Note: Descriptions are shown in the official language in which they were submitted.
CA 02586329 2007-05-10
1
A PORTABLE OPTICAL SCANNING SYSTEM WORN BY A USER FOR
READING INDICIA OF DIFFERING LIGHT REFLECTIVITY
This is a division of co-pending Canadian Patent
Application No. 2,168,687 filed on February 2, 1996.
BACKGROUND OF INVENTION
Field of the Invention
This invention relates to portable optical scanners
for reading indicia of varying light reflectivity and,
more particularly, to a portable optical scanning system
having the capability to transmit and/or receive
information over one or more radio or infrared (IR)
frequencies, and optionally housing the light emitter and
reflected liglit detecting elements in separate
unconnected housings that are adapted to be worn by a
user or attached to an article of clothing worn by a
user.
Description of the Related Art
Various optical readers and optical scanning systems
have been developed heretofore for reading indicia such
as bar code symbols appearing on the label or on the
surface of an article. The symbol itself is a coded
pattern of indicia comprised of, for example, a series of
bars of various widths spaced apart from one another to
CA 02586329 2007-05-10
2
bound spaces of various widths, the bars and spaces
having different light reflecting characteristics. The
readers in scanning systems electro-optically transform
the graphic indicia into electrical signals, which are
decoded into alphanumeric characters that are intended to
be descriptive of the article or some characteristic
thereof. Such characteristics are typically represented
in digital form and utilized as an input to a data
processing system for applications in point-of-sale
processing, inventory control and the like. Scanning
systems of this general type have been disclosed, for
example, in U.S. Patent Nos. 4,251,798; 4,369,361;
4,387,297; 4,409,470; 4,760,248; 4,896,026, all of which
have been assigned to the same assignee as the instant
application. As disclosed in the above patents, one
embodiment of such scanning systems includes, inter alia,
a hand held, portable laser scanning device supported by
a user, which is configured to allow the user to aim the
scanning head of the device, and more particularly, a
light beam, at a targeted symbol to be read.
There remains a need for a portable optical scanning
system in which all body mounted components can be
mounted on the hand, wrist or arm of a user and do not
require a vest, glove or other apparel or restrictive
mounting mechanisms to be worn by the user. There also
remains a need for a totally wireless body mounted
portable optical scan system and even more preferably one
which has only a hand mounted optical scan module and
wrist or arm mounted second module, and is capable of
transmitting and receiving data from a base station. A
CA 02586329 2007-05-10
3
still further need exists for a portable optical scanning
system which is ergonomically more acceptable to users.
It is a general object of the present invention to
provide an improved portable indicia reader.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present
invention there is provided an optical scanning system
for reading indicia of differing light reflectivity
comprising: an optical scan module having a light
emitter for generating and emitting light onto said
indicia; and a peripheral module, housed separate and
apart from said optical scan module, having at least one
light detector for detecting the reflection of light from
said indicia.
In accordance with another aspect of the present
invention there is provided an optical scanning system
for reading indicia of differing light reflectivity
comprising: an optical scan module (i) including a
light emitter for emitting light directed at said indicia
and a light detector for detecting the reflection of
light from said indicia, and (ii) adapted to be mounted
on at least one finger of a user; a first peripheral
module (i) including a receiver for receiving a first
signal corresponding to said detected reflection of light
from said optical scan module and (ii) adapted to be
mounted on one arm or wrist of the user; and a second
peripheral module including a wireless receiver for
receiving a second signal, corresponding to said first
CA 02586329 2007-05-10
4
signal, from said first peripheral module wherein
(i) said first signal is an analog signal and
(ii) said first peripheral module includes a digitizer
for converting said first signal to a digitized signal
and a decoder means for decoding information contained in
said digitized signal and (iii) said decoder is
automatically activated upon said receiver receiving a
signal indicative of said indicia.
The system includes two peripheral modules. A first
peripheral module has a receiver for receiving a first
signal corresponding to the detected reflection of light
from the optical scan module. The first peripheral
module is adapted to be mounted on one arm or wrist of
the user. Preferably, if the optical scan module is
mounted on the right hand, the first peripheral module is
mounted on the right arm or wrist. Likewise, if the
optical scan module is mounted on the left hand, the
first peripheral module is preferably mounted on the left
arm or wrist. The second peripheral module has a radio
frequency receiver, which is preferably a transceiver,
for receiving a second signal corresponding to the first
signal from the first peripheral module. If a
transceiver is provided, it can also be used to transmit
a third signal corresponding to the second signal to, for
example, a base station.
If desired, a power supply such as a battery can be
located in the first peripheral module and an electrical
wire or other type of electrical conductor, provided for
transmitting power from the first peripheral module to
the optical scan module. The electrical conductor may be
CA 02586329 2007-05-10
retractable into the first peripheral module so that only
that length of wire required to extend between the scan
unit and first peripheral module is exposed. The optical
scan module may also include a radio frequency
5 transmitter and the first peripheral module a radio
frequency receiver to facilitate communication of the
first signal.
The first signal, typically, although not
necessarily, includes an analog signal generated by a
photosensor in the optical scan module which corresponds
to the detected light reflected from the indicia. It is
possible to process the first signal, in whole or part,
in the first peripheral module. However, it is not
required that any processing be performed by the first
peripheral module. Thus, the second peripheral module
may include a digitizer or other typed analog/digital
conversion means for performing conversion of the second
signal to a pulse width modulated digitized signal. The
second peripheral module may also beneficially include a
processing circuitry and/or software for processing the
digital signal. The processor can, for example, include
a decoder for decoding information, i.e., the information
originally encoded in the indicia, contained in the
digitized signal. The second peripheral module may also
include an indicator for signaling the user when the
decoding has been successfully accomplished by the
decoder.
CA 02586329 2007-05-10
6
With respect to all the above described embodiments
of the invention, the frequency of the radio frequency
signals is preferably selectable by the user and may
beneficially be in the range of 902 and 928 MHz, or
2.4 GHz, for use within certain geographic regions or at
approximately 433.9 MHz, for use in certain other
geographic regions. Depending upon the applicable
communications regulations the frequencies for usage of
the invention within different countries or regions will
vary. Also the transmitters, receivers and transceivers
may beneficially include an interface, conforming to an
RS232 standard, to facilitate communications with other
peripheral modules or devices. A filter for filtering
the received signals may also be included. The optical
scan unit or module housing may be rotated with respect
to the ring mounting so that the direction of the
emitted light beam can be easily adjusted by the user.
The scan unit or module housing may also be
CA 02586329 2007-05-10
. 7
detachable from the ring to allow easy substitution of scan
units or modules for different tasks and/or different ring
sizes to be utilized.
A microphone may be provided for receiving an audio
command from a user and generating a signal corresponding
to the audio command. A peripheral module includes a
multiplexer for receiving the signal along with a signal
representative of the reflected light detected by the light
detector. The two signals are multiplexed to form a single
multiplexed signal. Processing circuitry within the
peripheral module receives the multiplexed signal and
processes it to decode information represented by the
indicia and recognize the audio command. The processing
circuitry can then generate a signal to activate the
optical scan module in response to the recognized audio
command.
In an alternate arrangement, the signal corresponding
to the audio command is filtered through a passband filter
in the peripheral module. A noise analyzer is also
provided in the peripheral module for analyzing the
unfiltered signal to identify background noise within the
signal. An output signal corresponding to the level of the
background noise is generated by the analyzer. A signal
level detector compares the filtered signal to parameters
adjusted in accordance with the output signal to identify
said audio command.
A peripheral module may also include an audio
transducer, along with the decoder and display. The
decoder may be adapted to generate an output signal
representing the status of the decoding. The audio
transducer can produce an audio signal while the display
produces a textual display corresponding to the output
signal. The decoder can also be adapted to generate a
CA 02586329 2007-05-10
8
second output signal representing its operating condition.
The audio transducer and display can also be designed to
produce an audio signal and textual display corresponding
to said second output signal.
The optical scan module can be supported by a user's
head, for example off a headband, glasses or helmet worn by
the user, and aimed at the indicia by movement of the
user's head.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 depicts an embodiment of a portable optical
scan system according to the invention.
Figure 2 depicts a portable optical scan system in
accordance with a further embodiment of the invention.
Figure 3 depicts a still further embodiment of the
portable optical scanning system of the present invention.
Figure 4 depicts the portable optical scanning system
similar to that shown in Figure 3 with a touch screen.
Figure 5 depicts a portable optical scanning system in
accordance with another embodiment of the invention.
Figure 6 depicts the portable optical scanning system
of Figure 5 used in a practical application.
Figure 7 depicts a pen computer.
Figure 8 depicts a pen computer with a scanner module.
Figure 9 depicts a pen scan module and computer with
wireless communication links.
Figure 10 depicts a pen scanner and computer in
accordance with another embodiment of the present
invention.
Figure 11 depicts a second configuration of pen
computer in accordance with the present invention.
CA 02586329 2007-05-10
9
Figure 12 depicts a ring scanner and arm/wrist mounted
peripheral module according to a further embodiment of the
present invention.
Figures 13A and 13B depict a single finger ring having
a mount suitable for use in the embodiment of Figures 2, 3,
5 and 12.
Figure 14 depicts a cable retraction mechanism adapted
for use in the embodiments of Figures 2, 3 and S.
Figures 15A and 15B are block diagrams of voice
recognition subsystems suitable for use in any of the
embodiments of the invention described above.
Figures 16A and 16B are respectively a block diagram
of an indicator subsystem suitable for use in any of the
embodiments of the invention described above and a list of
status/conditions of which a user can be notified using the
Figure 16A subsystem.
Figures 17A-17D depict alternative mountings for the
optical scan modules of the embodiments of Figures 2, 3, 5
and 12.
Figures 18A-18C depict symbols conforming to various
prior art symbologies.
DESCRIPTION OF THE EMBODIMENTS
One type of portable scanning device is shown in
Figure 1. The device includes a hand mounted scanning unit
200 which includes an optical scanner. The optical scanner
has a light generator, such as a laser diode, for producing
a light beam which is scanned across the target symbol. The
scanner unit 200 also includes a photodetector for
detecting the reflection of light from the light beam off
symbol and for producing an electrical signal corresponding
to the detected light and representative of the symbol.
The scanning unit may be activated by a triggering
CA 02586329 2007-05-10
mechanism, such as a movable trigger switch or by
triggerless means, for example, using active or passive
photosensoring.
A battery pack 202 is also mounted to the user 206 and
5 provides power to the scanning unit 200 through cable 208.
Module 204 which might typically include signal processing
and data storage subsystems is mounted to the user's wrist
or arm opposite the hand on which the scanning unit 200 is
mounted. As shown, the scanning unit 200 is mounted on the
10 user's right hand and the module 204 is mounted on the
user's left wrist, however the side of the body upon which
each is located could be reversed if so desired.
Alternatively unit 200 and module 204 could be supported by
the hand and arm on the same side at the user's body, for
example, the right hand and arm. The module 204 is also
connected to battery pack 202 by cable 210 which
facilitates the transmission of electricity to the power
module 204. Cables 208 also serve as a conduit for a
communications link between scanning unit 200 and module
204. Signals generated by the photodetector in scanning
unit 200 are transmitted to module 204 via this
communication link for processing and/or storage.
The light source in a laser scanner bar code reader is
typically a gas laser or semiconductor laser. The use of
semiconductor devices as the light source is especially
desirable because of their small size, low cost and low
voltage requirements. The laser beam is optically
modified, typically by an optical assembly, to form a beam
spot of a certain size at the target distance. It is
preferred that the cross section of the beam spot at the
target distance be approximately the same as the minimum
width between regions of different light reflectivity,
e.g., the bars and spaces of symbol. Bar code readers have
CA 02586329 2007-05-10
11
been proposed with two light sources to produce two light
beams.
Bar code symbols are formed from bars or elements
typically rectangular in shape with a variety of possible
widths. The specific arrangement of elements defines the
character represented according to a set of rules and
definitions specified by the code or "symbology" used. The
relative size of the bars and spaces is determined by the
type of coding used as is the actual size of the bars and
spaces. The number of characters (represented by the bar
code symbol) is referred to as the density of the symbol.
To encode the desired sequence of the characters, a
collection of element arrangements are concatenated
together to form the complete bar code symbol, with each
character of the message being represented by its own
corresponding group of elements. In some symbologies, a
unique "start" and "stop" character is used to indicate
when the bar code begins and ends. A number of different
bar code symbologies exist, these symbologies include
UPC/EAN, Code 39, Code 128, Codeabar, and Interleaved 2 of
5 etc.
In order to increase the amount of data that can be
represented or stored on a given amount of surface area,
several new bar code symbologies have recently been
developed. One of these new code standards, Code 49,
introduces a "two dimensional" concept for stacking rows of
characters vertically instead of extending the bars
horizontally. That is, there are several rows of bar and
space patterns, instead of only one row. The structure of
Code 49 is described in U.S. Patent No. 4,794,239.
Another two-dimensional symbology, known as "PDF417", is
described in U.S. Patent No. 5,304,786.
CA 02586329 2007-05-10
12
Still other symbologies have been developed in which
the symbol is comprised of a matrix array made up of
hexagonal, square, polygonal and/or other geometric shapes
to form a symbol. Such symbols are further described in,
for example, U.S. Patent 5,276,315. Such symbols may
include VericodeT"', DatacodeTM and UPScodeT'''. Prior
art Figures 18A-18C depict known matrix and other type
symbols.
In laser beam scanning systems, the laser light beam
is directed by a lens or other optical components along the
light path toward a target that includes a symbol on the
surface. The moving-beam scanner operates by repetitively
scanning the light beam in a line or series of lines across
the symbol by means of motion of a scanning component, such
as, the light source itself or a mirror disposed in the
path of the light beam. The scanning component may either
sweep the beam spot across the symbol and trace a scan line
across the pattern of the symbol, or scan the field of view
of the scanner, or perform some condition thereof.
Other scanning systems require the physical movement
of the scanning unit by the user to obtain a reading from
the targeted symbol. For example, pen computers as shown
in Figure 9 have a pen 302 associated with the computer
module 300.
Bar code reading systems also include a sensor or
photodetector which detects light reflected or scattered
from the symbol. The photodetector or sensor is positioned
in the scanner in an optical path so that it has a field of
view which ensures the capture of a portion of the light
which is reflected or scattered off the symbol. An
electrical signal corresponding to the detected light is
generated. Electronic circuitry and software decodes the
electrical signal into a digital representation of the data
CA 02586329 2007-05-10
13
represented by the symbol that has been scanned. For
example, the analog electrical signal generated by the
photodetector is converted by a digitizer into a pulse
modulated digital signal, with the widths corresponding to
the physical widths of the bars and spaces of a scanned bar
code symbol. The digitized signal is then decoded, based
on the specific symbology used by the symbol, into a binary
representation of the data encoded in the symbol, and
subsequently to the alphanumeric characters so represented.
The decoding process of a known bar code reading
system usually works in the following way. The decoder
receives the pulse width modulated digital signal from the
digitizer, and an algorithm, implemented in the software,
attempts to decode the scan. If the start and stop
characters and the characters between them in the scan were
decoded successfully and completely, the decoding process
terminates and an indicator of a successful read (such as
a green light and/or an audible beep) is provided to the
user. Otherwise, the decoder receives the next scan,
performs another decode attempt on that scan, and so on,
until a completely decoded scan is achieved or no more
scans are available.
Such a signal is then decoded according to the
specific symbology into a binary representation of the data
encoded in the symbol, and to the alphanumeric characters
so represented.
Systems have been developed which incorporate optical
indicia reading capabilities in pen computers of the type
shown in Figure 7. Typical of these systems are those
shown in Figures 8 and 9.
In the Figure 8 system, the computer module has been
modified to include a scanning unit 304 which generates a
light beam which scans the targeted symbol 306. The
CA 02586329 2007-05-10
= 14
scanning unit 304 also includes a photodetector which
detects the reflection of light from the symbol and
generates an electrical signal representing the scanned
symbol 306. The electrical signal may be processed and/or
stored in the computer module 300. Module 300 may also
include a touch screen display, 308 for inputting data to
the system and/or displaying the data representing the
symbol.
In the Figure 9 system, the pen computer has been
modified such that pen module 302 includes a scanning unit
312 which generates a light beam which scans the targeted
symbol 306 by physically moving the pen 302 across the
target symbol 306. The scanning unit 312 also includes a
photodetector which detects the reflection of light from
the symbol and generates an electrical signal representing
the scanned symbol 306. The electrical signal is
transformed into a radio frequency, infrared, acoustic or
other modulated wireless communication signal and
transmitted by transmitter 312 to the computer module
receiver 314. The received signal may be processed and/or
stored in the computer module 300. Module 300 may also
include a touch screen display, 308 for inputting data to
the system and/or displaying the data representing the
symbol.
Moving-beam laser scanners are not the only type of
optical instrument capable of reading symbols. Another
type of reader is one which incorporates detectors based on
charge coupled device (CCD) technology. In such readers
the sides of the detector are typically smaller than the
symbol to be read because of the image reduction by the
objective lens in front of the CCD. The entire symbol is
flooded with light from a light source such as a light
emitting diode (LED) in the scanning device, and each CCD
CA 02586329 2007-05-10
cell is sequentially read out to determine the presence of,
for example, a bar or a space.
The working range of CCD scanners is rather limited as
compared to laser based scanners and is especially low for
5 CCD based scanners with an LED illumination source. Other
features of CCD based scanners are set forth in U.S. Patent
Number 5,396,054, and in U.S. Patent Number 5,210,398.
These references are illustrative of the earlier
technological techniques proposed for use in CCD type
10 scanners,to acquire and read indicia in which information
is arranged in a two dimensional pattern.
Various systems, in addition to those described above,
have been proposed to improve the ease of use of optical
scanning systems. Such systems have included miniature
15 optical scanning modules which include light emitters and
detectors which are mounted on a hand. These systems have
also included a separate module mounted on the body or arm
or wrist of a user with a wire communication link to the
optical scan module. Such systems have also included
wireless communication devices to allow communications
between the second module and a base station, typically
using radio frequency communications. However, such
systems are either cumbersome, in that they require the
user to wear a vest or belt or other body mounting apparel
or require the use of a restrictive hand mount. One such
system requires the use of a glove in which the wire for
communications between the optical scan module and a second
module are transmitted. Further, systems which require
only a hand mounted optical scan module and wrist/arm
mounted second module have had capacity limitations which
limit the.amount of processing and data storage which can
be performed by the portable modules.
CA 02586329 2007-05-10
= 16
As noted above, pen computers can be used in optical
scanning applications. However, locating the optical scan
module in the computer module may be ergonomically
disadvantageous since it may be difficult for the user to
orient the computer module in the necessary direction in
order to get a satisfactory reading of the indicia.
Incorporating the optical scan module in the pen module
requires a communications line to transmit a signal
representing the indicia to the computer module.
Additionally, incorporating the optical scan module with
both light emitting and light detecting devices in the pen
module causes an increase in the physical size and weight
of the pen. It will be understood that these size and
weight increases are caused by both the additional
components and the battery cells required to power them.
Figure 2 shows a portable optical scan system in
accordance with an embodiment of the present invention.
An optical scan module 1 is detachably mounted on a
single finger of a user 3 using a ring shaped mounting.
The detachable mounting may be of any number of
conventional types suitably adapted for its ease of use for
the desired application. For example, a ball and
flexible socket mounting or a slide mounting could be
used. Other mountings with movable restraining members
might also be used. The optical scan module 1 includes
a light emitter and light detector. The light
CA 02586329 2007-05-10
17
= emitter typically includes an optical component such as
a mirror and lens as well as a mechanism for oscillating
or reciprocating components of the light emitter to cause
a scan across the target indicia. The light emitter and
detector are beneficially activated by a switch which may
be responsive to sound or to light level variations or to
physical or manual operation. The switch might, for
example, include a manually operated trigger switch or an
active or passive photosensor. In the preferred
embodiment, the switch can optionally be locked in an
"on" position so that the scan module components remain
activated without, for example, the need to continue to
squeeze a trigger. Voice activation is preferably
implemented as described below with reference to Figures
15A and 15B.
An electromagnetic device and spring assembly or
scan motor or other means can be used to drive the scan
function. Alternatively, the scan can be performed with
stationary light emitter components by physically moving
the optical scan module 1 across the indicia.
The light emitter will typically include one or more
light generators, for example light emitting or laser
diodes, which are housed in the optical scan module 1.
The optical scan module 1 may also include one or more
light detectors which are typically photosensors such as
a charge coupled or other solid state imaging device or
photodetector such as photodiodes. These components
could alternatively be housed in the first peripheral
module 7. If a charge coupled device or other imaging
device is utilized, it may be possible to detect the
reflection of either ambient light or emitted light from
the targeted indicia. It may be desirable to use an
optical scan module and mounting of the type shown in
Figure 12 or 13 of U.S. Patent No. 5,543,610.
CA 02586329 2007-05-10
18
The optical scan module 1 is connected to a first
peripheral module 7 by a flexible cable 5. The cable 5
is preferably retractable so that a minimum length of
cable is exposed during operation. The retraction
mechanism may be adapted from any of a number of
conventional retraction techniques arld systems. For
example, recess in tirst peripheral module 7 is
provided for retracting cable 5. A more sophisticate
retraction system is shown in Figure 14. The first
peripheral module 7 preferably houses a power supply 7a
for powering the components of optica]. scan module 1.
Module 1 is connected to the power supply 7a by an
electrical conductor, such as a copper wire, in cable 5.
The power supply would typically be a battery.
Alternatively, the power supply could be located in
optical scan module 1, however this may reduce the
operating time between recharge or replacement of the
battery.
The first peripheral module 7 also includes a
receiver 7b for receiving a signal corresponding to the
detected reflection of light representing the target
symbol from the optical scan module 1 via cable 5. The
signal may be in the form of an electrical signal
generated by a photosensor or photodetector located in
Module 1. Alternatively, if such component is located in
the first peripheral module 7, the received signal is
preferably an optical signal received via optical fiber
running through cable 5. The photosensor or detector
located in the first peripheral module 7 would thus
detect the transmitted optical signal. Also included in
peripheral 7 is a radio frequency (RF) or other wireless
transmitter which is used to transmit a signal
corresponding to the detected reflection of light, i.e.
representative of the target symbol, from the first
peripheral module to a second peripheral module 9 which
is located on the left arm or wrist of the user. The
CA 02586329 2007-05-10
19
transmitter could be a transceiver which is also
capable of receiving signals from a second peripheral
module 9 or base station 13.
The first peripheral module 7 is preferably mounted
on the same side of the user's body as the optical scan
module 1. Thus as shown, optical scan module 1 is
mounted on a single finger of the right hand and the
first peripheral module 7 is mounted on the right
arm/wrist of the user. Depending on the user's
preference, the various modules could be switched so that
the optical scan module 1 and first peripheral module 7
are mounted on the left hand and arm/wrist and
optionally, a second peripheral module 9 is mounted on
the right arm/wrist.
The optical scan module and the first peripheral
module may optionally include, either together with or in
lieu of cable 5, a wireless transmitter la and wireless
receiver 7d in combination with, or in lieu of, cable 5
for facilitating communications of the signal
corresponding to the detected reflection of light from
the targeted indicia.
The electrical or optical transmitted signal from
optical scan module 1 to the first peripheral module 7
can be further transmitted, typically in a transformed
state, via radio frequency transmitter to a radio
frequency receiver 9a of the second peripheral module 9
or the base station 13, or to a third peripheral device
11. If both transmissions are by a wireless link, the
transmission frequencies will typically be different.
The second peripheral module 9 includes digitizing and
processing circuits 9b which convert the transmitted
analog signal to a digital signal and decode the signal
in the conventional manner. An indicator.light, beeper
or audio transducer 9c signals the user when the decoding
has been satisfactorily accomplished. Such notice could
also or alternatively be provided by information
CA 02586329 2007-05-10
displayed on 9f. An indicator subsystem in accordance
with the present invention is described below with
reference to Figure 16. The second peripheral module 9
also preferably includes a memory storage device 9h to
5 temporarily store the decoded data. The second
peripheral module may also have a radio frequency
transmitter 9d to transmit decoded data to a base station
13, which could, for example, be a personal or other
computing device. A keypad 9e and display 9f are also
10 included as part of the second peripheral module. A
touch screen could alternatively be used in lieu of the
keypad and display. The keypad 9e is used for inputting
data to the system and the display 9f is used to display
the input data and decoded information. The input data
15 can also be transmitted via the radio frequency
transmitter 9d to, for example, the base station. A
third peripheral device 11 is optionally provided for a
power supply to power the second peripheral module and/or
for a transceiver lla for receiving and transmitting
20 signals from and to the first peripheral module 7 and the
base station 13. The power supply as shown is mounted to
a belt worn by the user 3. Alternatively, a battery
could be included as part of the second peripheral module
9.
In Figure 3, a further embodiment of the portable
optical scanner of the present invention is shown. This
embodiment is similar to the embodiment of Figure 2 and
like components are designated with same numeric
reference. In the Figure 3 embodiment, the analog to
digital conversion and decoding of the signal are
performed by the processor 7e in the first peripheral
module 7. The first peripheral module 7 also has an
indicator light or beeper 7f which signals the user when
the decoding has been satisfactorily performed. Thus, no
processor and beeper is required in the second peripheral
module 9. As in the above described embodiment, the
CA 02586329 2007-05-10
21
second peripheral module includes an electronic storage
device 9h f or storing the decoded data. It will be
understood that although keypad 9e and display 9f are
shown, a touch screen could be easily substituted
therefor in the conventional manner. Additionally,
Figure 3 shows a radio frequency transceiver 9i
substituted for the receiver 9a of Figure 2. The
transceiver 9i is not only capable of receiving a radio
frequency transmission from the first peripheral module
but can also transmit data input via the keypad to the
first peripheral module 7. Likewise, a radio frequency
transceiver 7g is substituted for transmitter in the
first peripheral module so that it can receive the input
data from as well as transmit the decoded information to
the second peripheral module. Except as noted in the
above, all components of the optical scanning system
depicted in Figure 3 are identical to those described
with reference to Figure 2 above.
In the Figure 3 split scanner configuration, a
transmitter la is provided in the optical scan module 1
and a receiver 7d is provided in the first peripheral
module 7. In such a configuration, there is no feedback
or two-way communications between the optical scan and
first peripheral modules. Various manual methods could
be used to turn on and off the light emitter of optical
scan module 1 and/or processor 7e of first peripheral
module 7. However, it is more advantageous for these
components to be automatically activated and deactivated
so as to reduce unnecessary power consumption without
3.0 adding complexity to the efficient operation of the
system. It is particularly desirable for the processor
7e to be activated only when necessary for decoding
targeted indicia and for the light emitter to be
deactivated once satisfactory decoding of the targeted
indicia has been achieved.
CA 02586329 2007-05-10
22
To provide automatic activation/deactivation of the
emitter and/or processor, the receiver 7d optionally
includes object sensing circuitry such as that previously
disclosed in, for example, U.S. Patent Nos. 4,933,538 and
5,250,791 which are issued to the assignee of all rights
in the present invention. A portion of the circuitry of
receiver 7d, which consumes a relatively small amount of
power from the power source 7a, is activated, either
continually or periodically, whenever the portable
optical scan system of Figure 3 is activated by a trigger
switch or other system activation mechanism of the type
described previously. The object sensing circuitry
checks for a received signal indicative of indicia of the
type beirig Largeted. If the check reveals that a
received signal is representative of, for example, a bar
code symbol of the desired type, the object sensing
circuitry generates a signal to activate the remaining
portion of the receiver 7d circuitry and the processor
7e. The fully activated receiver 7d transmits, to
processor 7e, the received signal which represents the
spatial intensity variation of the targeted symbol. The
processor 7e then processes and decodes the signal from
receiver 7d. Once the decoding has been completed, or
after the expiration of a predetermined time period
following full activation of the receiver 7d and
processor 7e, a portion of the circuitry of the receiver
7d and the processor 7e are automatically deactivated and
the object sensing circuitry again goes into a continuous
or periodic checking mode to check for a received signal
indicative of the desired type of indicia.
The light emitter and, if desired, the detector can
be activated/deactivated by connection to a timeout
circuit or an audio signal sensing means. In the former
case, a conventional clock or timing circuit is connected
to the light emitter and/or detector circuitry to
automatically deactivate the light emitter and/or
CA 02586329 2007-05-10
23
detector after a preset period of time has expired
subsequent to the activation of the emitter and detector
by the trigger switch or other system activation
mechanism. For example, if the receiver/processor is
capable of receiving and decoding one symbol per second,
the clock circuitry may be beneficially set to
automatically deactivate the light emitter. and/or
detector one second after activation to avoid a double
read of the same symbol. If desired, the clock circuitry
could be implemented so that timed deactivation does not
occur when the operator has set a lock on the trigger
switch. When the trigger switch is locked, the light
emitter and detector remain in a continuously activated
statP, which mav be preferable for certain operations.
After deactivation, the emitter and/or detector are
reactivated by, for example, releasing and resqueezing
the trigger switch to rescan the same symbol, if
satisfactory decoding has not been achieved, or to scan
another symbol.
Alternatively, the emitter and/or detector are
connected to a conventional audio sensor for sensing the
audio signal produced by beeper 7f. Such sensors
typically include an acoustic transducer and associated
receiver circuitry, as is well understood in the art.
The beeper 7f provides an audible indication of the
satisfactory decoding of the scanned indicia. ypon
sensing the beeper signal, the light emitter and/or
detector are deactivated. After deactivation, the
emitter and/or detector are reactivated by, for example,
releasing and resqueezing the trigger switch to scan
another symbol. Since deactivation using the audio
sensor only occurs after confirmation of satisfactory
decoding, reactivation to rescan a symbol is not
required. If desired, the audio sensor can be
implemented such that deactivation, based on reception of
CA 02586329 2007-05-10
24
the beeper signal, does not occur when the operator has
set a lock on the trigger switch.
Figure 4 shows an optical scan system similar to
that shown iri Figure 3 except that the second peripheral
module 9 is located 25 to 150 feet from, rather than
mounted on, the user. Although this specific range is
preferred, it should be understood that implementation is
not limited to this or any other specific transmission
ranges.
Figure 5 shows still another embodiment of the
invention. In this embodiment, the first peripheral
module includes all of the components described in
connection with Figure 4 and additionally includes a
keypad 7h and display 7i. As noted above, a touch screen
can be substituted in the conventiona]. manner for the
keypad 7h and display 7i. Additionally, electrbnic
memory storage 7j is included in the first peripheral
module for storage of the decoded data. The second
peripheral device is completely unnecessary. Base
station 13 is preferably located between 25 and 150 feet
from the user.
Figure 10 shows a pen computer optical scanning
system in accordance with the present invention. The pen
302 includes a light emitting module 320 which generates
and directs light towards the indicia 306 to be read.
The module includes components of the type described
above in connection with the other embodiments of the
invention. The computer module 300 includes a detector
322 which detects reflected light from the target
indicia. The detector 322 ca.n be a photodiode or sensor,
such as a charge coupled or other solid state imaging
device. The optical scan module 320 can be similar to
that shown in Figure 3B of U.S. Patent Number 5,514,861.
The processing of the detected reflection of light could,
as is conventional, be performed within computer
module 300. Figure 11 shows a further
CA 02586329 2007-05-10
configuration of the computer module 300. In this
configuration, the computer module has multiple detectors
322 to allow greater flexibility in the positioning of
computer module 300 during scanning operations. The
5 computer module 300 has a processor 324 which includes an
analog to digital converter, and/or decoding circuitry
and software. The computer module also includes an
indicator light or buzzer 326 for signalling the user
when the decoding has been successfully accomplished. An
10 electronic data storage diode is also included in the
computer module. A keypad display and display (not
shown) or touch screen 308 is located on a face of the
computer module for inputting data and displaying the
decoded information. A receiver which together with the
15 transmitter forms a transceiver 328 is also included in
the computer module so that data can be received from and
sent to the base station or other peripheral modules (not
shown). The transceiver 328 can be of a radio frequency,
acoustic or infrared type depending on the application
20 and preferably operates in the range of 25 to 150 feet.
Figure 12 depicts a further embodiment of the
invention wherein the optical scan module 400 is mounted
on a single finger ring. The module 400 includes a light
emitter similar to that used in the pen computer scanners
25 described above with reference to Figures 10 and 11. The
light emitter generates and directs light towards the
indicia 306 to be read. The peripheral module 7 mounted
on a wrist or arm of the user preferably on the side of
the user opposite that of the hand on which the optical
scan module 400 is mounted. The peripheral module 7 is
identical to that described with_reference to Figure 5,
except as will be hereafter noted.
Peripheral module 7 includes a detector 7k which
detects reflected light from the target indicia 306.
Because the reflected light is directly detected by
module 7k, wireless receiver 7d is unnecessary and has
CA 02586329 2007-05-10
26
been eliminated in this embodiment. The optical scan
module 400 can be similar to that shown in Figure 12 of
U.S. Patent Number 5,543,610. The detector 7k can be a
photodetector or sensor, such as a charge coupled or
other solid state imaging device.
The processing=of the detected reflection of light
would conventionally be performed as described above with
reference to module 7. Thus, the peripheral module has
a processor which includes an analog to digital
converter, and decoding circuitry and/or software. The
peripheral module also includes an indicator light or
buzzer for signalling the user when the decoding has been
successfully accomplished. An electronic data storage
device is also included in the peripheral module.
A keypad and display or touch screen (not shown) is
located on a face of the peripheral module for inputting
data and displaying the decoded information. A receiver
which together with the transmitter forms a transceiver
is also included in the module 7 so that data can be
received from the base station or other peripheral
modules (not shown). The transceiver can be of a radio
frequency, acoustic or infrared type depending on the
application and preferably operates in the range of 25 to
150 feet.
Figures 13 and 13A show a single finger ring housing
and mount suitable for use in the embodiments of Figures
2, 3, 5 and 12. More particularly, Figure 13A depicts a
housing and mount which is particularly adapted for use
in the embodiments of Figures 2, 3 and 5, while Figure
13B depicts a housing and mount adapted for use in the
Figure 12 embodiment.
Referring now to Figure 13A, the scan module 1 is
connected to cable 5 and optionally includes a wireless
transmitter la as described above. The scan module
housing lc is attached to a single finger ring mounting
ld. Scanner housing lc is cylindrical in form, with
CA 02586329 2007-05-10
27
smooth outer surfaces. The ring portion ld is also
cylindrical in form with smooth outer surfaces. The
cylindrical single finger ring mount ld is attached to
the cylindrical housing ic by means of a pivotal joint
le. The pivotal joint allows cylindrical housing lc to
be rotated about the pivotal connection le so that light
is emitted in directions other than the natural pointing
direction of the finger on which the assembly is mounted.
Thus, for example, housing lc could be rotated 90 in
either direction so as to emit a light beam above the
user's thumb or the back of the user's hand, as
applicable. The rotation is not limited to 90 but can
be any angle which the user deems appropriate under the
circumstances.
The pivot connection can, for example, include a
plastic bearing or pivot shaft structure which allows
movement of the housing only when a physical force is
applied, preferably applied by the user's free hand, to
the housing lc. It will be recognized by those in the
art that, if desired, the pivot connection could be
adapted to allow rotation both in a plane approximately
parallel to a plane formed by the back of the user's
extended hand, i.e. with fingers extended, as well as
limited rotation in another plane approximately
perpendicular to the plane formed by the back of the
user's extended hand.
Figure 13B depicts a housing and mount
configuration, similar to that of 13A, but which houses
only the light emitter. The arrangement of Figure 13B is
particularly suitable for use in the embodiment of Figure
12, wherein the detection of reflected light off the
indicia is performed by a separate unit. Housing 400A
and ring 400B are cylindrical with smooth outer surfaces.
Rotational connection 400C is identical to connection le
of Figure 13A and serves an identical function.
CA 02586329 2007-05-10
28
Connection 400C could likewise be modified to provide
rotation in multiple planes as described above.
Figure 14 depicts a retractable cable reel which may
be utilized in the Figures 2, 3 and 5 embodiments. As
shown in Figure 14, a non-coiled flexible cable 5a has
one end fixed or removably mounted to the optical scan
module 1. If removably mounted, one end of the cable 5a
is connected to a conventional plug-in-socket lb in the
scan module 1. In either case, the other end the cable 5a
is retractably mounted to module 7 using reel 7n. Reel
7n is spring loaded. In one configuration, the spring is
designed, using conventional techniques, to provide a
constant tension force on the cable which is resisted by
the user's finger during operation. The constant tension
force ensures that there is no slack in the cable during
operation and also provides the force necessary to
retract the cable onto the reel when the system is not in
use. If cable 5a is removably connected to scan module
1 the constant tension force must necessarily be less
than a force which would disconnect cable 5a from socket
lb. The constant tension force applied by the spring
must also be small enough so as not to make the use and
operation of the system uncomfortable for the user.
Alternatively, the spring loaded reel could include
a positional locking mechanism. Such mechanisms are
commonly incorporated, for example, in the retraction
reel used for various commercially available electrical
devices such as vacuum cleaners, power hedge trimmers and
the like. If such a locking mechanism is utilized,
sufficient cable is pulled from the reel to allow
comfortable operation by the user. A small amount of
slack in the cable is present during operation but there
is no tension on the cable which must be resisted by the
users finger. When scanning operations are completed,
the user simply uses a free hand to sufficiently tension
the cable, or to move a lock release mechanism, to
CA 02586329 2007-05-10
29
release the lock. Once the lock is released, the spring
automatically provides the necessary force to cause the
cable to be rewound on the reel. Spring loaded cable
reels have been described in, for example, US Patent No.
3,657,491.
The cable opening in module 7 is sized to be large
enough to allow for the extension and retraction of the
cable. The cable opening is smaller than the scan module
1 housing or, in the case of cable which is removably
connected to scan module 1, the connector portion of the
cable which plugs into socket lb so as to provide a stop
during retraction. Rather than using a spring loaded
reel, a motorized reel, similar to that used in a camera
with a power film advance and rewind function or
described in, for example, US Patent No. 4,842,108, or a
manual spool, similar to that used in a fishing reel or
camera without power film winding, could be adapted and
used in a scanning system of the type described herein.
Figures 15A and 15B are block diagrams of two
alternative voice recognition subsystems of the present
invention which may be utilized in any of the described
embodiments of the portable optical and pen computer scan
systems to facilitate activation of the scan/read, signal
processing, data entry, data display and/or signal
transmission elements by the user. The subsystems may
also be used, if desired, to identify the current user,
change the operating modes of system elements and provide
a data entry capability additional to, or in substitution
for, the keypad or touch screen described above.
Referring to Figure 15A,. a microphond 1500, which is
customarily mounted to a headband, helmut or glasses
worn by the user but could be mounted using conventional
techniques to the mouth, throat, ear or clothing of the
user, detects a voice command, such as "GO", from a user.
The microphone transmits a clear, identifiable analog
spectrum response signal, corresponding to the voice
CA 02586329 2007-05-10
command, to the amplifier 1502 which may be housed
together with or separate from microphone 1500. The
analog response signal is independent of the user's voice
characteristics, such as those reflective of the user's
5 age, sex or accent. The analog response signal is
amplified in amplifier 1502. The amplified response
signal is transmitted via wire or wireless communications
link to multiplexer 1504 which is preferably housed in
module 7 or 300 of the previously described embodiments.
10 Such commanding can occur simultaneous with scanning
operations. In such cases, an analog read signal,
corresponding to the detected reflected light from, for
example, a bar code is simultaneously being transmitted
by photodetector 1506 to amplifier 1508, amplified by
15 amplifier 1508, and transmitted to multiplexer 1504. The
analog signals from the amplifiers 1502 and 1508 are
multiplexed in multiplexer 1504 and the multiplexed
analog signal transmitted to digitizer circuit 1510. The
multiplexed analog signal is converted in digitizer
20 circuit 1510 into a digital pulse signal stream. The
width of the each digital pulse signal represents either
the bar/space transitions of the bar code or an
inflection point in the voice response signal.
The system microprocessor 1512, which includes the
25 previously described processing circuitry used to process
the signals generated by the system sensor or
photodetector, preferably controls the multiplexer and
adjusts the operating parameters, e..g. the sensitivity,
of the digitizer circuitry to optimize the circuitry for
30 conversion of the multiplexed voice response and read
signals. By counting the number of transitions in a
given time period, the microprocessor 1512 determines the
frequency of the voice response signal within the
selected time period.
The microprocessor then applies the voice response
signal frequency measurement to a recognition algorithm,
CA 02586329 2007-05-10
31
stored for example in the microprocessor's or a separate
memory device, and activates the scan/read, signal
processing, data entry, data display and/or signal
transmission elements, or changes the operating mode of
one or more of the elements depending on the results.
For example, the operating mode or parameters of the
scan/read elements may be adjusted based upon the
distance to or density of the target, or the processing
circuitry may be activated to download total data, or
the current user may be identified in accordance with the
voice command recognized by the algorithm. Alternatively,
the voice command may include data to be entered to the
system which is recognized by the recognition algorithm
and entered on the system as previously discussed but
without using the keypad or touch screen.
Figure 15B depicts a block diagram of a second voice
recognition subsystem which is somewhat simpler than that
of Figure 15A and is primary useful in activating and/or
deactivation the scan/read elements. Microphone 1500 and
amplifier 1502 are identical to those described with
reference to Figure 15A above. The amplified analog
voice response signal is transmitted to a band pass
filter with a predetermined passband frequency range.
The amplified analog voice response signal is also
transmitted simultaneously to noise analyzer 1516 which
analyses the signal for background noise and transmits a
signal corresponding to the results of the analysis to
the'level detector 1518. The detector 1518 threshold
parameters are automatically adjusted for the background
noise level based upon the transmitted results of the
analysis. The magnitude of the filtered signal is then
compared to the adjusted threshold parameters and based
upon this comparison a signal is generated and
transmitted by the detector 1518 to activate or
deactivate the scan/read elements.
CA 02586329 2007-05-10
32
Figure 16A is a block diagram of a indicator
subsystem in accordance with the present invention and
Figure 16B is a list of status/conditions of which the
user can be notified using the indicator subsystem. The
indicator subsystem is suitable for use in any of the
embodiments of the portable optical and pen computer scan
systems described herein.
Referring to Figure 16A, the system microprocessor
1600 is connected to an interface 1602 which is in turn
connected to the optical scan element. The system
microprocessor 1600 is also connected to a second
interface 1604 which is in turn connected to those other
elements of the system whose status and/or condition is
of interest to the user. Such elements will typically
include, for example, the photodetector or sensor, the
decoder, the battery or any other elementregarding which
status or condition information is required. Figure 16B
is an exemplary list of some of the items normally of
interest to the user. It will be understood by those
skilled in the art that the list is provided, not as a
comprehensive listing of status and condition items of
interest since such items are well-known in the art.
Rather the list is provided simply to indicate the types
of status and condition items under discussion.
Information received from the elements to which the
interfaces are connected is received via the interfaces
by the processor 1600 and compared to threshold
information stored in and retrieved from the processor's
or a separate memory device 1606. If desired, the
information can also be stored in the memory 1606. Based
upon the comparison, the processor can generate and
transmit a signal to the system display 1608 which
results in a multiple digit numeric, alpha-numeric or
graphic display of information representing the status
and/or condition of one or more elements of the system.
Additionally or alternatively, the processor 1600
CA 02586329 2007-05-10
33
= transmits the generated signal to a sound generator
circuit 1610, which optionally includes a synthesizer.
Sound generator circuit 1610 applies the received signal
to a recognition algorithm, stored for example in the
memory 1606, and generates and transmits a signal to
audio transducer 1612 reflective of the received signal.
The transducer 1612, which is preferably a high-grade,
micro audio-speaker, is driven by the signal from the
sound generating circuit to produce an audible
synthesized or tone sound which provides the user with
information representing the status and/or condition of
one or more elements of the system.
With. regard to Figure 16B, the designations used
should be clear to those skilled in the art. However, to
avoid any possible questions which may arise as to the
meaning of certain of the listed designations, "1-D
decoder" refers to a single dimension bar code decoder,
"macro PDF decoder" refers to a specific subset within
the PDF-417 symbology type, "heap space" refers to a
portion of memory, "ADF rule" refers to advance data
formatting rules, and "PDF optional field" refers to an
area within the PDF symbol reserved for optical encoding
of special data. It should also be understood that the
list of status/conditions is, exemplary in nature, since
the status and condition indications required or desired
are well understood in the art.
Figures 17A-17D depict alternative mountings for the
optical scan module of the embodiments of Figures 2, 3,
5 and 12 and for the microphone/amplifier of Figures 15A
and 15B. Using any of the Figure 17A-17D arrangements,
aiming is done by movement of the user's head.
In Figure 17A the scan module 1700, which is
identical to module 1 of Figures 2, 3 and 5 or 400 of
Figure 12 is mounted in helmet 1702. A
microphone/amplifier assembly 1704, which preferably
includes the microphone and amplifier, 1500 and 1502 of
CA 02586329 2007-05-10
34
Figures 15A and B, is mounted from a support member 1706
which is attached to helmet 1702. Support member 1706
may be either of plastic or metal and is preferably
deformable so that a user can, by bending member 1706 in
an appropriate direction or directions, adjust the
location of assembly 1704 to a comfortable position in
the general proximity of the user's mouth and outside
the user's line of sight and the scan module field of
view.
Figure 17B depicts a support arrangement similar to
that of Figure 17A, with all like elements designated
with reference numerals identical to those of Figure 17A.
The primary difference between Figure 17A and 17B is that
the optical module 1700 is supported in Figure 17B by an
adjustable headband 1708. The headband may be made of
flexible elastic material or may have a buckle or other
means for adjusting the headband to the size of the
user's head so that the optical module 1700 and assembly
1704 are comfortably supported during operation of the
system by the user. The optical module 1700 and support
member 1706 are attached to the headband 1708 in a
removable manner using any conventional technique which
does not make the wearing of the headband uncomfortable
to the user. It will be noted that optical module is
positioned over one of the user's eyes which some user's
find to be the preferable positioning for aiming
purposes.
The support arrangement of Figure 17C is identical
to that of Figure 17B, except in Figure 17C the optical
module 1700 is positioned to be centered between the
user's eyes. This positioning of the optical module 1700
is found, by some user's, preferable for aiming and from
a comfort of use viewpoint.
Figure 17D depicts still another arrangement wherein
the optical module 1700 and support member 1706 are
attached to an eye glass frame 1710. This arrangement is
CA 02586329 2007-05-10
particularly suitable where the system is being used in
areas where safety glasses are required or for user's who
normally wear eye glasses.
All of =the disclosed embodiments with radio
5 frequency communications capabilities preferably operate
for usages in the United States in a rarige of 902 to 928
MHz, or 2.4 GHz, and for European applications at
approximately 433.9 MHz. Other frequencies would be used
elsewhere depending on the applicable governmental
10 regulations for radio frequency transmissions.
Additionally, all of the transceivers may optionally
include a modem with an RF 232 interface for facilitating
communications with the base station or other peripheral
items. The RF transceivers also include fi.iters on the
15 receive side to filter receive signals.
Although certain embodiments of the invention have
been discussed without reference to the scanner housing,
triggering mechanism and other features of conventional
scanners, it will be understood that a variety of housing
20 styles and shapes and triggering mechanisms could be
used. Other conventional features can also be included
if so desired. The invention is directed primarily to a
portable hand-held scanning device and thus is preferably
implemented using miniaturized components such as those
25 described in the materials referenced herein, or
otherwise known in the art. However, the scanner of the
present invention is not limited to use in portable
devices and can also be easily adapted for use in a
stationary housing wherein the item on which the symbol
30 resides is moved across the scanner head.
Additionally, even though the present invention has
been described with respect to reading one or two
dimensional bar code and matrix array symbols, it is not
limited to such embodiments, but may also be applicable
35 to more complex indicia scanning or data acquisition
applications. It is conceivable that the method of the
CA 02586329 2007-05-10
36
present invention may also find application for use with
various machine vision or optical character recognition
applications in which information is derived from indicia
such as printed characters or symbols, or from the
surface or configurational characteristics of the article
being scanned.
In all of the various embodiments, the elements of
the scanner may be implemented in a very compact assembly
or package such as a single printed circuit board or
integral module. Such a board or module can
interchangeably be used as the dedicated scanning element
for a variety of different operating modalities and types
of data acquisition systems. For example, the module may
be alternately used in a hand-held manner, a table top
scanner attached to a flexible arm or mounting extending
over the surface of the table or attached to the
underside of the table top, or mounted as a subcomponent
or subassembly of a more sophisticated data acquisition
system.
Each of these different implementations is
associated with a different modality of reading bar code
or other symbols. Thus, for example, the hand-held
scanner is typically operated by the user "aiming" the
scanner at the target; the table top scanner operated by
the target moved rapidly through the scan field, or
"presented" to a scan pattern which is imaged on a
background surface. Still other modalities within the
scope of the present invention envision the articles
being moved past a plurality of scan modules oriented in
different directions so at least the field of view allows
one scan of a symbol which may be- arbitrarily positioned
on the article.
The module would advantageously comprise an optics
subassembly mounted on a support, and a photodetector
component. Control or data lines associated with such
components may be connected to an electrical connector
CA 02586329 2007-05-10
37
mounted on the edge or external surface of the module to
enable the module to be electrically connected to a
mating connector associated with other elements of the
data acquisition system.
An individual module may have specific scanning or
decoding characteristics associated with it, e.g.
operability at a certain working distance, or operability
with one or more specific symbologies or printing
densities. The characteristics may also be defined
through the manual setting of control switches associated
with the module. The user may also adapt the data
acquisition system to scan different types of articles or
the system may be adapted for different applications by
interchanging modules in the data acquisition system
through the use of a simple electrical connector.
The scanning module described above may also be
implemented within a self-contained data acquisition
system including one or more such components as keyboard,
display, printer, data storage, application software, and
data bases. Such a system may also include a
communications interface to permit the data acquisition
system to communicate with other components of a local or
wide area network or with the telephone exchange network,
either through a modem or an ISDN interface, or by low
power radio broadcast from a portable terminal to a
stationary receiver.
It will be understood that each of the features
described above, or two or more together, may find a
useful application in other types of scanners and readers
differing from the types described above.
