Laminated radio frequency identification device

An RFID wristband incorporates identification circuitry which may be of a read only, a read/write, a passive, or an active configuration. The wristband consists of a plurality of laminae which bear components of the RFID circuitry and which encapsulate said circuitry upon the securement or adherence of said laminae to each or one another. The wristband is incorporated in an identification system particularly adapted for hospital patient identification and is associated with an RFID reader which generates a magnetic signal requesting identification from the wristband. The wristband is automatically assembled by the utilization of at least two laminae of a polymorphic flexible nature to encapsulate the RFID circuit and includes the utilization of polymeric in conductive components in said circuit. The method of assembling the RFID components with the respective laminae results in the complete isolation of the RFID circuit from contact with deleterious and corrosive substances characteristic of hospital environments.

This invention relates to a radio frequency identification device (RFID) 
which is laminated from a plurality of laminae in a continuous process and 
which is exemplified by the utilization of the resulting laminate in an 
RFID wristband or the like. Such wristbands are commonly utilized in the 
identification of individuals and the transmission of relevant information 
pertaining to said individuals to a receiver which may be a hand-held 
receiver or a master receiving and transmitting station. The RF circuitry 
is incorporated between the laminae during assembly of the laminae into a 
laminate and, as will be disclosed in greater detail below, the resulting 
laminated RF wristband is produced more efficiently and functions more 
effectively than conventional RFID tags. 
BACKGROUND OF THE INVENTION 
At the present time, identification devices, such as wristbands or the 
like, are widely used in hospitals or in crowd control situations, such as 
concerts, amusement parks, or the like, to identify patients or 
individuals and provide information regarding patients or individuals. In 
addition, such wristbands may be utilized in penal and similar 
institutions for the purpose of inmate control. 
Initially, such wristbands were confined to providing the bare minimum of 
the patient's name and, possibly, of the patient's illness. In crowd 
control situations, the wristband was utilized to indicate the 
admissibility of the individual wearing the band and, frequently, the 
duration, by color indication, of the attendance period of the person 
wearing the wristband. 
Recently, identification wristbands have been provided with encoded 
information in the form of bar codes or the like whereby considerable 
additional information about the individual wearing the wristband can be 
ascertained, including, in the case of a hospital patient, relevant data 
such as medication, the patient's condition, or the like. 
In crowd control situations, the wristbands can be utilized to provide such 
data as the amount of money or payments unexpended by the individual 
wearing the wristband. 
Thus, in amusement parks or the like, the wristband, by the use of encoded 
information, can control the admission of the individual wearing the band 
to specific attractions. As each attraction is assessed against the 
wristband, the sum of money remaining for expenditures is reduced. 
In utilizing such wristbands, various types of bar code readers are 
provided to the relevant staff which read the bar codes to determine, in 
case of patient care, therapeutic measures, such as administering 
medication or various other services for the patient. In the case of crowd 
control, such as in amusement parks, the reader charges the wristband for 
the entry to the specific attraction desired by the wristband wearer. 
While the use of bar codes or other encoded materials has constituted a 
considerable advance over prior imprinted information, once the bar code 
has been applied to the identification wristband, particularly in the case 
of a hospital patient, alteration of the information on the wristband 
entails the substitution of a new or companion band. In addition, because 
of physical limitations, the information imparted by bar codes or the like 
is necessarily limited. 
A possible solution which would overcome the limitations of identification 
wristbands which are bar-coded or provided with similar encoded imprinted 
material would be to provide an RF circuit in the wristband which would 
incorporate a semi-conductor circuit with logic, memory, and an RF circuit 
connected to an antenna capable of storing and dispensing information so 
that a staff member carrying a transponder could query the RF circuit of 
the wristband to elicit a wide spectrum of information not presently 
available in conventional wristbands. 
Unfortunately, available RF circuits are relatively expensive and, since 
conventional wristbands are disposable after use, such circuits would have 
to be discarded if they were integral components of the wristband. 
OBJECTS AND ADVANTAGES OF THE INVENTION 
An object of the invention is the provision of a wristband fabricated from 
a laminate consisting of at least two laminae and, preferably, three 
laminae wherein a tag incorporating an RF circuit is provided on one or 
more of the laminae which are formed from flexible materials such as 
polyester and low-density polyethylene. 
The respective laminae, therefore, constitute a flexible substrate for the 
tag which will, thus, be readily secured to the wrist of an individual 
utilizing the laminated wristband. 
Another object of my invention is the provision of an RF wristband which is 
constituted by three laminae, namely, a center lamina formed from 
polyester sheet material and two outer upper and lower laminae fabricated 
from low-density polyethylene sheet materials or any suitable material 
that can be laminated. 
Obviously, there are numerous methods by which the sheet materials can be 
utilized as laminae secured to one another to provide the resulting 
laminate. One of the most efficient methods involves the feeding of the 
polyester center lamina as the initial lamina. 
Another object of my invention is the provision of an article, such as a 
laminated wristband, wherein a plurality of tags are secured to a surface 
of the center laminate prior to the subsequent assemblage of the second 
and third upper and lower polyethylene laminae with the center lamina. 
A further object of my invention includes the concept of temporarily 
securing the aforesaid tags in spaced relationship on the center lamina, 
said securement being merely sufficient to locate and retain the tags on 
the center lamina prior to the assemblage process. 
A further object of my invention is the provision of a wristband in which 
the retention of the aforesaid tags in a predetermined relationship with 
the wristband is accomplished by the process of adhering the upper or 
lower lamina to the center lamina so that the tag is retained in a 
predetermined secure position in the wristband and no further means of 
securement of the tag is necessary. 
An additional object of my invention is the method of securing a plurality 
of tags in spaced relationship on one of the lamina wherein the adherence 
of the tags prior to lamination is merely sufficient to retain the tags in 
operative relationship with the lamina during the lamination process and 
the actual securement of the tags occurs when the ultimate lamination of 
the plurality of laminae occurs. 
Another object of my invention is a method of assembling a plurality of 
tags in operative, spaced relationship with the laminae of a laminate 
during the assemblage of the laminae of the laminate by inserting said 
tags between the respective laminae during the securement of the laminae 
to one another. 
Another object of my invention includes the step of depositing various 
components of the RF circuit on the laminae prior to or during the 
laminating process. Such deposition can be accomplished by various types 
of conductive or semi-conductive or non-conductive inks or conductive 
polymers to build the necessary RF circuitry. 
A related object of the invention is the provision of a wristband wherein 
one or more of the laminae incorporate printed circuitry. 
An additional object of the invention is the provision of a wristband in 
which the various elements of an RF circuit can be assembled on one of the 
laminae of a laminated wristband prior to the securement of all of the 
laminae to one another. 
Other objects and advantages of the invention will be apparent from the 
following specification and the accompanying drawings which are for the 
purpose of illustration only.

PREFERRED EMBODIMENTS OF THE INVENTION 
LAMINATED WRISTBANDS 
Referring to the drawings, and particularly to FIGS. 1-3 thereof, I show a 
laminated wristband 10 whose opposite extremities 16 and 18 are maintained 
in operative relationship with each other about an object to be 
identified, such as the wrist of a hospital patient, as best shown in FIG. 
2 by means of a fastener 20. The fastener 20 and its relationship with the 
wristband 10 are disclosed in U.S. Pat. No. 5,448,846 and reference is 
made to said patent for the operation and construction of said fastener. 
The wristband 10 is a tri-laminate wristband, as best shown in FIG. 3 of 
the drawings. It includes a top lamina 30, an intermediate lamina 32, and 
a bottom lamina 34. The laminae may be fabricated from a wide variety of 
sheet materials such as polyester, low-density polyethylene and the like. 
In this case, the top and bottom laminae 30 and 34 are fabricated from 
low-density polyethylene and the intermediate or middle lamina 32 is 
fabricated from polyester resin. 
There is a wide variety of methods of fabricating laminated wristbands such 
as the wristband 10, but the preferred method is providing rolls of sheet 
plastic material which are dispensed synchronously and are ultimately 
secured to one another by glue or other expedients. In the manufacture of 
the wristband 10, the intermediate lamina 32 is initially dispensed from 
its roll and the top and bottom laminae 30 and 34 are subsequently secured 
thereto. After being so secured, the laminated sheets are subjected to the 
formation of a plurality of wristbands by the utilization of scoring dies 
or the like. 
As the resulting laminate issues from the lamination site, it is rolled 
upon a collection roll from which it is subsequently dispensed to permit 
the severance of the wristbands from one another. In some cases, the 
wristbands are permitted to remain in sheet form, roll form, or individual 
sheets and are shipped to the ultimate user in that configuration. 
Conventionally, when an identification wristband is prepared for 
application to, let us say, the wrist of a hospital patient, the basic 
information about the patient, namely, his name, hospital identification 
number, and the like, are imprinted upon the top lamina and a bar code 40 
is also imprinted upon the top lamina 30 which contains other relevant but 
limited information relating to the patient. 
Once the wristband 10 is installed on the wrist of a patient, the imprinted 
information on the top lamina 30 is consulted by the nurse or other 
attendant ministering to the needs of the patient. Anyone familiar with 
present-day hospital procedures has observed that the imprinted materials 
on the upper lamina 30 of the wristband 10 are, frequently, hard to read 
and partially obliterated due to frequent handling during the patient's 
stay in the hospital. Additionally, visual comparisons are frequently 
hurriedly made in dim light and confined quarters all contributing to the 
possibility of mistakes upon the part of the attendants. 
In addition to tri-laminate wristbands like the wristband 10 of FIGS. 1-3, 
bi-laminate wristbands are provided which are frequently manufactured from 
vinyl sheet material or the like with the wristband configurations being 
incorporated in the sheets by heat stamping or the like. It is possible to 
incorporate the teachings of the invention in bi-laminate wristbands, but 
the use of tri-laminate wristbands is preferred because of the increased 
strength of the tri-laminate wristbands and various other structural and 
operative advantages thereof over bi-laminate wristbands. 
LAMINATED WRISTBAND/RFID CIRCUITRY ASSEMBLY 
The broad concept of the invention is that one or more laminae will have 
one or more components of an RFID circuit assembled thereupon or imprinted 
thereupon or connected thereto during the fabrication of the wristband by 
the securement of the respective top, intermediate, and bottom laminae to 
one another. For instance, the assemblage of a totally pre-fabricated tag 
50 is shown in FIG. 4 of the drawings with the tag 50 being secured to the 
intermediate lamina 32 of the wristband 10. 
The temporary securement of the tag 50 to the upper or lower surface of the 
intermediate lamina 32 is accomplished prior to the initiation of the 
assembly process for the laminae of the wristband 10. One or more tags 50 
are temporarily secured to the upper or lower surface of the intermediate 
lamina 32 by a dot of glue or the like, since the intent is not to achieve 
permanent securement of the tag 50 to the respective surface of the lamina 
32 but merely to insure that the tags 50 will be carried on the 
intermediate lamina 32 to the point at which the tags 50 can be enshrouded 
in the desired location on the intermediate lamina 32 by the overlying top 
lamina 30 or, conversely, the bottom lamina 34, as illustrated in FIG. 5 
of the drawings. This method of assembly relies upon the permanent 
location of the tag 50 in the wristband 10 by the action of the respective 
upper or lower lamina 30 or 34 as it is secured to the intermediate 
laminate 32 upon which the tag 50 has been previously deposited. 
In another assembly method, the tag 50 is deposited on the intermediate 
lamina 32 immediately prior to the assemblage of the top lamina 30 with 
said intermediate lamina. 
The deposition of the tags 50 on the intermediate lamina 32 can be 
accomplished by automatic dispensing heads located in proximity to the 
line of traverse of the laminae of the wristband during the assembly 
process. The deposition of the tags 50 can be accomplished from an 
overhead, drop-down arrangement or by a transverse shuttle which feeds the 
tags 50 from the side of the path of movement of the laminae 30, 32, and 
34. 
In contradistinction to the utilization of a totally integrated RFID 
circuit, such as the tag 50, it is also possible to provide for the 
deposition of separate components of the circuit in conjunction with other 
components which may be imprinted, foil-deposited, wire-deposited, or the 
like. 
Illustrative of the combination of prefabricated RFID circuitry with 
portions of the RFID circuit which are imprinted or otherwise provided on 
a surface of the intermediate lamina 32 is the showing of FIG. 6 wherein 
all of the components 60 of an RFID circuit are provided on a surface of 
the lamina 32 with a separate antenna 62, said antenna being fabricated 
from foil or the like or being imprinted upon the surface of the 
intermediate lamina 32. The antenna is operatively connected to bumps or 
pads on the housing 64 of the RFID circuitry components. 
Once again, the entire assemblage of circuitry 60 and antenna 62 can be 
accomplished by applying a multiplicity of such combinations to the 
respective surface of the intermediate lamina 32 prior to the dispensing 
of the lamina 32 from its roll in conjunction with the upper and lower 
laminae 30 and 34. 
On the other hand, the imprinting of the antenna 62 can be accomplished 
prior to the assemblage of the respective laminae 30, 32, and 34 with the 
other RFID components being assembled with the antenna during the 
assemblage of the laminae 30, 32, and 34. 
It is well known to those skilled in the art that RFID circuitry of the 
type under discussion is provided in a plurality of configurations; for 
example, read only, read/write, passive, and active. The read only 
provides previously installed information from the RFID circuit through a 
compatible reader. The read/write circuit permits the reader to install or 
alter information stored in the circuit. The passive circuit is one which 
depends for activation and operating power upon the signal emitted by the 
reader while the active circuit includes a battery or other internal power 
source which may be activated by the signal from the reader. 
A read/write RFID circuit is disclosed in FIGS. 7-10 of the drawings as 
including a silicon tag 70 and di-pole antennae 72, said di-pole antennae 
being fabricated by a wide variety of procedures such as wire 
implantation, foil securement, conductive ink imprinting, and the like. 
The installation of the antennae and associated circuit can be accomplished 
by various means, equipment, and at the times referred to hereinabove in 
discussing previous embodiments of the invention. The top lamina 30 has a 
bar code 65 and additional readable information 66 disposed on the upper 
surface thereof while the bottom lamina is secured to the underside of the 
intermediate lamina 32. The read/write RFID circuit is shown in FIG. 10 as 
including the antennae 72, a power converter 74, control logic 76, NV Ram 
78, and de-modulation and modulation circuitry 82. 
As best shown in FIGS. 11-13 of the drawings, an alternative RFID 
read/write circuit 90 can be utilized to impart and receive the 
information which is required of the particular situation that a laminated 
wristband is capable of providing by the use of an appropriate reader, not 
shown. 
The circuit 90 is intended to be utilized in a tri-laminae wristband and to 
be installed on the top and bottom surfaces of the intermediate lamina 32. 
The circuit 90 includes a conductive plate 92 which is applied to the 
upper surface of the lamina 32 and may be in the form of a foil applique, 
imprint, or the like and functions as one side of a first capacitor 
circuit. An RFID chip 94 is secured to the upper surface of the lamina 32 
in juxtaposition to the plate 92 and is connected thereto by a conductor 
96. The chip 94 is electrically connected to the chip terminals 98 and 102 
by the utilization of conductive ink, foil, or other means. The electrical 
connection may be made by conductive adhesive, ultrasonic weld, solder 
bump, or the like. 
The conductor 96 connects the chip terminal 98 to the plate 92 which has a 
significant surface area and forms one side of a capacitor circuit. 
The conductor 103, electrically connected to the terminal 102 of the chip 
94, is deposited in a spiral pattern 104 on the top surface of the lamina 
32. This spiral pattern forms an inductor coil 106. The other side of the 
coil 106 is connected to a conductive plate 108 which forms one side of a 
second capacitor circuit. 
Formed on the bottom surface of the lamina 32 in essentially the same 
manner as the circuit on the top surface of the lamina is a plate 92' 
which completes the first capacitor circuit with the plate 92 on the top 
of the lamina 32. The plate 92' is connected at one end of a spiral coil 
106' which, in turn, is connected to a plate 108' which establishes the 
second capacitor circuit with the plate 108. 
Consequently, two capacitor circuits are provided: the first circuit 
constituted by the plates 92 and 92' and the second circuit constituted by 
the plates 108 and 108'. 
When the circuits incorporating the capacitor plates 92/92' and 108/108' 
are imprinted or otherwise formed upon the upper and lower surfaces of the 
substrate constituted by the centrally-located lamina 32, they are 
positioned in overlying relationship with one another so that the 
aforesaid capacitor circuits may incorporate the dielectric capacity of 
the plastic material utilized in forming the substrate constituted by the 
lamina 32. 
When the respective components on the top and bottom of the lamina 32 are 
juxtaposed in the manner suggested hereinabove, they form an electronic 
circuit connecting the antenna terminals of the RFID chip to a network 
consisting of two inductors and two capacitors. In this embodiment of the 
invention, the turns of the top and bottom spirals are wound in the same 
direction. Consequently, the top and bottom inductor patterns form an 
inductive antenna to receive and transmit electromagnetic signals to and 
from an RFID reader. 
Shown in FIG. 13 of the drawings is a series resonant L-C circuit 90 
electrically connected to the antenna terminals 98 and 102 of the chip 94. 
Therefore, the circuit, operating with equivalent circuit values 
corresponding to the dimensions in geometry of the structures on the 
opposite surfaces of the lamina 32 would be operated at the resonant 
frequency of the equivalent circuit. 
A schematic view of the assemblage of an RFID circuit in the bi-laminae 
wristband is shown in FIG. 14 of the drawings wherein an upper lamina 30 
of sheet plastic material is drawn from a dispensing roll 120 between 
circuit-imprinting means 122 and a back-up roll 124. The 
circuit-imprinting means 122 may be composed of a plurality of different 
imprinting devices which result in the formation of a complete circuit. 
The RFID circuit (not shown) is printed on the underside 123 of the upper 
lamina 30 and the upper lamina 30 is fed to a laminating station 126 where 
it is adhesively or otherwise fastened to the lower lamina 32 drawn from a 
dispensing roll 130. A back-up roll 132 supports the assemblage during the 
final fabrication of the wristband 10. 
A tri-laminae assembly apparatus is shown schematically in FIG. 15 of the 
drawings as including a dispensing roll 140 for plastic sheet material for 
an intermediate lamina 32 which is entrained upon a guide roll 142. An 
imprinting means 144 imprints the RFID circuitry on the upper surface 146 
of the intermediate lamina 32 which is supported during the imprinting 
process by a back-up roller 138. 
If desired, downstream from the imprinting apparatus 144, a supplemental 
apparatus can be located under the lamina 32 to provide supplemental 
circuitry to that deposited by the imprinting apparatus 144. 
After the imprinting process has been completed, the top lamina 30 and 
bottom lamina 34 are drawn from supply rolls 152 and 154 into an assembly 
station 156 where they are sealed into encompassing and encapsulating 
relationship with the intermediate lamina 32. 
The mutual communication between the RFID reader 160 and the wristband 10 
is illustrated in FIG. 16 of the drawings. Initially, the RFID circuitry 
of the wristband is programmed to provide identifying and other 
information and the reader is capable of eliciting such information from 
the RFID circuitry of the wristband. In a read/write configuration of the 
circuitry of the wristband 10, the reader may also impart information to, 
alter information on, or delete information from the wristband 10. 
Although I have described specific exemplifications of the assemblage and 
construction of the wristband and of the RFID components associated 
therewith, it will be obvious to those skilled in the art that alternative 
configurations may be utilized which will still fall within the scope of 
the invention.