U.S. patent application number 15/244786 was filed with the patent office on 2017-07-06 for infrared imaging probe.
The applicant listed for this patent is Fluke Corporation. Invention is credited to Thomas J. McManus, Matthew F. Schmidt.
Application Number | 20170191875 15/244786 |
Document ID | / |
Family ID | 42283683 |
Filed Date | 2017-07-06 |
United States Patent
Application |
20170191875 |
Kind Code |
A1 |
Schmidt; Matthew F. ; et
al. |
July 6, 2017 |
INFRARED IMAGING PROBE
Abstract
An infrared imaging probe that includes an elongated wand and an
electrically isolating connection between the imaging components,
located at the distal end of the wand, and the image processing
components, located at the proximal end of the wand.
Inventors: |
Schmidt; Matthew F.; (River
Falls, WI) ; McManus; Thomas J.; (Plymouth,
MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fluke Corporation |
Everett |
WA |
US |
|
|
Family ID: |
42283683 |
Appl. No.: |
15/244786 |
Filed: |
August 23, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12647175 |
Dec 24, 2009 |
9442019 |
|
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15244786 |
|
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61140912 |
Dec 26, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01J 5/0265 20130101;
G01J 2005/0081 20130101; G01J 5/025 20130101; G01J 5/02 20130101;
G01J 5/0066 20130101; G01J 5/10 20130101; G01J 5/047 20130101; G01J
5/0821 20130101; H01L 27/14649 20130101; G01J 5/0096 20130101; G01J
5/046 20130101; G01J 5/08 20130101; G01J 2005/0077 20130101 |
International
Class: |
G01J 5/10 20060101
G01J005/10; H01L 27/146 20060101 H01L027/146; G01J 5/04 20060101
G01J005/04; G01J 5/00 20060101 G01J005/00; G01J 5/02 20060101
G01J005/02 |
Claims
1. A method of thermally imaging components within an enclosed
cabinet, comprising: providing (i) an infrared imaging system
comprising a wand having a front-end assembly sized to fit through
an access opening within a panel of the cabinet and coupled to a
distal end of the wand, the front-end assembly including a lens, a
focal plane array, and distal circuitry, the wand further including
processing circuitry connected to and electrically isolated from
the front-end assembly, and (ii) one or more output devices
connected to the infrared imaging system; inserting the distal end
of the wand through the access opening; and maneuvering the distal
end of the wand to provide the lens a view of the components.
2. The method of claim 1, wherein the one or more output devices
comprise one or more of a digital multimeter, a personal computer,
a personal digital assistant, a display device, and a cellular
phone.
3. The method of claim 1, wherein the access opening is
approximately 12 mm in diameter.
4. The method of claim 1, wherein the processing circuitry is
located proximate to a proximate end of the wand.
Description
PRIORITY CLAIM
[0001] The present application is a divisional application of U.S.
patent application Ser. No. 12/647,175, entitled INFRARED IMAGING
PROBE and filed Dec. 24, 2009, which claims priority to U.S.
Provisional Patent Application No. 61/140,912 entitled INFRARED
IMAGING PROBE, and filed Dec. 26, 2008, the disclosures of which
are herein incorporated by reference in their entirety.
BACKGROUND
[0002] Infrared (IR) imaging devices can be used, for example, for
the purpose of obtaining thermal images of an object by absorbing
IR energy irradiated from the targeted object. From such images,
the surface temperature distribution of the object can be obtained
and analyzed. IR imaging devices require a line of sight to deliver
a suitably accurate thermal image. But it can often be difficult to
obtain a line of sight view of components that need to be thermally
imaged.
[0003] IR imaging has been found particularly useful for analyzing
heat distribution of electrically charged components. For example,
in the preventative maintenance of high voltage electrical circuits
and components an IR image of the components can often reveal hot
spots which may indicate malfunctioning, improperly connected, or
overloaded components. Timely identification of problem components
can save on system downtime and expenses associated with replacing
blown or destroyed components. However, the location of such
components may be difficult to reach and may be located in
hazardous, electrical environments, such as the interior of an
electrical cabinet. In another application, an IR imaging device
can be used as a bench tool for a technician or engineer in the
design and testing of printed circuit boards, integrated circuits,
and other electronic device components.
SUMMARY
[0004] Certain embodiments of the invention relate to an infrared
imaging probe having a front-end assembly coupled to a distal end
of the wand. The front-end assembly includes a lens, a focal plane
array, and distal circuitry. The lens is configured to receive
image information in the form of infrared energy and direct the
infrared energy onto the focal plane array. The distal circuitry is
adapted to process signals from the focal plane array and produce
an output signal. Processing circuitry is connected to and
electrically isolated from the distal circuitry. The processing
circuitry provides an output connection that is connectable to one
or more output/control devices. The processing circuitry is adapted
to receive and process the output signal for transmission to the
one or more output/control devices via the output connection.
[0005] Certain embodiments of the invention relate to an infrared
imaging probe system including a wand, one or more output devices,
and an electrically isolating connector. The wand includes a
front-end assembly coupled to a distal end of the wand that is
configured to receive image information in the form of infrared
energy and process the image information to produce an output
signal. The electrically isolating connector connects the front-end
assembly to the one or more output devices.
[0006] Certain embodiments of the invention relate to a method of
thermally imaging components within an enclosed cabinet. The method
includes providing an infrared imaging system including a wand
having a front-end assembly sized to fit through an access opening
in the cabinet and coupled to a distal end of the wand. The
front-end assembly includes a lens, a focal plane array, and distal
circuitry. The wand further includes processing circuitry connected
to and electrically isolated from the front-end assembly. The
method also includes providing one or more output devices connected
to the infrared imaging system. Further, the method includes
inserting the distal end of the wand through the access opening
within the panel of the cabinet and maneuvering the distal end of
the wand to provide the lens a view of the components.
[0007] Certain embodiments of the invention relate to an infrared
imaging probe that includes an elongate wand, an image collecting
assembly, and processing circuitry. The image collecting assembly
is coupled to a distal end of the wand and is configured to receive
image information in the form of infrared energy and process the
image information to produce an output signal. The processing
circuitry is connected to and electrically isolated from the image
collecting assembly, and the processing circuitry is adapted to
process the output signal for output to one or more output
devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following drawings are illustrative of particular
embodiments of the invention and therefore do not limit the scope
of the invention. The drawings are not to scale (unless so stated)
and are intended for use in conjunction with the explanations in
the following detailed description. Embodiments of the invention
will hereinafter be described in conjunction with the appended
drawings, wherein like numerals denote like elements.
[0009] FIG. 1 is a perspective view of an infrared imaging device
connected with an output/control device, according to some
embodiments of the invention.
[0010] FIG. 2 is a component level block diagram of an infrared
imaging device according to some embodiments of the invention.
[0011] FIG. 3 is a block diagram of an electrically isolating
connection according to some embodiments of the invention.
[0012] FIG. 4A is a side sectional view of an enclosure being
imaged according to embodiments of the invention.
[0013] FIG. 4B is a side sectional view of an enclosure being
imaged according to embodiments of the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0014] For the purpose of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiments illustrated in the drawing and specific language will
be used to describe the same. It will, nevertheless, be understood
that no limitation of the scope of the invention is thereby
intended; any alterations and further modifications of the
described or illustrated embodiments, and any further applications
of the principles of the invention as illustrated therein, are
contemplated as would normally occur to one skilled in the art to
which the invention relates.
[0015] FIG. 1 shows a perspective view of an infrared imaging probe
100 (or thermal imaging device) according to an embodiment of the
invention. The infrared imaging probe 100 provides an electrically
isolated infrared camera which can be especially useful for viewing
hard-to-reach, hazardous areas, such as the interior of an
electrical cabinet, or as a bench tool for viewing small components
at close range. In particular, the infrared imaging probe 100
includes a wand 102, a distal housing 104, a lens 106, and an
output connection 108 connectable to one or more output/control
devices 110. That is, the infrared imaging probe 100 may be merely
a thermal imaging probe that connects to one or more different
output/control devices 110. In addition, the infrared imaging probe
includes various electronics located within the distal housing 104
and connected thereto as will be described with reference to FIG.
2.
[0016] Referring to the embodiment of FIG. 1, an infrared imaging
probe 100 according to the invention includes a front-end assembly
112 mounted at the distal end of a wand 102. The front-end assembly
112 can include a distal housing 104 that houses the lens 106,
focal plane array, and distal circuitry of the infrared imaging
probe 100. Lens 106 can be configured to receive image information
from a targeted scene in the form of infrared energy and direct the
infrared energy onto front-end imaging components within the distal
housing 104. The wand enables a user to manipulate the distal
housing 104 and lens 106 by gripping a handle 114 or grip coupled
to the proximal end of the wand 102. The relatively small package
size of the distal housing 104 and agility provided by the wand 102
allow the infrared imaging probe to be used to obtain thermal
images from a target scene that may be otherwise unreachable by the
user with a traditional thermal imaging device. An isolating
connection 116, transmits collected scene image information from
the front-end assembly 112 to electrically isolated processing
circuitry which, in some embodiments, is housed within the handle
114. The processing circuitry processes and transmits the output
signal to one or more output/control devices 110 via an output
connection 108. The output/control device 110 is used to display
the image on a display 118 and/or store in memory for future
use.
[0017] In the embodiment of FIG. 1, the distal housing 104 is a
generally cylindrical body fixedly coupled at the distal end of the
wand 102. The distal housing 104 is generally rigid and in some
embodiments and can comprise and injection molded plastic. Further,
some embodiments include an insulating layer lining the distal
housing 104 to shield electronics disposed therein. For certain
applications, the distal housing 104 must be maintained within
certain package dimensions. For example, in one embodiment, the
diameter of a cylindrical distal housing 104 is less than 12 mm so
that the infrared imaging probe can be used for inspection of
electrical cabinets having a 12 mm viewing port. Sizing
considerations can further determine where to locate the infrared
imaging probe 100 electronics (discussed below). Generally, the
fewer components installed at the distal end of the wand 102, the
smaller the necessary distal housing 104 size. Moreover, while the
distal housing 104 of FIG. 1 is fixedly coupled with the wand 102,
one should appreciate that other connections are within the scope
of the invention. For example, some embodiments may include a
hinged connection between the distal housing 104 and wand 102 to
allow for articulation of the tip of the infrared imaging probe
100.
[0018] Installed within the distal surface of the distal housing
104, the lens 106 directs image information from the target scene
onto the thermal imaging components therein. Lenses are well known
in the art and any suitable lens material, shape, and character of
appropriate size can be used. In some embodiments, the lens 106 can
be a fixed focus lens having a standard field of view, a narrow
field of view or a wide angle field of view. When the infrared
imaging probe 100 is used as a bench tool, for example, for
obtaining thermal images of a printed circuit board in operation
within a device, a close focus lens having a narrow field of view
may be preferred. Whereas a wide angle lens may be more
appropriate, for example, in preventative maintenance of high
voltage electronic devices kept within electrical cabinets. In
other embodiments, the lens 106 may have an adjustable focus and
field of view. Focus and field of view adjustments can be
accomplished manually or automatically, and embodiments
incorporating such features should include appropriate controls
(electronic or otherwise) for accomplishing such adjustments.
[0019] The wand 102 is a generally elongate member that provides a
fixed or adjustable separation distance between the proximal and
distal ends of the infrared imaging probe 100. Suitable wands 102,
according to embodiments of the invention, comprise a
non-conductive material so that the infrared imaging probe 100 can
be used to view electrically charged components such as, for
example, in the inspection of high power electrical components
within an enclosed cabinet. The wand 102 can be rigid, semi-rigid,
or flexible. A flexible wand, can be useful for manipulating the
infrared imaging probe 100 into a shape appropriate for accessing
hard to reach target scenes. However, the wand 102 should be sturdy
enough to support the distal housing in the desired arrangement.
Suitable wand materials can include, for example, carbon fiber,
fiberglass, plastic, or other polymers. Other adjustable wand
characteristics can be provided as well. For example, in some
embodiments, the wand 102 can be a telescoping wand for adjusting
the wand 102 length.
[0020] In some embodiments, an isolating connection 116 can extend
along the length of the wand 102 between the distal housing 104 and
the infrared imaging probe's 100 processing circuitry. The type of
isolating connection 116 used depends upon the on the electrically
isolating connection between the front-end stages and the
processing circuitry (see discussion below). For example, in
embodiments where the electrically isolating connection comprises
an opto-electric connection, the isolating connection 116 could be
a length of fiber optic cable. In some embodiments, such as where
the electrical isolation is accomplished by wireless communication,
the infrared imaging probe 100 may not include a separate isolating
connection. While FIG. 1 shows the isolating connection 116 as
being coupled to and alongside the wand 102, many other
arrangements should be appreciated. For example, the isolating
connection 116 need not be coupled with the wand 102 at all so long
as the front-end assembly 112 communicates with the processing
circuitry. Alternatively, the wand 102 can be hollow having an
interior lumen along the wand 102 length through which the
isolating connection 116 can pass. Moreover, in some embodiments
the wand 102 and isolating connection 116 can be combined, for
example, the wand 102 could comprise a rigid fiber optic material
for relaying an optical signal.
[0021] At the proximal end of the wand 102, some embodiments
include a handle 114. The handle 114 can provide a grip for the
user such that the infrared imaging probe 100 is easier to
manipulate. In addition, the handle 114 can house the infrared
imaging probe's 100 processing circuitry, controls, and/or other
proximally located electronics.
[0022] Finally the infrared imaging probe 100 may include an output
connection 108 for operatively coupling the infrared imaging probe
100 to an output/control device 110. The output connection 108 can
be any connection capable of transmitting the processed scene
information and data to the output/control device 110. Preferably,
the output connection 108 is a standard connection (e.g. USB,
Firewire, or Ethernet) with respective standard connectors on
either end so that the infrared imaging probe 100 can be easily
adapted for use with a variety of output/control devices 110. In
some embodiments, the output connection 108 can be a wireless
antenna for wirelessly connecting with an output/control device 110
via a wireless communication protocol.
[0023] With reference to FIG. 2, electronic components of the
infrared imaging probe 100 will now be discussed. Generally the
infrared imaging probe 100 can be described as having three stages:
an optical stage 200, a distal stage 202 and a processing stage
204. In some embodiments according to the invention, the optical
stage 200 and distal stage 202 (collectively referred to here as
the "front end stages 206") reside in the distal housing 104 of the
infrared imaging probe 100, and are connected with the processing
stage 204 by an electrically isolating connection 116. In most
embodiments, the processing stage 204 does not reside at the distal
end of the wand 102. Instead, the processing stage 204 can be
coupled with the proximal end of the wand 102, for example in the
handle 114. Alternatively, in some embodiments, the non-distally
located processing stage 204, is located within a separate housing
that is not coupled to the wand. The output connection 108 provides
for connection from the processing stage 204, wherever located, to
an output/control device 110. In another aspect of the invention,
the infrared imaging probe 100 does not include a processing stage
204, rather, the functionality of the processing stage 204 (and in
some embodiments, at least a portion of the functionality of the
distal stage 202) is incorporated into the output/control device
110.
[0024] In operation, the infrared imaging probe 100 receives image
information in the form of infrared energy through the lens 106,
and in turn, the lens 106 directs the infrared energy onto the
focal plane array (FPA) 226. The combined functioning of the lens
106 and FPA 226 enables further electronics within the infrared
imaging probe 100 to create an image based on the image view
captured by the lens 106, as described below.
[0025] The FPA 226 can include a plurality of infrared detector
elements (not shown), e.g., including bolometers, photon detectors,
or other suitable infrared detectors well known in the art,
arranged in a grid pattern (e.g., an array of detector elements
arranged in horizontal rows and vertical columns). The size of the
array can be provided as desired and appropriate given the desire
or need to limit the size of the distal housing to provide access
to tight or enclosed areas. For example, many embodiments have an
array of 50.times.50 detector elements, but the invention should
not be limited to such. In fact, for certain applications, an array
as small a single detector (i.e. a 1.times.1 array) may be
appropriate. (It should be noted a infrared imaging probe 100
including a single detector, should be considered within the scope
of the terms "imaging probe" and "imager" as they are used
throughout this application, even though such a device may not be
used to create an "image"). Alternatively, some embodiments can
incorporate very large arrays of detectors. In some embodiments
involving bolometers as the infrared detector elements, each
detector element is adapted to absorb heat energy from the scene of
interest (focused upon by the lens 106) in the form of infrared
radiation, resulting in a corresponding change in its temperature,
which results in a corresponding change in its resistance. With
each detector element functioning as a pixel, a two-dimensional
image or picture representation of the infrared radiation can be
further generated by translating the changes in resistance of each
detector element into a time-multiplexed electrical signal that can
be processed for visualization on a display or storage in memory
(e.g., of a computer). Further circuitry downstream from the FPA
226, as is described below, is used to perform this translation.
Incorporated on the FPA 226 is a Read Out Integrated Circuit
(ROIC), which is used to output signals corresponding to each of
the pixels. Such ROIC is commonly fabricated as an integrated
circuit on a silicon substrate. The plurality of detector elements
may be fabricated on top of the ROIC, wherein their combination
provides for the FPA 226. In some embodiments, the ROIC can include
components discussed elsewhere in this disclosure (e.g. an
analog-to-digital converter (ADC) 230) incorporated directly onto
the FPA circuitry. Such integration of the ROIC, or other further
levels of integration not explicitly discussed, should be
considered within the scope of this disclosure.
[0026] As described above, the FPA 226 generates a series of
electrical signals corresponding to the infrared radiation received
by each infrared detector element to represent a thermal image. A
"frame" of thermal image data is generated when the voltage signal
from each infrared detector element is obtained by scanning all of
the rows that make up the FPA 226. Again, in certain embodiments
involving bolometers as the infrared detector elements, such
scanning is done by switching a corresponding detector element into
the system circuit and applying a bias voltage across such
switched-in element. Successive frames of thermal image data are
generated by repeatedly scanning the rows of the FPA 226, with such
frames being produced at a rate sufficient to generate a video
representation (e.g. 30 Hz, or 60 Hz) of the thermal image
data.
[0027] In some embodiments, optical stage components can further
include a shutter 208. A shutter 208 can be externally 210 or
internally 212 located relative to the lens 106 and operate to open
or close the view provided by the lens 106. As is known in the art,
the shutter 208 can be mechanically positionable, or can be
actuated by an electro-mechanical device such as a DC motor or
solenoid. Embodiments of the invention may include a calibration or
setup software implemented method or setting which utilize the
shutter 208 to establish appropriate bias (e.g. see discussion
below) levels for each detector element.
[0028] The distal stage 202 includes circuitry (distal circuitry)
for interfacing with and controlling the optical stage 200. In
addition, the distal stage 202 circuitry initially processes and
transmits collected infrared image data to the processing stage
204. More specifically, the signals generated by the FPA 226 are
initially conditioned by the distal stage 202 circuitry of the
infrared imaging probe 100. In certain embodiments, as shown, the
distal stage 202 circuitry includes a bias generator 220 and a
pre-amp/integrator 222. In addition to providing the detector bias,
the bias generator 220 can optionally add or subtract an average
bias current from the total current generated for each switched-in
detector element. The average bias current can be changed in order
(i) to compensate for deviations to the entire array of resistances
of the detector elements resulting from changes in ambient
temperatures inside the infrared imaging probe 100 and (ii) to
compensate for array-to-array variations in the average detector
elements of the FPA 226. Such bias compensation can be
automatically controlled by the infrared imaging probe 100 or
software, or can be user controlled via input to the output/control
device 110 or processing stage 204. Following provision of the
detector bias and optional subtraction or addition of the average
bias current, the signals can be passed through a
pre-amp/integrator 222. Typically, the pre-amp/integrator 222 is
used to condition incoming signals, e.g., prior to their
digitization. As a result, the incoming signals can be adjusted to
a form that enables more effective interpretation of the signals,
and in turn, can lead to more effective resolution of the created
image. Subsequently, the conditioned signals are sent downstream
into the processing stage 204 of the infrared imaging probe
100.
[0029] In some embodiments, the distal stage 202 circuitry can
include one or more additional elements for example, additional
sensors 224 or an ADC 230. Additional sensors 224 can include, for
example, temperature sensors, visual light sensors (such as a CCD),
pressure sensors, magnetic sensors, etc. Such sensors can provide
additional calibration and detection information to enhance the
functionality of the infrared imaging probe 100. For example,
temperature sensors can provide an ambient temperature reading near
the FPA 226 to assist in radiometry calculations. A magnetic
sensor, such as a Hall effect sensor, can be used in combination
with a magnet mounted on the lens to provide lens focus position
information. Such information can be useful for calculating
distances, or determining a parallax offset for use with visual
light scene data gathered from a visual light sensor.
[0030] An ADC 230 can provide the same function and operate in
substantially the same manner as discussed below, however its
inclusion in the distal stage 202 may provide certain benefits, for
example, digitization of scene and other sensor information prior
to transmittal via the electrically isolating connection 116. In
some embodiments, the ADC 230 can be integrated into the ROIC, as
discussed above, thereby eliminating the need for a separately
mounted and installed ADC 230.
[0031] Because of the electrical isolation of the distal circuitry
(discussed below), some embodiments include a separate power supply
for the front-end stages 206. For example, a battery can be
installed within the front-end assembly 112 to power the distal
circuitry, FPA 226 and other distal components.
[0032] As discussed above, the front end stages 206 are generally
located within the distal housing 104 of the infrared imaging probe
100. Embodiments according to the invention include an electrically
isolating connection 116 between the front end stages 206 and the
processing stage 204. The isolating connection 116 in combination
with a non-conductive wand allows for the gathering of scene data
without providing a conductive path between the distal wand end and
the user who typically grips the infrared imaging probe 100 at the
proximal end of the wand. Thus, the infrared imaging probe 100 can
be used to view electrically active components with significantly
reduced risk of electrical shock to the user.
[0033] The electrical isolation can be accomplished by various
methods. For example, with reference to the isolation schematic of
FIG. 3, an electrically isolating connection 116 can generally
include two transducers 300 coupled by a non-electrically
conductive communication medium 302 (generally corresponding to the
isolating connection 116 of FIG. 1). In certain embodiments, the
transducers 300 are opto-electrical transducers, translating
electrical signals into optical pulses and vice versa. With such
transducers, a fiber optic connection medium can be used to
transfer optical signals generated by one transducer 300 to the
other transducer 300, and vice versa. Alternatively, in some
embodiments, the non-electrically conductive communication medium
302 can be an electromagnetic wave transmissible medium such as,
for example, air. In such an example, the transducers 300 can be in
wireless communication with each other. In such case, the
transducers 300 can include wireless antennas, and any number of
wireless communication protocols may be used, for example,
Bluetooth or WiFi.
[0034] In the schematic of FIG. 2, the electrically isolating
connection 116 is represented as being separate from the distal
stage 202. However, it should be understood that components of the
electrically isolating connection 116, such as a transducer 300,
can be integrated into distal stage 202. Likewise, a transducer 300
on the proximal end of the electrically isolating connection 116
can be integrated with the processing stage 204 or can be a
separate component.
[0035] Generally, the processing stage 204, can include one or more
of a field-programmable gate array (FPGA) 228, a complex
programmable logic device (CPLD) controller and a processor 214
(e.g., computer processing unit (CPU) or digital signal processor
(DSP)). These elements manipulate the conditioned scene image data
delivered from the front end stages 206 in order to provide output
scene data that can be displayed or stored for use by the user.
Subsequently, the processing stage 204 circuitry (processing
circuitry) sends the processed data to the output/control device
110.
[0036] In addition to providing needed processing for infrared
imagery, the processing stage 204 circuitry can be employed for a
wide variety of additional functions. For example, in some
embodiments, the processor 214 can perform temperature
calculation/conversion (radiometry), combine scene information with
data and/or imagery from other sensors, or compress and translate
the image data. Additionally, in some embodiments, the processor
214 can interpret and execute commands from the output/control
device 110. This can involve processing of various input signals
and transferring those signals via the electrically isolating
connection 116 to the front end stages 206 where components at the
front end (e.g. motors, or solenoids) can be actuated to accomplish
the desired control function. Exemplary control functions can
include adjusting the focus, opening/closing a shutter, triggering
sensor readings, adjusting bias values, etc. Moreover, input
signals may be used to alter the processing of the image data that
occurs at the processing stage 204.
[0037] The processing stage 204 circuitry can further include other
components 216 to assist with the processing and control of the
infrared imaging probe 100. For example, as discussed above, in
some embodiments, an ADC 230 can be incorporated into the
processing stage 204. In such a case, analog signals conditioned by
the front-end stages 206 are not digitized until reaching the
processing stage 204. Moreover, some embodiments can include
additional on board memory for storage of processing command
information and scene data, prior to transmission to the
output/control device 110. In addition, some embodiments may
include one or more controls for controlling device functionality
independent of the output/control device 110. For example, the
infrared imaging probe 100 may include a knob or buttons installed
in the handle for adjusting the focus or triggering the
shutter.
[0038] As described above, the output connection 108 is preferably
a standard connection such as USB, Firewire, or Ethernet. The
general operation of the output connection 108 resembles that of
the insulating connection 116 shown in FIG. 3, i.e. a pair of
transducers 300 coupled via a transmission medium 302. It should be
noted that because the output connection 108 resides between
components electrically isolated from the potentially hazardous
target scene, it is not necessary to provide a non-conductive
connection medium as described above. This not to say that
non-conductive connection media 302 (such as those described above)
cannot be used, but merely that standard connectors, which are
typically conductive, can be used. Moreover, the processing stage
204 circuitry need not be directly connected to the output/control
device 110 as shown. For example, in some embodiments, the infrared
imaging probe 100 includes a connection to an intermediate network
or system, for example, the Internet or a LAN. Communication
protocols of the intermediate system can be used to provide data
transfer between the infrared imaging probe 100 and one or more
output/control devices 110 similarly connected to the intermediate
system.
[0039] The output/control device 110 to which the infrared imaging
probe 100 is connected can include any number of devices. For
example, the output/control device 110 can include one or more of a
digital multimeter, a personal computer, a personal digital
assistant, a display device, and a cellular phone. Typical
output/control devices 110 include a display capable of displaying
the image generated from the scene data collected by the infrared
imaging probe 100. Some output/control devices 110 may further
include one or more input interfaces such as buttons, or a
graphical user interface to allow the user to control or alter the
operation of the infrared imaging probe 100.
[0040] In another aspect of the invention, the infrared imaging
probe 100 (shown in FIG. 1) does not include a processing stage
204. Rather, the functionality of the processing stage 204 (and in
some embodiments, at least a portion of the functionality of the
distal stage 202) is incorporated into the output/control device
110. In this aspect, the electrically isolating connection 116 can
connect directly to an output/control device 110. The functionality
of the front-end (generally the analog control of the optical
stage) remains with the distal stage 202 circuitry, but the output
signal from the distal stage 202 circuitry arrives at the
output/control device 110 un-processed. In such embodiments, the
output/control device 110 can include an optical input, for
example, to receive the electrically isolating connection 116.
Further, the output/control device 110 can include software
instructions or additional hardware to accomplish the processing
for which the processing stage was responsible in the above
described embodiments. In some embodiments, the output/control
device 110 is equipped to process analog data sent from the distal
stage 202 circuitry, while in other embodiments, the distal stage
202 circuitry includes an ADC 230 (as discussed above) to provide a
digital signal to the output/control device 110.
[0041] As shown in FIGS. 4A and 4B, infrared imaging probes 100
according to embodiments of the invention can be used in the field
of preventative maintenance of electrical equipment. Here,
electrical equipment/components 218 within a closed enclosure 400
can be viewed without requiring the enclosure 400 to be opened, or
the electrical equipment/components 218 within to be powered down.
In each exemplary use shown, the distal housing 104 of the infrared
imaging probe 100 has been inserted into the enclosure 400 through
an access opening 402 within a panel 404 of the enclosure 400. The
access opening 402 can be any aperture through the panel sized
large enough to receive the distal housing 104. In some
embodiments, the access opening 402 can be a portal installed
within the panel 404 designed to meet safety standards regarding
electrical enclosures, such as those provided by the National
Electrical Manufacturers Association (NEMA). A user positioned
outside of the enclosure can grip the infrared imaging probe 100 by
its handle 114 and maneuver the distal end to provide the desired
view which can be displayed or stored on the connected
output/control device 110. In such a use, the desire to
electrically isolate the distal end of the wand 102 becomes
apparent. The electrically isolating connection 116 and
non-conductive wand 102 (both described above) prevent the
formation of a conductive path from the distal housing 104 through
the user gripping the infrared imaging probe 100 to ground. Thus,
the risk of arcing can be avoided.
[0042] In FIG. 4A, an infrared imaging probe 100 having a generally
straight, rigid wand 102 is used to inspect operating electrical
equipment/components 218. The infrared imaging probe 100 can be
inserted straight (indicated as Position I) into the enclosure 400
to view electrical equipment/components 218 directly aligned with
the access opening 402. To view electrical equipment/components 218
in the bottom of the enclosure 400, the handle 114 of the infrared
imaging probe 100 can be pivoted upward (e.g. to Position II).
Likewise, the user can pivot the handle 114 of the infrared imaging
probe 100 downward (e.g. to Position III) to view electrical
equipment/components 218 in the top of the enclosure 400. Moreover,
the infrared imaging probe 100 can be pivoted side-to-side to view
electrical equipment/components 218 outside of the horizontal field
of view of the infrared imaging probe 100.
[0043] In FIG. 4B, an infrared imaging probe 100 having a bendable,
or articulatable wand 102 has been inserted through the access
opening 402. In Position I, the wand 102 has been bent such that
the distal housing 104 can maneuver around an obstacle 406 within
the enclosure 400 to view electrical equipment/components 218 that
would otherwise be hidden from line of sight view. In an
alternative position (e.g. Position II), a bendable wand 102 can be
used to obtain other hard to reach views, such as the inner surface
of the panel 404 in which the access opening 402 is installed.
[0044] In another example, a infrared imaging probe 100 according
to embodiments of the invention can be used as a bench tool
alongside for example, a signal generator, multimeter, and other
electronic analysis and design tools. An engineer, technician,
tester, or designer of electronic devices can use a thermal imaging
wand according to the invention to thermally analyze components at
their workbench. Specifically, in some applications such as, for
example, consumer electronics, design constraints may require
circuit boards and electronic components to be installed in small,
tight packages. Embodiments of the invention can be positioned
relative to such packages so as to obtain a proper contextual frame
for analysis of the thermal profile of the device, or a portion
thereof.
[0045] While the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, it is
intended to embrace all such alternatives, modifications, and
variations, which fall within the spirit and broad scope of the
invention or as set forth in the appended claims.
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