening 4 and the heat sink 20 are
close to each other with the opening member 50 being disposed
therebetween.
[0233] The first storage portion 60 is disposed at a position close
to a left edge portion 4c of the blower opening 4, and the second
storage portion 70 is disposed at a position close to a right edge
portion 4d of the blower opening. In other words, the first storage
portion 60 and the second storage portion 70 are disposed so as to
sandwich the blower opening 4 in a longitudinal direction (x-axis
direction) of the blower opening 4.
[0234] The first storage portion 60 disposed at the left side of
the blower opening 4 includes a first drive mechanism 64 that
drives the opening member 50 and a first case 61 that stores the
opening member 50 that is rolled up. The first drive mechanism 64
includes a first spindle 62 that is rotatable about a shaft
extended in the z-axis direction and a first motor 63 that rotates
and drives the first spindle 62. The first spindle 62 is connected
to a left end portion of the opening member 50. The first case 61
has, for example, a cylindrical shape, but the shape thereof is not
limited to this.
[0235] Similarly, the second storage portion 70 disposed at the
right side of the blower opening 4 includes a second drive
mechanism 74 and a second case 71 that stores the opening member 50
that is rolled up. The second drive mechanism 74 has a second
spindle 72 and a second motor 73. The second spindle 72 is
connected to a right end portion of the opening member 50.
[0236] FIG. 8 is a development view showing the opening member
50.
[0237] As shown in FIG. 8, the opening member 50 is long in one
direction (x-axis direction). The opening member 50 is a band-like
shape, and is formed of paper, cloth, or a resin having flexibility
such as a film, for example. But, the material of the opening
member 50 is not limited to those, and any material may be used as
long as it is flexible and capable of being rolled up.
[0238] The opening member 50 includes an adjustment opening 51
having an area smaller than that of the blower opening 4. The
opening member 50 further includes first and second openings 52 and
53 (hereinafter, referred to as full opening) each having an area
that is almost the same as the blower opening 4. That is, the
opening member 50 has the three openings, specifically, the
adjustment opening 51 formed at the center of the opening member
50, the first full opening 52 formed at the left side of the
adjustment opening 51, and the second full opening 53 formed at the
right side of the adjustment opening 51.
[0239] The first full opening 52 disposed at the left side of the
adjustment opening 51 has a height h1 and a width w1 which are
almost the same as the height H1 and the length L1 of the blower
opening 4, respectively. Similarly, the second full opening 53
disposed at the right side of the adjustment opening 51 has a
height h2 and a width w2 which are almost the same as the height H1
and the length L1 of the blower opening 4, respectively.
[0240] A distance d1 between a right end portion of the first full
opening 52 and a left end portion of the adjustment opening 51 is
preset to be almost the same as the length L1 of the blower opening
4. Similarly, a distance d2 between a left end portion of the
second full opening 53 and a right end portion of the adjustment
opening 51 is preset to be almost the same as the length L1 of the
blower opening 4.
[0241] The opening member 50 can be moved along the blower opening
4 by being driven by the first drive mechanism 64 and the second
drive mechanism 74.
[0242] (Description of Operation)
[0243] Next, a description will be given on an operation of the
cooling apparatus 200 according to the second embodiment. FIGS. 9A
to 9G are diagrams for explaining the operation when the blower
opening 4 and the opening member 50 are viewed from the front of
the blower opening 4.
[0244] As shown in FIG. 9A, the opening member 50 is stopped at a
position where the first full opening 52 is opposed to the blower
opening 4. In this case, the blower opening 4 is fully opened, and
the airflow delivered from the blower opening 4 is directed to the
entire opposed surface 20a of the heat sink 20 through the first
full opening 52, thereby cooling the heat sink (cooling mode).
[0245] When the drive of the first motor 61 is started, a rotary
drive of the first spindle 62 is started, and then a roll-up
operation of the opening member 50 is started by the first spindle
62. When the first spindle 62 is rotated and driven, the second
spindle 72 is rotated in conjunction therewith, thereby rolling out
the opening member 50 rolled up. In this case, typically, the
second motor 73 is not driven, but may be driven to forcibly roll
out the opening member 50.
[0246] As shown in FIG. 9B, when the first spindle 62 starts to
roll up the opening member 50, the opening member 50 is started to
move leftward, and along with this movement, the first full opening
52 is started to move leftward.
[0247] As shown in FIG. 9C, when the first full opening 52 is moved
to a position outside the front of the blower opening 4, the
adjustment opening 51 put out by the second spindle 72 is moved to
a position where the adjustment opening 51 is opposed to the right
end portion of the blower opening 4. When the adjustment opening 51
is put out to the front of the blower opening 4 and disposed
between the blower opening 4 and the heat sink 20, the strong
airflow is directed to the heat sink 20 (dust removal mode). As a
result, the dust that adheres to and accumulates on the radiation
fins 21 can be blown away.
[0248] As shown in FIG. 9D, the adjustment opening 51 is moved
along the blower opening 4 while directing the strong airflow to
the heat sink 20. Thus, the dust that adheres to the heat sink 20
can be removed from the entire heat sink 20.
[0249] As shown in FIG. 9E, when the adjustment opening 51 is moved
to the outside of the front of the blower opening 4, the second
full opening 53 gets to the front of the blower opening 4 from the
right side of the blower opening 4.
[0250] As shown in FIG. 9F, the second full opening 53 is moved
leftward along the blower opening.
[0251] As shown in FIG. 9G, when the second full opening 53 is
moved to the position opposed to the blower opening 4, the drive of
the first motor is stopped, and the movement of the opening member
50 is stopped. When the movement of the opening member 50 is
stopped, the airflow delivered from the blower opening 4 is
directed to the entire opposed surface 20a of the heat sink 20
through the second full opening 53, thereby cooling the heat sink
(cooling mode).
[0252] In a case where the state in which the second full opening
53 is opposed to the blower opening 4 is switched to the dust
removal mode by moving the opening member 50, the second spindle 72
is rotated and driven, and the opening member 50 is moved
rightward. It should be noted that the operation in this case is
the same as the operation of moving the opening member 50 leftward,
so the detailed description thereof will be omitted.
[0253] In the description with reference to FIGS. 9A to 9G, the
case where the opening member 50 is moved in one direction is
shown. However, the movement of the opening member 50 is not
limited to this, and the opening member 50 may be reciprocated.
Further, the opening member may of course be reciprocated two or
more times.
[0254] Further, in the description of the second embodiment, the
number of the adjustment opening 51 is set to one but is not
limited to this. The opening member 50 may include two or more
adjustment openings 51. In addition, the opening member 50 may
include two or more full openings. That is, in the opening member
50, the numbers of adjustment openings and full openings and the
distance between the adjustment opening and the full opening may be
changed as appropriate without departing from the gist of the
present invention.
[0255] In the second embodiment, the first storage portion 60 and
the second storage portion 70 can roll up the opening member 50 to
store it, with the result that a space in which the opening member
50 is disposed can be made small. With this structure, the cooling
apparatus 200 can be downsized. It should be noted that the other
effects are the same as the first embodiment and their description
will be omitted.
Third Embodiment
[0256] Next, a cooling apparatus according to a third embodiment of
the present invention will be described.
[0257] FIG. 10 is a perspective view showing a cooling apparatus
300 according to the third embodiment.
[0258] As shown in FIG. 10, the cooling apparatus 300 according to
the third embodiment includes the blower mechanism 10 having the
blower opening 4, the heat sink 20 disposed at the position opposed
to the blower opening 4, and an annular opening member 80 provided
so as to surround the blower mechanism 10. The cooling apparatus
300 further includes first to fifth spindles 85 to 89 that are
provided around the blower mechanism 10.
[0259] The first to fifth spindles 85 to 89 support the opening
member 80 so as to rotate the opening member 80 around the blower
mechanism 10. The first spindle 85 has a cylindrical shape whose
radius is larger than those of the second to fifth spindles 86 to
89, and is electrically connected to a motor 84. The first spindle
85 and the motor 84 constitute a drive mechanism 90 that drives the
opening member 80.
[0260] FIG. 11 is a development view showing the opening member
80.
[0261] As shown in FIG. 11, the opening member 80 has three
openings, that is, adjustment openings 81 and 82 and a full opening
83. The adjustment openings 81 and 82 each have an area smaller
than that of the blower opening 4, and the full opening 83 has an
area that is almost the same as the blower opening 4. The opening
member 80 is a band-like annular member, and is made of paper,
cloth, or a resin having flexibility such as a film, for example.
But, the opening member 80 may be made of any material as long as
it is flexible and capable of being annularly rotated.
[0262] The opening member 80 has a length L4 that is almost the
same as a length of the side peripheral surface 1b of the blower
mechanism 10. The full opening 83 has a height h1 and a width w1
that are almost the same as the height H1 and the length L1 of the
blower opening 4, respectively. A distance d1 between a right end
portion of the full opening 83 and a left end portion of the first
adjustment opening 81 and a distance d2 between a right end portion
of the first adjustment opening 81 and a left end portion of the
second adjustment opening 82 are set to be almost the same as the
length L1 of the blower opening 4. In addition, a distance d3
between a right end portion of the second adjustment opening 82 and
a left end portion of the full opening 83 is also set to be almost
the same as the length L1 of the blower opening 4.
[0263] (Description of Operation)
[0264] Next, an operation of the cooling apparatus 300 according to
the third embodiment of the present invention will be described.
FIGS. 12A to 12I are diagrams for explaining the operation, when
the blower opening 4 and the opening member 80 are viewed from the
front of the blower opening 4.
[0265] As shown in FIG. 12A, in the cooling mode, the full opening
83 is stopped at a position opposed to the blower opening 4. The
airflow flown out from the blower opening 4 is directed to the
entire opposed surface 20a of the heat sink 20 through the full
opening 83.
[0266] When the drive of the motor 84 is started, the rotary drive
of the first spindle 85 is started, and then the opening member 80
is rotated clockwise around the blower mechanism 10. As shown in
FIG. 12B, the clockwise rotation is started, the leftward movement
of the opening member 80 is started, and along with this movement,
the leftward movement of the full opening 83 is started.
[0267] As shown in FIG. 12C, when the full opening 83 is moved to
the outside of the front of the blower opening 4, the first
adjustment opening 81 is moved to a position opposed to the right
end portion of the blower opening 4. When the first adjustment
opening 81 is moved to the front of the blower opening 4 and
disposed between the blower opening 4 and the heat sink 20, the
strong airflow is directed to the heat sink 20 (dust removal
mode).
[0268] As shown in FIG. 12D, the first adjustment opening 81 is
moved along the blower opening 4 while directing the strong airflow
to the heat sink 20. As shown in FIG. 12E, when the first
adjustment opening 81 is moved to the outside of the front of the
blower opening 4, the second adjustment opening 82 is moved to the
position opposed to the right end portion of the blower opening 4.
As shown in FIG. 12F, the second adjustment opening 82 is moved
along the blower opening 4 while directing the strong airflow to
the heat sink 20.
[0269] As shown in FIG. 12G, when the second adjustment opening 82
is moved to the outside of the front of the blower opening 4, the
full opening 83 moved around the blower mechanism 10 gets to the
front of the blower opening 4 from the right side thereof.
[0270] As shown in FIG. 12H, the full opening 83 is moved leftward
along the blower opening 4. Then, as shown in FIG. 12I, when the
full opening 83 is moved to the position opposed to the blower
opening 4, the drive of the motor 84 is stopped, and the movement
of the opening member 80 is stopped. When the movement of the
opening member 80 is stopped, the airflow flown out from the blower
opening 4 is directed to the entire opposed surface 20a of the heat
sink 20 through the full opening 83, thereby cooling the heat sink
(cooling mode).
[0271] In the above description, the case where the opening member
80 is rotated clockwise around the blower mechanism 10 is shown.
However, the opening member 80 may be rotated counterclockwise.
Further, the number of rotations is not limited to one, and the
opening member 80 may rotate around the blower mechanism 10 two or
more times.
[0272] In the description of the third embodiment, the opening
member 80 is set to have the two adjustment openings. However, the
number of adjustment openings may be one or three or more. In
addition, the opening member 80 is set to have the one full
opening, but may have two or more full openings. That is, the
numbers of adjustment openings and full openings and the distance
between the adjustment opening and the full opening may be changed
as appropriate depending on the size of the blower mechanism 10
without departing from the gist of the present invention.
[0273] In the third embodiment, the opening member 80 can be
rotated around the blower opening 4, with the result that the space
in which the opening member 80 is disposed can be made small. Thus,
the cooling apparatus 300 can be downsized. It should be noted that
the other effects are the same as those of the first embodiment, so
their descriptions will be omitted.
Fourth Embodiment
[0274] Next, the fourth embodiment of the present invention will be
described.
[0275] FIG. 13 is an exploded perspective view of a cooling
apparatus 400 according to the fourth embodiment of the present
invention, and FIG. 14 is a perspective view of the cooling
apparatus 400 according to the fourth embodiment. It should be
noted that, in FIG. 14, a lid portion 154 is omitted to facilitate
visualization.
[0276] As shown in FIGS. 13 and 14, the cooling apparatus 400
according to the fourth embodiment includes the blower mechanism 10
having the blower opening 4 and the heat sink 20 provided so as to
be opposed to the blower opening 4. The cooling apparatus 400
further includes a rotary member 130, a drive mechanism 140, and a
support stage 150. The rotary member 130 can be rotated between the
blower opening 4 and the heat sink. The drive mechanism 140 drives
the rotary member 130. The support stage 150 supports the blower
mechanism 10, the heat sink 20, and the rotary member 130.
[0277] The rotary member 130 is provided between the blower opening
4 and the heat sink 20. The rotary member 130 has a rectangular
thin-plate-like shape that is long in one direction (x-axis
direction), and a length L5 of the rotary member is set to be
almost the same as the length L1 of the blower opening 4. The
rotary member 130 is connected to a spindle 141 at one end portion
thereof in a short-side direction and is rotatable about the
spindle 141. By the rotation of the rotary member 130, an apparent
area of the blower opening 4 can be made small. A material of the
rotary member 130 is, for example, a resin or a metal but is not
particularly limited.
[0278] The drive mechanism 40 includes the spindle 141 that is
rotatable about a shaft extended in the x-axis direction and a
motor 142 that rotates and drives the spindle 141.
[0279] The spindle 141 can rotate at a position opposed to an edge
portion 4a (hereinafter, referred to as lower edge portion 4a) on a
lower side of the blower opening 4. With this structure, the rotary
member 130 is caused to rotate about the shaft disposed at the
position opposed to the lower edge portion 4a.
[0280] The support stage 150 includes a bottom portion 151, a first
side wall portion 152, a second side wall portion 153, and the lid
portion 154. The bottom portion 151 supports the rotary member 130
and the heat sink 20 from below. The first side wall portion 152
forms a side wall on the right side of the bottom portion 151, and
the second side wall portion 153 forms a side wall on the left side
of the bottom portion 151.
[0281] The first side wall portion 152 has a through hole 155 that
penetrates the first side wall portion 152. Into the through hole
155, the spindle 141 is inserted.
[0282] The heat sink 20 is surrounded by the bottom portion 151,
the first side wall portion 152, the second side wall portion 153,
and the lid portion 154 of the support stage 150 and is fixed to
the support stage 150. Further, the blower mechanism 10 is fixed to
the support stage 150 in the vicinity of the blower opening 4. The
support stage 150 supports the blower mechanism 10, the rotary
member 130, and the heat sink 20, and regulates the airflow flown
out from the blower opening 4 so that the airflow is directed to
the heat sink 20 (y-axis direction).
[0283] (Description of Operation)
[0284] Next, a description will be given on an operation of the
cooling apparatus 400 according to the fourth embodiment. FIGS. 15A
and 15B are diagrams for explaining the operation, when the cooling
apparatus is viewed from the side.
[0285] As shown in FIG. 15A, in the cooling mode, the rotary member
130 is stopped in parallel to a horizontal surface. The airflow
flown out from the blower opening 4 is directed to the entire
opposed surface 20a of the heat sink 20.
[0286] As shown in FIG. 15B, in the dust removal mode, by
performing the rotary drive of the spindle 141 by the motor 142,
the rotary member 130 is rotated. In this case, the rotary member
130 is rotated about the shaft extended in a direction along the
longitudinal direction of the blower opening 4, which is disposed
at a position opposed to the lower edge portion 4a. The rotary
member 130 is stopped for several seconds in the state of being
tilted at a 40-degree angle, for example. As a result, the area of
the blower opening 4 is temporarily made small, and thus the strong
airflow can be directed to the heat sink 20 and the dust can be
removed from the heat sink 20. Consequently, the radiation fins 21
can be prevented from being clogged with the dust, and the cooling
performance of the cooling apparatus 400 can be prevented from
deteriorating. Here, as described above, because the rotary member
130 has the same length as the blower opening 4, the dust can be
removed from the entire heat sink 20.
[0287] In addition, because the cooling apparatus 400 can
automatically remove the dust that adheres to the heat sink 20, the
troublesome task of detaching the heat sink 20 from the laptop PC
101 and washing it can be eliminated.
[0288] Further, the dust can be removed from the heat sink 20 by
directing the strong airflow thereto without increasing the
rotation speed of the blade member 2 of the blower mechanism 10.
Thus, an excessive increase of power consumption of the cooling
apparatus 400 can be suppressed. In addition, even when the power
of the fan drive motor 5 that rotates the blade member 2 is small
and the strong airflow is difficult to be generated, the dust can
be removed from the heat sink 20 by directing the strong airflow to
the heat sink 20.
[0289] In the description with reference to FIG. 15, the rotary
member 130 is stopped with the rotary member 130 being tilted at a
40-degree angle with respect to the horizontal surface. But, the
tilt angle with respect to the horizontal surface may be less than
or more than 40 degrees. In addition, the time period for which the
rotary member is stopped in the state of being tilted is set to
several seconds in the above description, but may be set to several
minutes.
[0290] Next, the dust removal performance of the cooling apparatus
400 according to the fourth embodiment will be described in more
detail.
[0291] The dust removal performance was evaluated in the same way
as the evaluation of the dust removal performance of the cooling
apparatus 100 according to the first embodiment. That is, the dust
removal performance was evaluated by comparing the flow rate of the
airflow at a time when the blower opening 4 was fully opened (in
the cooling mode) with the flow rate of the airflow at a time when
the apparent area of the blower opening 4 was made smaller by the
rotary member 130 (in the dust removal mode).
[0292] Conditions of measuring the flow rate of the airflow in the
dust removal mode were as follows. The rotary member 130 was
stopped with the rotary member 130 being tilted at a 40-degree
angle, and the height H1 (10 mm) of the blower opening was
apparently reduced to 2 mm. The measurement positions of the
airflow were set at upper part of the rotary member 130 in the
position coordinates (10, 15, . . . and 60). It should be noted
that the other measurement conditions of the airflow were the same
as the case described with reference to FIG. 6, so their
descriptions will be omitted.
[0293] FIG. 16A is a table showing a relationship between the
position coordinates of the blower opening 4 and the flow rates of
the airflow flown out from the blower opening 4 in the cooling mode
and the dust removal mode.
[0294] FIG. 16B is a graph showing the relationship shown in FIG.
16A. In FIG. 16B, the graph represented by the dashed line and the
square dots shows the relationship between the positions in the
blower opening 4 and the flow rates in the cooling mode, and the
graph represented by the solid line and the triangular dots shows
the relationship between the positions in the blower opening 4 and
the flow rates in the dust removal mode.
[0295] From FIGS. 16A and 16B, it was found that the flow rate in
the case where the area of the blower opening 4 was made smaller by
the rotary member 130 is increased as compared to the case where
the blower opening 4 was fully opened. In addition, in the case
where the rotary member 130 was used, the lower the flow rate in
the fully opened state of the blower opening 4, the higher the flow
rate of the airflow in the cooling mode, as in the case where the
opening member 30 (opening member 50, 80) was used. This reveals
that the more likely the position is to get the dust because of the
low flow rate in the fully opened state of the blower opening 4,
the more strongly the dust can be removed therefrom.
[0296] (Modified Examples)
[0297] Next, modified examples of the cooling apparatus 400
according to the fourth embodiment will be described. FIGS. 17A and
17B are side views of the cooling apparatuses for explaining the
modified examples.
[0298] FIG. 17A shows a first modified example. As shown in FIG.
17A, the rotary member 130 of a cooling apparatus 500 according to
the first modified example is rotatable about a shaft that is
disposed at a position opposed to the center of the blower opening
4 and extended in the longitudinal direction (x-axis direction) of
the blower opening 4. The rotary member 130 is rotated upward or
downward about the shaft disposed at the position opposed to the
center of the blower opening 4. With this structure, the apparent
area of the blower opening 4 is made smaller, and the strong
airflow is directed to the heat sink 20, with the result that the
dust can be removed therefrom.
[0299] In the description with reference to FIG. 17A, the rotary
member 130 is rotatable about the shaft disposed at the center of
the blower opening 4, but is not limited to this. The rotary member
130 may be rotatable about a shaft disposed at a position opposed
to an upper edge portion 4b of the blower opening 4.
[0300] FIG. 17B shows a second modified example. As shown in FIG.
17B, a cooling apparatus 600 according to the second modified
example is provided with first and second rotary members 131 and
132 so that the blower opening 4 is disposed between the two rotary
members 131 and 132. The first rotary member 131 is rotatable about
the shaft disposed at the position opposed to the lower edge
portion 4a of the blower opening 4, and the second rotary member
132 is rotatable about a shaft disposed at the position opposed to
the upper edge portion 4b of the blower opening 4. In this way, by
providing the two rotary members 131 and 132, the distance d
between the blower opening 4 and the heat sink 20 can be reduced.
As a result, the cooling apparatus 400 can be downsized.
[0301] In the fourth embodiment, the rotary member 130 is rotatable
about the shaft extended in the longitudinal direction (x-axis
direction) of the blower opening 4. But, the rotary member 130 may
instead be rotatable about a shaft extended in the short-side
direction (y-axis direction) of the blower opening.
[0302] (First Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0303] Next, a description will be given on a first mode regarding
timing of switching between the cooling mode and the dust removal
mode. Although modes relating to the timing of switching between
the cooling mode and the dust removal mode, which will be described
in the following, may be applied to any one of the cooling
apparatuses 100 to 400 described above, the cooling apparatus 100
is used as an example for convenience of the explanation.
[0304] FIG. 18 is a flowchart showing an operation of the first
mode regarding the mode switching timing. It should be noted that a
CPU is used as a control system of the cooling apparatus 100 in
this case.
[0305] As shown in FIG. 18, the CPU of the cooling apparatus 100
judges whether a drive start signal of the fan drive motor 5 is
input (Step 101). When the drive start signal is not input (No in
Step 101), the CPU judges again whether the drive start signal of
the fan drive motor 5 is input. In this case, the blower opening 4
is fully opened, and the heat sink 20 is cooled (cooling mode).
[0306] For example, when the drive start signal of the fan drive
motor 5 is output from the electronic apparatus such as the laptop
PC 101, the drive start signal is input to the CPU of the cooling
apparatus 100.
[0307] When the drive start signal of the fan drive motor 5 is
input (Yes in Step 101), the CPU starts to drive the fan drive
motor 5 (Step 102). When the drive of the fan drive motor is
started, the rotation of the blade member 2 is started, and the
airflow is delivered from the blower opening 4.
[0308] Next, the CPU starts to drive the motor 42 and controls the
movement of the opening member 30 (Step 103). When the opening
member 30 is moved, the adjustment opening 31 is moved along the
blower opening 4 while directing the strong airflow to the heat
sink 20, thereby blowing the dust away from the entire heat sink 20
(see, FIG. 5) (dust removal mode).
[0309] After causing the opening member 30 to reciprocate once (or
more times) between the blower opening 4 and the heat sink, the CPU
stops the drive of the motor 42 and the movement of the opening
member 30 (Step 104). When the opening member 30 is stopped, the
blower opening 4 is fully opened, and the heat sink 20 is cooled
(cooling mode).
[0310] When the CPU stops the drive of the motor, the processing
returns to Step 101 again, and the subsequent steps are
repeated.
[0311] By the above processing, it is possible to periodically
switch the cooling mode to the dust removal mode. Therefore, it is
possible to remove the dust from the heat sink before the dust that
adheres to the heat sink accumulates thereon and the clogging of
the radiation fins is caused.
[0312] (Second Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0313] Next, a description will be given on a second mode regarding
timing of switching between the cooling mode and the dust removal
mode. FIG. 19 is a flowchart showing an operation of the second
mode.
[0314] As shown in FIG. 19, the CPU judges whether a stop notice
signal of the fan drive motor 5 is input (Step 201). When the stop
notice signal is not input (No in Step 201), the CPU judges again
whether the stop notice signal is input. In this case, the blower
opening 4 is fully opened, and the heat sink 20 is cooled (cooling
mode).
[0315] When the stop notice signal is input (Yes in Step 201), the
CPU does not stop the fan drive motor 5 immediately but starts to
drive the motor 42 to control the movement of the opening member 30
(Step 202). When the movement of the opening member 30 is started,
the adjustment opening 31 is disposed between the blower opening 4
and the heat sink 20, thereby blowing the dust away from the heat
sink 20 (dust removal mode).
[0316] Next, the CPU stops the drive of the motor 42 (Step 203) and
stops the drive of the fan drive motor 5 (Step 204).
[0317] By the above processing, it is also possible to periodically
remove the dust from the heat sink 20. Thus, the same effect as the
first mode can be obtained.
[0318] (Third Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0319] Next, a description will be given on a third mode regarding
timing of switching between the cooling mode and the dust removal
mode. FIG. 20 is a flowchart showing an operation of the third
mode.
[0320] The CPU judges whether the drive of the motor 42 rotated is
stopped (Step 301). That is, the CPU judges whether the dust
removal mode is switched to the cooling mode and the cooling mode
is started. When the drive of the motor 42 rotated is stopped (Yes
in Step 301), the CPU sets a timer of a counter to be on and starts
counting of count values generated at predetermined intervals. For
the counter, a counter dedicated to the cooling apparatus 100 may
be used, or a counter equipped to the electronic apparatus such as
the laptop PC 101 may be used.
[0321] Next, the CPU judges whether the count value reaches a
specified value (Step 303). The specified value corresponds to a
certain time period, e.g., one week, but is not limited to
this.
[0322] When the count value reaches the specified value (Yes in
Step 303), that is, the certain time period (e.g., one week)
elapses from when the cooling mode is started, the CPU judges
whether the fan drive motor 5 is driven (Step 304).
[0323] In a case where the fan drive motor 5 is driven (Yes in Step
304), the CPU drives the motor 42 and controls the movement of the
opening member 30 (Step 305), and thereafter stops the drive of the
motor 42 (Step 306) (dust removal mode).
[0324] On the other hand, in a case where the fan drive motor 5 is
not driven when the count value reaches the specified value (No in
Step 304), the CPU judges whether a drive signal of the fan drive
motor 5 is input from the electronic apparatus such as the laptop
PC 101, for example (Step 307).
[0325] When the drive signal of the fan drive motor 5 is input (Yes
in Step 307), the CPU drives the fan drive motor 5 (Step 308), and
thereafter starts the drive of the motor 42 (Step 305). That is, in
a case where the fan drive motor 5 is not driven when the count
value reaches the specified value, the CPU drives the motor 42
after the drive signal of the fan drive motor 5 is input.
[0326] When the drive of the motor 42 is stopped (Step 306), that
is, when the cooling mode is started, the CPU resets the timer
(Step 302) and restarts counting by the counter.
[0327] By the above processing, it is also possible to periodically
switch the cooling mode to the dust removal mode.
[0328] (Fourth Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0329] Next, a description will be given on a fourth mode regarding
timing of switching between the cooling mode and the dust removal
mode. FIG. 21 is a flowchart showing an operation of the fourth
mode.
[0330] As shown in FIG. 21, the CPU judges whether the drive of the
motor 42 rotated is stopped (Step 401) and judges whether the
cooling mode is started.
[0331] When the drive of the motor 42 rotated is stopped and the
cooling mode is started (Yes in Step 401), the CPU inputs a
rotation signal from the fan drive motor 5 and starts counting of
the number of rotations of the fan drive motor 5 by using the
counter (Step 402).
[0332] Next, the CPU judges whether the count value of the number
of rotations reaches the specified value (Step 403). The specified
value is set to, for example, one million but is not limited to
this.
[0333] When the count value reaches the specified value (Yes in
Step 403), that is, when the number of rotations of the blade
member 2 reaches the specified number of times (for example, one
million times), the CPU starts the drive of the motor 42 (Step 404)
and controls the movement of the opening member 30. After that, the
CPU stops the drive of the motor (Step 405), resets the number of
rotations, and restarts counting of the number of rotations of the
fan drive motor 5 (Step 402).
[0334] By the above processing, it is also possible to periodically
switch the cooling mode to the dust removal mode.
[0335] The above embodiments and modes can be variously
modified.
[0336] For example, in order to ensure the movements of the opening
members 30, 50, and 80 or the control of the rotation of the rotary
member 130, an optical sensor or a magnetic sensor may be used.
[0337] Further, in the description with reference to FIG. 1, the
laptop PC 101 is used as an example of the electronic apparatus
equipped with the cooling apparatus 100, 200, 300, or 400, but the
electronic apparatus is not limited to this. Examples of the
electronic apparatus include a desktop PC, audiovisual equipment, a
projector, a game machine, a robot apparatus, and the like.
[0338] In the above embodiments, the motors are used for driving
the opening member, but a solenoid may instead be used.
Fifth Embodiment
[0339] FIG. 22 is a perspective view showing an electronic
apparatus equipped with a cooling apparatus according to this
embodiment. It should be noted that in the description of this
embodiment, a laptop PC is used as an example of the electronic
apparatus equipped with the cooling apparatus. Further, figures for
the following description do not show actual dimensions in some
cases to make the figures clearly understandable.
[0340] As shown in FIG. 22, a laptop PC 1101 includes an upper
casing 1091, a lower casing 1092, and a hinge portion 1093 that
rotatably connects the upper casing 1091 and the lower casing 1092
with each other. The upper casing 1091 includes a display portion
1094 such as a liquid crystal display and an EL
(electro-luminescence) display.
[0341] The lower casing 1092 includes a plurality of input keys
1095 and a touch pad 1096 on an upper surface 1092a and includes an
outlet 1097 on a side surface 1092b. Further, the lower casing 1092
includes an intake (not shown) on a bottom surface 1093c, for
example.
[0342] The lower casing 1092 includes a control circuit board (not
shown) on which electronic circuit components such as the CPU are
mounted.
[0343] A cooling apparatus 1100 is disposed so as to be close to
the outlet 1097 in the lower casing 1092.
[0344] FIG. 23 is a perspective view of the cooling apparatus
according to this embodiment, and FIG. 24 is an exploded
perspective view of the cooling apparatus. FIG. 25 is a side
cross-sectional view of the cooling apparatus.
[0345] As shown in FIGS. 23 to 25, the cooling apparatus 1100
according to the fifth embodiment includes a heat sink 1060 and a
blower apparatus 1050 that generates airflow to the heat sink
1060.
[0346] The heat sink 1060 has a rectangular parallelepiped shape
that is long in one direction (x-axis direction), and has a
predetermined width W1 (x-axis direction) and a predetermined
height H1 (z-axis direction). The heat sink 1060 includes a
plurality of radiation fins 1061, and an upper plate member 1062
and a lower plate member 1063 that support the radiation fins 1061
from above and below. The plurality of radiation fins 1061 are
arranged in a line at predetermined intervals along the
longitudinal direction (x-axis direction) of the heat sink 1060.
The airflow generated by the blower apparatus 1050 passes through
gaps between the radiation fins 1061. The heat sink 1060 is formed
of, for example, a metal such as aluminum and copper, but the
material is not particularly limited.
[0347] It should be noted that, out of all the surfaces of the heat
sink 60, a surface opposed to a blade member 1010 is referred to as
an opposed surface 1060a.
[0348] In the heat sink 1060, the upper plate member 1062 is
thermally connected to a heat pipe 1070. The heat pipe 1070 is
thermally connected to a heat source such as a CPU of the laptop PC
1101 through a heat spreader 1080, for example. Heat generated in
the CPU is received and diffused by the heat spreader 1080 and
transferred to the heat sink 1060 through the heat pipe 1070.
[0349] A method of thermally connecting the heat sink 1060 and the
heat generation source such as the CPU is not particularly limited.
For example, the heat sink 1060 may be directly connected with the
heat spreader 1080 without the heat pipe 1070.
[0350] The blower apparatus 1050 includes the blade member 1010, a
fan case 1020, and a fan drive motor 1015. The blade member 1010 is
rotatable. The fan case 1020 stores the blade member 1010 therein.
The fan drive motor 1015 rotates and drives the blade member 1010.
In addition, the blower apparatus 1050 includes a rotary member
(limiting member) 1030 and a drive mechanism 1040. The rotary
member 1030 is provided between the blade member 1010 and the heat
sink 1060. The drive mechanism 1040 drives the rotary member
1030.
[0351] The blade member 1010 is a centrifugal blade member, and
includes a boss portion 1011 and a plurality of blade portions 1012
provided so as to extend from the boss portion 1011 in a
centrifugal direction. The blade member 1010 is rotatable about a
shaft extended in the z-axis direction and is rotated
counterclockwise by the fan drive motor 1015. The rotation of the
blade member 1010 causes the airflow to the heat sink 1060.
[0352] The fan drive motor 1015 is constituted of a stator, a
magnet, and a rotor yoke (not shown), for example. The fan drive
motor 1015 is electrically connected to the CPU of the laptop PC
1101, and the CPU controls the drive and stop of the fan drive
motor 1015, for example.
[0353] The fan case 1020 is constituted of a case main body 1021
and a lid member 1022, for example. The case main body 1021 forms a
side peripheral portion 1020b and a lower portion 1020c of the fan
case 1020. The lid member 1022 forms an upper portion 1020a of the
fan case 1020.
[0354] On the upper portion 1020a and the lower portion 1020c of
the fan case 1020, an upper intake 1023 and a lower intake 1024 are
provided, respectively. The upper intake 1023 and the lower intake
1024 are provided in the vicinity of the center of the upper
portion 1020a and the lower portion 1020c, respectively.
[0355] In addition to the function of storing the blade member
1010, the fan case 1020 functions as a flow path for guiding the
airflow generated by the blade member 1010 to the heat sink 1060.
Hereinafter, an area that mainly functions as the flow path of the
airflow between the blade member 1010 and the heat sink 1060 is
referred to as a flow path area 1020P of the fan case 1020 (see,
FIG. 4). In addition, in the flow path area 1020P, a direction in
which the airflow is directed is referred to as a flow path
direction.
[0356] In the flow path area 1020P, a flow path 1026 is a
rectangular flow path having a width W2 and a height H2, each of
which is approximately constant in the flow path direction (y-axis
direction) (cross-sectional area of the flow path=W2*H2). The width
W2 and the height H2 of the flow path 1026 are relatively set with
respect to the width W1 and the height H1 of the heat sink 1060 so
that the width W2 and the height H2 of the flow path 1026 are
approximately equal to the width W1 and the height H1 of the heat
sink 1060, respectively. With this structure, the airflow that
passes through the flow path 1026 is directed to the entire heat
sink 1060.
[0357] The rotary member 1030 is provided between the blade member
1010 and the heat sink 1060 in the fan case 1020. That is, the
rotary member 1030 is provided in the flow path area 1020P of the
fan case 1020.
[0358] The rotary member 1030 has a rectangular thin-plate shape
that is long in one direction (x-axis direction). A width W3 of the
rotary member 1030 is approximately equal to the width W2 of the
flow path 1026. It should be noted that a detailed description will
be given on a height H3 of the rotary member 1030 later. The rotary
member 1030 is made of a resin or a metal, for example, but the
material is not particularly limited.
[0359] The drive mechanism 1040 includes a spindle 1041 connected
to the rotary member 1030, an arm portion 1042 connected to one end
portion of the spindle 1041, a spring 1043 connected to the arm
portion 1042, and a solenoid 1044 that drives the arm portion
1042.
[0360] The spindle 1041 is rotatably disposed along the x-axis
direction in the lower part of the flow path area 1020P and
connected to one end portion of the rotary member 1030 in a
short-side direction thereof. With this structure, the rotary
member 1030 is rotatable about the spindle 1041 in the flow path
area 1020P.
[0361] The arm portion 1042 is connected to one end portion of the
spindle 1041 through a hole formed in the side peripheral portion
1020b of the fan case 1020.
[0362] One end portion of the spring 1043 is connected to a spring
support portion 1045 provided on the side peripheral portion 1020b
of the fan case 1020, and the other end portion of the spring 1043
is connected to the arm portion 1042.
[0363] The solenoid 1044 is electrically connected to the CPU of
the laptop PC 1101, for example, and the CPU performs control to
drive the spindle 1041 and the rotary member 1030 by using the arm
portion 1042.
[0364] (Description of Operation)
[0365] Next, an operation of the cooling apparatus 1100 will be
described. FIGS. 26A and 26B are schematic diagrams each showing
the operation of the cooling apparatus 1100. FIG. 26A schematically
shows a state in which the rotary member 1030 is laid down, and
FIG. 26B schematically shows a state in which the rotary member
1030 is raised at a predetermined angle with respect to the flow
path direction.
[0366] First, with reference to FIG. 26A, the operation in the
state where the rotary member 1030 is laid down will be
described.
[0367] As shown in FIG. 26A, the rotary member 1030 is generally
laid down with the rotary member 1030 being parallel to the airflow
and stopped. That is, the rotary member 1030 is stopped without
limiting the flow path 1026.
[0368] For example, when the fan drive motor 1015 is started to
drive by the control of the CPU, the blade member 1010 starts to
rotate. When the blade member 1010 starts to rotate, air in the
lower casing 1092 of the laptop PC 1101 is taken in the fan case
1020 through the upper intake 1023 and the lower intake 1024.
[0369] The air taken in the fan case 1020 is accelerated by the
blade member 1010 in the centrifugal direction, thereby generating
the airflow to the heat sink 1060. The airflow generated by the
blade member 1010 passes through the flow path 1026 and is directed
to the opposed surface 1060a of the heat sink 1060.
[0370] The heat sink 1060 radiates, from the radiation fins 1061,
heat transferred from the heat generation source such as the CPU
through the heat spreader 1080 and the heat pipe. The air warmed in
the radiation fins 1061 is exhausted to the outside of the laptop
PC 1101 through the outlet 1097 of the laptop PC 1101 by the
airflow generated by the blade member 1010. As a result, the CPU
and the heat sink 1060 are cooled.
[0371] It should be noted that the state in which the rotary member
1030 does not limit the flow path 1026 to be released and the heat
sink 1060 is cooled is referred to as a cooling mode in this
specification.
[0372] Here, the air in the lower casing 1092, which is taken
therein from the upper intake 1023 and the lower intake 1024,
contains the dust. Accordingly, the airflow directed to the heat
sink 1060 also contains the dust. For this reason, the dust adheres
to and accumulates on the heat sink 1060.
[0373] FIG. 27 is a view showing a state where the dust adheres to
the heat sink. FIG. 28 is an enlarged view of the heat sink in a
state where the dust adheres thereto.
[0374] If the cooling mode is maintained for a long time period,
the radiation fins 1061 are clogged with the dust. The dust that
adheres to and accumulates on the heat sink 1060 is mainly
constituted of filiform dusts. The filiform dust is likely to
adhere to and accumulate on the opposed surface 1060a of the heat
sink 1060 in particular.
[0375] If the heat sink 1060 is left in the state where the dust
adheres to and accumulates on the heat sink 1060, ventilation of
the radiation fins 1061 is hindered, leading to deterioration of
the cooling performance for the cooling apparatus 1100.
[0376] Next, with reference to FIG. 26B, the operation in the state
where the rotary member 1030 is raised at the predetermined angle
with respect to the flow path direction will be described.
[0377] For example, when the solenoid 1044 is driven by the control
of the CPU, the rotary member 1030 is rotated about the spindle
1041. In this case, the rotary member 1030 is stopped for several
seconds or several minutes with the rotary member 1030 being tilted
at 90 degrees with respect to the flow path direction, for
example.
[0378] When the rotary member 1030 is rotated and the flow path
1026 of the airflow is locally reduced in area (the flow path 1026
in this state will be referred to as a narrow flow path 1027
hereinafter), the airflow is changed to generate a secondary vortex
on the right side of the rotary member 1030. That is, when the
airflow is delivered from the narrow flow path to a wide flow path,
the secondary vortex is generated due to a relationship of an
expansion factor of the flow path. The cooling apparatus 1100
according to this embodiment uses the secondary vortex generated
due to the relationship of the expansion factor of the flow
path.
[0379] When the rotary member 1030 limits the flow path 1026 to
generate the secondary vortex, the dust that adheres to the opposed
surface 1060a of the heat sink 1060 is blown away by the secondary
vortex. The dust removed by the secondary vortex is caught into the
secondary vortex, released from the gaps between the radiation fins
1061, and then released to the outside of the laptop PC 1101
through the outlet 1097 of the laptop PC 1101.
[0380] In this specification, the state where the rotary member
1030 limits the flow path 1026 to generate the secondary vortex and
remove the dust by the secondary vortex is referred to as a dust
removal mode.
[0381] As described above, in the cooling apparatus 1100 according
to this embodiment, in the dust removal mode, it is possible to
strongly remove the dust that adheres to the opposed surface 1060a
of the heat sink 1060 by the secondary vortex. As a result, the
cooling performance of the cooling apparatus 1100 can be prevented
from deteriorating.
[0382] Further, in the cooling apparatus 1100 according to this
embodiment, the switching operation between the cooling mode and
the dust removal mode is controlled by the CPU. Therefore, the
switching between the cooling mode and the dust removal mode can be
automatically performed. Accordingly, it is possible to
automatically remove the dust that adheres to the heat sink 1060,
with the result that the troublesome task of detaching the heat
sink 1060 from the laptop PC 1101 and washing the heat sink can be
eliminated.
[0383] Further, in this embodiment, the dust can be removed from
the heat sink 1060 without increasing the rotation speed of the
blade member 1010. Thus, an excessive increase in power consumption
of the cooling apparatus 1100 can be suppressed. In addition, even
when the strong airflow is difficult to be generated due to small
power of the fan drive motor 1015 that rotates the blade member
1010, the dust can be removed from the heat sink 1060.
[0384] In the description with reference to FIG. 26B, the rotary
member 1030 is stopped with the rotary member being tilted at 90
degrees with respect to the flow path direction in the dust removal
mode. However, the state of the rotary member 1030 is not limited
to this. The angle with respect to the flow path 1026 may be less
than or more than 90 degrees. In other words, in the dust removal
mode, it is only necessary to meet the condition that the secondary
vortex is in contact with at least the opposed surface 1060a of the
heat sink. The angle at which the rotary member 1030 is raised is
not particularly limited.
[0385] (Relationship Between Generation Area of Secondary Vortex
and Various Parameters)
[0386] As described above, the cooling apparatus 1100 according to
this embodiment partly intends to remove the dust that adheres to
the heat sink 1060 by using the secondary vortex generated by the
rotary member 1030. To realize this, various parameters are set so
that at least the opposed surface 1060a of the heat sink 1060 is
disposed in the generation area of the secondary vortex. The
various parameters include the height H2 of the flow path 1026, the
height H3 of the rotary member 1030, an angle .PHI. by which the
rotary member 1030 is rotated, the distance d between the rotary
member 1030 and the opposed surface 1060a of the heat sink, a gap a
of the narrow flow path 1027, and the like.
[0387] FIGS. 29A and 29B are diagrams each showing the relationship
between the generation area of the secondary vortex and the various
parameters.
[0388] FIG. 29A shows the relationship between the generation area
of the secondary vortex and the various parameters in a case where
the rotary member 1030 is rotated by 90 degrees (.PHI.=90 degrees).
FIG. 29B shows the relationship between the generation area of the
secondary vortex and the various parameters in a case where the
rotary member 1030 is rotated by 45 degrees (.PHI.=45 degrees).
[0389] Here, the relationship between the expansion factor of the
flow path and the size of the secondary vortex will be
described.
[0390] FIG. 30 is a diagram for explaining the relationship between
the expansion factor of the flow path and the size of the secondary
vortex. FIG. 30 shows a schematic model of enlarged airflow.
[0391] In FIG. 30, the gap of a slit is represented by b.sub.0, a
height from the bottom surface to the slit is represented by D, a
re-adhesion distance is represented by x.sub.R, an adhesion angle
is represented by .theta., and a distance from an end of the narrow
flow path to a virtual origin is represented by x.sub.0. Further,
in FIG. 30, a re-adhesion flow line is indicated by a dashed line,
and a coordinate system with its origin being set on a center flow
line is indicated by x-y axes.
[0392] The adhesion angle .theta. is expressed by the following
expression (1) based on a momentum equilibrium condition.
cos .theta.=3t/2-t.sup.3/2 (1)
[0393] t used in the expression (1) is expressed by the following
expression (2).
t=tan h(.sigma.y'/(x+x.sub.0)) (2)
[0394] Here, in the expression (2), a diffusion coefficient is
represented by .sigma., and an intersection point of the y axis
with the re-adhesion flow line in the coordinate system with its
origin being set on the center flow line is represented by y'.
[0395] Based on a geometric relationship, an expansion ratio
D/b.sub.0 is expressed by the following expression (3).
D/b.sub.0=.sigma.(1/t.sup.2-1){(1-cos .theta.)/3.theta.}-1/2
(3)
[0396] Further, a ratio x.sub.R/b.sub.0 of the re-adhesion distance
x.sub.R to the slit gap b.sub.0 is expressed by the following
expression (4).
x.sub.R/b.sub.0=.sigma.(1/t.sup.2-1)sin .theta./3.theta.-tan
h.sup.-1t/3t.sup.2 sin .theta. (4)
[0397] By solving the simultaneous equations of the expressions (1)
and (3), t and .theta. are obtained as functions of the expansion
ratio D/b.sub.0, and the obtained values are assigned to the
expression (4). As a result, the ratio x.sub.R/b.sub.0 of the
re-adhesion distance x.sub.R to the slit gap b.sub.0 can be
obtained as a function of the expansion ratio D/b.sub.0.
[0398] In this case, an approximate expression indicating a
relationship between the ratio x.sub.R/b.sub.0 of the re-adhesion
distance x.sub.R to the slit gap b.sub.0 and the expansion ratio
D/b.sub.0 is expressed by the following expression (5).
x.sub.R/b.sub.0=2.22(D/b.sub.0).sup.0.636+0.780D/b.sub.0+0.939
(5)
[0399] FIG. 31 is a graph showing the relationship between the
ratio x.sub.R/b.sub.0 of the re-adhesion distance x.sub.R to the
slit gap b.sub.0 and the expansion ratio D/b.sub.0.
[0400] In FIG. 31, rhomboid dots indicate numeric solutions
obtained by actually solving the expressions (1), (3), and (4), and
the solid line indicates the approximate expression (5) mentioned
above.
[0401] Further, in FIG. 31, a shaded area indicates the generation
area of the secondary vortex.
[0402] When the FIG. 29A and FIG. 30 are compared, in the case
where the rotary member 1030 is rotated by the angle .PHI. of 90
degrees, the height H.sub.3 of the rotary member 1030 corresponds
to the height D from the bottom surface to the slit, and the gap a
of the narrow flow path 1027 corresponds to the slit gap b.sub.0.
In this case, D and b.sub.0 shown in FIG. 31 are replaced with
H.sub.3 and a, respectively, and the parameters including the
height H.sub.3, the gap a of the narrow flow path 1027, and the
distance d between the rotary member 1030 and the opposed surface
1060a of the heat sink are set so that the value in the shaded area
of FIG. 31 is obtained.
[0403] In addition, when FIG. 29B and FIG. 30 are compared, in the
case where the rotary member 1030 is rotated by 45 degrees, a sine
component of the height H.sub.3 of the rotary member 1030, i.e.,
H.sub.3sin .PHI. (.PHI.=45 degrees) corresponds to the height D
from the bottom surface to the slit, and the gap a of the narrow
flow path 1027 corresponds to the slit gap b.sub.0. In this case,
the height D and b.sub.0 shown in FIG. 31 are replaced with
H.sub.3sin45.degree. and a, respectively, and the parameters
including the height H.sub.3, the gap a of the narrow flow path
1027, and the distance d between the rotary member 1030 and the
opposed surface 1060a of the heat sink are set so that the value in
the shaded area of FIG. 31 is obtained.
[0404] As a result, the opposed surface 1060a of the heat sink 1060
is disposed in the generation area of the secondary vortex, and
therefore the dust that adheres to and accumulates on the opposed
surface 1060a of the heat sink 1060 can be appropriately
removed.
[0405] (Evaluation of Dust Removal Performance)
[0406] Next, the dust removal performance of the cooling apparatus
1100 will be described in more detail.
[0407] FIG. 32 is a diagram showing a test apparatus 1081 used for
evaluating the dust removal performance.
[0408] As shown in FIG. 32, the test apparatus 1081 included a
hollow test apparatus main body 1082 and two sirocco fans 1083
provided inside the test apparatus main body 1082. The dimensions
of the test apparatus main body 1082 were set to
300.times.300.times.300 mm. The two sirocco fans 1083 were provided
on side walls of the test apparatus main body 1082 so as to be
opposed to each other.
[0409] Inside the test apparatus main body 1082, a cotton waste
1085 likened to the dust and the cooling apparatus 1100 were
disposed. Over the cooling apparatus 1100, a net 1084 was covered
for preventing a large dust ball from getting thereinto.
[0410] First, the sirocco fans 1083 were driven for thirty seconds
with the blade member 1010 of the cooling apparatus 1100 being
rotated (Step 1).
[0411] Next, the rotary member 1030 was rotated by 45 degrees with
respect to the flow path direction and maintained for ten seconds,
and thereafter the rotary member 1030 was returned to the position
at 0 degree with respect to the flow path direction and maintained
for ten seconds. This operation was repeated twice (Step 2).
[0412] After that, Step 1 and Step 2 were repeated ten times.
[0413] It should be noted that in a cooling apparatus used for
comparison (cooling apparatus having no dust removal performance),
the rotary member 1030 was maintained at 0 degree with respect to
the flow path direction without being rotated in Step 2 above.
[0414] FIG. 33 is a diagram showing comparison among flow path
resistances of the heat sink prior to the test, in the case where
the dust removal performance was provided, and in the case where
the dust removal performance was not provided.
[0415] In FIG. 33, a vertical axis represents a pressure difference
.DELTA.P (Pa) between the airflow before passing through the heat
sink 1060 and the airflow after passing through the heat sink 1060,
and a horizontal axis represents an air volume Q (m.sup.3/min) of
the airflow passing through the heat sink 1060.
[0416] In FIG. 33, a curved line obtained by linking triangular
dots indicates the flow path resistance prior to the test. A curved
line obtained by linking square dots indicates the flow path
resistance in the case where the dust removal performance was
provided, that is, the case where the rotary member 1030 was
driven. Further, a curved line obtained by linking rhomboid dots
indicates the flow path resistance in the case where the dust
removal performance was not provided, that is, the case where the
rotary member 1030 was not driven.
[0417] It should be noted that approximate expressions (6), (7),
and (8) of the curved lines prior to the test, in the case where
the dust removal performance was provided, and in the case where
the dust removal performance was not provided shown in FIG. 33 are
as follows, respectively.
.DELTA.P=4.82.times.10.sup.3Q.sup.2+2.54.times.10.sup.2Q (6)
.DELTA.P=4.88.times.10.sup.3Q.sup.2+2.62.times.10.sup.2Q (7)
.DELTA.P=7.71.times.10.sup.3Q.sup.2+5.42.times.10.sup.2Q (8)
[0418] As shown in FIG. 33, the flow path resistance of the heat
sink 1060 in the case where the dust removal performance was
provided was markedly smaller than that in the case where the dust
removal performance was not provided. In addition, the flow path
resistance of the heat sink 1060 in the case where the dust removal
performance was provided was almost the same as that prior to the
test.
[0419] As shown in FIG. 33, it was found that, in the cooling
apparatus 1100 according to this embodiment, the dust causing the
flow path resistance of the heat sink 60 was desirably removed. In
other words, the cooling apparatus 1100 according to this
embodiment has high dust removal performance.
[0420] The state where the dust adhered to the heat sink 1060 not
having the dust removal performance and the state where the dust
adhered to the heat sink 1060 having the dust removal performance
were observed. As a result, in the heat sink 1060 not having the
dust removal performance, the entire radiation fins 1061 on the
opposed surface 1060a were clogged with the dust, which merely
allowed the gaps between the radiation fins in the center of the
heat sink 1060 to be partly seen. In contrast, in the heat sink
1060 having the dust removal performance, the dust hardly adhered
to the opposed surface 1060a, and a little dust just adhered to the
both sides of the heat sink.
[0421] (Fifth Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0422] Next, a description will be given on a fifth mode regarding
timing of switching between the cooling mode and the dust removal
mode.
[0423] FIG. 34 is a flowchart showing an operation of the fifth
mode regarding the mode switching timing.
[0424] As shown in FIG. 34, the CPU of the laptop PC judges whether
a drive start signal of the fan drive motor 1015 is input (Step
1101). When the drive start signal is not input (No in Step 1101),
the CPU judges again whether the drive start signal of the fan
drive motor 1015 is input.
[0425] When the drive start signal of the fan drive motor 1015 is
input (Yes in Step 1101), the CPU starts to drive the fan drive
motor 1015 (Step 1102). When the drive of the fan drive motor is
started, the rotation of the blade member 1010 is started, and the
airflow is generated to the heat sink 1060.
[0426] When starting the drive of the fan drive motor 1015, the CPU
starts to drive the solenoid 1044 subsequently (Step 1103). When
the solenoid 1044 is driven, the rotary member 1030 is rotated by
45 degrees with respect to the flow path direction. The rotation of
the rotary member 1030 locally makes the flow path 1026 smaller,
which generates the secondary vortex. The secondary vortex blows
away the dust that adheres to the opposed surface 1060a of the heat
sink 1060 to remove the dust (dust removal mode).
[0427] After several seconds or several minutes later since the
start of the drive of the solenoid 1044, the CPU stops the drive of
the solenoid 1044 (Step 1104). When the drive of the solenoid 1044
is stopped, the rotary member 1030 is returned to the position at 0
degree with respect to the flow path direction, thereby causing the
rotary member 1030 to be parallel to the airflow. In this case, the
heat sink 1060 is cooled (cooling mode).
[0428] When the CPU stops the drive of the solenoid 1044, the
processing returns to Step 1101 again, and the steps subsequent to
Step 1101 are repeated.
[0429] By the above processing, it is possible to periodically
switch the cooling mode to the dust removal mode, with the result
that the dust can be removed from the heat sink before the dust
that adheres to the heat sink 60 accumulates thereon and causes
clogging of the radiation fins.
[0430] (Sixth Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0431] Next, a description will be given on a sixth mode regarding
timing of switching between the cooling mode and the dust removal
mode. FIG. 35 is a flowchart showing an operation of the sixth mode
regarding the mode switching timing.
[0432] As shown in FIG. 35, the CPU judges whether a stop notice
signal of the fan drive motor 1015 is input (Step 1201). When the
stop notice signal is not input (No in Step 1201), the CPU judges
again whether the stop notice signal is input. In this case, the
rotary member 1030 is not rotated, and the heat sink 1060 is cooled
(cooling mode).
[0433] When the stop notice signal of the fan drive motor 1015 is
input (Yes in Step 1201), the CPU does not immediately stop the fan
drive motor 1015 but starts to drive the solenoid 1044 (Step 1202).
When the drive of the solenoid 1044 is started, the rotary member
1030 is rotated, and thus the secondary vortex is generated. As a
result, the dust that adheres to the opposed surface 1060a of the
heat sink 1060 is blown away and removed therefrom (dust removal
mode).
[0434] After several seconds or several minutes later since the
start of the drive of the solenoid 1044, the CPU stops the drive of
the solenoid 1044 (Step 1203). When the drive of the solenoid 1044
is stopped, the rotary member 1030 is returned to the position at 0
degree with respect to the flow path direction, thereby causing the
rotary member 1030 to be parallel to the airflow.
[0435] After stopping the drive of the solenoid 1044, the CPU stops
the drive of the fan drive motor 1015 (Step 1204).
[0436] By the above processing, it is also possible to periodically
remove the dust from the heat sink 1060, and therefore the same
effect as the fifth mode can be obtained.
[0437] (Seventh Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0438] Next, a description will be given on a seventh mode
regarding timing of switching between the cooling mode and the dust
removal mode. FIG. 36 is a flowchart showing an operation of the
seventh mode.
[0439] The CPU judges whether the drive of the solenoid 1044 is
stopped (Step 1301). That is, the CPU judges whether the dust
removal mode is switched to the cooling mode and the cooling mode
is started. When the drive of the solenoid 1044 is stopped (Yes in
Step 1301), the CPU sets a timer of a counter to be on and starts
counting of count values generated at predetermined intervals. For
the counter, a counter dedicated to the cooling apparatus 1100 may
be used, or a counter equipped to the electronic apparatus such as
the laptop PC 1101 may be used.
[0440] Next, the CPU judges whether the count value reaches a
specified value (Step 1303). The specified value corresponds to a
certain time period, e.g., one week, but is not limited to
this.
[0441] When the count value reaches the specified value (Yes in
Step 1303), that is, when the certain time period (e.g., one week)
elapses from when the cooling mode is started, the CPU judges
whether the fan drive motor 1015 is driven (Step 1304).
[0442] When the fan drive motor 1015 is driven (Yes in Step 1304),
the CPU starts to drive the solenoid 1044 (Step 1305). In this
case, the rotary member 1030 is rotated, thereby generating the
secondary vortex. As a result, the dust is removed from the opposed
surface 1060a of the heat sink 1060 (dust removal mode).
[0443] After several seconds or several minutes later since the
start of the drive of the solenoid 1044, the CPU stops the drive of
the solenoid 1044 (Step 1306). In this case, the rotary member 1030
is returned to the position at 0 degree with respect to the flow
path direction, thereby cooling the heat sink 1060 (cooling
mode).
[0444] On the other hand, in a case where the fan drive motor 1015
is not driven when the count value reaches the specified value (No
in Step 1304), the CPU judges whether a drive signal of the fan
drive motor 1015 is input (Step 1307).
[0445] When the drive signal of the fan drive motor 1015 is input
(Yes in Step 1307), the CPU drives the fan drive motor 1015 (Step
1308) and thereafter starts the drive of the solenoid 1044 (Step
1305). That is, in a case where the fan drive motor 1015 is not
driven when the count value reaches the specified value, the CPU
drives the solenoid 1044 after the drive signal of the fan drive
motor 1015 is input.
[0446] When the drive of the solenoid 1044 is stopped (Step 1306),
that is, when the cooling mode is started, the CPU resets the timer
(Step 1302) and restarts counting by the counter.
[0447] By the above processing, it is also possible to periodically
switch the cooling mode to the dust removal mode.
[0448] (Eighth Mode Regarding Timing of Switching Between Cooling
Mode and Dust Removal Mode)
[0449] Next, a description will be given on an eighth mode
regarding timing of switching between the cooling mode and the dust
removal mode. FIG. 37 is a flowchart showing an operation of the
eighth mode.
[0450] As shown in FIG. 37, the CPU judges whether the drive of the
solenoid 1044 is stopped (Step 1401) and judges whether the cooling
mode is started.
[0451] When the drive of the solenoid 1044 is stopped and the
cooling mode is started (Yes in Step 1401), the CPU inputs a
rotation signal from the fan drive motor 1015 and starts counting
of the number of rotations of the fan drive motor 1015 by using the
counter (Step 1402).
[0452] Next, the CPU judges whether the count value of the number
of rotations reaches the specified value (Step 1403). The specified
value is set to, for example, one million but is not limited to
this.
[0453] When the count value reaches the specified value (Yes in
Step 1403), that is, when the number of rotations of the blade
member 1010 reaches the specified number of times (for example, one
million times), the CPU starts the drive of the solenoid 1044 (Step
1404) and rotates the rotary member 1030. After that, the CPU stops
the drive of the solenoid 1044 (Step 1405), resets the number of
rotations, and restarts counting of the number of rotations of the
fan drive motor 1015 (Step 1402).
[0454] By the above processing, it is also possible to periodically
switch the cooling mode to the dust removal mode.
[0455] (Various Modified Examples)
[0456] The above embodiments can be variously modified.
[0457] For example, in order to ensure the control of the angle by
which the rotary member 1030 is rotated, an optical sensor or a
magnetic sensor may be used.
[0458] In the above embodiments, the drive mechanism 1040 that
drives the rotary member 1030 includes the arm portion 1042, the
spring 1043, and the solenoid 1044. However, the structure of the
drive mechanism 1040 is not limited to this. For example, as the
drive mechanism 1040 for driving the rotary member 1030, a motor
may be used instead of the solenoid. In this case, in order to
ensure the control of the angle by which the rotary member 30 is
rotated, a stepper motor may be used.
[0459] In the above embodiments, the CPU of the laptop PC controls
the drives of the fan drive motor 1015 and the solenoid 1044, but
the structure is not limited to this. A CPU dedicated to the
cooling apparatus 1100 may be provided and may control the drives
of the fan drive motor 1015 and the solenoid 1044.
[0460] In the description with reference to FIG. 22, the laptop PC
1101 is used as an example of the electronic apparatus equipped
with the cooling apparatus 1100, but the electronic apparatus is
not limited to this. Examples of the electronic apparatus include a
desktop PC, audiovisual equipment, a projector, a game machine, a
robot apparatus, and others.
[0461] It should be understood that various changes and
modifications to the presently preferred embodiments described
herein will be apparent to those skilled in the art. Such changes
and modifications can be made without departing from the spirit and
scope of the present subject matter and without diminishing its
intended advantages. It is therefore intended that such changes and
modifications be covered by the appended claims.
* * * * *