U.S. patent application number 10/660856 was filed with the patent office on 2005-03-17 for rfid tag and printer system.
Invention is credited to Chapman, Theodore A., Edwards, Andrew W., Harkins, James P., Jarvis, Bradley S., Morris, Stephen S., Schumaker, Richard E..
Application Number | 20050058483 10/660856 |
Document ID | / |
Family ID | 34273736 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050058483 |
Kind Code |
A1 |
Chapman, Theodore A. ; et
al. |
March 17, 2005 |
RFID tag and printer system
Abstract
An RFID label with embedded tag is passed through an RFID
antenna in a printer system, where the RFID antenna allows a roll
of such labels to pass in close proximity to the antenna and still
allow each individual RFID tag to be read and/or programmed. The
RFID antenna has a rectangular RF field spreader in contact with a
triangular divergent RF conductor with an RF source point at the
point. Ground planes are located on either side of the antenna. In
another embodiment, the printer system extracts or parses bar code
commands from a data stream and passes the commands to both a
printer and an RFID reader to print the image and program the tag
with the bar code information.
Inventors: |
Chapman, Theodore A.; (San
Juan Capistrano, CA) ; Schumaker, Richard E.;
(Orange, CA) ; Edwards, Andrew W.; (Irvine,
CA) ; Morris, Stephen S.; (Anaheim, CA) ;
Harkins, James P.; (Lake Forest, CA) ; Jarvis,
Bradley S.; (Newport Beach, CA) |
Correspondence
Address: |
Tom Chen
MacPHERSON KWOK CHEN & HEID LLP
Suite 226
1762 Technology Drive
San Jose
CA
95110
US
|
Family ID: |
34273736 |
Appl. No.: |
10/660856 |
Filed: |
September 12, 2003 |
Current U.S.
Class: |
400/76 |
Current CPC
Class: |
G06K 7/10346 20130101;
B41J 3/4075 20130101; G06K 7/10316 20130101; G06K 5/02 20130101;
B41J 11/0095 20130101; B41J 3/44 20130101; G06K 17/0025 20130101;
G06K 19/07749 20130101 |
Class at
Publication: |
400/076 |
International
Class: |
B41J 011/44 |
Claims
What is claimed is:
1. A printer system, comprising: a roll of labels, wherein each
label comprises a radio frequency identification (RFID) tag; an
RFID reader system comprising: an RFID reader; and an RFID antenna,
wherein the RFID antenna comprises: an RF field spreader; an RF
divergent conductor, with a divergent side contacting the RF field
spreader and an opposite side forming an RF source node; a first
ground plane adjacent to the RF field spreader; and a second ground
plane adjacent to the RF divergent conductor; and a print head,
wherein the RFID antenna is between the roll of labels and the
print head.
2. The printer system of claim 1, wherein the RF field spreader is
a rectangular-shaped conductor.
3. The printer system of claim 1, wherein the RF divergent
conductor is a triangular-shaped conductor.
4. The printer system of claim 1, where the RF field spreader and
the RF divergent conductor are copper.
5. The printer system of claim 1, wherein the print head is a
thermal print head.
6. The printer system of claim 1, wherein the RFID tag is located
in an approximately middle section of the label along the
width-wise direction.
7. The printer system of claim 1, wherein the RF field spreader and
the RF divergent conductor are formed on a first portion of a
printed circuit board assembly.
8. The printer system of claim 7, wherein the second ground plane
is formed on a second portion of the printed circuit board
assembly.
9. The printer system of claim 8, wherein the first and second
portions are approximately the same size.
10. The printer system of claim 1, wherein the first ground plane
is smaller than the second ground plane.
11. The printer system of claim 1, wherein the RFID tag passes over
the RF source node source.
12. The printer system of claim 1, wherein the RFID reader system
writes to and reads from the RFID tag.
13. The printer system of claim 1, wherein the RFID antenna further
comprises a microstrip transmission line to transmit an RF signal
from an edge of the antenna to the RF source node.
14. The printer system of claim 1, wherein the RFID reader system
operates in a frequency range of approximately 902 MHz to 928
MHz.
15. The printer system of claim 1, wherein the RFID antenna
comprises a dielectric material having a dielectric constant of at
least 4.0.
16. A printing system, comprising: a host computer, wherein the
host computer is capable of transmitting a data stream using a
first programming language; and a printer system, comprising: an
extractor coupled to receive the data stream, wherein the extractor
extracts a first portion of the data stream and generates RFID
commands from the first portion; a parser coupled to the extractor,
wherein the parser parses image portions from RFID portions of the
first portion of the data stream; an image formatter coupled to
receive the image portions from the parser; an RFID data formatter
coupled to receive the RFID portions from the parser; a print
sub-system coupled to the image formatter for printing an image on
a label; and an RFID system coupled to the RFID data formatter for
programming data on an RFID tag in the label.
17. The printing system of claim 16, wherein the first programming
language is different than the programming language from the
printer system.
18. The printing system of claim 16, wherein the first portion is
bar code commands.
19. The printing system of claim 16, wherein the extractor is a
character substitution table.
20. The printing system of claim 18, wherein the extractor
generates an RFID command from bar code data.
21. The printing system of claim 16, wherein the print sub-system
comprises a thermal print head.
22. A method for printing labels from a roll, with each label
having a radio frequency identification (RFID) tag, the method
comprising: passing a label over an RFID antenna; interrogating the
RFID tag in the label; determining if the interrogating was
successful; attempting N-1 additional interrogations until a
successful interrogation is determined; and printing the label once
a successful interrogation is determined.
23. The method of claim 22, further comprising receiving print and
tag data from a host computer.
24. The method of claim 22, wherein the interrogating is reading
data from the RFID tag.
25. The method of claim 22, wherein the interrogating is
programming data in the RFID tag.
26. The method of claim 22, wherein N is 5 or less.
27. The method of claim 22, further comprising over striking the
label if a successful interrogation cannot be determined after N
interrogations.
28. The method of claim 22, further comprising halting operation of
the process if a successful interrogation cannot be determined
after N interrogations.
29. The method of claim 22, wherein the printing is by thermal
printing.
30. A method of processing an label with an RFID tag, comprising:
receiving, from a host computer, a data stream in a programming
language; extracting a first portion from the data stream;
formatting at least part of the first portion into an RFID command;
programming bar code data into the RFID tag using the formatted
portion; and printing the label using commands from the first
portion of the data stream.
31. The method of claim 30, wherein the first portion are bar code
commands.
32. The method of claim 30, further comprising parsing the RFID
command to an RFID system and at least a portion of the data stream
to a printer portion.
33. The method of claim 32, wherein the printer portion includes a
thermal print head.
34. The method of claim 32, wherein the programming language is
different than the programming language of the printer portion.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to printer systems, and in
particular, a printer system for communicating with radio frequency
identification (RFID) labels.
[0003] 2. Related Art
[0004] RFID transponders or tags, either active or passive, are
typically used with an RFID reader to read information from the
RFID tag. The information is then stored or otherwise used in
various applications, such as monitoring, cataloging, and/or
tracking of the item associated with the RFID tag, paying tolls,
and managing security access. For example, RFID tags can be
obtained through companies such as Alien Technology Corporation of
Morgan Hill, Calif. Many applications for bar codes can also be
used in conjunction with RFID systems.
[0005] A conventional RFID tag and reader uses radio frequency
signals to acquire data remotely from the tags within the range of
the reader. One example is reading the information associated with
a transponder carried in a car, which allows the RFID system to
determine the number of times a car passes through an RFID reader
mounted over a toll road. This information can then be processed
and a bill may be sent to the owner of the transponder based on the
number of times the toll road was used. Another example is reading
information from a group of objects, such as a cart of groceries.
Each grocery item would have an RFID tag or label, which may
include the description and price of the item. An RFID reader can
then read the entire cart of items, print out the item description
and price, and total price. This is in contrast to bar code
systems, in which a bar code scanner must be brought within
sufficient range and direction to the bar code in order for a
scanner to read each individual item. Yet another example is
reading RFID tags on cartons stored on pallets as the pallets are
moved through a warehouse. This allows efficient inventory tracking
of arriving and/or departing items.
[0006] These and other typical RFID systems require antennas that
are able to interrogate RFID tags that are many wavelengths away.
Such antennas typically have large power and beam widths. These
types of antennas are not suitable for use in applications that
require directional and confined interrogation.
[0007] RFID labels, such as for cartons or pallets, can be produced
by placing an RFID tag in a label, programming information into the
tag, such as from a host computer, and based on the information,
printing the label with a proper bar code and/or other printable
information using a thermal printer. RFID labels can also be
produced in a thermal printer by first printing on the label and
then programming or encoding the RFID tag on the label. These
labels can then be read by both a bar code scanner and an RFID
reader. However, printing after programming forces additional
handling of the roll of labels and requires the use of additional
hardware. To ensure that the correct information is printed on a
label, an RFID reader must be used to synchronize the thermal
printing process with the associated RFID tag. Furthermore, the
capabilities of programming and reading RFID tags used in thermal
printer labels is limited, due in part, to the mechanical profile
of the printer, which may cause performance issues with radio
frequency signals associated with RFID technology, and to the
proximity of multiple tags coupled with the need to address
(program) only one tag at a time.
[0008] Accordingly, there is a need for printers and components
that are able to process RFID labels that overcomes the
deficiencies in the prior art as discussed above.
SUMMARY
[0009] According to one aspect of the invention, a thermal printer
is used to read and write an RFID tag on a label and to print the
label based on information read from the RFID tag. A thin quarter
wave resonant antenna is used in one embodiment for interrogation
of the RFID tag, with an operation frequency between 902 and 928
MHz and a free space wavelength between 12.73 and 13.9 inches. Such
an antenna allows 1) the RF field to be controlled so that only the
RFID tag associated with the label to be printed by the thermal
print head is encoded, while not interrogating other RFID tags in a
label roll, and 2) communication with an RFID tag as the label is
moving across the antenna field.
[0010] According to one embodiment, a roll of blank labels includes
an RFID tag embedded onto each label. The roll is inserted into a
thermal printer having a thermal print head and an RFID antenna
located between the print head and the roll of RFID labels and
underneath the path of the labels. The RFID tags can be programmed
with known information, such as from a host computer, and verified
that the programmed information is correct. When a tag is
programmed or encoded, any existing data is first erased and the
new information transmitted, via the RFID antenna, to the tag. A
read operation then follows to verify that the correct information
was written. In one embodiment, if a first read (verify) operation
indicates an improperly programmed tag, additional write
operations, each followed by a read (verify) operation, are
performed before the RFID tag is considered defective. If the RFID
tag is defective, an error notification can be given to the
operator and the printing halted or the thermal print head can
print onto the label with an indication that the RFID tag is
defective.
[0011] This allows the printer to have the capability to program
data into an RFID label and verify that correct data was programmed
before printing. If an error is detected, the printer can
over-strike the label, indicating an error in the tag.
[0012] According to another embodiment, the RFID tag is
interrogated at decreasing RF power levels until a minimum power
level is determined that still allows the RFID tag to be read. This
allows the system to determine a level of RFID tag performance
margin or RFID tag quality level.
[0013] Any data accumulated associated with the RFID tag can be
stored and retrieved for later usage, such as the number of
defective tags, the number of RFID tag retries are needed for a
successful write, and the minimum RF power level for an RFID
tag.
[0014] According to yet another embodiment of the invention,
information from a data stream from a host computer is intercepted,
reconfigured, and used for programming or writing to the RFID tag.
In one embodiment, bar code commands are extracted from the data
stream. The bar code data is then formatted into an RFID command
and the bar code data is subsequently programmed into the RFID tag,
and the RFID tag is printed with the commands from the data stream.
The bar code data may be manipulated to ensure compliance with the
RFID tag capabilities. Modifying the bar code data stream into an
RFID programming command eliminates the need to modify the host
application software.
[0015] It is noted that some company's thermal printers can print
labels based on other company's languages allowing easy migration
into competitor applications. Thus, the concept of converting the
bar code command into an RFID command can be applied to a thermal
printer that supports not only its standard programming language
but also any competitor languages that the printer happens to
support.
[0016] This invention will be more fully understood in conjunction
with the following detailed description taken together with the
following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows a block diagram of a thermal printer system
with the RFID subsystem installed according to one embodiment;
[0018] FIG. 2 shows a label with an RFID tag according to one
embodiment;
[0019] FIG. 3 shows an RFID antenna for use in the system of FIG. 1
according to one embodiment;
[0020] FIG. 4 is a flow chart showing a process for writing to and
printing on a label according to one embodiment;
[0021] FIG. 5 is a flow chart showing a process for reading from
and printing on a label according to one embodiment; and
[0022] FIG. 6 is a block diagram of a printer system for extracting
commands from a data stream and printing and programming a label
according to one embodiment of the invention.
[0023] Use of the same or similar reference numbers in different
figures indicates same or like elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] FIG. 1 shows a block diagram of a printer system 100 with a
radio frequency identification (RFID) reader subsystem 102
according to one embodiment. Printer system 100 also includes a
roll 104 of labels or media, where an RFID tag is embedded in each
label. RFID tags are conventional passive tags, such as
manufactured by Alien Technology Corporation. Labels from roll 104
are fed over an RFID antenna 106, interrogated, and printed by a
thermal print head 108. A host computer 112 coupled to a system
controller 110 that is in turn coupled to RFID reader subsystem 102
and antenna 106 allows the RFID tag on each label to be written to
and verified. If the RFID tag was programmed correctly, the label
passes through thermal print head 108 for printing. The resulting
label then has both a printed media as well as a programmed RFID
tag that can be read, such as with bar code scanners and RF
readers, respectively.
[0025] FIG. 2 shows a label 200 from roll 104 of FIG. 1, where
label 200 includes an RFID tag 202. RFID tag 202, in one
embodiment, is embedded on label 200 between a layer of wax paper
or liner 204 and the adhesive side of label 200. As seen from FIG.
2, RFID tag 202 is approximately centered width-wise and slightly
off-center length-wise. An outline of an RFID antenna 206,
associated with RFID tag 202, is also shown, along with the outline
of an RFID tag assembly (inlay) 208. This example is from an RFID
tag assembly manufactured by Alien Technology Corporation. RFID tag
202 and RFID antenna 206 are conventional elements. Also, as shown
in FIG. 2, label 200 is one of many labels from roll 104, each
label 200 can be separated from an adjacent label by a perforation
210. Perforation 210 allows labels to be easily separated after
printing. Label 200 shown in FIG. 2 is a 4.times.6 inch label,
although other size labels can also be used, such as 4.times.4 inch
labels.
[0026] Referring back to FIG. 1, labels 200 from roll 104 pass over
RFID antenna 106 for interrogation. In one embodiment, labels 200
pass at a speed of up to 10 inches per second, which for a 6 inch
label is up to 5 labels every 3 seconds. A media drive motor 116,
coupled to system controller 110, drives a platen 118 to pull
labels 200 through the printer, as is known in the art. System
controller 110 is also coupled to a power supply 120 and a
user-operated control panel 122 that allows the user to control
certain operations of the print system, as will be discussed below.
System controller 110 also controls thermal ribbon drive motors 124
and receives information from a label position sensor 130, which
allows system controller 110 to communicate the appropriate actions
to other portions of the printer system. An interface adapter and
power supply 128 within RFID reader subsystem 102 provides power to
RFID reader 114 and RFID antenna 106 and allows signals between
system controller 110 and RFID antenna 106 and reader 114 to be
received and transmitted.
[0027] Due in part to the small areas within a printer system,
labels 200 are brought in close proximity to RFID antenna 106
during interrogation. A label position sensor 130 senses the start
of a new label and conveys that information to system controller
110. In one embodiment, labels 200 pass within approximately 0.30
inches or less of RFID antenna 106. Thus, contrary to conventional
antennas used for RFID tag interrogation having large beam widths,
RFID antenna 106 of the present invention, according to one
embodiment, is a quarter wave resonant antenna having a free space
wavelength between approximately 12.73 inches and 13.9 inches.
[0028] FIG. 3 shows RFID antenna 106 according to one embodiment.
RFID antenna 106 is a quarter wave resonant antenna formed on a
printed circuit board assembly 300 having a rectangular shaped RF
field spreader 302 and a triangular shaped divergent RF conductor
304, both formed from copper according to one embodiment, although
other conductive materials may also be suitable. The narrow end of
divergent RF conductor 304 is connected to an RF source node
306.
[0029] On either side of RF field spreader 302 and RF conductor 304
are ground planes 308. In one embodiment, RF source node 306 is
electrically connected to RFID reader 114 by means of a coaxial
cable and a microstrip transmission line, both having a
characteristic impedance of 50 ohms. The microstrip line transports
the RF signal from the edge of the board, which is where the
coaxial cable is terminated, to the desired center connect point.
This eliminates the need to terminate the coaxial cable at the
center of the antenna, which would be difficult due to the
mechanical constraints of the printer system. In one embodiment,
the transition from coaxial cable to the microstrip transmission
line incorporates an 6 dB attenuator as part of the antenna printed
circuit board assembly 300. FIG. 3 shows the various dimensions of
RFID antenna 106 according to one embodiment. Also shown in FIG. 3
by dotted lines 310 is the outline of RFID tag assembly 208, which
moves over RFID antenna 106 along the direction of arrow 312. Note
that the length of RFID antenna 106 and positioning of label 200
allows RFID tag 202 to pass over RFID antenna 106 with RF source
point 306 closely centered relative to tag 202.
[0030] The RFID antenna used in the present invention is designed
to meet the specific requirements of the application, e.g., reading
and writing RFID tags in a small area with hundreds of RFID labels
in close proximity to each other, i.e., in a roll. In one
embodiment, the operating frequency of RFID reader 114 (from FIG.
1) is time varying (frequency hopping) between approximately 902
and 928 MHz inclusive in the ultra high frequency (UHF) band. The
frequency hopping is known and is required by regulatory agencies
such as the Federal Communications Commission (FCC) in order to
minimize interference. This frequency range has a wavelength in
free space between 13.9" and 12.73" inclusive. Other suitable RFID
frequencies include 13.46 MHz in the HF band, 860 MHz in the UHF
band, and 2.45 GHz in the UHF band.
[0031] As mentioned above, the RFID tags pass very close to the
RFID antenna (e.g., 0.3 inches). This is in sharp contrast to
conventional RFID tag antennas, which are designed to operate at
multiple wavelength distances between the RFID tag and the RFID
receiver. These conventional applications required the RFID tags to
be read at a much larger distance. Consequently, these RFID
antennas are designed for use at a distance of multiple wavelengths
of the operating frequency. However, in the present invention, the
interrogation distance as the RFID tag or label passes through the
controlled RF field radiating from the antenna is just a small
fraction of the wavelength. For example, in one embodiment where
the distance between the RFID antenna and the RFID tag is 0.25
inches and the operating wavelength is 12.73 inches, the distance
is approximately 0.02 wavelengths. In order to maximize
performance, the antenna is designed to be near resonance when an
RFID tag is in close proximity to the antenna. Furthermore, at
these close distances and speeds of up to 10 inches per second, the
RFID antenna must be able to accurately read from and write to the
RFID tag as it passes through the RF field. The close distances
also require that the RFID antenna be able to properly read from
and write to RFID tags in the presence of various metallic
structures within the thermal printer itself.
[0032] Other issues include the fact that there may be hundreds of
RFID tags or labels in a roll, all of which are in close proximity
to the RFID antenna and reader. Therefore, the RF field of RFID
antenna must be controlled so that only the RFID tag passing over
the RFID antenna is read/programmed and only the corresponding
label is printed. Interrogation with one label should not affect
any of the other RFID labels or tags, either within the roll or
outside the roll. This would require a narrow RF field pattern;
however, the RF field pattern from the RFID antenna must not be so
narrow that communication is not possible when the RFID tag is in
motion and traveling over a minimum distance of 2.5 inches. This
distance results from the physical space available in the T5000
thermal printer from Printronix and the distance between the label
position sensor 130 and the stop point of a printed label as it
waits for the user to remove the label. This allows communication
with the RFID tag while in this wait mode position. Further,
because the RF frequency is not fixed (i.e., it is frequency hopped
over 902 and 928 MHz), the RFID antenna should have broadband
characteristics in order to be efficient over the operating
frequency range. Divergent RF conductor 304 allows RFID antenna 106
to be somewhat broadband over the 902 to 928 MHz operating
range.
[0033] To achieve the foregoing requirements, RFID antenna 106 is
designed as a quarter wave resonant antenna, such as shown in FIG.
3. In one embodiment, the antenna elements are constructed on a
printed circuit board with a nominal thickness of 0.062" and a
relative dielectric constant of 4.0. A relatively high dielectric
constant material is desired to minimize the level of RF radiation
off of the back of the antenna. Backside radiation would add to the
level of reflected RF energy present inside the printer housing and
increase the possibility of accessing unwanted RFID tags. The
driven element of the antenna is made broadband by utilizing
divergent RF conductor 304 with the narrow end connected to RF
source node 306. RF field spreader 302 is provided at right angles
to the main axis of divergent conductor 304 to help spread the RF
field along the media or label path. Because it is required that
communications with the RFID tag be possible as the tag is moved
over a controlled distance, some RF field distortion relative to a
normal quarter-wave dipole is desired. This is achieved by
expanding the far end of the basic radiating element. Ground planes
306 on either side of the RF radiating element (RF conductor 304
and RF field spreader 302) are provided to minimize radiation of
unwanted RF energy. Ground planes 306 close to the radiating
element of the antenna restrain the extent of the RF field radiated
by the antenna, thereby preventing unwanted communications with
adjacent or nearby RFID tags on the roll of labels. Communicating
with nearby RFID tags may greatly reduce the accuracy of reading or
programming specific tags.
[0034] In the embodiment described with respect to and shown in
FIG. 3, RFID antenna 106 can be used in a system for interrogating
RFID tags (inlays) that are approximately 4 inches in length and
0.5 inches in width. The RF field is concentrated over this 4 inch
width and spread over about 2.5 inches of the label length.
[0035] FIG. 4 is a flow chart showing steps used during a
programming and printing of RFID label 200 according to one
embodiment. In step 400, the host computer sends print image and
tag data in one file to the printer. A counter is incremented, in
step 402, to indicate that a new tag or label is passing through
for processing. Data is then written onto the RFID tag via RFID
circuitry and the RFID antenna in step 404. The write or
programming operation is checked to determine if the data was
written correctly in step 406. If the programming operation was
successful, the label is printed in step 408, such as by a thermal
print head. However, if the programming operation was not
successful, the system determines if a certain number N of write
operations have been attempted on the specific label in step 410.
In one embodiment, N is between 1 and 5 and can be set by the user.
If the number of attempts has reached N (i.e., N unsuccessful
writes), an error is designated in step 412. The appropriate action
is then taken in step 414. In one embodiment, the user can select
one of two actions. The first action is halting operation of the
printing process until the user re-starts the process. The second
action is continuing the process by over-striking the label with an
indication that the label is defective.
[0036] If, as determined in step 410, the maximum number of
attempts has been reached, the systems attempts a re-write of the
same information on the next label in step 416. A counter for the
number of write attempts on each label is incremented in step 418,
and the programming operation is again verified in step 406.
[0037] FIG. 5 is a flow chart showing steps used during a reading
and printing of RFID label 200 according to one embodiment. In this
embodiment, the RFID label has been pre-programmed. In step 500,
the printer system is sent print image instructions and a read
command to read the RFID tag. Next, a label counter is incremented
in step 502, which counts the number of RFID labels passing through
the printer. As the RFID label passes over the RFID antenna, the
RFID tag within the label is read, in step 504. The printer system
then determines, in step 506, if the information read from the RFID
tag is what should be programmed, i.e., if there is an error with
the programming. If the data in the tag is correct, the label is
printed with image data from a thermal print head in step 508.
However, if the read operation determines, in step 510, that the
data stored in the tag is in error or cannot be read, the printer
system determines if a certain number N read attempts have been
made on the RFID label. In one embodiment, N is between 1 and 5, as
determined by the user. If there has been N read attempts, an error
in the tag is noted in step 512. Next, an appropriate action is
taken in step 514. In one embodiment, the user can select whether
the printing stops until the user re-starts the process or the
printing continues with a thermal print head over striking the
label to indicate a faulty RFID tag.
[0038] If, in step 510, the number of read attempts has not reached
N, another read operation on the RFID tag is performed in step 516.
A read counter indicating the number of read attempts on the tag is
then incremented in step 518. The information in the tag is again
checked for proper programming. Multiple read attempts allow the
printer system to designate a faulty label with a higher level of
confidence since some reads may not properly read the tag data, due
to various factors, including interference from other sources.
[0039] Labels are advanced from the roll of labels for processing
on the next RFID label. Processing continues until an end-of-label
indicator is reached, the required number of labels have been
printed, or the user halts operation, such as when a faulty label
is encountered or a job needs to be interrupted.
[0040] FIG. 6 is a block diagram showing a printer system 600 that
extracts information from a data stream, transforms or converts
portions of the data stream, if needed, and uses the portion to
program the RFID tag, while also printing the label in the normal
manner. In one embodiment, the portion is the bar code command.
Printer system 600 receives information via a data stream 602 from
a host computer 604 that includes a host application, typically
specific to the system through an electrical and software
interface. The electrical interface can be any suitable
communication means, such as, but not limited to, a serial or
parallel physical link, an Ethernet connection, or a wireless link.
The data stream contains various commands, such as line, box, font,
and bar code commands, for printing lines, boxes, text, bar codes,
and other images. The data stream is transmitted to the printer in
specific languages to cause the printer to print an image on a
label or other media.
[0041] Typically, each manufacturer uses a unique and specific
language or software interface, such as PGL (Programmable Graphics
Language used and supported by Printronix of Irvine, Calif.), ZPL
(Zebra Programming Language used and supported by Zebra
Technologies of Illinois), and IPL (Intermec Programming Language
used and supported by Intermec of Washington). To add RFID tag
programming capability to the printer, additional printer language
commands must be developed. Further, in the normal situation these
commands would have to be integrated into host software
application, at significant cost and effort, in order for the
printer to deliver programmed RFID tags. In one embodiment, the
data encapsulated in the bar code command is also programmed into
the RFID tag. In this situation, the host application need not be
modified when used in conjunction with additional software embedded
in the printer. The additional printer software detects the bar
code command from the incoming data stream and generates RFID
specific commands which include the bar code data. These in turn
are routed to the RFID system for programming into the RFID
label.
[0042] In FIG. 6, printer 600 includes a printer data control
section 606 that receives the data stream and a printer engine
control section 608 for programming and printing the RFID label.
Character substitution table 610, within printer data control
section 606, is coupled to receive the data stream from host
computer 604. Character substitution table 610 intercepts any
incoming bar code command, identifies the bar code of interest,
transmits this bar code command to a printer command parser 612 for
normal bar code printing, and in addition creates an RFID write
command to allow programming of the RFID tag. Character
substitution table 610 is a distinct software application that is
downloaded to the printer to effect the data manipulation. The data
manipulation can be diverse. In one embodiment, character
substitution table 610 pre-parses the incoming data stream to
identify the specific bar code command of interest and associated
bar code data. The bar code data is extracted from the bar code
command and applied to the RFID write-tag command. The resulting
data string is transmitted to command parser 612 for normal command
processing. The bar code command is also sent to command parser 612
according to conventional methods, as is known in the art.
[0043] Printer command parser 612 identifies the print commands and
transmits the print commands to an image formatter software module
614. Image formatter 614 processes the print commands such as to
create a bit image of the desired print format. This bit image is
transmitted to a print engine control system 616, within printer
engine control 608, which manages the printer components (e.g., the
print head, ribbon motors, platen motor and roller, sensors, etc.)
to cause a printed image to be created on the label.
[0044] In parallel with this print process, command parser 612 also
transmits the RFID specific commands to an RFID data formatting
software module 618. This module formats the RFID data (or bar code
data as was) sent with the RFID command to meet the formatting
requirements of the RFID tag. In turn, this formatted RFID data is
sent to an RFID control system 620, within printer engine control
608, which includes an RFID reader (or transceiver) capable of
programming the RFID tag embedded within the label. The reader is
attached to the antenna described above. The result is an RFID
label that has been printed with images, as well as an RFID tag
programmed with information from the data stream. This allows users
to use their existing bar code application for RFID tags without
extensive and costly modifications of the host computer application
software.
[0045] In one embodiment, this same technique can be applied to
thermal print systems that support more than one thermal printer
language. The character substitution table can be configured to
identify, for example, Zebra ZPL language bar code commands.
Converting the bar code command from the data stream into an RFID
command for programming the RFID tag can be utilized in systems
that support various programming languages, such as from Zebra,
Intermec, etc.
[0046] According to one embodiment, the bar codes can be supported
in two modes, a copy mode and a transform mode. In the copy mode,
an RFID tag with the exact information in the bar code is created,
with a possible exception of checksum data. The checksum data may
be supplied with the data or calculated by the printer. If
calculated or generated by the printer, the checksum data is not
present in the RFID tag. In the transform mode, data in the bar
code is transformed before encoding into a tag. Two types of bar
codes suitable for the invention are Integrated Two of Five (ITF)
and Code 128C, although other codes may also be used. In the
transform mode, data encoded in a bar code may be copied or
programmed directly onto an RFID tag, but not printed on the label.
This may be the application where the RFID tag data is not related
to or supplements any of the printed bar code data. Data from the
bar code may also be programmed exactly onto the RFID tag, except
for the checksum and an application identifier or other type
code.
[0047] Printer system 100 can be a standard thermal printing
system, such as the T5000 from Printronix of Irvine, Calif. The
RFID antenna and reader may simply be inserted into the existing
print system to obtain the advantages discussed above of the
present invention. Further, a simple modification of inserting a
character substitution table into the existing code of the printer
allows a printer to achieve the advantages discussed herein.
[0048] The above-described embodiments of the present invention are
merely meant to be illustrative and not limiting. It will thus be
obvious to those skilled in the art that various changes and
modifications may be made without departing from this invention in
its broader aspects. Therefore, the appended claims encompass all
such changes and modifications as fall within the true spirit and
scope of this invention.
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