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BACKGROUND OF THE INVENTION
The invention relates generally to connection assemblies for electronics
and, more particularly to a fiber-optic cable system which provides a
connection between a fiber optic cable and an electronic device. The
system of the invention provides high precision interconnections which
makes it particularly well suited for microelectronic device packages.
Because of their inherent capability of transmitting more data than any
comparably sized electrical wire, fiber optic cable transmission lines
have become more widely used in various electronic applications including
those utilizing microelectronic components. Since fiber optic cables do
not produce electromagnetic interference and are not susceptible to radio
frequency interference, they have become more desirable in computer
systems and avionic systems and many other types of systems in which noise
interference can cause malfunction thereof. Moreover, fiber optic cable
transmission systems have an additional advantage of having lower power
requirements than electrical wire transmission lines of comparable data
transmission capabilities. However, fiber optic cable transmission systems
have the disadvantage of requiring precise alignment of their connections
in order to function properly. This important disadvantage of fiber-optic
cable systems has to a certain degree obviated the advantages such systems
have and prevented them from more widespread use.
Current electronic packaging of devices are now confronting the problem of
input and output bounding wherein the number of inputs and outputs needed
is the most important factor determining the size of the device package.
For example, it is now common that there are 500-700 I/O bald grid arrays
in midrange personal computers. There are also higher I/O counts in high
end computers as well as in data fusion or graphics applications. However,
using such high pin counts has a significant drawback in that soldering
the many pin connections has a certain element of risk as it takes only
one failed solder joint to cause a system failure. As a result designers
have investigated the use of optical interconnections between these large
package devices including FPGAs, microprocessors, memory devices etc.
Current fiber-optic systems use discrete devices to convert the light
pulses from the fiber-optic cable into electrical signals. The signals are
then conducted to the next device using a printed circuit board to connect
to high count I/O packages. The signals are then demultiplexed down to a
lower data rate required by the lower speed low-power technologies. As a
consequence, the I/O increases to maintain the data rate. I/O power is a
significant contributor to the overall power consumption of the integrated
circuit.
An optical interconnections system for electronic devices has the important
advantage of enabling high data transfer between microelectronic devices.
However, the development of such a system involves various problems. Such
systems would require that a microelectronic package be used to mount the
VCSEL transmitters and detectors as well as the fiber optic connector body
onto. In addition, very precise alignment of the fiber-optic connector
body and the electronic device base is required. This alignment
requirement is on the order of approximately 5 to 10 microns for multimode
fiber. Some applications would desire a fixed connection whereas other
applications would desire a removable connection.
Prior art systems used in applying photo resistors to semiconductor wafers
have utilized an alignment method. In the fabrication of the semiconductor
substrates a holographic system using an infrared light is used to
backlight alignment patterns on a substrate fabricated in the wafer. The
substrate is transparent to the infrared light and thus can be detected by
a holographic imaging and detection system to automatically align the
wafer.
Some prior art approaches to providing optical communication for electronic
devices involve mounting the electronic devices in a transparent
substrate. Ultra-thin silicon-on-sapphire CMOS technology produces
circuitry extremely well suited for optical communications functions on a
transparent substrate. The silicon and sapphire process allows for flip
chip bonding of optical electronic devices and to CMOS circuitry to build
flipped optical chip and UTSi (FOCUTS) modules. Flip chip bonding
eliminates the wire bond inductance between driving/receiving circuits and
the OE devices which becomes problematic at data rates greater than 2.5
Gbps. The flip chip bonding also reduces the number of discrete chips that
must be handled, packaged and aligned in the final module thereby reducing
manufacturing costs. Because of the isolating substrate and the
elimination of the substrate parasitic effects, the UTSI process produces
high-performance CMOS circuitry requiring less power than bulk Si CMOS
circuitry. In the current 0.5 micron UTSI process, modulation rates
greater than 5 Gigahertz are achievable. UTSI with 0.25 micron features
will be available allowing greater than 10 Gigahertz modulation.
Additional byproducts of the UTSi are the availability of multi-threshold
transistors in the EEPROM devices. Even with these enhancements, the
standard semiconductor tools used for CMOS are also used for designing
simulation fabrication packaging and testing UTSi. The fabrication process
yield is comparable to bulk SI and the processed wafer cost is much less
than competing high-performance technologies such as GaAs, BiCMOS and
SiGe. The isolating substrate allows for mixed signal integration, as
demonstrated in prior art wireless products.
Optical data communication products such as VCSELs are very cost effective
due to wafer scale processing and testing and standard IC handling. Their
optical properties also allow more tolerance on alignment thereby being
preferable in less stringent packaging techniques. Similar cost reductions
are offered by flip chip bonding OE devices to UTSi and packaging in a
method compatible with electronic and fiber optic technologies.
The UTSi technology applied to optical transmitter/receiver modules allows
a high degree of functional integration within the module. The
non-conducting sapphire substrate of the UTSi provides a high degree of
isolation between mixed signal circuits, enabling the integration of
high-performance transmitters, receivers and other sensitive analog
circuitry with digital circuitry. The fact that UTSi uses standard CMOS
CAD tools allows easy importing of standard digital CMOS function block.
Examples of key telecom blocks are digital modulation coding, your
correction coding, routing, deskewing, equalization, ADC/DAC, multiplexing
and demultiplexing circuitry. This integration ultimately reduces the cost
and increases performance as compared to board level integration.
Additionally, the UTSi process has the capability of multilevel threshold
transistors and EEPROM devices. Multilevel transistors give the circuit
designer added flexibility to increase performance and reduce power
consumption.
EEPROM devices integrated with the drivers and logic circuitry reduces
board level complexity and thereby provides another cost savings. EEPROM
memory can be used for several functions including storage of trim values
to equalize the drive bias on VCSEL devices across the parallel channels,
hardware node address information for networking, network fault codes,
error correction coefficients, initialization and training sequences for
link startup.
The use of VCSELs to emit light through the UTSi substrate provides several
advantages related to device packaging. Mating the fiber coupling assembly
directly to the sapphire substrate creates a physically compact module.
The transparent substrate enables alignment between marks on the UTSi and
the fiber coupling assembly. Integration of an optical photodetector
fabricated in the UTSi process for automated power control provides
further advantages. The detector picks off a small percentage of the light
to control the output optical power, an essential function in optical
links. In addition, this through substrate design allows integration of
microlens arrays directly etched into the sapphire or fabricated onto
another type of substrate (such as glass) or contact mounted on the
sapphire.
SUMMARY OF THE INVENTION
It is a principal object to the present invention to provide a connector
system for an electronic device which enables optical signal transmission
thereto and therefrom.
It is also an object of the present invention to provide a connector system
for an electronic device which utilizes optical connections at the
electronic device terminals for providing single point ground connections
for the electronic device as well as electronic units and subsystems
associated therewith.
It is also an object of the present invention to provide a connector system
for connecting a fiber-optic cable plug connector to an electronic device
capable of high precision alignment and attachment of a fiber-optic cable
terminus connection thereto.
It is also an object of the present invention to provide a connector system
for connecting a micro fiber optic cable to a micro electronic device to a
micro electronic device capable of high precision alignment and attachment
of a micro fiber optic cable terminus connection thereto.
It is also an object of the present invention to provide a connector system
for connecting a fiber-optic cable plug connector to an electronic device
having a minimal number of components thereof.
It is an object to the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
which has a minimal number of electrical transmission lines for minimal
power consumption.
It is an object of the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
which utilizes a high precision optical alignment system providing signal
transmission capability without signal loss or degradation.
It is an object to the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
which has a minimal number of I/O pin connections for minimal power
consumption and maximal data transfer rates.
It is an object of the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
which integrates the transmitter, detector and fiber-optic cable plug into
the electronic device package.
It is an object of the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
which utilizes a substrate for containing the electronic device as well as
the electronic units and transmission lines associated therewith.
It is an object of the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
which is relatively inexpensive.
It is an object of the present invention to provide a connector system for
connecting a fiber-optic cable plug connector to an electronic device
utilizing optical interconnections for minimizing susceptibility to EMI
and RFI.
The system of the present invention provides a connection between an
optical transmission line and an electrical subsystem such as an
electronic device and a fiber optic cable in order to interconnect various
desired systems via the fiber optic cable interconnect. A modern
electronic device is typically connected to a transmitter and detector for
carrying signal data to and from the device. Essentially, the system of
the invention specifically provides an interface between the terminus of
the fiber optic cable and the transmitter and detector elements. The
system of the present invention includes a base and a plug connector in
which the fiber optic cable plug and terminus are located. The plug
connector has a receptacle for receiving the fiber optic cable plug. The
base has a substrate which contains the electronic device. The base also
incorporates a converter for converting an electrical signal to an optical
signal or for converting an optical signal to an electrical signal.
Transmitting data streams through fiber optic cable increases data
transmission rates to a level that is significantly higher than what
current printed wiring board technologies can support. For example, a
printed wiring board made from epoxy glass material has variations in
dielectric constants which make high-speed data communications difficult
due to parasitic losses in the material. The higher the dielectric
constant of the material the lower the maximum signal speed thus requiring
controlled impedance structures typically under one Gigahertz. Polyimide
glass materials have a more uniform dielectric constant that allows
controlled impedance structures to support higher transmission speeds
typically under two gigahertz. Using the more exotic printed materials
made from Teflon derivatives will allow increased transmission speeds in
the one to thirty gigahertz range. However, these types of printed wiring
boards are not suitable for high layer count construction. However,
optical transmission has been demonstrated to transmit ten GBit/s without
any degradation in signal due to parasitic losses and noise.
Relatively low power consumption is realized by using prior art
semiconductor device packaging technology using sapphire substrate. Other
types of transparent mediums may be used in the substrate, but an added
advantage of using sapphire is that there is no capacitive loss. The
sapphire is also transparent thus allowing the VCSEL and detectors to be
flip chip mounted onto the interior surface of the device while facing out
toward the fiber optic cable. The sapphire is also very hard and durable
allowing it to withstand handling without damaging the optical window to
the VCSEL or detector. It also has the inherent characteristic of
radiation hardness.
In order to produce the desired interconnections between the electronic
device and the fiber optic cable plug connector, a high degree of accuracy
in aligning the plug connector to the electronic device is required. The
alignment method of the present invention provides alignment to within a
five to ten microns positional tolerance. The positioning method of the
present invention accurately, quickly and efficiently aligns the plug
connector onto the base in which the opto-microelectronic device is
mounted. When sapphire is used as a transparent medium, its beneficial
characteristic of functioning as an optical waveguide results in light
being channeled through the substrate to the area which has an alignment
means used to enable determination of the position of the substrate in
relation to the plug. The optical waveguide method is similar to that used
in an automobile holographic center mount stoplight system and in other
automobile holographic displays. The method used in automotive
applications is based on that originally developed in heads up display
systems for fighter aircraft.
The system of the present invention utilizes a trapped beam lighting
technology to accomplish the alignment. Due to the particular optical
waveguide characteristics of sapphire, light rays are refracted by the
substrate and are reflected from the sides of the substrate into the
interior of the substrate so that they propagate through the medium rather
than passing out through the sides of the substrate. The light is injected
into the side of the substrate at an angle which induces refraction of the
light into the interior of the substrate and promotes internal light
reflections between the sapphire/air interface at the sides of the
substrate. This allows the plug connector to be aligned with either
packaged or unpackaged substrate. The light is from a remote source using
a fiber optic cable to direct the light into the substrate. The input
angle of the light beam is selected so that it is refracted out of the
substrate and through the alignment determination area with only a minor
angular change. The theory and calculations of light ray reflection and
refraction are defined by Snell's Law. Light from the light source is
essentially trapped inside the substrate by total internal reflections
from the air/sapphire interface at the various outer surfaces of the
substrate.
The positioning and placement of the plug connector onto the opto micro
electronic device is a several step process involving alignment of the
plug connector with the substrate and secure attachment of the plug
connector to the base at the substrate. This operation requires an
automated positioning system consisting of a vision system for viewing the
alignment images to enable determination of the position of the components
to be joined and a position adjustment system for horizontal rotational
and vertical linear movement to bring these components into the desired
position of alignment.
The vision system used in alignment of the plug connector to the base
utilizes one or more cameras to view alignment images. Essentially, the
cameras receive the light passing out of the substrate and through the
alignment pattern which produces the alignment images. The cameras
transmit image data to a microprocessor which compares the data to
reference image data. The microprocessor determines whether there is
alignment and, if not, calculates the positional change of the plug
relative to the base required to bring the structures into the desired
alignment. The alignment system may utilize an alignment pattern in the
substrate in conjunction with an alignment feature on the plug or simply
utilize a holographic image from the substrate (with or without an
alignment feature on the plug) to determine position and orientation of
the viewing cameras/and thereby the plug in relation to the three
dimensional image produced by the hologram in the substrate.
A physical translation system is utilized to move the plug vertically and
to move the base horizontally. This vertical translation system is used to
bring the structures into alignment in response to operational commands
from the microprocessor and also move the structures into the desired
degree of proximity. The translation system utilized has a repeatability
of plus or minus five microns.
Once the base and the plug connector are in mutual alignment and in the
desired degree of proximity to each other, the structures are secured
together. This securement process preferably includes adhesive injected
into the separation gap between the base and the plug. Alternatively,
instead of bonding, a mating pin and hole structure may be machined into
appropriate portions of the plug and base for removable connection
thereof.
The system hardware is expected to provide a data flow rate of two and
one-half Gbit/s. However, data flow rates can be increased to ten Gbit/s
by decreasing the feature size of the electronic device to 0.25 microns.
In the commercial network market the incorporation of fiber optic cables
that are integrated directly into optical electronic devices will enable
the reduction in volume and cost and increase the bandwidth of the
existing fiber based networks. Taking this one step further, this proposed
fiber optic connector system and opto packaging assemblies become
optically linked.
Additional improvements over the integration of opto and PGA devices
include fitting an entire array or a variety of devices with the opto
front end, enabling the creation of an integrated optical network for
spacecraft. The devices needed to realize this include analog digital
converters, microprocessors, memory modules and multichip modules.
It can be expected that as the space infrastructure continues to develop
and on-orbit assets are deployed there will be a need to perform repair,
refurbishment and refueling. Repair is self-explanatory. When an orbital
asset has a module or subsystem that fails it will be far easier to send a
microsat with a needed subsystem to become a permanent part of the asset.
Refurbishment occurs when the entire subsystem is taken off line and
replaced by a new subsystem brought to the assets by the microsat. By
utilizing a fiber optic connection between the two craft the chances for
any static electricity to cause harm during the docking process is
mitigated.
In another application, the sensor and data fusion engine (SAFE) is used to
analyze external data and relay it in a usable form by the vehicle's
controlled guidance system or relay it back to the war fighter for further
analysis or use. The reliability of the SAFE is a critical factor in
performing its mission. To this end the SAFE must be protected from both
natural and man-made phenomena. One method is to isolate the SAFE by using
opto isolators on all I/O lines. This is easily accomplished by using an
opto-FPGA as the I/O front end.
Another application relates to threat awareness on board spacecraft which
is typically performed by a number of sensors to detect the external
application of non-natural energy sources such as laser, high-energy and
kinetic sources. The opto connection system of the present invention
provides a robust means of data transfer from the sensors to the threat
analysis computer to prevent any stray electrical noise pickup. This
prevents any natural energy sources from creating a ghost signal to the
threat analysis computer and interpreting the ghost signal as an attack.
On the other side, a robust data transmission system will allow the
spacecraft to continue to operate when an assault attempts to disrupt
internal data flow.
The connector system of the present invention thus provides a means for
aligning and attaching a fiber optic cable connector to an electronic
device with a very high degree of precision. In addition, the system of
the present invention has the desirable features of enabling such
alignment and attachment to be performed on component structures which
include micro electronics. The utilization of microprocessors enables the
alignment to be an automated process. After the component structures are
properly aligning they are either permanently securely attached with the
plug securely attached to the plug connector, or the plug may be removably
attached to the plug connector via appropriate pin and hole structures.
The connector system advantageously provides an optical interconnect to
the transmitter and detector elements of an electronic device interface
that improves system performance through increased data transmission
rates, lower power consumption, and opto isolation of I/O that enables a
single point ground connection between subsystems that further improves
performance. Essentially, the system provides integration of optical and
electrical converters with an electronic device and with a fiber optic
cable plug connector producing an electronic device assembly that is able
to optically interconnect with other electronic devices and systems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevated perspective view of a first embodiment of the
connector system of the present invention showing the fiber optic plug
connector separated from the base component containing the electronic
device.
FIG. 2 is an elevated perspective view of the first embodiment of the
invention showing the plug, plug connector and base components thereof
joined together.
FIG. 3 is an elevated perspective view of the first embodiment of the
invention showing the substrate component thereof in detail.
FIG. 4 is an elevated perspective view of a second embodiment of the
connector system of the present invention showing the fiber optic plug
connector separated from the base component containing the electronic
device.
FIG. 5 is an elevated perspective view of the second embodiment of the
invention showing the plug, plug connector and base components thereof
joined together.
FIG. 6 is an elevated perspective view of the second embodiment of the
invention showing the substrate component thereof in detail.
FIG. 7 is an elevated perspective view of a third embodiment of the
connector system of the present invention showing the fiber optic plug
connector separated from the base component containing the electronic
device.
FIG. 8 is an elevated perspective view of the third embodiment of the
invention showing the plug, plug connector and base components thereof
joined together.
FIG. 9 is an elevated perspective view of the third embodiment of the
invention showing the substrate component thereof in detail.
FIG. 10 is a block diagram showing a switch link fabric utilized in the
electronic device and fiber optic cable plug interconnection subsystem of
the first embodiment of the present invention.
FIG. 11 is a block diagram of an optical crossbar switch used in the switch
link fabric of FIG. 10.
FIG. 12 is a flow chart showing the software program of the alignment
subsystem of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown a first embodiment of the
connector system invention generally designated by the 10. FIG. 4 shows
the second embodiment 110. FIG. 7 is a perspective view similar to FIG. 4
and shows a third embodiment 210 of the connector system invention.
Embodiments 10, 110 and 210 are generally identical in structure except
for one of the component structures thereof and except for component
attachment means which will be described in detail hereinbelow.
All of the embodiments 10, 110 and 210 include a fiber-optic cable plug
connector 12, 112 and 212 into which is inserted a fiber-optic cable plug
13, 113 and 213 which contains a fiber-optic cable 14, 114 and 214 so that
the plug 13, 113 and 213 contains the ferule end or terminus 16, 116 and
216 thereof. The terminus 16, 116 and 216 is at a lower side of the plug
13, 113 and 213 such that it faces outward from the plug 13, 113 and 213,
as shown. The plug 13, 113 and 213 preferably includes a socket 15, 115
and 215 for receiving the cable 14, 114 and 214 as well as the terminus
16, 116 and 216. The fiber-optic cable 14, 114 and 214 is a conventional
fiber-optic cable.
The fiber optic cable plug 13, 113 and 213 is designed to be connected to
the plug connector 12, 112 and 212 by a simple insertion of the plug 13,
113 and 213 into a receptacle 20, 120 and 220 of the plug connector 12,
112 and 212. The receptacle 20, 120 and 220 has walls 21, 121 and 221
which are preferably oriented so that they are perpendicular to the lower
surface of the plug connector 12, 112 and 212. The fiber-optic cable plug
connector 12, 112 and 212 is preferably oriented so that it is
perpendicular to the base 18, 118 and 218, as shown in FIGS. 2, 5 and 8.
The base 18, 118 and 218 preferably includes one or more electronic
devices 22 which receive and transmit data to and/or from the fiber-optic
cable 14, 114 and 214. Thus, the base 18, 118 and 218 is preferably
connected to an electrical converter 24, 124 and 224 for converting
electrical data signals into optical signals and an optical converter 26,
126 and 226 for converting optical signals into electrical data signals.
The electrical converter 24, 124 and 224 is preferably an optical
transmitter 24, 124 and 224. Similarly, the optical converter 26, 126 and
226 is preferably an optical detector 26, 126 and 226. The transmitter 24,
124 and 224 and detector 26, 126 and 226 are positioned at preferably an
upper surface 28, 128 and 228 of the base 18, 118 and 218 so that it is
proximal to the fiber-optic cable terminus 16, 116 and 216. In order to
transmit optical signals between the fiber-optic cable and the transmitter
24, 124 and 224 and detector 26, 126 and 226 the gap therebetween must be
optimally two-hundred and fifty microns. In addition, axial alignment
therebetween cannot vary by more than five to ten microns. Thus, a high
precision alignment system 30 is provided in order to enable the plug
connector 12, 112 and 212 and base 18, 118 and 218 to be joined together
properly so that there is complete signal transmission between the
fiber-optic cable and the converter 24, 124 and 224 and 26. The base 18,
118 and 218 also has a single point ground terminal 29, 129 and 229 for
connection to the electronic device 22, 122 and 222 as well as for the
converters 24, 124 and 224 and 26, 126 and 226.
The transmitter 22, 122 and 222 is preferably a VCSEL type of laser 22, 122
and 222. VCSEL type laser transmitters are semiconductors and micro sized
rendering them suitable for use in conjunction with fiber optic data
transfer lines in which the strands thereof are only two-hundred and fifty
microns apart.
The base 18, 118 and 21818 preferably includes a substrate 32, 132 and 232
in which are embedded the electronic device 22, 122 and 222 and the
converter 24, 124 and 224 and 26, 126 and 226. The substrate 32, 132 and
232 is preferably composed of sapphire so that it is electrically
insulating for the electronic devices 22, 122 and 222, the converter 24,
124 and 224 and 26 as well as the electrical interconnections
therebetween. The sapphire substrate 32, 132 and 232 also provides thermal
insulation for these electronic components thereby protecting them from
thermal damage or impaired performance due to adverse thermal effects. The
substrate 32, 132 and 232 also provides environmental isolation of the
electronic device 22, 122 and 222 as well as other electronic components
and transmission lines therein. The substrate 32, 132 and 232 preferably
also includes an alignment pattern 34, 134 and 234 which is etched therein
preferably at upper surface 28. The sapphire substrate 32, 132 and 232 is
transparent allowing a laser 35, 135 and 235 to emit a beam into the
substrate 32, 132 and 232 for the purpose of backlighting the alignment
pattern 34, 134 and 234 thereby producing a pattern image. The alignment
pattern 34, 134 and 234 is preferably a transmission hologram 34, 134 and
234. The holographic image which is produced provides a three-dimensional
image which also provides the location of the hologram and of the base 18,
118 and 218 in three dimensions. However, other suitable types of
alignment patterns may be etched or otherwise provided in the sapphire
substrate 32, 132 and 232. The light beam which provides the image is
preferably emitted from the substrate 32, 132 and 232 through a window or
opening 36, 136 and 236 in the plug connector 12, 112 and 212. The
direction of propagation of the beam from the substrate 32, 132 and 232
and through the window 36, 136 and 236 is preferably in the direction of
the axis of the plug connector 12, 112 and 212 and perpendicular to the
base 18, 118 and 218. Preferably a pair of cameras 38, 138 and 238 are
provided and fixed to the plug connector 12, 112 and 212 so that there is
no relative movement therebetween. Alternatively, the cameras 38, 138 and
238 may be mounted separate from the other components of the system 10,
110 and 210. The cameras 38, 138 and 238 are preferably oriented and
positioned so that they face the window 36, 136 and 236 and receive the
pattern image that is displayed therethrough. The cameras 38, 138 and 238
also view a pair of alignment marks 40, 140 and 240 located on opposing
sides of the plug connector 12, 112 and 212. The laser 35, 135 and 235
light beam which provides the pattern image also illuminates the alignment
marks 40, 140 and 240 so that the cameras 38, 138 and 238 view the
alignment marks in conjunction with the pattern image. Thus, the pattern
image essentially provides visual information regarding the position of
the base 18, 118 and 218 while the alignment mark image provides visual
information regarding the position of the plug connector. The cameras 38,
138 and 238 which view the pattern image together with the alignment marks
consequently receive visual information regarding the position of the base
18, 118 and 218 relative to the plug connector 12, 112 and 212. The
cameras 38, 138 and 238 preferably have a magnification lens (or other
type of suitable magnification optics) 39, 139 and 239 to provide a
desired view of images from a micro electronic device assembly. The
cameras 38, 138 and 238 preferably are digital cameras 38, 138 and 238
incorporating a digitizer which digitizes the visual information of the
pattern image and alignment marks and transmits the digitized data to a
microprocessor 42, 142 and 242. The microprocessor 42, 142 and 242
preferably includes a software program 44, 144 and 244 which acquires the
image data relating to the pattern image and the alignment mark image and
compares them to reference data relating to references images contained in
a databank 46, 146 and 246. From this comparison the microprocessor 42,
142 and 242 determines the location parameters of the base 18, 118 and 218
relative to the plug connector 12, 112 and 212 and determines whether or
not the plug connector 12, 112 and 212 is in alignment with the base 18,
118 and 218. If it determines they are in misalignment, the microprocessor
42, 142 and 242 calculates the degree of misalignment and the direction of
misalignment. The holographic image provides data that allows this to be
calculated for three dimensions thereby providing calculations relating to
tilt, relative vertical position and relative horizontal position.
A vertical translation structure 48, 148 and 248 is securely attached to
the plug connector 12, 112 and 212 and includes a motor 50, 150 and 250.
The cameras 38, 138 and 238 are preferably mounted on the vertical
translation structure 48, 148 and 248 so that there is no movement
therebetween. Vertical translation structure 48, 148 and 248 and motor 50,
150 and 250 are used to move the plug connector 12, 112 and 212 up and
down in a vertical direction in response to the microprocessor's commands
when the microprocessor 42, 142 and 242 has determined the plug connector
12, 112 and 212 and base 18, 118 and 218 are in the desired position of
alignment so that moving the plug connector 12, 112 and 212 and the base
18, 118 and 218 together is appropriate.
An orientation table 52, 152 and 252 is securely attached to the base 18,
118 and 218 and includes a motor 50, 150 and 250. The orientation table
52, 152 and 252 and the motor 50, 150 and 250 are used to move the base
18, 118 and 218 horizontally in a linear direction as well as horizontally
in a rotational direction. The table and motor 50, 150 and 250 are also
able to move the base 18, 118 and 218 in a vertical rotational direction
i.e., to adjust tilt between the plug connector and the base 18, 118 and
218. Thus, when the microprocessor 42, 142 and 242 has determined that
there is misalignment it commands the table 52, 152 and 252 and motor 50,
150 and 250 to move the base 18, 118 and 218 in accordance therewith and
thereby placing the plug connector 12, 112 and 212 and base 18, 118 and
218 in the desired relative position in which they are in mutual
alignment. The software program 44, 144 and 244 of the microprocessor 42,
142 and 242 makes a calculation of the degree of movement required for the
plug connector 12, 112 and 212 and the base 18, 118 and 218 and converts
these calculations into control signals for operation of the m | | |
