U.S. patent application number 10/604303 was filed with the patent office on 2005-01-13 for real time ir optical sensor.
This patent application is currently assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION. Invention is credited to Reyes, Ray A., Schmoke, David L., Ziemins, Uldis A..
Application Number | 20050007578 10/604303 |
Document ID | / |
Family ID | 33518133 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050007578 |
Kind Code |
A1 |
Ziemins, Uldis A. ; et
al. |
January 13, 2005 |
REAL TIME IR OPTICAL SENSOR
Abstract
An apparatus and method to align an invisible light beam sensor,
such as an IR sensor, utilizing a visible light beam such as a
visible LED or HeNe laser, and provide the ability to visually
monitor when the sensor needs adjustment in real time and avoid off
line adjustments. Various embodiments synchronize and position both
the invisible light beam and the visible light beam to travel the
same path to a common desired location.
Inventors: |
Ziemins, Uldis A.;
(Poughkeepsie, NY) ; Reyes, Ray A.; (New Windsor,
NY) ; Schmoke, David L.; (Verbank, NY) |
Correspondence
Address: |
INTERNATIONAL BUSINESS MACHINES CORPORATION
DEPT. 18G
BLDG. 300-482
2070 ROUTE 52
HOPEWELL JUNCTION
NY
12533
US
|
Assignee: |
INTERNATIONAL BUSINESS MACHINES
CORPORATION
NEW ORCHARD ROAD
ARMONK
NY
|
Family ID: |
33518133 |
Appl. No.: |
10/604303 |
Filed: |
July 9, 2003 |
Current U.S.
Class: |
356/153 |
Current CPC
Class: |
G01B 11/27 20130101 |
Class at
Publication: |
356/153 |
International
Class: |
G01B 011/26 |
Claims
What is claimed is:
1. An apparatus for performing alignment and monitoring of optical
sensors comprising: an invisible light source emitting an invisible
light beam: a visible light source emitting a visible light beam
and positioned opposite from and approximately coaxial with said
invisible light source; an optical polarizing beam splitter having
an outer reflecting surface and an inner reflecting surface, said
outer reflecting surface reflecting approximately 100% of said
invisible right beam and said inner reflecting surface reflecting
approximately 50% of said visible light beam in the same path as
said invisible light beam, said optical polarizing beam splitter
positioned between and approximately coaxial with said invisible
light source and said visible light source; and an optical detector
positioned opposite and approximately coaxial with said outer
reflecting surface to collect both said reflected invisible and
visible light beams.
2. The apparatus of claim 1 wherein said optical polarizing beam
splitter is rotatable.
3. The apparatus of claim 2, further comprising: a motor connected
to said rotatable optical beam splitter with a rotatable shaft said
rotatable shaft having a longitudinal opening concentric with its
axis of rotation; and said visible light source positioned
approximately coaxial with said longitudinal opening.
4. The apparatus of claim 1 wherein said visible light source is a
He--Ne laser.
5. The apparatus of claim 1 wherein said invisible light source is
an infrared laser.
6. The apparatus of claim 1 wherein said invisible light source is
an ultraviolet laser.
7. An apparatus for performing alignment and monitoring of optical
sensors comprising: an invisible light source; a visible light
source: a reflecting mirror; means for alternatively shuttling said
visible light source and said invisible light source in optical
alignment with said reflecting mirror, and an optical detector
positioned opposite and approximately coaxial with said reflecting
mirror.
8. An apparatus for performing alignment and monitoring of optical
sensors comprising: an invisible fight source emitting an invisible
light beam; a visible light source emitting a visible light beam
and positioned opposite and approximately coaxial to said invisible
light source; a dual mirror assembly positioned between and
approximately coaxial with said visible light source and said
invisible light source, said dual mirror assembly having a first
side opposite said invisible light source and a second side
opposite said visible fight source such that in operation said
invisible light beam and said visible light beam are both reflected
and converge at a common point; a reflecting mirror positioned in
alignment with said common point such that both said invisible
light beam and said visible light beam are reflected in the same
direction; and an optical detector positioned opposite and
approximately coaxial with said reflecting mirror to collect said
invisible light beam and said visible light beam.
9. An apparatus for performing alignment and monitoring of optical
sensors comprising: a laser emitting diode having a visible light
source and an invisible light source such that said laser emitting
diode emits a visible light beam and an invisible light beam; a
reflecting mirror positioned opposite and approximately coaxial
with said laser emitting diode; and an optical detector positioned
opposite and approximately coaxial with said reflecting mirror to
collect said invisible light beam and said visible light beam.
10. The apparatus of claim 9 wherein said laser emitting diode is a
dual element laser emitting diode which emits a visible laser beam
and an invisible laser beam from the same component.
11. The apparatus of claim 9 wherein said light emitting diode is a
dual light emitting diode comprising a visible laser source and an
invisible laser source positioned adjacent to each other.
12. The apparatus of claim 9 wherein said light emitting diode is a
coaxial light emitting diode comprising a visible laser source
aligned directly in front of or behind an invisible laser
source.
13. A method for performing alignment and monitoring of optical
sensors comprising the steps of: providing an invisible light
source emitting an invisible light beam; positioning a visible
light source emitting a visible light beam opposite from and
approximately coaxial with said invisible light source; positioning
an optical polarizing beam splitter between and approximately
coaxial with said invisible light source and said visible light
source, said optical polarizing beam splitter having an outer
reflecting surface and an inner reflecting surface, said outer
reflecting surface reflecting approximately 100% of said invisible
light beam and said inner reflecting surface reflecting
approximately 50% of said visible light beam in the same path as
said invisible light beam; and positioning an optical detector
opposite and approximately coaxial with said outer reflecting
surface to collect both said reflected invisible and visible light
beams.
14. The method of claim 13 wherein said optical polarizing beam
splitter is rotatable.
15. The method of claim 13 further comprising the steps of;
connecting a motor to said rotatable optical beam splitter with a
rotatable shaft, said rotatable shaft having a longitudinal opening
concentric with its axis of rotation; and positioning said visible
light source approximately coaxial with said longitudinal
opening.
16. The method of claim 13 wherein said visible light source is a
He--Ne laser.
17. The method of claim 13 wherein said invisible light source is
an infrared laser.
18. The method of claim 13 wherein said invisible light source is
an ultraviolet laser.
19. A method for performing alignment and monitoring of optical
sensors comprising the steps of: providing an invisible light
source, a visible light source and a reflecting mirror; providing
means for alternatively shuttling said visible light source and
said invisible light source in optical alignment with said
reflecting mirror; and positioning an optical detector opposite and
approximately coaxial with said reflecting mirror.
20. A method for performing alignment and monitoring of optical
sensors comprising the steps of; providing an invisible light
source emitting an invisible light beam; positioning a visible
light source emitting a visible light beam opposite and
approximately coaxial to said invisible light source; positioning a
dual mirror assembly between and approximately coaxial with said
visible light source and said invisible light source, said dual
minor assembly having a first side opposite said invisible light
source and a second side opposite said visible light source such
that in operation said invisible light beam and said visible light
beam are both reflected and converge at a common point; positioning
a reflecting mirror in alignment with said common point such that
both said invisible light beam and said visible light beam are
reflected in the same direction; and positioning an optical
detector opposite and approximately coaxial with said reflecting
mirror to collect said invisible light beam and said visible light
beam.
21. A method for performing alignment and monitoring of optical
sensors comprising the steps of: providing a laser emitting diode
having a visible light source and an invisible light source such
that said laser emitting diode emits a visible light beam and an
invisible light beam; positioning a reflecting mirror opposite and
approximately coaxial with said laser emitting diode: and
positioning an optical detector opposite and approximately coaxial
with said reflecting mirror to collect said invisible light beam
and said visible light beam.
22. The method of claim 21 wherein said laser emitting diode is a
dual element laser emitting diode which emits a visible laser beam
and an invisible laser beam from the same component.
23. The method of claim 21 wherein said light emitting diode is a
dual light emitting diode comprising a visible laser source and an
invisible laser source positioned adjacent to each other.
24. The method of claim 21 wherein said light emitting diode is a
coaxial light emitting diode comprising a visible laser source
aligned directly in front of or behind an invisible laser source.
Description
BACKGROUND OF INVENTION
[0001] The present invention is directed to the alignment of
optical sensors and, more particularly, is directed to a method and
apparatus for visually aligning an optical sensor such as an
infrared laser where the laser operates outside the visible
spectrum.
[0002] The use of optical sensors where the laser operates outside
the visible spectrum is common in many industrial applications as
well as consumer applications such as hand held remote controllers
for TV, stereo etc.
[0003] Automated sensing equipment using invisible optical sensors
is being increasingly integrated into industrial and manufacturing
facilities. A typical example is the overhead infrared (IR) sensing
vehicle shown in FIG. 1. This particular vehicle is used to
transport semiconductor wafers in an automated clean room
semiconductor wafer facility.
[0004] Each vehicle contains IR sensors which project a three
dimensional cone of light. For simplicity, such a three dimensional
cone of light will hereafter be referred to as a "beam". The
sensors are used in the safety and guidance of the moving vehicles.
Any disruption in the IR beam will stop the motion of the
vehicle.
[0005] Referring again to FIG. 1, an initial sensor alignment and
then periodic alignment checks are currently required to determine
proper beam alignment and operation of the unit. A typical unit
will utilize an IR light emitting diode (LED), for example,
emitting light at a wavelength of approximately 870 nanometers. The
human eye is unable to detect this wavelength and therefore
reference fixtures or other detectors are required to align the
sensors.
[0006] This inability to visually monitor the sensor alignment
requires that the unit be taken out of normal manufacturing
operation for periodic monitoring using fixtures or jigs to check
the beam alignment. What is needed is the ability to perform
in-situ or real time checks on the sensor beam alignment, while the
unit is in normal manufacturing operation, to eliminate costly
interruption of the manufacturing operation.
[0007] Accordingly, it is a purpose of the present invention to
provide an apparatus and method to align an invisible light beam
sensor utilizing a visible light beam such as a visible LED or HeNe
laser.
[0008] It is another purpose of the present invention to provide
the ability to align and periodically adjust invisible light beam
sensors without fixtures or jigs.
[0009] It is another purpose of the present invention to provide
the ability to visually monitor when the sensor needs adjustment in
real time and avoid off line adjustments.
[0010] It is another purpose of the present invention to achieve
faster alignment and more repeatable alignments utilizing the
visible wavelength.
[0011] These and other purposes of the present invention will
become more apparent after referring to the following description
considered in conjunction with the accompanying drawings.
SUMMARY OF INVENTION
[0012] The purposes and advantages of the present invention have
been achieved by providing, according to a first embodiment of the
invention an apparatus for performing alignment and monitoring of
optical sensors comprising: an invisible light source, such as an
infrared or ultraviolet laser, emitting an invisible light beam; a
visible light source, such as a He--Ne laser, emitting a visible
light beam and positioned opposite from and approximately coaxial
with the invisible light source; an optical polarizing beam
splitter having an outer reflecting surface and an inner reflecting
surface, the outer reflecting surface reflecting approximately 100%
of the invisible light beam and the inner reflecting surface
reflecting approximately 50% of the visible light beam in the same
path as the invisible light beam, the optical polarizing beam
splitter positioned between and approximately coaxial with both the
invisible light source and the visible light source; and an optical
detector positioned opposite and approximately coaxial with the
outer reflecting surface to collect both the reflected invisible
and visible light beams.
[0013] The apparatus may further comprise a motor connected to the
optical beam splitter, which may be rotatable, with a rotatable
shaft having a longitudinal opening concentric with its axis of
rotation; and the visible light source positioned approximately
coaxial with the longitudinal opening.
[0014] According to another embodiment of the invention there is
provided an apparatus for performing alignment and monitoring of
optical sensors comprising: an invisible light source; a visible
light source; a reflecting mirror; means for alternatively
shuttling the visible light source and the invisible light source
in optical alignment with the reflecting mirror, and an optical
detector positioned opposite and approximately coaxial with the
reflecting mirror.
[0015] According to another embodiment of the invention there is
provided an apparatus for performing alignment and monitoring of
optical sensors comprising: an invisible light source emitting an
invisible light beam; a visible light source emitting a visible
light beam and positioned opposite and approximately coaxial to the
invisible light source; a dual mirror assembly positioned between
and approximately coaxial with the visible light source and the
invisible light source, the dual mirror assembly having a first
side opposite the invisible light source and a second side opposite
the visible light source such that in operation the invisible light
beam and the visible light beam are both reflected and converge at
a common point; a reflecting mirror positioned in alignment with
the common point such that both the invisible light beam and the
visible light beam are reflected in the same direction; and an
optical detector positioned opposite and approximately coaxial with
the reflecting mirror to collect both the invisible light beam and
the visible light beam.
[0016] According to another embodiment of the invention there is
provided an apparatus for performing alignment and monitoring of
optical sensors comprising: a laser emitting diode having a visible
light source and an invisible light source such that the laser
emitting diode emits both a visible light beam and an invisible
light beam; a reflecting mirror positioned opposite and
approximately coaxial with the laser emitting diode; and an optical
detector positioned opposite and approximately coaxial with the
reflecting mirror to collect both the invisible light beam and the
visible light beam.
[0017] In one aspect of this embodiment the laser emitting diode is
a dual element laser emitting diode which emits a visible laser
beam and an invisible laser beam from the same component. In
another aspect of this embodiment the light emitting diode is a
dual light emitting diode comprising a visible laser source and an
invisible laser source positioned adjacent to each other. In
another aspect of this embodiment the light emitting diode is a
coaxial light emitting diode comprising a visible laser source
aligned directly in front of or behind an invisible laser
source.
[0018] According to another aspect of the invention there is
provided a method for performing alignment and monitoring of
optical sensors comprising the steps of: providing an invisible
light source emitting an invisible light beam; positioning a
visible light source emitting a visible light beam opposite from
and approximately coaxial with the invisible light source;
positioning an optical polarizing beam splitter between and
approximately coaxial with the invisible light source and the
visible light source, the optical polarizing beam splitter having
an outer reflecting surface and an inner reflecting surface, the
outer reflecting surface reflecting approximately 100% of the
invisible light beam and the inner reflecting surface reflecting
approximately 50% of the visible light beam in the same path as the
invisible light beam; and positioning an optical detector opposite
and approximately coaxial with the outer reflecting surface to
collect both the reflected invisible and visible light beams.
[0019] The method may further comprise the steps of connecting a
motor to the optical beam splitter, which may be rotatable, with a
rotatable shaft, the rotatable shaft having a longitudinal opening
concentric with its axis of rotation; and positioning the visible
light source approximately coaxial with the longitudinal
opening.
[0020] According to another embodiment of the invention there is
provided a method for performing alignment and monitoring of
optical sensors comprising the steps of: providing an invisible
light source, a visible light source and a reflecting mirror;
providing means for alternatively shutting the visible light source
and the invisible light source in optical alignment with the
reflecting mirror; and positioning an optical detector opposite and
approximately coaxial with the reflecting mirror.
[0021] According to another embodiment of the invention there is
provided a method for performing alignment and monitoring of
optical sensors comprising the steps of: providing an invisible
light source emitting an invisible light beam; positioning a
visible light source emitting a visible light beam opposite and
approximately coaxial to the invisible light source; positioning a
dual mirror assembly between and approximately coaxial with the
visible light source and the invisible light source, the dual
mirror assembly having a first side opposite the invisible light
source and a second side opposite the visible light source such
that in operation the invisible light beam and the visible light
beam are both reflected and converge at a common point; positioning
a reflecting mirror in alignment with the common point such that
both the invisible light beam and the visible light beam are
reflected in the same direction; and positioning an optical
detector opposite and approximately coaxial with the reflecting
mirror to collect the invisible light beam and the visible light
beam.
[0022] According to another embodiment of the invention there is
provided a method for performing alignment and monitoring of
optical sensors comprising the steps of: providing a laser emitting
diode having a visible light source and an invisible light source
such that the laser emitting diode emits both a visible light beam
and an invisible light beam; positioning a reflecting mirror
opposite and approximately coaxial with the laser emitting diode;
and positioning an optical detector opposite and approximately
coaxial with the reflecting mirror to collect both the invisible
light beam and the visible light beam. The laser emitting diode may
be a dual element laser emitting diode which emits a visible laser
beam and an invisible laser beam from the same component, a dual
light emitting diode comprising a visible laser source and an
invisible laser source positioned adjacent to each other, or a
coaxial light emitting diode comprising a visible laser source
aligned directly in front of or behind an invisible laser
source.
BRIEF DESCRIPTION OF DRAWINGS
[0023] The features of the invention believed to be novel and the
elements characteristic of the invention are set forth with
particularity in the appended claims. The Figures are for
illustration purposes only and are not drawn to scale. The
invention itself, however, both as to organization and method of
operation, may best be understood by reference to the detailed
description which follows taken in conjunction with the
accompanying drawings in which:
[0024] FIG. 1 is a perspective view of a conventional overhead IR
sensing vehicle.
[0025] FIG. 2 is a perspective view of an overhead IR sensing
vehicle including a visible light source and polarizing beam
splitter in accordance with an embodiment of the invention.
[0026] FIG. 3 is a schematical view of a polarizing beam splitter
positioned between a visible and invisible light source in
accordance with an embodiment of the invention.
[0027] FIG. 4 is a schematical view of a shuttle mechanism
installed in a sensor unit in accordance with an embodiment of the
invention.
[0028] FIG. 5 is a schematical view of a dual mirror positioned in
a sensor unit in accordance with an embodiment of the
invention.
[0029] FIG. 6 is a schematical view of an overhead IR sensing
vehicle including a dual element LED in accordance with an
embodiment of the invention.
[0030] FIG. 7 is a schematical view of an overhead IR sensing
vehicle including a dual LED in accordance with an embodiment of
the invention.
[0031] FIG. 8 is a schematical view of an overhead IR sensing
vehicle including a coaxial LED in accordance with an embodiment of
the invention.
DETAILED DESCRIPTION
[0032] The present invention now will be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout.
[0033] In a first embodiment of the present invention there is
disclosed the use of an IR light source in conjunction with a
visible light source to perform insitu alignment and monitoring of
the invisible IR beam. Referring again FIG. 1 there is a shown an
IR sensor unit 10 used in a conventional System Resource Controller
(SRC) overhead vehicle. The invisible IR beam (not shown)
originates from a conventional IR LED source 12. An example of a
typical IR LED source is an 870 nm wavelength Lambda Physik LED.
The human eye is unable to detect this wavelength and therefore
reference fixtures or other detectors are required to align the
sensors.
[0034] The IR beam is emitted from stationary source 12 and is
reflected from a reflecting scanning mirror 11. There are optics
between the source 12 and reflecting scanning mirror 11 which
collimate and process the beam, which are common in the art, that
are not shown. Such optics are well known and need not be described
further herein. A drive motor 16 turns a drive shaft 15 which
operates a drive belt 17 coupled to the reflecting scanning mirror
11 which causes the reflecting scanning mirror 11 to swing back and
forth with a regular motion.
[0035] As the reflecting scanning mirror 11 oscillates, the
reflected IR beam (not shown) from source 12 propagates out to a
predetermined scan angle and intensity to be reflected from any
object in its path. The reflected beam is then captured by a
synchronized scanning mirror 13 which is also coupled to drive
motor 16. The synchronized scanning mirror 13 is a reflecting
mirror which oscillates in synchronization with reflecting scanning
mirror 11. The synchronized scanning mirror 13 captures reflected
IR light from any detected object and irradiates an optical
detector 14. From the optical detector 14 signals are processed and
the electronics, which are not shown and are well known in the art,
impedes or stops forward progress of the vehicle.
[0036] The initial alignment of the IR beam is currently performed
using a viewing scope. Typical IR or ultraviolet (UV) viewing
scopes employ a high resolution image converter and photocathode
arrangement to produce a visible image from invisible radiation.
This alignment, and any subsequent monitoring, can only be
performed when the unit is off line. The use of a viewing scope
requires that the adjustment be performed while the unit is
stationary. As discussed previously, it would be very advantageous
to perform in-situ checks of the equipment to eliminate costly
interruption of the manufacturing facility.
[0037] Referring now to FIG. 2 a visible alignment and tracking
means is provided by the present invention to accomplish this task
in real time. A visible light source 19 is positioned opposite from
and approximately coaxial with the stationary IR source 12. In the
particular embodiment shown in FIG. 2, the visible light source 19
is also positioned above a hollow drive motor shaft 18. The hollow
drive motor shaft 18 replaces the drive motor shaft 15 shown in
FIG. 1. This is to allow visible light from the visible light
source 19, for example He--Ne laser radiation, to coaxially travel
down the shaft and irradiate visible radiation on a polarizing beam
splitter 20. The polarizing beam splitter 20 replaces the scanning
mirror 11 shown in FIG. 1. The polarizing beam splitter 20 is
positioned between and approximately coaxial with the visible light
source 19 and stationary IR source 12.
[0038] The polarizing beam splitter 20, shown in more detail in
FIG. 3, is well known in the optical field. It consists of an outer
invisible light reflective surface 23 which will reflect
approximately 100% of the incident invisible light beam 22, in this
embodiment an IR beam, at a positive 90.degree. angle. It also has
an inner surface 24 which is coated with a suitable coating
material which will split the visible light beam 21, in this
example He--Ne radiation, with approximately 50% of the visible
light beam reflected at a positive 90.degree. angle and
approximately 50% of the visible light beam reflected at a negative
90.degree. angle. Such coating materials are well known in the art
and have a horizontal or vertical polarization which is optimized
to pass one or the other light wave.
[0039] Referring again to FIG. 2, substituting the polarizing beam
splitter 20 for the scanning mirror 11, and mounting and
configuring the polarizing beam splitter 20 between visible light
source 19 and IR source 12, allows the visible He--Ne radiation (or
other visible collimated light) to be projected to combine and
travel the same path as the IR radiation after reflection from
polarizing beam splitter 20. An optical detector, not shown, is
positioned opposite and approximately coaxial with the invisible
light reflecting surface 23 of the optical polarizing beam
splitter. In this embodiment the polarizing beam splitter is
rotatable, coupled to a motor by a rotating shaft in a similar
manner as the scanning mirror shown in FIG. 1. However in this
embodiment the rotatable shaft 18 is hollow, i.e., the rotatable
shaft 18 has a longitudinal opening concentric with its axis of
rotation. The visible light source 19 is positioned above
approximately coaxial with the rotatable shaft 18 to allow the
visible light beam 21 to pass through the longitudinal opening.
[0040] As illustrated in FIG. 3, approximately 50% of the visible
light beam 21 and approximately 100% of the IR light beam 22 is
reflected from polarizing beam 20 to be collected by an optical
detector (not shown). The present invention therefore implements a
beam splitter cube which allows the IR wavelength to pass and
reflects the visible wavelength in unison, therefore allowing an
individual to visually view the sensor output and align the sensor
correctly. Initially the IR and visible wavelengths combine at the
beam splitter where they overlay on top of each other and therefore
represent the optical path of both wavelengths.
[0041] The two beams can be aligned by turning on the light source
19 and viewing the IR radiation with an IR viewer as discussed
previously. By viewing the IR radiation and visible radiation the
two optical paths can be aligned accurately and in real time. The
IR viewer has certain limitations in contrast; range and resolution
of the IR beam thereby making it a good initial alignment tool and
then utilizing the visible light source 19 to be the in-situ
resolving means.
[0042] Referring to FIG. 4 there is illustrated another embodiment
of the present invention which shows another means of incorporating
a visible light alignment path to an invisible light path. In this
embodiment a shuttle mechanism 33 is installed in the sensor unit
to position either the visible light source 32 or invisible light
source 31 in the desired alignment position 34.
[0043] Both the invisible light source 31, in this particular
example an IR LED, and visible light source 32, for example an LED,
laser diode, or collimated light source, are superimposed by the
use of a shuttle mechanism 33 to position the invisible light
source 31 or the visible light source 32 in the desired optical
sensor position 34. The shuttle mechanism 33 is preferably a
shuttle or slide mechanism which can be configured and actuated in
various ways and is not pertinent to the invention. A person of
ordinary skill in the mechanical arts will recognize numerous ways
to provide a shuttle mechanism 33 which can accurately and
repeatably provide alignment between a visible light source 32 and
a reflecting mirror 35 or other target, and then shuttle or move
the invisible light source to the same location 34 and have the two
beams align spatially and coaxially to the predetermined target 35.
Initial alignment can be accomplished with an invisible viewer as
previously discussed. Preferably the alignment is accomplished with
a visible LED and then the IR LED is shuttled back into the exact
location to align in the same optical path.
[0044] Referring now to FIG. 5 there is illustrated another
embodiment of the present invention. An invisible light source 41
and a visible light source 42 are positioned coaxially with respect
to each other and a single focal dual mirror 43 is positioned
coaxially between them. The dual mirror assembly 43 has a first
side 47 opposite the invisible light source 41 and a second side 48
opposite the visible light source 42.
[0045] In this embodiment both the invisible light beam 45 and the
visible light beam 46 are diverged 90 degrees by the dual mirror
assembly 43 to spatially align both the visible light beam 46 and
invisible light beam 45 at the same predetermined location 44. In a
preferred embodiment the opposite reflecting surfaces of the dual
mirror assembly will have a different reflective coating to achieve
the desired spatial alignment. The invisible light beam 45 and
visible light beam 46 are typically collimated, but can be set at
the desired focal length and aligned by the use of various optics
well known in the art. In the particular example shown in FIG. 5
the predetermined location 44 is a reflecting mirror similar the
reflecting mirror illustrated in FIG. 1.
[0046] In another embodiment of the present invention a dual
element LED is used that can illuminate in both the visible and
invisible wavelengths to provide both visible light and IR light
from the same source. Referring to FIG. 6 there is a shown an IR
sensor unit 10 as illustrated in FIG. 1. In this embodiment the
stationary IR source 12 is replaced with a dual element
LED51positioned opposite and approximately coaxial with a
reflecting mirror 11. The dual element LED 51 projects a visible
light beam 52 along with the invisible IR laser 53 from the same
component.
[0047] Another embodiment of the present invention is shown in FIG.
7. Here the IR sensor unit 10 as illustrated in FIG. 1 is shown,
but now the stationary IR source 12 is replaced with a dual LED 61
with known offset. The dual LED 61 involves the use of two
independent light sources, invisible light source 62 and visible
light source 63, mounted side by side simulating the function of
the dual element LED 51.
[0048] Another embodiment of the present invention is shown in FIG.
8. In this embodiment alignment is accomplished with the use of a
visible laser aligned directly in front of or behind the IR LED
which would again simulate the optical path in a visible means to
ascertain direct alignment. Here the IR sensor unit 10 as
illustrated in FIG. 1 is shown, but now the stationary IR source 12
is replaced with a coaxial LED 71. The coaxial LED 71 uses two
independent light sources, invisible light source 72 and visible
light source 73, mounted coaxially to provide an encompassing area
of visible light 74 around the projected area of invisible light
75.
[0049] In all the various embodiments discussed above the problem
solved by this invention is the ability to align an invisible
sensor, such as IR or UV wavelength light, utilizing a visible
means such as a visible LED or HeNe laser. The present invention
accomplishes this using a green, red or other visible light source
to align the invisible light to the required location.
[0050] The advantage realized by the present invention is the
ability in real time to align and periodically adjust the IR
sensors without fixtures or jigs. Another advantage is the ability
to see when the sensor needs adjustment in real time and not
perform unnecessary adjustments. Another advantage is to achieve
much faster alignment and more repeatable alignments utilizing the
visible wavelength.
[0051] It will be apparent to those skilled in the art having
regard to this disclosure that other modifications of this
invention beyond those embodiments specifically described here may
be made without departing from the spirit of the invention.
Accordingly, such modifications are considered within the scope of
the invention as limited solely by the appended claims.
* * * * *