BACKGROUND
[0001] The invention relates to a fan assembly, and in particular to a fan assembly applicable
to a light source producing heat.
With the continuous development of electronic devices, heat dissipation systems become
necessary as temperature is significantly increased due to heat produced during operation.
If heat is not appropriately dissipated, high temperature causes performance to deteriorate
and may cause the electronic devices to fail. Particularly, since semiconductor and
integrated circuits (IC) design has improved, the integrated circuit size has been
reduced and the number of transistors per unit area has substantially increased, further
concentrating heat energy. Thus, a heat dissipation system is required to effectively
dissipate the excess heat and maintain working temperature.
[0002] Fan assembly is the most popular heat dissipation apparatus. Fig. 1A is a top view
of a conventional fan assembly, and Fig. 1B is a cross section of Fig. 1A. As shown
in Figs. 1A and 1B, the conventional fan 10 comprises a frame 11, an impeller 15,
and a motor (not shown). The motor is disposed in a motor base 12 to drive the impeller
15. The frame 11 comprises a body with an opening defined therein. The motor base
12 disposed in the frame11 is supported by a plurality of ribs 13. The ribs 13 can
be cylindrical, arced, or streamlined. The impeller 15 comprises a plurality of radially
arranged blades 14.
[0003] In Fig. 1B, as known, when two ribs 13 are both connected to the motor base 12 and
the frame 11, they are not located along the same diameter of the impeller 15, and
the cross section of the two ribs 13 would be discontinuous. For clear illustration,
however, the ribs are shown in their entirety in Fig. 1B.
[0004] During rotation of the impeller 15, a gap is formed between the frame 11 and the
blades 14 to prevent contact therebetween, which produces friction and noise, as shown
in Fig. 1A. If the fan assembly 10, however, is applied to an optical machine to dissipate
heat of the light source (lamp) L, the emitted light Lp may partially penetrate the
gap between the frame 11 and the blades 14, causing light loss, as shown in Fig. 1B.
Consequently, projected light intensity is reduced, and if escaped light Lp continuously
illuminates other areas or objects such as a desk, the surface of the desk can be
damaged by the light. The escaped light not only damages the surroundings but also
causes safety concerns.
SUMMARY
[0005] Embodiments of the invention provide a fan assembly with various frames and corresponding
blade edge designs to fully obstruct a light path between the blades and the frame,
for preventing loss of light.
[0006] Embodiments of the invention further provide a fan assembly applicable to a light
source that produces heat. The fan assembly comprises a frame and an impeller. The
frame comprises an opening and a periphery of the opening has a curved surface. The
impeller is disposed in the body. When light emitted by the light source enters the
opening, the light is blocked from penetrating the opening by the curved surface.
Moreover, the opening of the body comprises an inlet and an outlet, the emitted light
entering the inlet is blocked by the curved surface, preventing light emission from
out of the outlet. Embodiments of the invention further provide a fan assembly applicable
to a light source that produces heat. The fan assembly comprises a frame and an impeller.
The frame comprises an opening and a periphery of the opening has at least one inclined
surface. The impeller is disposed in the body. When light emitted by the light source
enters the opening of the frame, the light is blocked from penetrating the opening
by the inclined surface. The periphery of the opening comprises multi-sectional inclined
surfaces with different inclined angles. The impeller comprises blade edges, parallel
to the multi-sectional inclined surfaces. Moreover, the periphery of the opening comprises
multi-sectional inclined surfaces, protruded toward a central axis of the opening,
and the impeller comprises blade edges facing the concave sides of the multi-sectional
inclined surfaces, and the periphery of the opening exceeds a line connected by two
ends of the concave sides.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Embodiments of the invention can be more fully understood by reading the subsequent
detailed description in conjunction with the examples and references made to the accompanying
drawings, wherein:
Fig. 1A is a top view of a conventional fan assembly;
Fig. 1B is a cross section of the conventional fan assembly;
Figs. 2A and 2B are cross sections of two fan assemblies according to a first embodiment
of the invention;
Figs. 3A and 3B are cross sections of two fan assemblies according to a second embodiment
of the invention;
Figs. 3C and 3D are two cross sections of another fan assemblies according to the
second embodiment of the invention;
Figs. 4A to 4F are cross sections of fan assemblies according to a third embodiment
of the invention; and
Fig. 4G is a top view of the entire fan assembly according to the third embodiment
of the invention.
DETAILED DESCRIPTION
First Embodiment
[0008] Figs. 2A and 2B are cross sections of a fan assembly according to a first embodiment
of the invention. The fan assembly 20 comprises a frame 21, an impeller 24, and a
motor (not shown). The motor is disposed in a motor base 22 for driving the impeller
25. The frame 21 comprises a body with an opening 26 defined therein. The periphery
27 of the opening 26 has a curved surface.
[0009] The motor base 22 is disposed in the body of the frame 21 and supported by a plurality
of ribs 23. The impeller 25 comprises a plurality of radially arranged blades 24.
[0010] When the fan assembly 20 for dissipating heat is applied to a light source L producing
heat such as a light bulb of a projector, light emitted by the light source L enters
the opening 26, and the periphery 27 of the opening 26 has a curved surface for blocking
the light, and thus, the light is prevented from penetrating the opening 26.
[0011] The periphery 27 of the opening 26 can have a curved surface depressed toward a central
axis of the opening 26, as shown in Fig. 2A. The curved surface of the periphery 27
gradually contracts, and the blade edges of the impeller 25 correspond to the curved
surface of the periphery 27 of the opening. Each edge of the blade 24 exceeds an imaginary
line connected by two ends of the curved surface of the periphery 27. The imaginary
line is represented by a dashed line in Fig. 2A. The blade edges of the impeller 25
are preferably parallel to the curved surface.
[0012] An inlet 211 and an outlet 212 are respectively formed at two ends of the opening
26 on the frame 21. The light emitted by the light source L enters the inlet 211 into
the frame 21. The periphery 27 of the opening 26 having a concave surface corresponding
to the blade edges can prevent light leakage from the outlet 212. Since a possible
light path can be completely blocked at the location between the blades 24 and the
frame 21, the problem of loss of light in a projector utilizing a conventional fan
can be prevented. Furthermore, according to differing curved surfaces of the periphery
27 of the opening 26, area of the external edge of the blades 24 can be further increased,
thereby increasing air pressure.
[0013] Alternatively, the periphery 27 of the opening 26 can have a convex surface protruded
toward a central axis of the opening 26, as shown in Fig. 2B. The frame 21 has an
inwardly concave side, and the blade edges of the impeller 25 correspond to the convex
surface of the periphery 27 of the opening 26 to form concave sides separately. The
concave side edge of each blade 24 is facing and corresponding to the curved surface
of the periphery 27. The blade edges of the impeller 25 are preferably parallel to
the convex surface. The protruded convex surface of the periphery 27 of the opening
26 exceeds an imaginary line connected by two ends of the concave side of the blade
24 edges. The imaginary line is represented by a dashed line in Fig. 2B. Thus, when
the light is emitted by the light source L, the light can be blocked from penetrating
the frame 21, since the protruded surface of the periphery 27 of the opening 26 corresponds
to the blade edges.
[0014] Furthermore, at the inlet 211 and the outlet 212 of the fan assembly 20 in both Figs.
2A and 2B, the periphery 27 of the opening 26 or a vicinity thereof can be formed
with an inclined angle or a guided inclined angle to increase the cross-sectional
area of the flow path and increase air flow intake. Moreover, the curved surface preferably
comprises a contracting and an expanding curved surface, or a plurality of radial
contracting and expanding curved surfaces in the fan assembly 20 in Fig. 2A or in
Fig. 2B. Also, any two adjacent curved surfaces can have different curvature.
Second Embodiment
[0015] Figs. 3A and 3B are cross sections of a fan assembly according to a second embodiment
of the invention. The fan assembly 30 comprises a frame 31, an impeller 35, and a
motor (not shown). The motor is disposed in a motor base 32 for driving the impeller
35. The frame 31 comprises a body with an opening 36 defined thereon.
[0016] The periphery of the opening 36 has at least one inclined surface. The motor base
32 is disposed in the body of the frame 31 and supported by a plurality of ribs 33.
The impeller 35 comprises a plurality of radially arranged blades 34.
[0017] When the fan assembly 30 for dissipating heat is applied to a light source L producing
heat such as a light bulb of a projector, light emitted by the light source L enters
the opening 36, and the periphery 37 of the opening 36 has an inclined surface for
blocking the light, and thus, the light is prevented from penetrating the opening
36.
[0018] The periphery 37 of the opening 36 comprises multi-sectional inclined surfaces with
different inclined angles. For example, an inclined surface comprises a radially contracting
inclined surface 3A
1 and a radially expanding inclined surface 3A
2, as shown in Fig. 3A.
[0019] The cross section of the frame 31 is preferably constituted of the contracting inclined
surface 3A
1 and the expanding inclined surface 3A
2 from the inlet 311 to the outlet 312. An external edge of the blade 34 is parallel
to the contracting inclined surface 3A
1 such that light is effectively blocked from penetrating the frame 31. Also, the expanding
inclined surface 3A
2 increases area of flow path, and increase airflow intake. Additionally, the inclined
surface comprises a plurality of a combination of radially contracting inclined surfaces
and radially expanding inclined surfaces, and each two adjacent inclined surfaces
are connected at different angles. For example, as shown in Fig. 3B, the cross section
of the frame 31 can be considered as being consisted of several inclined surfaces
with different angles, such as two contracting inclined surfaces 3B
1, 3B
2, and one expanding inclined surface 3B
3, from the inlet 311 to the outlet 312. The contracting inclined surfaces 3B
1, 3B
2 can obstruct a potential light path between the blades 34 and the frame 31, and the
external edges of the blades 34are parallel to the contracting inclined surfaces 3B
2. Also, the expanding inclined surfaces 3B
3 increase area of the flow path, thereby increasing airflow intake.
[0020] Furthermore, as shown in Figs. 3C and 3D, the motor base 32 is disposed in the frame
31 and supported by a plurality of ribs 33. The motor base 32 and the ribs 33 can
be disposed at the inlet 311 or the outlet 312. In Figs. 3C and 3D, the motor base
32 comprises a slope inclined radially in order to increase air outflow area, when
the motor base 32 and the ribs 33 are disposed at the outlet 312. The slope can have
a flat surface (Fig. 3C) or a curved surface (Fig. 3D). If the motor base 32 and the
ribs 33 are disposed at the inlet 31 of the frame 31, the inclined motor base 32 can
increase inflow area.
[0021] Furthermore, the inclined angle of the motor base 32 can be varied in accordance
with different curvature of the cross section of the frame 31 to allow air smoothly
flow between the motor base 32 and the frame 31, when the blades 34 rotate, so that
noise can be reduced.
Third Embodiment
[0022] Figs. 4A to 4F are cross sections of a fan assembly according to a third embodiment
of the invention. The fan 40 comprises a frame 41, an impeller 45, and a motor (not
shown). The motor is disposed in a motor base 42 for driving the impeller 45. The
frame 41 comprises a body with an opening 46 defined thereon. The periphery 47 of
the opening 46 comprises at least one inclined surface. The motor base 42 is disposed
in the frame 41 and supported by a plurality of ribs 43. The impeller 45 comprises
a plurality of radially arranged blades 44. When the fan assembly 40 for dissipating
heat is applied to a light source producing heat such as a light bulb of a projector,
light emitted by the light source enters the opening 46, and the periphery 47 of the
opening 46 has an inclined surface for blocking the light. The blades 44 have a maximum
outer diameter greater than the inner diameter of the periphery 47 of the opening
46.
[0023] As a result, a potential light path between the blades 44 and the frame 41 can be
obstructed by an overlapping portion between the blades 44 and the periphery 47 of
the opening 46. Thus, the light is prevented from penetrating the opening 46.
[0024] The frame 41 comprises at least one inclined surface or curved surface from an inlet
411 to an outlet 412. The cross section of the frame 41 can be gradually contracting
curved surface, expanding curved surface or a combination thereof. The contracting
curved surface obstructs the light path between the blades 44 and the frame 41. The
expanding curved surface can increase area of the flow path and increase the airflow
intake. Furthermore, the external edges of the blades can be designed with various
shapes in accordance with the frame 41. For example, the external edges of the blades
can be flat (as shown in Figs. 4C and 4D), conical (as shown in Figs. 4E and 4F),
stepped shapes (as shown in Figs. 4A and 4B), and so on.
[0025] The invention is not limited to the above embodiments. Moreover, the blades 44 not
only have maximum outer diameter greater than a minimum inner diameter of the periphery
47 of the opening 46, each blade 44a also partially overlaps with an adjacent blade
44b in an axial direction of the opening 46, as shown in Fig. 4G. Fig. 4G is a top
view of the entire fan assembly according to the third embodiment of the invention.
The overlapping blades can further effectively block the light. Embodiments of the
invention are compared to a conventional fan with a light-blocking experiment with
the same size of frame from 50mm, 60mm, and 70mm frames in a black box. A 3000 Lux.
of light irradiates in the black box. The amount of light passing through the fans
is recorded in Table 1 as follows.
Table 1
|
Frame size |
|
SQ 50mm |
SQ 60mm |
SQ 70mm |
fan assembly of the present invention |
7.2 Lux |
4.13 Lux |
1.3 Lux |
conventional fan assembly |
490 Lux |
329 Lux |
318 Lux |
[0026] In a 50mm-sized frame, the amount of light passing through the conventional fan assembly
is 490 Lux, but the amount of light passing through the fan assembly of embodiments
of the invention designed with light-blocking characteristics is only 7.2 Lux. Thus
it demonstrates that the present invention can block light effectively.
[0027] While the invention has been described by way of example and in terms of preferred
embodiment, it is to be understood that the invention is not limited thereto. To the
contrary, it is intended to cover various modifications and similar arrangements (as
would be apparent to those skilled in the art). Therefore, the scope of the appended
claims should be accorded the broadest interpretation so as to encompass all such
modifications and similar arrangements.
1. A fan assembly, applicable to a light source producing heat, the fan assembly comprising:
a frame comprising an opening and a periphery of the opening having a curved surface;
and
an impeller, disposed in the frame;
wherein when light emitted by the light source enters the opening, the light is blocked
from penetrating the opening by the curved surface.
2. The fan assembly as claimed in claim 1, wherein the opening forms an inlet and an
outlet of the frame, and the emitted light entering the inlet is blocked from emitting
out of the outlet by the curved surface.
3. The fan assembly as claimed in claim 2, wherein the periphery of the opening comprises
an inclined angle at the inlet or the outlet, or a vicinity of the periphery comprises
a guided inclined angle.
4. The fan assembly as claimed in claim 1, wherein the curved surface comprises a concave
surface, depressed toward a central axis of the opening, and the impeller comprises
blade edges, exceeding a line connected by two ends of the curved surface.
5. The fan assembly as claimed in claim 1, wherein the curved surface comprises a convex
surface, protruded toward a central axis of the opening, the impeller comprises blade
edges and a concave side facing the curved surface of the opening, and the curved
surface of the periphery of the opening exceed a line connected by two ends of the
concave side of the impeller.
6. The fan assembly as claimed in claim 5, wherein the periphery of the opening comprises
an inclined angle or a vicinity of the periphery comprises a guided inclined angle.
7. The fan assembly as claimed in claim 1, wherein the impeller comprises blade edges,
parallel to the curved surface.
8. The fan assembly as claimed in claim 1, wherein the curved surface comprises a contracting
curved surface and an expanding curved surface.
9. The fan assembly as claimed in claim 1, further comprising a motor base disposed in
the frame, and a plurality of ribs for supporting the motor base; wherein the motor
base comprises a slope inclined radially, thereby increasing areas of air flow intake
or outtake.
10. The fan assembly as claimed in claim 9, wherein the slope is flat or curved.
11. The fan assembly as claimed in claim 1, wherein the impeller has blades with a maximum
outer diameter greater than a minimum inner diameter of the periphery of the opening.
12. The fan assembly as claimed in claim 11, wherein the impeller comprises blades with
flat, conical, or stepped edges.
13. The fan assembly as claimed in claim 12, wherein each blade of the impeller overlaps
an adjacent blade in an axial direction of the opening.
14. A fan assembly, applied to a light source producing heat, the fan assembly comprising:
a frame comprising an opening, and a periphery of the opening having at least one
inclined surface; and
an impeller, disposed in the frame;
wherein when light emitted by the light source enters the opening, the light is blocked
from penetrating the opening by the inclined surface.
15. The fan assembly as claimed in claim 14, wherein the periphery of the opening comprises
multi-sectional inclined surfaces with different inclined angles.
16. The fan assembly as claimed in claim 15, wherein the impeller comprises blade edges,
parallel to the multi-sectional inclined surfaces.
17. The fan assembly as claimed in claim 14, wherein the periphery of the opening comprises
multi-sectional inclined surfaces, depressed toward a central axis of the opening,
and the impeller comprises blade edges exceeding a line connected by two ends of the
opening.
18. The fan assembly as claimed in claim 14, wherein the periphery of the opening comprises
multi-sectional inclined surfaces having convex sides, protruded toward a central
axis of the opening, the impeller comprises blade edges and a concave surface facing
the convex sides of the multi-sectional inclined surfaces, and the periphery of the
opening exceeds a line connected by two ends of the concave surface of the impeller.
19. The fan assembly as claimed in claim 14, wherein the impeller comprises blade edges,
parallel to the inclined surface.
20. The fan assembly as claimed in claim 14, wherein the periphery of the opening comprises
an expanding inclined surface.
21. The fan assembly as claimed in claim 14, further comprising a motor base disposed
in the frame, and a plurality of ribs for supporting the motor base; wherein the motor
base comprises a flat or curved slope inclined radially, thereby increasing areas
of air flow intake or outtake.
22. The fan assembly as claimed in claim 14, wherein the impeller has blades with a maximum
outer diameter greater than a minimum inner diameter of the periphery of the opening.
23. The fan assembly as claimed in claim 14, wherein the impeller comprises blades with
flat, conical, or stepped edges.
24. The fan assembly as claimed in claim 14, wherein each blade of the impeller overlaps
an adjacent blade in an axial direction of the opening.