Hidden entry system and use thereof

A hidden entry system comprises a document having a localized coating of a non-pressure sensitive heat activated autogenous chromogenic composition to provide a latent image which reveals hidden indicia when heated at moderate temperatures. The hidden entry system is especially useful for contests and promotional forms. Quickly striking the chromogenic composition with a fingernail or blunt object converts the latent image to a visible colored image by frictional heat. The chromogenic composition contains a chromogenic compound and a color developer which are non-pressure sensitive and non-reactive at room temperature. The latent image can be provided by an intimate mixture of the chromogenic compound and the developer or alternatively, one component can be printed on a separate layer or coating of the other component.

CROSS-REFERENCE TO RELATED APPLICATION 
Reference is made to co-pending application Ser. No. 07/987,710 entitled 
"Heat Sensitive System and Use Thereof" to John C. H. Chang filed of even 
date, the disclosure of which is hereby incorporated by reference. 
FIELD OF THE INVENTION 
The present invention is directed to a hidden entry system for maintaining 
information hidden until utilized by the intended person. More 
particularly, this invention relates to documents having a localized heat 
sensitive chromogenic coating that can be activated by heat to produce 
visible colored indicia. 
BACKGROUND OF THE INVENTION 
Various methods have been proposed for preparation of sweepstakes contest 
awards, lottery tickets, promotional game cards, premium cards, and the 
like, containing hidden entries, such as numerals, messages, symbols, or 
the like, which can be revealed to the recipient by various means. 
For example, U.S. Pat. No. 4,726,608 to Walton discloses the use of an 
opaque coating over hidden indicia. The image of the indicia is later made 
visible by scratching off the opaque coating or by applying a solvent to 
disperse the coating. This system has the disadvantages of either 
requiring extraneous solvents or producing unwanted dust. 
Co-pending U.S. application Ser. No. 07/987,710 to John C. H. Chang 
entitled "Heat Sensitive System and Use Thereof" filed on even date 
herewith, the disclosure of which is hereby incorporated herein by 
reference, discloses a heat sensitive chromogenic system in the production 
of documents to prevent unauthorized or fraudulent use of a xerographic 
color copier for reproduction of negotiable instruments, such as checks, 
money orders and the like. When, for example, a check bearing the heat 
sensitive chromogenic coating in a verification thereof is presented for 
payment, the bank teller can simply apply heat to the verification area, 
and if a visible image symbol appears in the verification area, the teller 
will know that the check is an original. 
SUMMARY OF THE INVENTION 
A hidden entry system has now been discovered which can be used to provide 
hidden indicia on a document used, for example, in a contest or promotion, 
such as sweepstakes contest awards, lottery tickets, premium cards, 
promotional game cards, or the like, to hide indicia, which system 
comprises a support having an information area bearing a localized coating 
of a heat activatable chromogenic composition, said localized heat 
activatable chromogenic coating providing a latent image of indicia which 
is convertible to a visible colored image by application of heat. 
Surprisingly, it has been found that by using a localized coating of a 
non-pressure sensitive, heat activatable chromogenic composition for 
revealing hidden indicia in, for example, a sweepstakes award, premature 
revelation of the hidden indicia by pressure is avoided. Moreover, 
production of unwanted dust or debris or use of extraneous solvents is 
avoided, since activation of the chromogenic coating is effected by 
application of heat. 
According to one embodiment of the present invention, the hidden indicia 
can be revealed simply by applying frictional heat to the chromogenic 
coating, such as by quickly rubbing or striking a human fingernail across 
the latent image indicia, to form visible colored indicia, whereby the 
chromogenic composition is activated by frictional heat. The expression 
"strike" as used in the present application is in the sense that one 
strikes a match across a rough surface to generate frictional heat. In the 
present invention, striking or quickly moving the human fingernail or 
other frictional heat generating stylus across and in contact with the 
chromogenic composition generates sufficient frictional heat to cause 
visible color formation. 
According to another embodiment of the present invention, heat is applied 
to the chromogenic coating by means of a radiant or convective heat 
source, such as the heat emanating from an ordinary light bulb used for 
reading, for example, a 100 watt light bulb, or from a hand-held electric 
hair dryer, to cause visible indicia formation in the chromogenic 
composition. Likewise, heat can be directly applied by conduction using an 
electrically or otherwise heated element such as a flat metal plate 
having, for example, a rectangular shape the shape and size of the 
information area. 
In a preferred embodiment of the present invention, the heat activatable 
chromogenic composition comprises a color forming chromogenic compound and 
a color developer material. In an especially preferred embodiment of the 
invention, a heat fusible material is also included in the chromogenic 
composition to lower the melting point of the color developer material. 
Preferably, the color developer material is a normally solid, acidic 
organic compound having a melting temperature between about 40.degree. C. 
and about 200.degree. C. so that the developer will melt or soften 
sufficiently by frictional heat or heat supplied by a relatively low heat 
generating device, such as an electric light bulb or hair dryer, to react 
with the chromogenic compound to produce a visible colored image. The 
latent image indicia can be made visible by applying heat, for example, by 
quickly rubbing or striking a fingernail, paper clip, coin, pen or other 
implement across the chromogenic composition to produce sufficient 
frictional heat, or by applying convective, radiant or conductive heat to 
the verification area to produce the visible colored image. 
According to a preferred embodiment of the present invention, the 
chromogenic composition comprises a first layer comprising a latent image 
indicia, such as the numerals "123456" formed of the color developer 
material printed over a layer or coating including the chromogenic 
compound. Alternatively, the latent image can be printed using the 
chromogenic compound on a coating or layer of the color developer material 
to form the heat activatable latent image indicia. By applying heat, e.g., 
frictional heat, to the chromogenic composition, the chromogenic compound 
and the color developer react to produce a visible, colored image in the 
form of the numeric indicia, for example. 
According to a further embodiment of the invention, the hidden entry system 
comprises a support bearing the chromogenic composition in the form of an 
autogenous mixture of solid particles of the chromogenic compound and the 
color developer material printed on the support to provide latent image 
indicia. Preferably, a fingernail or blunt instrument having a low heat 
conductivity is rubbed or struck quickly across the latent image to 
produce sufficient heat to provide a visible colored image of the indicia. 
According to another embodiment of the present invention, the information 
area may be treated to conceal the latent image indicia. Despite use of 
the present colorless or chromogenic hidden entry system, light reflection 
can reveal the latent image indicia. According to this embodiment of the 
invention, the latent image indicia is coated with a thin coating 
comprising pigment in a binder which conceals the latent image without 
substantially reducing frictional heat activatable color development nor 
frictional heat activation characteristics of the chromogenic composition. 
Alternatively, concealment of the latent image of the chromogenic coating 
may be accomplished by dot printing the information area using 
conventional printing inks in any color other than that of the latent 
image. Since the chromogenic coating is colorless, application of the thin 
pigmented coating or dot printing may be accomplished prior to application 
of the chromogenic coating, if desired. 
As used in the present application, the term "indicia" is used to include 
any number, letter or symbol in a general sense. 
Other objects, advantages and salient features of the present invention 
will become apparent from the following detailed description, which, taken 
in conjunction with the annexed drawings, discloses preferred embodiments 
of the invention.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings, FIG. 1 illustrates a hidden entry system in 
combination with document 10. 
The term "document" as used herein is intended to include any type of 
document or paper used to secret indicia until it is desired to reveal 
such indicia, including lottery tickets, sweepstakes, raffles, prizes and 
awards. 
In the embodiment illustrated in FIG. 1, document 10 is a sweepstakes award 
having an information area 12 comprising a localized coating of a 
chromogenic composition 14. A chromogenic compound is formed into a 
colorless ink and printed to form, as combination 16, numerals "1234", as 
latent image indicia on the information area 12. Of course, any indicia, 
including alphanumeric, symbols or design indicia may be imprinted in lieu 
of the numerals 16. A localized coating 18 comprising a color developer is 
then coated over the chromogenic compound-printed numerals 16 to form the 
image-forming chromogenic coating 14. In alternative embodiments, the 
color developer may be applied as the printed latent image message 16 
followed by the chromogenic compound as coating 18 according to the 
process described in U.S. Pat. No. 4,425,386 to Chang. The color reactants 
may be dissolved or dispersed in a vehicle such as a printing ink base, 
and the resulting solution printed onto the substrate. Although color 
developer may be printed to form the latent image, it is generally 
preferred to produce the latent image from the chromogenic compound. 
The chromogenic compound in preferred embodiments is colorless before 
reacting with the color developer to produce the colored image. Suitable 
chromogenic compounds include diarylmethanes, triarylmethanes, 
indolylphthalides, azaphthalides, fluorans, and spiropyrans. Exemplary 
diarylmethanes include 4,4'-bis(dimethylaminobenzhydrylbenzyl)ether, 
N-halophenyl leuco auramine, and N-2,4,5-trichlorophenyl leuco auramine. 
Examples of triarylmethanes include 
3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide and 
3,3-bis(p-dimethylaminophenyl)phthalide. Examples of indolylphthalides 
include 3-(p-dimethylaminophenyl)-3-(1,2-dimethylindole-3-yl)phthalide and 
3-(p-dimethylaminophenyl)-3-(2-methylindole-3-yl)phthalide. Examples of 
azaphthalides include 
3-(2-ethoxy-4-diethylaminophenyl)-3-(1-octyl-2-methylindole-3-yl)-4-azapht 
halide and 
3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azapht 
halide. Examples of fluorans include 2-dibenzylamino-6-diethylaminofluoran, 
2-anilino-6-diethylaminofluoran, 3-methyl-2-anilino-6-diethylaminofluoran, 
2-anilino-3-methyl-6-(ethyl-isopentylamino)fluoran, 
2-anilino-3-methyl-6-dibutylaminofluoran, 
2-chloro-3-methyl-6-diethylaminofluoran, 3,6-dimethoxyfluoran, and 
7,7'-bis(3-diethylaminofluoran). Examples of spiropyrans include 
3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 
3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, and 
3-methylnaphtho-(3-methoxybenzo)spiropyran. 
The preferred color developers are acidic compounds which have melting or 
softening points of about 40.degree. C. to about 200.degree. C. In 
preferred embodiments of the invention, the lower melting point developers 
having melting or softening points preferably from about 40.degree. C. to 
about 140.degree. C., with a range of from about 50.degree. C. to about 
80.degree. C. being especially preferred, so that the colored image is 
easily formed by applying frictional heat or similar low temperatures. The 
developer melting point should, however, be sufficiently high to avoid 
melting and thus premature activation and formation of the colored image 
during drying of the coating, shipping and handling of the document. 
Examples of useful color developers include: 4,4'-isopropylidenediphenol, 
4,4'-isopropylidene-bis(2-tertbutylphenol), 4,4'-sec-butylidenediphenol, 
2,2'-methylene-bis(4-chlorophenol), phenol-formaldehyde novolak resin, 
alpha-naphthol, beta-naphthol, p-hydroxybenzyl benzoate, 
3,5-dimethyl-4-hydroxybenzoic acid, 3-isopropylsalicylic acid, 
3-benzylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 
1,5-di(4-hydroxyphenylthio)-3-oxapentane, 
4-hydroxy-phenyl-4'-isopropoxyphenylsulfone, bis(3-allyl-4-hydroxyphenyl) 
sulfone, 4,4'thiodiphenol, and 3,3'-dimethyl-4,4'thiodiphenol. 
The proportions of chromogenic compound and color developer in the coating 
varies according to the required color density of the image. Generally, 
about 1 to 50 parts by weight, and preferably about 1 to 10 parts by 
weight, of color developer is used per part by weight of chromogenic 
compound to produce a colored image with sufficiently sharp contrast to 
readily distinguish the colored image from the principal image. If 
desired, however, the colored image may be the same as the principal 
image, i.e., other printed matter on the document. 
When the color developers have a high melting point, a heat-fusible 
material may be used in the chromogenic composition to lower the 
activation point or temperature of the color developer to facilitate the 
color development. Exemplary heat-fusible materials include stearic acid 
amide, stearic acid methylene bisamide, oleic acid amide, palmitic acid 
amide, coconut fatty acid amide, monoethanolamide of fatty acid, dibenzyl 
terephthalate, p-benzyl biphenyl, beta-naphthol benzyl ether, ethylene 
glycol-m-tolyl ether, di(p-chlorobenzyl) oxalate, and di(p-methylbenzyl) 
oxalate. 
The chromogenic coating composition may also contain one or more inorganic 
or organic fillers, such as kaolin, talc, titanium dioxide, calcium 
carbonate, magnesium carbonate, barium carbonate, aluminum hydroxide, zinc 
oxide, silicone oxide, urea-formaldehyde resin, styrene-methacrylic acid 
copolymer, polystyrene resin, polycarbonate resin, polypropylene resin. 
The amount of filler used may vary depending on the chromogenic compound, 
developer and support material. The filler material is included as an 
extender material to reduce the amount of chromogenic compound and 
developer used and may be used to enhance the film-forming qualities of 
the chromogenic coating. The amount of filler material incorporated into 
the chromogenic coating composition should not substantially interfere 
with the development of the colored image. 
A suitable binder material is needed to adhere the chromogenic compound and 
the color developer onto the substrate. The amount of binder generally 
used is about 10% to about 50% by weight, and preferably about 15% to 
about 35% by weight, based on the total weight of the solids of the 
coating composition. Examples of useful binders include starch, 
hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, 
gelatin, casein, gum arabic, polyvinyl alcohol, styrene-maleic anhydride 
copolymers, ethylene-acrylic acid copolymers, styrene-butadiene 
copolymers, acrylonitrile-butadiene copolymers, vinyl acetate emulsions, 
ethylene-vinyl acetate emulsions. 
The heat activatable chromogenic composition of the present invention may 
optionally additionally contain a color suppressant to prevent premature 
coloration. The color suppressant must be so chosen that it will not 
inhibit or adversely affect the color formation in the final product. 
Examples are ammonium hydroxide, alkanolamines, such as monoethanol amine, 
diethanolamine, N, N-dimethylethanolamine, and the like, condensates of 
amine-formaldehyde, such as urea-formaldehyde, melamine-formaldehyde, and 
the like. Suitable amounts of such color suppressants include from about 
0.1 to about 10, preferably from about 0.5 to about 4 percent by weight 
based on the total dry weight of the coating composition. Other suitable 
color suppressants are disclosed, for example, in U.S. Pat. Nos. 4,010,292 
and 4,170,483, which are hereby incorporated by reference. 
The chromogenic coating composition may be prepared by a number of methods 
as known in the art. A preferred method of preparing the coating 
composition is to disperse one or more of the reactants into a volume of 
water as a dispersing medium. The reactants are generally ground for about 
one hour to a particle size of about 1 to 10 microns in diameter. The 
reactants may be ground in the presence of dispersants or binders. 
Examples of suitable dispersants include sodium dioctylsulfosuccinate, 
sodium dodecylbenzene sulfonate, alginates and fatty acid metal salts. The 
binder material may also function as a protective colloid to disperse the 
reactants. The chromogenic compound and the color developer may be mixed 
together and applied as one coating or prepared as separate coating 
compositions and printed or applied in layers as discussed hereinafter in 
greater detail. The reactants are then ground or pulverized in a suitable 
device such as, for example, a ball mill, sand mill or attritor. 
The information area comprising the localized coating of a chromogenic 
composition may be treated so as to conceal location of the latent image 
message, since light reflection can reveal location of the message of the 
verification system. Thus, the latent image message can be coated with a 
thin coating comprising pigment in binder which conceals the latent image 
message without substantially reducing heat activated color development or 
heat activation characteristics of the chromogenic coating. A suitable 
coating may comprise, for example, inorganic fillers, such as calcium 
carbonate, titanium dioxide, talc, clay, or the like, in a polyvinyl 
alcohol solution. The thin coating provides the same texture to the 
support as the coating forming the latent image message and, thus, 
effectively conceals the message. Alternatively, concealment of the latent 
image message of the chromogenic coating may be accomplished by dot 
printing the latent image message or the entire surface of the document 
including the verification area using conventional printing inks in any 
color other than that of the latent image. Since the chromogenic coating 
is colorless, the pigmented coating or dot printing may be applied either 
prior to or after application of the chromogenic coating to the substrate. 
The chromogenic coating composition is applied to the substrate, for 
example, paper, plastic, or the like, which forms the document by any 
suitable technique as known in the art. The entire substrate may be coated 
although in preferred embodiments a localized, spot or band coating is 
used. The coating may be coextensive with just the information area or may 
be extended into principal image areas, if desired, since the coating is 
non-pressure sensitive and not affected by the pressure applied when the 
document is printed to supply additional information. In one embodiment of 
the invention, the chromogenic coating composition is prepared as a slurry 
comprising the chromogenic compound and the color developer. A preferred 
method of coating is by off-set gravure coating as disclosed in U.S. Pat. 
No. 4,425,386 to Chang which is hereby incorporated by reference. 
Alternative preferred coating methods include flexographic, screen 
printing, nozzle extrusion and ink jet printing. 
Preferably, the chromogenic coating material is activated by quickly 
rubbing a blunt implement across the information area to generate 
sufficient frictional heat to produce a colored image. For convenience, a 
suitable implement may be a fingernail rubbed quickly across the 
verification area to generate frictional heat and produce a colored line. 
Other implements which may be used include a non-writing end of a pen, a 
stylus, paper clip, coin and the like. Generally, metal objects are not as 
effective in producing a colored image since the metal conducts the 
frictional heat quickly away from the point of contact and has a lower 
friction coefficient than many other objects. Thus, a fingernail or 
plastic object is generally preferred. 
Referring again to FIG. 1, the hidden entry system of the present invention 
is activated by applying frictional heat, such as by quickly rubbing the 
verification area with a fingernail as illustrated in FIG. 2, or other 
blunt object. A single stroke across and in contact with the chromogenic 
composition 14 will supply sufficient frictional heat to cause the 
chromogenic compound latent image 16 to react with overlying color 
developer 18 and partially convert the latent image 18 to a visible 
colored image in the form of colored segments 20 as shown in FIG. 2. 
Applying repetitive strokes across composition 14 will cause the entire 
visible image 22 to develop as shown in FIG. 3. 
Information area 12 in the embodiment of FIG. 1 is positioned in the lower 
center of the front face of the sweepstakes document. It is to be 
understood that the information area 12 comprising chromogenic composition 
14 may be located in any position or area on the document and that 
multiple localized coating of such chromogenic compositions may be present 
on the front of the document and on both the front and back of the 
document, as desired. 
In the embodiment of FIG. 1, latent image 16 is in the form of numerals. In 
alternative embodiments, the latent image can be, for example, a business 
logo, design, diagram, serial number, winning number, combinations of 
numbers and letters, or other indicia. 
Referring now to FIG. 4, a sweepstakes document 30 is shown having 
information area 32. A red color-yielding autogenous mixture of 
chromogenic compound and color developer is coated onto information area 
32 as localized or spot coating 33. Latent image 34 is provided in 
information area 32 by printing a black color yielding mixture of the 
chromogenic compound and color developer onto the coating 33, thereby 
providing a localized, autogenous, heat activatable latent image coating 
34 in the form of numerals "5678". While the latent image of indicia of 
FIG. 4 may be activated by frictional heat, any suitable means for 
applying sufficient heat, whether frictional or otherwise, can be used to 
heat the black and red-yielding chromogenic compositions and produce 
visible colored images. The heat providing means should be capable of 
heating the chromogenic composition to a temperature of between about 
40.degree. C. to 200.degree. C., preferably between about 40.degree. C. or 
50.degree. C. to about 110.degree. C. or 140.degree. C., with between 
about 50.degree. C. and about 80.degree. C. being especially preferred. 
Thus, latent image 34 of FIG. 4 is activated and converted to black 
visible image 38 while coating 33 is activated and converted to red 
visible image 39 in FIG. 5 using heat supply 40 which may include, for 
example, heat sources such as ordinary electric light bulbs, for example, 
80-150 watt bulbs, hand-held electric hair dryers, or the like. Similarly, 
a heated metal element, such as a flat plate-like element for direct 
application of heat to the latent image, could be used. 
If a fingernail were quickly drawn across the coating of FIG. 4 to supply 
frictional heat in the manner of FIG. 2, the visible portions of the 
numerals 34 would appear red, and the visible portions of the background 
would appear black, yielding a visible line with red and black segments. 
Although the embodiment of FIGS. 4-5 use two autogenous coatings to provide 
colored indicia with a contrasting colored background, it is understood 
that coating 33 in FIG. 4 could be omitted such that only the black 
indicia 38 would appear upon heat activation in FIG. 5 with no red 
background 39, if desired. In such event, each numeral "5, 6, 7 and 8" in 
FIG. 4 would constitute a localized autogenous coating of a heat 
activatable chromogenic composition providing a latent image of indicia. 
In preferred embodiments, the color developer has a melting or softening 
point of about 40.degree. C. to about 200.degree. C., preferably from 
about 40.degree. C. or 50.degree. C. to about 110.degree. C. or 
140.degree. C., especially 50.degree. C. to about 80.degree. C., so as not 
to react with the chromogenic reactant at room temperature. Application of 
heat at temperatures in the range of 40.degree. C. to about 200.degree. C. 
softens or melts the developer rendering it sufficiently mobile to mix and 
react with the chromogenic compound and produce the distinct visible 
colored image in situ. Since the reactants are solids at room temperature, 
no physical separation of the reactants is necessary in the coating. The 
reactants can be mixed together as a slurry and coated on the document to 
form an autogenous latent image. The chromogenic coating is activated by 
heat and the coating is non-pressure sensitive. 
To have an eye catching result to reveal award information, for example, it 
is desirable for the autogenous chromogenic coating to present a striking 
color contrast to other printed matter on the document. For example, the 
autogenous latent image can be heated to yield red, violet, orange, green, 
blue, or yellow to obtain a high degree of contrast. Alternatively, the 
developed color can be coordinated with the requirements of the 
institution circulating the document, and may be, for example, the same 
color as the printed matter on the document. Of course, in the case of a 
form used for a sweepstake award, or the like, highly contrasting colors 
can be used, and multiple autogenous chromogenic coatings each producing a 
different colored visible image can be used in the information area. 
When the present invention is used to provide lottery tickets or 
sweepstakes awards, for example, the latent image indicia of the hidden 
entry system of the present invention will normally be a numerical 
sequence on each ticket or form which varies from form to form depending 
upon the number of winners in each category, for example. 
Referring now to FIG. 6, form 110 comprises a plurality of sweepstakes 
award forms 112, 114, 116 separated by perforated lines 118. Each 
individual form has sequences of predetermined indicia printed thereon 
with the heat activatable chromogenic composition to form latent images 
122 of indicia, in which at least a portion of the forms have sequences of 
latent image numbers which differ from form to form or ticket to ticket. 
Latent image 122 may be formed from, for example, an autogenous mixture of 
red color producing chromogen and color developer. Likewise, latent image 
122 may be printed from a chromogen followed by a coating 124 of a color 
developer, as desired. The forms are joined end to end for easy passage 
through a computer printer adapted to print varying sequences of latent 
image numbers with the heat activatable chromogenic composition of the 
present invention. The forms are then separated and mailed or otherwise 
distributed as desired. 
The invention will be further illustrated by the following example. It 
should be understood that it is not intended to limit the scope of this 
invention. 
EXAMPLE 
A chromogenic composition is prepared from a mixture of 25 grams of 
7,7'-bis(3-diethylaminofluoran) and 85 grams of calcium carbonate in 275 
grams of a 10% aqueous polyvinyl alcohol solution. The mixture is ground 
in an attritor for one hour to reduce the size of the particles and 
produce a dispersion. 
A color developer is produced by mixing 80 grams of 
4-hydroxy-4'-isopropoxyphenylsulfone and 20 grams of dibenzyl oxalate in 
250 grams of 10% polyvinyl alcohol aqueous solution. The mixture is ground 
in an attritor for one hour to reduce the particle size of the components 
and produce a dispersion. 
An autogenous chromogenic coating composition is prepared by mixing equal 
parts by weight of the chromogenic dispersion and the color developer 
dispersion, which could be printed. A spot is then coated on a document 
and allowed to dry. Striking the coating with a fingernail immediately 
produces a red-colored line. 
Although the invention has been described with a certain degree of 
particularity, it is understood that the present disclosure has been made 
only by way of example and that numerous changes in the details of 
construction and the combination and arrangement of parts may be resorted 
to without departing from the spirit and scope of the invention. Thus, the 
scope of the invention should not be limited by the foregoing 
specification, but rather, only by the scope of the claims appended hereto 
.