U.S. patent application number 15/398890 was filed with the patent office on 2017-04-27 for charged powder supply device.
The applicant listed for this patent is ACHROLUX INC.. Invention is credited to Peiching Ling, Dezhong Liu.
Application Number | 20170115601 15/398890 |
Document ID | / |
Family ID | 52020907 |
Filed Date | 2017-04-27 |
United States Patent
Application |
20170115601 |
Kind Code |
A1 |
Ling; Peiching ; et
al. |
April 27, 2017 |
CHARGED POWDER SUPPLY DEVICE
Abstract
A charged powder supply device is disclosed. A plurality of
charged powder particles are disposed on an upper side of a carrier
and at least an action source is positioned at a lower side of the
carrier for acting on the carrier so as to vibrate the charged
powder particles on the upper side of the carrier. As such, the
vibrated charged powder particles are attached to objects to be
coated, such as LEDs, under the effect of an electric field so as
to form a powder layer, such as a phosphor layer. Since there are
no other external forces that affect the moving direction of the
charged powder particles, the powder layer can be uniformly formed
on the objects.
Inventors: |
Ling; Peiching; (Sunnyvale,
CA) ; Liu; Dezhong; (Sunnyvale, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ACHROLUX INC. |
Sunnyvale |
CA |
US |
|
|
Family ID: |
52020907 |
Appl. No.: |
15/398890 |
Filed: |
January 5, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14461507 |
Aug 18, 2014 |
9586216 |
|
|
15398890 |
|
|
|
|
61896169 |
Oct 28, 2013 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 5/1608 20130101;
B05B 5/1683 20130101; B05C 19/00 20130101; H01L 33/44 20130101;
B05C 19/002 20130101; B05C 19/025 20130101; G03G 15/0887 20130101;
B05C 19/04 20130101; B05B 5/057 20130101; H01L 2933/0041
20130101 |
International
Class: |
G03G 15/08 20060101
G03G015/08; B05B 5/057 20060101 B05B005/057; B05B 5/16 20060101
B05B005/16 |
Claims
1. A charged powder supply device, comprising: a carrier having
opposite first and second sides, wherein a plurality of charged
powder particles are disposed on the first side of the carrier; and
at least an action source positioned at the second side of the
carrier for acting on the carrier so as to vibrate the charged
powder particles on the first side of the carrier, thereby causing
the charged powder particles to leave the first side of the
carrier.
2. The device of claim 1, wherein the action source provides an
impact force, a fluid motion, or an acoustic or ultrasonic
wave.
3. The device of claim 1, further comprising a receiving member
positioned over and separated from the first side of the carrier
for receiving the vibrated charged powder particles.
4. The device of claim 1, wherein the action source is in contact
with the second side of the carrier.
5. The device of claim 1, wherein the action source is separated
from the second side of the carrier.
6. The device of claim 1, wherein a support member is disposed on
the second side of the carrier.
7. The device of claim 6, wherein the support member has a
plurality of through holes corresponding in position to a plurality
of action sources.
8. The device of claim 7, wherein the action sources are disposed
in the through holes, respectively.
9. The device of claim 1, wherein the carrier further has: a
plurality of through holes penetrating the first and second sides,
and a carrying portion positioned on the first side of the carrier
and covering one ends of the through holes, wherein the carrying
portion is used for carrying the charged powder particles.
10. The device of claim 9, wherein the action source acts on the
carrying portion through the through holes of the carrier so as to
vibrate the charged powder particles.
11. The device of claim 9, further comprising a receiving member
positioned over and separated from the first side of the carrier
for receiving the vibrated charged powder particles.
12. The device of claim 11, wherein the distance between the
receiving member and the first side of the carrier is greater than
the distance between any adjacent two of the through holes of the
carrier.
13. The device of claim 1, wherein the carrier has a plurality of
uniformly distributed conductive traces or a planar conductor
structure having uniformly distributed points formed by metal
etching.
14. The device of claim 1, further comprising power supplies
disposed on the first side of the carrier.
15. The device of claim 14, further comprising a receiving member
positioned over and separated from the first side of the carrier
for receiving the vibrated charged powder particles.
16. The device of claim 15, wherein the power supplies are arranged
in parallel or crossed to form a grid pattern with gaps in a manner
that the distance between the receiving member and the power
supplies is greater than the width of the gaps.
17. The device of claim 14, wherein the carrier has a plurality of
through holes penetrating the first and second sides, and the power
supplies are arranged in parallel or crossed to form a grid pattern
with gaps in a manner that the distance between any adjacent two of
the through holes of the carrier and the width of the gaps are in a
relationship of integer times.
18. The device of claim 1, wherein the carrier is a power supply
for generating an electric field and a corona discharge.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Division of application Ser. No.
14/461,507 filed on Aug. 18, 2014, which claims the benefit of
priority to Provisional application Ser. No. 61/896,169 filed on
Oct. 28, 2013, the entire contents of both of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to devices used for forming
uniform powder layers on objects, and more particularly, to a
charged powder supply device.
[0004] 2. Description of Related Art
[0005] Along with the rapid development of electronic industries,
electronic products are becoming lighter, thinner, shorter and
smaller and developed towards high performance, high function and
high speed.
[0006] In a conventional LED fabrication process, phosphor is
formed on an object by dispensing or coating. During coating, it is
difficult to control the coating amount of phosphor in different
areas of the object and consequently the phosphor in different
areas often has different thicknesses. Also, the phosphor may be
distributed on LEDs by a diffusion process. However, it is
difficult to control the diffusion direction of the phosphor. As a
result, the LEDs have different amount of phosphor formed
thereon.
[0007] FIG. 1 shows a conventional coating process in other
industries. Referring to FIG. 1, a powder supply device 1 has: a
fluidized board 10 having a plurality of micro-holes (not shown), a
supply portion 11 disposed below the fluidized board 10, and a
receiving member 12 disposed over the fluidized board 10 and having
a plurality of objects 13 to be coated. The fluidized board 10 is
used for carrying powder 8.
[0008] In operation, air is supplied from one side of the fluidized
board 10 by the supply portion 11 so as to provide an air flow A to
a lower side of the fluidized board 10. The air flow A then passes
through the micro-holes of the fluidized board 10 to cause the
powder 8 to rise up and be attached to the receiving member 12.
[0009] However, since it is difficult to control the direction of
the air flow A after it passes through the micro-holes of the
fluidized board 10, undirected flows, such as turbulent flows, can
easily occur, especially after the air flow A arrives at and then
bounces back from the receiving member 12. Consequently, the powder
8 cannot rise up and be distributed uniformly on the receiving
member 12. Accordingly, the powder 8 cannot be uniformly attached
to the objects 13.
[0010] Further, since the micro-holes of the fluidized board 10
have a very small size, some of them may be blocked by the powder 8
in operation and prevent the air flow A from passing through,
thereby preventing the powder 8 from being uniformly attached to
the receiving member 12.
[0011] If the coating process shown in FIG. 1 is applied to the
manufacturing process of LEDs, since the air flow A, after passing
through the fluidized board 10, cannot flow unidirectionally, the
powder 8 will not rise uniformly. As a result, the powder 8 will
not be distributed uniformly on the LEDs disposed on the receiving
member 12, and the LEDs do not have highly uniform phosphor formed
thereon.
[0012] Therefore, how to overcome the above-described drawbacks has
become urgent.
SUMMARY OF THE INVENTION
[0013] In view of the above-described drawbacks, the present
invention provides a charged powder supply device, which comprises:
a carrier having opposite first and second sides, wherein a
plurality of charged powder particles are disposed on the first
side of the carrier; and at least an action source positioned at
the second side of the carrier for acting on the carrier so as to
vibrate the charged powder particles on the first side of the
carrier, thereby causing the charged powder particles to leave the
first side of the carrier.
[0014] In the above-described device, the action force can be in
contact with or separated from the second side of the carrier.
[0015] In the above-described device, the carrier can have a
plurality of uniformly distributed conductive traces or a planar
conductor structure having uniformly distributed points formed by
metal etching.
[0016] The above-described device can further comprise power
supplies disposed on the first side of the carrier.
[0017] In an embodiment, the carrier can be a power supply for
generating an electric field and a corona discharge.
[0018] The present invention further provides another charged
powder supply device, which comprises: a carrier having opposite
first and second sides, a plurality of through holes penetrating
the first and second sides, a plurality of balls positioned in the
through holes, and a plurality of carrying portions positioned on
the first side and respectively covering one ends of the through
holes, wherein the carrying portions are used for carrying a
plurality of charged powder particles; and at least an action
source positioned at the second side of the carrier for acting on
the carrier so as to vibrate the charged powder particles on the
first side of the carrier, thereby causing the charged powder
particles to leave the first side of the carrier.
[0019] In the above-described device, the carrier can further have
a positioning plate on the second side thereof. Further, the balls
can protrude from the positioning plate.
[0020] Therefore, the present invention forms a powder layer on
objects through the charged powder supply device. That is, the
action force acts on the carrier to vibrate the charged powder
particles, thereby causing the charged powder particles to leave
the carrier so as to be attached to the objects under the effect of
an electric field. By vibrating the charged powder particles
through the carrier, the present invention can effectively control
the action force on each vibrating position of the carrier such
that the vibrated charged powder particles on each vibrating
position of the carrier have a uniform height. Accordingly, the
charged powder particles are uniformly attached to the objects.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a schematic cross-sectional view of a conventional
powder supply device;
[0022] FIGS. 2, 2' and 2'' are schematic cross-sectional views of a
charged powder supply device according to a first embodiment of the
present invention;
[0023] FIGS. 3 and 3' are schematic cross-sectional and partial
upper views of a charged powder supply device according to a second
embodiment of the present invention;
[0024] FIGS. 4A to 4C are schematic cross-sectional views of a
charged powder supply device according to a third embodiment of the
present invention, wherein FIG. 4A' is a partial upper view of FIG.
4A;
[0025] FIG. 5 is a schematic cross-sectional view of a charged
powder supply device having power supplies disposed on the carrier
thereof according to the present invention; and
[0026] FIGS. 6A and 6B are schematic cross-sectional views showing
a charged powder supply device according to a fourth embodiment of
the present invention, wherein FIGS. 6A' and 6A'' are partial upper
views of FIG. 6A.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] The following illustrative embodiments are provided to
illustrate the disclosure of the present invention, these and other
advantages and effects can be apparent to those in the art after
reading this specification.
[0028] It should be noted that all the drawings are not intended to
limit the present invention. Various modifications and variations
can be made without departing from the spirit of the present
invention. Further, terms such as "first", "second", "on", "a" etc.
are merely for illustrative purposes and should not be construed to
limit the scope of the present invention.
[0029] In the following embodiments, an action source 21 provides
an action force such as an impact force, a fluid motion, or an
acoustic or ultrasonic wave for vibrating charged powder. An object
to be coated can be such an LED element.
[0030] The present invention provides a vibration source to vibrate
charged powder and does not use the conventional air flow force.
Under the effect of an electric field on a carrier, the present
invention causes vibrated charged powder to be uniformly attached
to a receiving member so as to form a uniform powder layer.
Preferably, by designing vibration height of the powder, a more
uniform powder layer can be formed.
[0031] FIGS. 2, 2' and 2'' are schematic cross-sectional views
showing charged powder supply devices 2, 2', 2'' according to a
first embodiment of the present invention.
[0032] Referring to FIG. 2, the charged powder supply device 2 has
a carrier 20, an action source 21 and a receiving member 22.
[0033] The carrier 20 has a first side 20a with powder 9 disposed
thereon and a second side 20b opposite to the first side 20a. The
powder 9 has a plurality of powder particles 90 and an adhesive
material 91. For example, the adhesive material 91 is in the form
of solid particles. The adhesive material 91 is adhered to or
separated from the powder particles 90 or encapsulates the powder
particles 90. The powder particles 90 can be phosphor, nano tube,
quantum dot, carbon tube or graphene particles.
[0034] The action source 21 is positioned at the second side 20b of
the carrier 20 and separated from the second side 20b and used for
acting on the carrier 20 so as to vibrate the powder particles 90
and the adhesive material 91 on the first side 20a of the carrier
20. The adhesive material 91 is in the form of solid particles. The
adhesive material 91 can be adhered to or separated from the powder
particles 90 or encapsulates the powder particles 90.
[0035] The receiving member 22 is positioned over and separated
from the first side 20a of the carrier 20 and used for receiving
the vibrated charged powder particles 90 and the adhesive material
91. The receiving member 22 can carry a plurality of objects 23 to
be coated, such as LED elements, so as for the charged powder
particles 90 and the adhesive material 91 to be formed thereon.
[0036] Referring to FIG. 2', the charged powder supply device 2'
can have a plurality of action sources 21' and the action sources
21' can be in contact with the second side 20b of the carrier 20.
The action sources 21' can be bumps or water columns to provide
impact forces or fluid motions.
[0037] During operation of the charged powder supply device 2, 2',
the action source(s) 21, 21' is started to provide an action force
to the carrier 20 in a direction B to vibrate the carrier 20,
thereby causing vibration of the charged powder particles 90 and
the adhesive material 91 on the first side 20a of the carrier 20.
Further, under the effect of an electric field, the vibrated
charged powder particles 90 and the adhesive material 91 leave the
first side 20a of the carrier 20 and rise up to the receiving
member 22. As such, the charged powder particles 90 are stuck to
the objects through the adhesive material 91.
[0038] Therefore, after the action source 21 vibrates the carrier
20 to cause vibration of the charged powder particles 90 and the
adhesive material 91, the charged powder particles 90 and the
adhesive material 91 are guided by the electric field so as to be
stuck to the objects. That is, there are no other external forces
(for example, conventional air flow forces) that affect the
vertical upward force between the carrier 20 and the receiving
member 22. Hence, the direction of the charged powder particles 90
and the adhesive material 91 can be effectively controlled such
that the charged powder particles 90 and the adhesive material 91
on each vibrating position have a uniform height and the powder
particles 90 are uniformly stuck to the objects 23.
[0039] Referring to FIG. 2'', the charged powder supply device 2''
can further have a support member 24. The support member 24 has a
plurality of through holes 240 formed corresponding in position to
a plurality of carriers 20' so as to be covered by the carriers
20', respectively. Alternatively, a single carrier 20' can be
provided to cover all the through holes 240. As such, the action
forces coming from the action sources 21' can be transmitted to the
carriers 20' through the through holes 240 without interfering with
each other so as to apply uniform forces on the carriers 20'.
Further, the action sources 21' can be received in the through
holes 240 of the support member 24. In addition, the carriers 20'
can be closely bonded with the support member 24.
[0040] FIGS. 3 and 3' are schematic cross-sectional and partial
upper views of a charged powder supply device 3 according to a
second embodiment of the present invention. The present embodiment
differs from the first embodiment in the design of the carrier 30
and the object 33.
[0041] Referring to FIGS. 3 and 3', the carrier 30 has a plurality
of through holes 300 penetrating the first side 30a and the second
side 30b, and a carrying portion 301 positioned on the first side
30a and covering one ends of the through holes 300. The carrying
portion 301 is used for carrying the powder 9'. The action sources
21 act on the carrying portion 301 through the through holes 300 so
as to vibrate the powder particles 90 and the adhesive material 91.
The adhesive material 91 is in the form of solid particles. The
adhesive material 91 can be attached to or separated from the
powder particles 90 or encapsulate the powder particles 90.
[0042] In the present embodiment, the carrying portion 301 is a
film or a plate. The material and thickness of the carrying portion
301 are suited to cause vibration of the powder particles 90 and
the adhesive material 91 on the carrying portion 301.
[0043] Further, the distance d formed between the receiving member
22 and the first side 30a of the carrier 30 is greater than the
distance t between any two adjacent through holes 300. Preferably,
the distance d is greater than five times the distance t, i.e,
d>5t.
[0044] Furthermore, a large-sized object 33 of a large size, such
as a vehicle component, can be disposed on the receiving member
22.
[0045] In addition, the carrying portion 301 is closely bonded with
the carrier 30. During operation of the charged powder supply
device 3, the action sources 21 are started to provide action
forces in the through holes 300 in a direction B to vibrate the
carrying portion 301, thereby causing vibration of the charged
powder particles 90 and the adhesive material 91 on the carrying
portion 301. Further, under the effect of an electric field, the
vibrated charged powder particles 90 and the adhesive material 91
leave the carrying portion 301 and rise up to the receiving member
22. As such, the charged powder particles 90 are stuck to the
object 33 through the adhesive material 91.
[0046] Therefore, after the action sources 21 vibrates the carrying
portion 301 to cause vibration of the charged powder particles 90
and the adhesive material 91, the charged powder particles 90 and
the adhesive material 91 are guided by the electric field so as to
be stuck to the object 33. Hence, the direction of the charged
powder particles 90 and the adhesive material 91 can be effectively
controlled to ensure the uniformity of the charged powder particles
90 on the object 33.
[0047] FIGS. 4A to 4C are schematic cross-sectional views showing
charged powder supply devices 4, 4', 4'' according to a third
embodiment of the present invention. The present embodiment differs
from the second embodiment in the design of the carrier 40.
[0048] Referring to FIGS. 4A and 4A', the carrier 40 has a
plurality of through holes 400 penetrating the first side 40a and
the second side 40b, a plurality of balls 402 positioned in the
through holes 400, and a plurality of carrying portions 401
positioned on the first side 40a of the carrier 40 and respectively
covering one ends of the through holes 400. The carrying portions
401 are used for carrying the powder 9. The balls 402 are exposed
from the second side 40b of the carrier 40. The action sources 21
provide impact forces on the carrying portions 401 through the
balls 402 so as to vibrate the charged powder particles 90 and the
adhesive material 91. The adhesive material 91 is in the form of
solid particles. The adhesive material 91 can be attached to or
separated from the powder particles 90 or encapsulate the powder
particles 90.
[0049] In the present embodiment, the carrying portions 401 are
separated films or plates. The material and thickness of the
carrying portions 401 are suited to cause vibration of the powder
particles 90 and the adhesive material 91 on the carrying portions
401.
[0050] Further, the distance h between the receiving member 22 and
the first side 40a of the carrier 40 is grater than the distance r
between any two adjacent through holes 400. Preferably, the
distance h is greater than five times the distance r, i.e.,
h>5r, thereby achieving a preferred uniformity of the powder
particles 90 on the objects.
[0051] Furthermore, each of the carrying portions 401 has a pad
401a positioned in the corresponding through hole 400. By impacting
the pads 401 with the balls 402, the powder particles 90 and the
adhesive material 91 on the carrying portions 401 are vibrated. The
pads 401 can be made of plastic or metal. In another embodiment,
the pads 401a can be positioned over the carrying portions 401.
[0052] In addition, the carrier 40 has a positioning plate 403 on
the second side 40b thereof for receiving the balls 402 in the
through holes 400. The balls 402 can have a ball shape or can be
any blocks having a symmetrical shape. The positioning plate 403
has a plurality of through holes 403a corresponding in position to
the through holes 400 of the carrier 40 and having a width less
than the diameter of the balls 402. Supported by the positioning
plate 403, the balls 402 can be received in the through holes 400
so as not to fall out of the through holes 400. Further, each of
the balls 402 is partially exposed from the second side 40b through
the corresponding through hole 403a of the positioning plate 402.
Therefore, the action sources 21 act on the balls 402 through the
through holes 403a of the positioning plate 403 so as to impact the
carrying portions 401 (or the pads 401a). In addition, the
positioning plate 403 supports the balls 402 at the same position
and in the same direction so as to ensure that the carrying
portions 401 are impacted and receive the action force at the same
position.
[0053] During operation of the charged powder supply device 4, the
action sources 21 are started to provide action forces to the balls
402 in a direction B so as to cause the balls 402 to rise and
impact the carrying portions 401 (or the pads 401a), thereby
vibrating the charged powder particles 90 and the adhesive material
91 on the carrying portions 401. Further, under the effect of an
electric field, the vibrated charged powder particles 90 and the
adhesive material 91 leave the carrying portions 401 and rise up to
the receiving member 22. As such, the charged powder particles 90
are stuck to the objects 33 through the adhesive material 91.
[0054] Therefore, after the action sources 21 vibrate the carrying
portions 401 so as to cause vibration of the charged powder
particles 90 and the adhesive material 91, the charged powder
particles 90 and the adhesive material 91 are guided by the
electric field so as to be stuck to the objects 23. Hence, the
direction of the charged powder particles 90 and the adhesive
material 91 can be effectively controlled to ensure the uniformity
of the charged powder particles 90 on the objects 23.
[0055] Referring to FIG. 4B, the carrying portion 401' is in the
form of a continuous film or plate. Further, each of the action
sources 41 has an abutting structure for impacting the
corresponding ball 402, thereby providing a preferred impact force
to the ball 402.
[0056] Referring to FIG. 4C, the action source 41' is a flat board
and the balls 402' protrude from the through holes 403a of the
positioning plate 403 such that the action source 41' can
effectively act on the middle portions of the balls 402'.
Therefore, the carrying portions 401'' can be impacted by the balls
402' at preferred positions so as to cause the powder particles 90
and the adhesive material 91 to move upward vertically and ensure
uniformity of the powder particles 90 on the objects 23.
[0057] Further, different from FIG. 4A in which each of the
carrying portions 401 covers one through hole 400, each of the
carrying portions 401'' of FIG. 4C covers a plurality of through
holes 400.
[0058] FIG. 5 is a schematic cross-sectional view of a charged
powder supply device having power supplies disposed on the carrier
50 thereof according to the present invention.
[0059] Referring to FIG. 5, a plurality of uniformly distributed
conductive traces 500 or a planar conductor structure 500' having a
plurality of uniformly distributed points is formed on the carrier
50 by metal etching. The conductive traces 500 or planar conductor
structure 500' can be arranged in parallel or crossed to form a
grid pattern.
[0060] During operation of the charged powder supply device 5, a
negative DC high voltage is applied on the carrier 50 to generate
an electric field and generate a corona discharge through the
uniformly distributed conductive traces 500 or points to negatively
charge the powder particles 90 and the adhesive material 91
(denoted by a minus sign in FIG. 5). The adhesive material 91 is in
the form of solid particles. The adhesive material 91 can be
attached to or separated from the powder particles 90 or
encapsulate the powder particles 90. A uniform electric field is
formed between the carrier 50 and the receiving member 22 first and
then the action source 21 is started to vibrate the charged powder
particles 90 and the adhesive material 91. As such, the sticking of
the charged powder particles 90 and the adhesive material 91 to the
objects 23 is speeded up under the effect of the electric
field.
[0061] Therefore, after the action source 21 vibrates the carrier
50 so as to cause vibration of the charged powder particles 90 and
the adhesive material 91, the charged powder particles 90 and the
adhesive material 91 are guided and attracted to the objects 23 by
the electric field. That is, the vertical upward force (electric
attraction) between the carrier 50 and the receiving member 22 is
enhanced. Hence, the direction of the charged powder particles 90
and the adhesive material 91 can be effectively controlled to
ensure the uniformity of the charged powder particles 90 on the
objects 23.
[0062] In other embodiment, the carrier 50 can be positively
charged.
[0063] FIGS. 6A and 6B are schematic cross-sectional views of
charged powder supply devices 6, 6' according to a fourth
embodiment of the present invention.
[0064] Referring to FIG. 6A, a plurality of power supplies 65 are
disposed at the first side 20a of the carrier 20 for providing
charges to the carrier 20, thereby generating a uniform electric
field between the carrier 20 and the receiving member 22. Further,
as described above, the powder particles 90 and the adhesive
material 91 are negatively charged by a corona discharge (denoted
by a minus sign in the drawing). The adhesive material 91 is in the
form of solid particles. The adhesive material 91 can be attached
to or separated from the powder particles 90 or encapsulate the
powder particles 90. In other embodiments, the powder particles 90
and the adhesive material 91 can be positively charged.
[0065] In the present embodiment, the power supplies 65 are
disposed over the powder particles 90 and the adhesive material 91.
Alternatively, the powder particles 90 and the adhesive material 91
can be disposed on the power supplies 65, or the power supplies 65
can be disposed in the powder particles 90 and the adhesive
material 91.
[0066] The power supplies can be arranged crossed or in parallel to
form a grid pattern 65 of FIG. 6A' or a grid pattern 65' of FIG.
6A'' with gaps, thus allowing the powder particles 90 and the
adhesive material 91 to pass therethrough.
[0067] Referring to FIGS. 6A, 6A' and 6A'', the distance L between
the receiving member 22 and the power supplies 65 is greater than
the width W, W' of the gaps in the grid pattern 65, 65'.
Preferably, the distance L is greater than five times the width W,
W' of the gaps, i.e., L>5W or L>5W'.
[0068] Further, if the carrier 30, 40 has a plurality of through
holes 300, 400, the distance D, D', D'' between any two adjacent
through holes 300, 400 and the width W, W' of the gaps are in a
relationship of integer times. For example, W=D, 2W=D', W'=2D''.
Referring to FIGS. 6A' and 6A'', the through holes 300, 400 are
uniformly distributed in the gaps such that the same amount of the
powder particles 90 and the adhesive material 91 can be vibrated
through the through holes 300, 400.
[0069] During operation of the charged powder supply device 6, the
objects 23 to be coated are maintained at a ground potential or a
certain potential and then the action source 21 is started to
vibrate the charged powder particles 90 and the adhesive material
91 on the carrier 20. Under the effect of the electric field
between the power supplies 65, 65' and the objects 23 to be coated,
the charged powder particles 90 and the adhesive material 91 are
stuck to the objects 23 at a high speed.
[0070] Further, referring to FIG. 6B, the carrier 20 can be
positively charged to generate an electric field and the powder
particles 90 and the adhesive material 91 are positively charged
(denoted by a plus sign in the drawing). In other embodiments, the
carrier 20 can be negatively charged.
[0071] Therefore, after the action source 21 vibrates the carrier
20 so as to cause vibration of the charged powder particles 90 and
the adhesive material 91, the charged powder particles 90 and the
adhesive material 91 are attracted and stuck to the objects 23 by
the vertical upward force (electric attraction) between the carrier
20 and the receiving member 22. Hence, the direction of the charged
powder particles 90 and the adhesive material 91 can be effectively
controlled to ensure the uniformity of the charged powder particles
90 on the objects 23.
[0072] Therefore, the charged powder supply device of the present
invention acts on the carrier through the action source to vibrate
the charged powder particles, thereby causing the charged powder
particles to leave the carrier so as to be stuck to the objects.
Since there are no other external forces that affect the moving
direction of the charged powder particles, the present invention
improves the uniformity of the charged powder particles on the
objects.
[0073] Further, the charged powder supply device of the present
invention provides a vibration force instead of a conventional air
flow force to the charged powder particles, thereby overcoming the
conventional drawback of non-uniform rising of the powder particles
caused by such as turbulent flows.
[0074] The present invention is also applicable to uncharged powder
particles. Therein, the uncharged powder particles and the adhesive
material are stuck to objects to be coated through a vibration
force. The objects to be coated can be heated objects.
[0075] The above-described descriptions of the detailed embodiments
are only to illustrate the preferred implementation according to
the present invention, and it is not to limit the scope of the
present invention. Accordingly, all modifications and variations
completed by those with ordinary skill in the art should fall
within the scope of present invention defined by the appended
claims.
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