U.S. patent application number 11/015264 was filed with the patent office on 2006-07-06 for contaminant containing apparatus and method.
Invention is credited to Joseph M. Nealon, Stephen J. Schultz, Edward F. Shroyer.
Application Number | 20060148397 11/015264 |
Document ID | / |
Family ID | 36641188 |
Filed Date | 2006-07-06 |
United States Patent
Application |
20060148397 |
Kind Code |
A1 |
Schultz; Stephen J. ; et
al. |
July 6, 2006 |
Contaminant containing apparatus and method
Abstract
An apparatus for use within a controlled environment, the
apparatus having an enclosure, an air filter, and an air flow
generator. The enclosure includes an interior region for receiving
an article and performing contaminant generating operations. The
air filter receives contaminated air from the enclosure and outputs
air substantially free of contaminants. The air flow generator can
be sealably disposed between the enclosure and the air filter for
establishing an air flow into the enclosure interior region from
the controlled environment and out of the air filter into the
controlled environment.
Inventors: |
Schultz; Stephen J.; (Simi
Valley, CA) ; Nealon; Joseph M.; (Woodland Hills,
CA) ; Shroyer; Edward F.; (Redondo Beach,
CA) |
Correspondence
Address: |
MACPHERSON KWOK CHEN & HEID LLP
1762 TECHNOLOGY DRIVE, SUITE 226
SAN JOSE
CA
95110
US
|
Family ID: |
36641188 |
Appl. No.: |
11/015264 |
Filed: |
December 16, 2004 |
Current U.S.
Class: |
454/56 |
Current CPC
Class: |
F24F 2011/0005 20130101;
F24F 3/167 20210101 |
Class at
Publication: |
454/056 |
International
Class: |
F24F 7/00 20060101
F24F007/00 |
Claims
1. An apparatus for use within a controlled environment,
comprising: an enclosure having an interior region for receiving an
article; an air filter for receiving contaminated air from the
enclosure and outputting air having a reduced amount of
contaminants; and an air flow generator for establishing an air
flow into the enclosure interior region from the controlled
environment and out of the air filter into the controlled
environment.
2. The apparatus of claim 1, wherein the air flow generator is
sealably disposed between the enclosure and the air filter.
3. The apparatus of claim 1, wherein the enclosure further
comprises a substantially transparent portion to permit the viewing
of an article disposed within the enclosure.
4. The apparatus of claim 3, wherein the substantially transparent
portion is an observation window.
5. The apparatus of claim 1, wherein the air filter is a High
Efficiency Particle Arresting (HEPA) type filter.
6. The apparatus of claim 1, wherein the air flow generator is
configured to reduce air pressure within the enclosure.
7. The apparatus of claim 1, wherein the air flow generator
comprises: a fan for producing a pressure difference between an
inflow opening and an outflow opening; and a one-way flow unit for
permitting air flow in a first direction through the air flow
generator while inhibiting air flow in a second direction that is
opposite to the first direction.
8. The apparatus of claim 1, further comprising a user area
adjacent to the enclosure.
9. The apparatus of claim 8, wherein the enclosure further
comprises a sealed glove port for receiving a hand of the user and
extending into the interior portion of the enclosure interior
region.
10. The apparatus of claim 1, further comprising a light source for
providing illumination upon the article within the enclosure
interior region.
11. The apparatus of claim 10, wherein the light source provides
illumination at a range of frequencies.
12. The apparatus of claim 11, wherein the light source can
selectively emit light substantially within the visible range.
13. The apparatus of claim 11, wherein the light source can
selectively emit light substantially outside the visible range.
14. The apparatus of claim 10, further comprising a light blocking
member for surrounding a predetermined portion of the enclosure to
block ambient light from entering the enclosure.
15. The apparatus of claim 1, further comprising a sensor device
for sensing a predetermined attribute of an article within the
enclosure and producing an image signal.
16. The apparatus of claim 15, further comprising: an image
processor for receiving the image signal and outputting a display
signal; and a display unit for receiving the display signal and
producing an image representation of the display signal, wherein
the sensor device includes a camera for producing an image signal
including image information from the interior region of the
enclosure.
17. The apparatus of claim 1, wherein the controlled environment is
a clean room.
18. A contaminant containing apparatus for use within a controlled
environment, comprising: an enclosure having an interior region for
receiving an article, the enclosure having at least one sealed
glove port for receiving a hand of a user and extending into the
interior portion of the enclosure interior region; an air filter
for receiving contaminated air from the enclosure and outputting
air having a reduced level of contaminants; an air flow generator
sealably disposed between the enclosure and the air filter for
establishing an air flow into the enclosure interior region from
the controlled environment and out of the air filter into the
controlled environment so that a contaminant producing operation
performed within the enclosure does not contaminate the controlled
environment, the air flow generator including a fan for producing a
pressure difference between an inflow opening and an outflow
opening, the air flow generator including a one-way flow unit for
allowing air flow in a first direction while inhibiting air flow in
a second direction that is opposite to the first direction; a light
source for providing illumination upon the article within the
enclosure interior region, the light source for selectively
emitting light in a plurality of ranges including visible light and
ultraviolet light; and a light blocking member for surrounding a
predetermined portion of the enclosure to block ambient light from
entering the enclosure.
19. A method of performing a contaminant generating operation
within a controlled environment, the method comprising:
establishing an air flow into an enclosure for receiving an article
within the controlled environment, the established air flow within
the enclosure being sufficient to prevent the escape of
contaminants from within the enclosure to the controlled
environment; positioning an article within the enclosure;
performing a contaminant generating operation on the article within
the enclosure; filtering contaminants from the air within the
enclosure to yield substantially contaminant free air; and
outputting the substantially contaminant free air to the controlled
environment.
20. The method of claim 19, further comprising illuminating the
interior region of the enclosure.
21. The method of claim 19, the filtering further comprising:
generating an air flow through the enclosure to carry airborne
contaminants; and removing the airborne contaminants carried by the
air flow to yield substantially contaminant free air.
22. The method of claim 19, further comprising blocking light into
the interior portion of the enclosure.
23. An article processing system in a controlled environment,
comprising: a first processing station within the controlled
environment for performing non-contaminant generating operations;
and a second processing station within the controlled environment
for performing contaminant generating operations, wherein the
second processing station comprises: an enclosure for performing
contaminant generating operations; an air flow generator for
drawing air through the enclosure and into the controlled
environment; and a filter for filtering contaminants from the air
within the enclosure and releasing the filtered air into the
controlled environment.
Description
TECHNICAL FIELD
[0001] The present invention relates generally to manufacturing
processes and, more particularly, to a contaminant containing
apparatus and method that facilitates the use of contaminant
producing processes within a controlled environment including a
clean room.
BACKGROUND
[0002] Processes performed within a clean room environment can be
especially susceptible to airborne contaminants. In the past, when
a particular process includes the possibility of introducing
contamination to the controlled environment, it has been desirable
to remove the article from the controlled environment in order to
perform the potentially contaminating process. The article is then
reintroduced to the controlled environment once the potentially
contaminating process is completed. Removing and reintroducing the
article can cause significant disruption to the manufacturing
process as well as costly delays. Transporting the work piece into
and out of the controlled environment can add additional packaging,
inspecting, repackaging, and transaction costs that can
significantly increase the cost to produce the final product.
Further, the removal and reintroduction of the article also
includes the risk of contamination from other sources associated
with a breach or opening of the controlled environment.
[0003] As a result, there is a need to address costly delays
associated with removing and reintroducing an article within a
controlled environment including a clean room.
SUMMARY
[0004] An apparatus for use within a controlled environment is
disclosed herein to provide, in one embodiment of the present
invention, an enclosure having an interior region for receiving an
article of manufacture, an air filter for receiving contaminated
air from the enclosure and outputting air substantially free of
contaminants, and an air flow generator sealably disposed between
the enclosure and the air filter for establishing an air flow into
the enclosure interior region from the controlled environment and
out of the air filter into the controlled environment. In this
manner, a contaminant producing operation may be performed upon the
article within the enclosure without removing the article from the
controlled environment.
[0005] In a controlled environment such as a clean room, when a
contaminant producing operation upon an article is desired, the
article within the clean room is typically sealed within a bag or
other sealable container, an inspection is performed, and the
article within the sealed bag is transferred out of clean room. The
contaminant producing operation is then performed on the article
outside the clean room environment. Once the contaminant producing
operation is completed, a reverse process of re-packaging,
re-inspecting, and transferring the processed article into the
clean room is typically performed. These non-value-added
operations, as a result of performing the contaminant producing
operation outside the controlled environment, can significantly
increase the cost to produce the final product. In keeping with
embodiments of the present invention, such costly and
time-consuming non-value-added operations are avoided.
[0006] In one embodiment of the present invention, the apparatus
includes a substantially transparent portion or observation window
to permit viewing of an article disposed within the enclosure. The
article can be an item of manufacture within a manufacturing
process, for example. The air filter can be a High Efficiency
Particle Arresting (HEPA) type filter or other suitable filter for
receiving air having a level of contaminants and outputting air
having a lower level of contaminants. The air flow generator
includes a fan for producing a pressure difference between an
inflow opening and an outflow opening, and a one-way flow unit for
permitting air flow in a first direction through the air flow
generator while inhibiting air flow in a second direction that is
opposite to the first direction.
[0007] In another embodiment, a user area is adjacent to the
enclosure providing a location for a user to stand or sit in
proximity to the contaminant containing apparatus. The contaminant
containing apparatus includes at least one sealed glove port for
receiving a hand of the user and extending into the interior
portion of the enclosure interior region to enable the user to
grasp or manipulate the article or other objects within the
enclosure. The contaminant containing apparatus includes a light
source for providing illumination upon the article within the
enclosure interior region. The light source provides illumination
at a range of frequencies including visible and ultraviolet. The
apparatus further includes a light blocking member for surrounding
a predetermined portion of the enclosure in order to block ambient
light from entering the enclosure. Ambient light is the light
within the controlled environment not supplied by the enclosure
light source.
[0008] According to another embodiment of the present invention,
the contaminant containing apparatus can include at least one
sensor device for sensing a predetermined attribute of the article
within the enclosure. The sensor device can be a camera for
producing an image signal including image information from the
interior region of the enclosure. The apparatus can include an
image processor for receiving at least one image signal and
outputting a display signal, and a display unit for receiving the
display signal and presenting an image representation of the
display signal.
[0009] In accordance with another embodiment of the present
invention, a method is disclosed of performing a contaminant
generating operation within a controlled environment while
preserving the controlled environment substantially free of
contaminants. The method includes establishing an air flow into an
enclosure for receiving an article of manufacture within the
controlled environment, positioning an article of manufacture
within the enclosure, performing a contaminant generating operation
on the article within the enclosure, filtering contaminants from
the air within the enclosure, and outputting the filtered air into
the controlled environment. The established air flow within the
enclosure is sufficient to prevent the escape of contaminants from
within the enclosure to the controlled environment. The filtering
method can include generating an air flow through the enclosure to
carry airborne contaminants, and removing the airborne contaminants
carried by the air flow to yield substantially contaminant free air
in accordance with a standard of cleanliness such as a clean room
specification or other guideline.
[0010] In another embodiment of the present invention, the method
includes illuminating the interior region of the enclosure with a
light source which can be a black light or a white light. The
method can further include surrounding a predetermined portion of
the enclosure with a light blocking member to prevent illumination
of the interior portion of the enclosure from a source other than
the enclosure light source.
[0011] In another embodiment of the present invention, an article
processing system in a controlled environment includes a first
processing station for performing non-contaminant generating
operations and a second processing station for performing
contaminant generating operations. The second processing station
includes an enclosure for performing contaminant generating
operations, an air flow generator for drawing air through the
enclosure and into the controlled environment, and a filter for
filtering contaminants from the air within the enclosure and
releasing the filtered air into the controlled environment.
[0012] The scope of the invention is defined by the claims, which
are incorporated into this section by reference. A more complete
understanding of embodiments of the present invention will be
afforded to those skilled in the art, as well as a realization of
additional advantages thereof, by a consideration of the following
detailed description of one or more embodiments. Reference will be
made to the appended sheets of drawings that will first be
described briefly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a block diagram view illustrating a clean room
environment including a contaminant containing enclosure apparatus
in accordance with an embodiment of the present invention.
[0014] FIG. 2 shows a side view of a contaminant containing
apparatus in accordance with an embodiment of the present
invention.
[0015] FIGS. 3A-3C show a frame for supporting the contaminant
containing apparatus and two positions for a light blocking member
surrounding a portion of the contaminant containing apparatus in
accordance with an embodiment of the present invention.
[0016] FIG. 4 shows a flow diagram illustrating a method of using
the contaminant containing apparatus in accordance with an
embodiment of the present invention.
[0017] FIG. 5 shows a flow diagram illustrating a method of
performing a Dye Penetrant Inspection process in accordance with an
embodiment of the present invention.
[0018] FIG. 6 shows a top-down view of the enclosure in accordance
with an embodiment of the present invention.
[0019] Various embodiments of the present invention and their
advantages are best understood by referring to the detailed
description that follows. It should be appreciated that like
reference numerals are used to identify like elements illustrated
in one or more of the figures.
DETAILED DESCRIPTION
[0020] FIG. 1 shows a block diagram illustrating one possible
layout for an article processing system 100 including a contaminant
containing apparatus 102 within a controlled environment 104 such
as a clean room. Controlled environment 104 can include an assembly
cell area 106 comprising a number of exemplary processing stations.
Although not limited to this description, the processing stations
can include one or more dirty processing stations such as
contaminant containing apparatus 102, and a number of clean
processing stations including a first station 108, a second station
110, a third station 112, a fourth station 114, a fifth station
116, and a sixth station 118, where a number of articles can be
processed in a sequential or serial fashion. Operations can be
performed upon an article at each station. A more detailed
description of dirty and clean operations will be discussed
below.
[0021] A sequential stream of articles can follow an example
assembly line process where a first article is introduced 120 to
first station 108. A first processing operation is performed upon
the article at first station 108. After the first processing
operation is completed, the first article is transported 122 to
second station 110 and a second article can then be introduced 120
to the unoccupied first station 108. At second station 110, a
second processing operation is performed upon the first article.
First station 108 and second station 110 can be considered as clean
processing stations since they do not produce contaminants that
could undesirably affect the controlled environment.
[0022] Meanwhile, the first processing operation can be performed
on the second article at first station 108 so that a number of
articles may be simultaneously processed in an assembly line
fashion where each article is in a different stage of processing
corresponding to an increasing degree of completeness. Although the
singular term article is used to describe a work piece being
operated upon at a particular station, the term article can also
include a number of elements grouped together that are intended to
be processed together or at the same processing stage.
[0023] Once the second processing operation is completed, the
article can be transferred 124 to third station 112. Alternatively,
it may be desirable to perform a separate, dirty processing
operation using the contaminant containing apparatus 102 before
transferring the article to third station 112. A dirty processing
operation can be any contaminant producing operation where it is
desirable to avoid contamination within the controlled environment.
When this is so, the article is removed from second station 110 on
the assembly line and introduced 126 to contaminant containing
apparatus 102 where the contaminant producing processing operation
may be performed without contaminating, or requiring the article be
removed from, controlled environment 104. Once the contaminant
producing processing operation is completed, the article is
returned 128 to the assembly line for further processing at the
same stage from which it previously left. In contrast to a clean
processing station, contaminant containing apparatus 102 can be
considered a dirty processing station for safely performing
contaminant generating operations without contaminating controlled
environment 104.
[0024] Alternatively, once the contaminant producing processing
operation is completed, the article may be transferred 130 to a
different stage on the assembly line. In reference to FIG. 1, after
the contaminant producing processing operation is completed
following the processing at second station 110, it may be desirable
to transfer 130 the processed article to third station 112. In one
embodiment, the contaminant producing processing operation is a
diagnostic process that can be used to determine if the processing
from second station 110 was completed properly by determining
whether the processed article conforms to a predetermined standard,
such as a specified MIL-SPEC (Military Specification) or MIL-STD
(Military Standard).
[0025] If the processed article from second station 110 conforms to
the specified standard, then processing from second station 110 is
completed and the second processed article may be transferred 130
to third station 112. Alternatively, if the processed article from
second station 110 does not conform to the standard, then
processing from second station 110 can be re-accomplished and the
second processed article may be transferred 128 again to second
station 110 where some or all of the second processing operation
may be performed on the article. The contaminant producing
processing operation can also include a modification process such
as altering or treating the article, or may include a combination
of diagnostic, altering, or treating operations. This testing and
recursion may be desirable following a non-deterministic processing
operation where the results depend on the skill of a particular
artisan performing the processing operation at a particular
station.
[0026] In one embodiment, the contaminant producing processing
operation includes a Non-Destructive Testing (NDT) process such as
a Dye Penetrant Inspection (DPI) process for determining surface
flaws or defects. DPI can be used on many different types of
non-porous articles having a relatively smooth surface, such as
metals, glass, ceramics, and plastics. In the DPI process, liquid
oil having a dye or other marker in suspension is applied to the
surface of a non-porous article to be inspected. In a fluorescent
DPI process, the markers are fluorescent particles suspended in the
applied liquid oil. The fluorescent particles can include phosphors
that receive energy at a wavelength outside the visible range and
convert a portion of that received energy to light within the
visible range. Excess oil can be removed and a developer can be
applied.
[0027] The developer can be a sprayed-on, fine powdery substance
used to bring to the surface the remaining oil containing the
fluorescent particles. In the DPI process, it is at least this
developing operation that is typically very disruptive to a clean
room or other controlled environment 104. The application of a fine
powder can produce airborne particles that can contaminate other
articles or processes within controlled environment 104. Even if
controlled environment 104 is not a clean room that is compliant
with a strict standard limiting contaminant particle size, for
example, it may be desirable to avoid contamination of a less
stringently clean environment. Once the developer is applied, the
developed surface can then be visually inspected under a specified
lighting or illumination condition to reveal flaws in the surface
including irregularities or discontinuities in the inspected
surface. Illumination can include specified lighting conditions
with a range of wavelengths or frequencies including visible light,
meaning light within the visible range for a human, also described
as white light.
[0028] For a fluorescent dye penetrant inspection process, the
specified lighting conditions can include the use of a black light
that emits light near the ultraviolet end of the visual spectrum.
Alternatively, an infra-red illumination, below visible light
range, may be desirable in combination with particular dyes,
markers, or developers. For a visible light penetrant inspection
process, the specified lighting conditions include a white light
broadly within the visual spectrum. Once the inspection process is
completed and any irregularities are noted, the inspected surface
can then be treated with a solvent, such as alcohol, to remove any
remaining oil and the suspended particles, dyes, or markers. Both
the visible light and fluorescent light liquid penetrant inspection
are non-destructive methods of revealing flaws on the surface of a
solid and essentially non-porous material. Other contaminant
producing processes, diagnostics, or treatments are possible.
[0029] Once the processing operation at third station 112 is
completed, the third processed article is transferred 132 to fourth
station 114. Similarly, third station 112 is then available to
process a trailing article in the assembly process. Once the fourth
processing operation is completed, the fourth processed article is
transferred 134 to fifth station 116. Once the fifth processing
operation is completed, the fifth processed article is transferred
136 to sixth station 118. Similar to the second station 110, after
processing at sixth station 118 completes, the sixth processed
article can be transferred 138 to contaminant containing apparatus
102 for performance of a second contaminant producing processing
operation. This second contaminant producing processing operation
can be the same as or different from the previously discussed DPI
operation.
[0030] The paths traced through the example assembly line in the
assembly cell area 106 are exemplary in nature and can include
transfers between stations in a different manner than that which is
shown and described. The number of clean processing stations (108,
110, 112, 114, 116, and 118) can vary from one to many. It is not
necessary that a particular contemporaneous process may be
interfered with by contaminants in order to practice the present
invention. Instead, it may simply be desirable to contain
contaminants rather than disperse them within the surrounding
environment. Similarly, the number of contaminant producing
processing stations 102 can vary from at least one to many.
[0031] FIG. 2 shows a side view of contaminant containing apparatus
102 according to one embodiment. Apparatus 102 includes a box-like
enclosure 202 for receiving an article of manufacture, an air
filter 204 adjacent to enclosure 202, and an air flow generator 206
sealably disposed between enclosure 202 and filter 204. Either or
both of air filter 204 and air flow generator 206 can be physically
attached to enclosure 202. When activated, air flow generator 206
draws air in a first direction 208, to enter enclosure 202, and
pushes air out in a second direction 210 to exit filter 204, so
that contaminant producing operations may be conducted on the
received article within enclosure 202 without emitting contaminants
into controlled environment 104. The air flow through enclosure 202
carries airborne contaminants into filter 204 where they are
trapped. Use of this apparatus enables a dirty process to be
conducted within a clean room environment, for example.
[0032] Enclosure 202 may be partially or entirely constructed from
a substantially transparent material in order to permit viewing of
an article disposed within enclosure 202. Alternatively, enclosure
202 can include a substantially transparent observation window 234
in order to permit viewing. Observation window 234 may be
constructed from clear glass, specially tinted or polarized glass,
or optical quality plastic, for example. The choice of materials
for enclosure 202 and observation window 234 can be determined by
the types of operations that will be conducted within enclosure
202. Similarly, the type of filter 204 can be determined by the
types of contaminant producing operations that will be conducted,
the type of contaminants expected, and the degree of contaminant
reduction or removal required to yield air flow out of the filter
204 that is acceptable, or substantially free of contaminants,
without violating the specifications describing the acceptability
of the controlled environment 104. For a clean room, this
contaminant removal requirement typically requires the output air
from the air filter be substantially free from contaminants of a
particular size or larger. For example, for particulate matter
contamination, the size of the emitted particles may be less than a
predetermined maximum, such as one micron. Alternatively, filter
204 may be specified based on a performance rating such as the
filter is 99.97% effective at capturing particles 0.3 microns and
larger in a test environment, in accordance with an accepted
performance qualification for a HEPA filter.
[0033] Air flow generator 206 can be implemented using a fan or
other structure to create air flow movement in a predetermined
direction. Air flow generator 206 can be regarded as a compressor
which receives air at a first pressure and outputs air at a second,
higher pressure. In this way, air flow generator 206 creates a
negative pressure in enclosure 202 causing air to flow into the
enclosure from controlled environment 104. Additionally, air flow
generator 206 preferably includes a one-way flow unit for allowing
air flow in a first direction 208 while inhibiting air flow in a
second direction that is opposite to the first direction. This
one-way flow unit will allow air flow into the enclosure from the
controlled environment in order to capture and filter out
contaminants liberated within the enclosure 202 interior region
while preventing contaminated air from entering the controlled
environment 104. Contaminants may be liberated by a heating
operation, especially if the dirty operation includes heating an
article with a volatile coating, for example. It is preferable that
filter 204 be located downstream of the airflow from the air flow
generator 206 in order to capture any contaminants that may be
generated by the air flow generator 206 itself such as by a motor
or similar device.
[0034] Enclosure 202 has a first opening and a second opening to
permit air flow through an interior region of enclosure 202. Air
flow can be drawn in from controlled environment 104 and through
enclosure 202 by activating air flow generator 206. Air flow 210 in
a direction out of the enclosure 202 continues through air flow
generator 206 and through filter 204 back into the controlled
environment 104. Thus, the contaminant containing apparatus 102 can
operate entirely within controlled environment 104 so that a
contaminant producing operation performed within enclosure 202 does
not contaminate controlled environment 104. Air flow generator 206
includes a first opening forming an air-tight seal with the second
opening of enclosure 202 at a junction 212. Air flow generator 206
also includes a second opening forming an air-tight seal with a
first opening of filter 204 at a junction 214. A second opening of
filter 204 allows air to flow out of apparatus 102.
[0035] According to one embodiment, a user can stand in proximity
to contaminant containing apparatus 102 at a user area 216 in order
to conduct the contaminant producing operations on the received
article within enclosure 202. The user standing in user area 216
can reach their hand into the one or more sealed glove ports (218,
220) to permit the user to grasp and manipulate an article within
the interior region of enclosure 202 as well as any supplies,
instruments, or materials present within enclosure 202 for use in
the isolated, contaminant generating process. The base of each
sealed glove port (218, 220) forms a seal with the enclosure in
order to maintain a continuous barrier at the sealing point where
the interior portion of each sealed glove port forms a part of the
exterior of the enclosure 202.
[0036] Similarly, the exterior portion of each sealed glove port
forms a part of the interior of enclosure 202. In this way, a user
can insert their hand and forearm into a sealed glove port to grasp
and manipulate items within the interior region of the enclosure
202. Alternatively, one or more remotely controlled instruments may
be partially or completely extended through a sealable junction
with a wall portion of enclosure 202 to enable a user to manipulate
the exterior portions of the remotely controlled instruments in
order to perform the contaminant producing operation within the
contaminant containing apparatus 102. In yet another alternative,
robotic instruments may be electronically controlled from a
distance in order to perform the contaminant producing operation
within enclosure 202.
[0037] In another embodiment, contaminant containing apparatus 102
includes an air lock 222 adjacent to enclosure 202 providing an
intermediate chamber for passing the received article to an
interior portion of enclosure 202. Air lock 222 has a first opening
and a second opening and can include a mechanism, characteristic,
or attribute that ensures the first opening and second opening are
not both opened at the same time so that air may not pass in either
direction directly through an interior portion of air lock 222
through the first opening and the second opening at the same time.
The second opening of air lock 222 forms an air-tight seal with the
first opening of enclosure 202 at a junction 224. The openings at
junction 224 allow an article disposed within air lock 222 to be
passed from an interior portion of air lock 222 into the interior
portion of enclosure 202.
[0038] In another embodiment, contaminant containing apparatus 102
includes a user controlled light source 226 to illuminate the
interior region of enclosure 202. The light source 226 can emit
light in one or more ranges including traditional broad-spectrum
visible light, or white light. Light source 226 may also emit light
in a higher visible range, a black light or ultra violet light,
which is beyond the normal range visible to a human user. Finally,
light source 226 may also emit light in a lower visible range
including infra-red light. In this way, the light source 226
provides illumination at a range of frequencies.
[0039] According to another embodiment, the contaminant containing
apparatus 102 includes a light blocking member 228, such as a dark
curtain or light-opaque material for blocking the passage of light,
surrounding at least a portion of contaminant containing apparatus
102 in order to shield enclosure 202 from ambient light in
controlled environment 104 other than illumination from light
source 226. Under some lighting conditions, or for some processes,
it may be desirable to limit the amount of ambient light in order
to perform certain diagnostic procedures on the article within
enclosure 202 and to satisfy candle light intensity
requirements.
[0040] According to another embodiment, the contaminant containing
apparatus 102 can include one or more sensing devices (230, 232),
such as optical devices including cameras, in order to observe or
determine some attribute of at least a portion of the article under
inspection within enclosure 202. A human user may require
specialized training in order to discern the acceptability or
unacceptability of a particular article at a particular stage. A
camera and associated image processor can receive and process image
information that can provide a more automated inspection process or
serve as a supplement to human observation. Further, the presence
of one or more cameras (230, 232) may render a human observer
unnecessary for some processes since visual inspection may be
performed completely automatically allowing an untrained or less
trained operator to assist in performing the desired process.
[0041] FIG. 3A shows one embodiment of a support stand or frame 302
that provides elevation of the contaminant containing apparatus 102
above a floor surface 304 defining a first open space 306 above and
a second open space 308 below the contaminant containing apparatus
102. The position of the contaminant containing apparatus 102 can
be adjusted vertically within the frame 302 to adjust the working
height of the apparatus 102 relative to the floor surface 304. In
one embodiment, the frame 302 includes wheels making the
contaminant containing apparatus 102 easily portable.
[0042] FIG. 3B shows one embodiment where the light blocking member
228 is in a partially open position to permit a user to approach
the tented contaminant containing apparatus 102 and permit ambient
light from outside the light blocking member 228 to pass into
enclosure 202 through the partially open light blocking member 228.
Frame 302 provides support for the upper portion of the light
blocking member 228. Alternatively, light blocking member 228 can
be seamless, without an opening, and configured in a partially open
position by rolling up in a vertical manner.
[0043] FIG. 3C shows light blocking member 228 in a fully closed
position to prevent outside or ambient light from reaching
contaminant containing apparatus 102. In one embodiment, light
blocking member 228 can cover contaminant containing apparatus 102
to form a dark-room like inspection booth with a tent-like
structure. The portion of frame 302 defining the open space 306 can
also be adjusted vertically in order to accommodate the presence of
a tall user or provide a larger open space 306. Alternatively, the
portion of the frame 302 defining open space 306 may be omitted if
light blocking member 228 is not used.
[0044] FIG. 4 is a flow diagram illustrating a method of using the
present invention described as a series of operations performed. In
operation 402, air flow generator 206 is activated to start the
flow of air through enclosure 202 as described. In operation 404,
an article is received within the interior portion of enclosure 202
in preparation for a contaminant producing operation. In operation
406, the contaminant producing operation is performed on the
received article within enclosure 202. In operation 408, after the
contaminant producing operation is completed, the processed article
is removed from enclosure 202. In operation 410, air flow generator
is deactivated to stop the flow of air through enclosure 202.
Alternatively, if a series of articles are to be processed one
after another, it would not be necessary to deactivate air flow
generator 206 between processing operations. It may also be
necessary to clean or otherwise treat the article immediately after
insertion into enclosure 202. It may also be necessary to wait a
significant amount of time before proceeding to a subsequent
operation in order to allow time for drying, reacting, or cooling,
for example.
[0045] FIG. 5 shows a particular embodiment of the present
invention including a series of operations involved in performing a
Dye Penetrant Inspection (DPI) process corresponding to operation
406. In operation 502, liquid oil including fluorescent particles
in suspension is applied to a portion of the surface of a
non-porous article to be inspected. The fluorescent particles can
include phosphors that receive energy at a wavelength outside the
visible range and convert a portion of that invisible energy to
light within the visible range.
[0046] In operation 504, an excess amount of the oil containing the
phosphor particles in suspension is removed. In operation 506, a
developer is applied to the oil-covered portion of the article
surface. In some applications, the developer can include a
sprayed-on, fine powdery substance with some properties similar to
baby powder. The application of the fine powdery substance brings
up the remaining oil containing the fluorescent particles. In the
DPI process, it is this developing operation that is typically most
disruptive to a clean room environment. The use of a fine powder
transferred through the air when the developer is applied can
contaminate other articles or processes within a clean room 104,
for example. In operation 508, a visual inspection is performed on
the developed portion of the surface of the article under
inspection. In operation 510, the developer remaining on the
surface of the inspected article is removed, typically by wiping
with a solvent and a clean fabric to provide physical removal of
the developer and remaining oil, and the DPI process is completed.
The solvent can be alcohol and the clean fabric can be a towel
suitable for this purpose. The DPI process for operation 406 is
only one example of a dirty process that may be conducted within
contaminant containing apparatus 102 in a controlled environment
104.
[0047] FIG. 6 shows a top-down view of the enclosure 202 showing
two sealed glove ports (218, 220) extended into an interior region
of enclosure 202. Cameras (230, 232) can be located at diagonal
corners of enclosure 202. Camera 230 has a field of view 602 while
camera 232 has an oppositely directed field of view 604 within
enclosure 202 to provide visualization within enclosure 202 at
various angles. Camera 230 outputs a first image signal 606
including image information to an image processor 608. Image
processor 608 can include a suitably programmed microcomputer.
Image processor 608 outputs a display signal 610 to a display unit
612 that displays a visual image representation based on the
display signal. Display unit 612 can include a television monitor.
Similarly, camera 232 outputs a second image signal 614 including
image information to the image processor 608.
[0048] Image processor 608 receives first and second image signals
(606, 614) and determines display signal 610. Display signal 610
can be determined from each of the cameras (230, 232) individually,
or from the cameras together to produce a synthesized or even a
stereoscopic image. Any number of cameras may be located in
positions to view the interior region of enclosure 202. Each camera
may be located entirely within enclosure 202, partially within
enclosure 202 forming a sealed portion of the boundary of enclosure
202, or entirely outside enclosure 202 if the enclosure material
permits adequate visual inspection from outside enclosure 202.
[0049] The embodiments described above illustrate but do not limit
the invention. It should also be understood that numerous
modifications and variations are possible in accordance with the
principles of the present invention. Accordingly, the scope of the
invention is defined only by the following claims.
* * * * *