Method and arrangement for alerting customers from purchasing perished items using bar codes with changeable properties when subjected to factors causing perishability

Retail establishment customers are prevented from unwittingly purchasing perishable items that may have been adversely affected by being subjected to at least one predetermined factor in that an identification object, such as a label, tag or packaging material, is provided with an initially machine-scannable bar code of such a character that its scannability is at least gravely impaired when the identification object is subjected to the predetermined factor. The identification object is secured to the respective item for both of them to be subsequently exposed to the same conditions such that a failed scan of the bar code occurring at the time of purchase alerts the customer to a previous occurrence among such conditions of the predetermined factor that may have adversely affected the item being purchased. In another aspect, a non-readable bar code is rendered readable by exposure to the predetermined factor, thereby alerting the customer.

BACKGROUND OF THE INVENTION 
1.Field of the Invention 
The present invention relates to consumer protection in general, and more 
particularly to a method of and an arrangement for alerting a customer to 
the possibility that particular perishable items being bought have been 
subjected to conditions that may have adversely affected their quality. 
2.Description of the Related Art 
There are already known various ways of informing customers at various 
retail establishments, such as department stores, grocery stores, drug 
stores and the like, about diverse attributes of the products on sale 
there. Some of that information, such as the name of the manufacturer 
and/or other information revealing the source of the goods, such as a 
trademark or brand name, is provided on a totally voluntary basis, usually 
as an enticement for the customer to purchase a particular product, to 
develop brand loyalty, and/or otherwise enhance the image of the 
manufacturer, while other information, such as a health hazard warning, 
nutritional information, or even an expiration date, may be provided on 
the products or their packaging at the prompting of authorities and/or 
because of legal requirements for providing such information. 
There is still another type of informative material that can be almost 
invariably found on or in conjunction with products being on sale in 
retail stores or similar establishments, namely indicia providing at least 
the store personnel if not the consumer with information about the price 
of the product. Such indicia are provided, if not directly on, then on 
objects such as price tags or labels that are securely attached to, the 
products or the packages containing the same. 
However, with the advent of widespread use of computer databases that 
include the latest product price information, whether such product is 
being offered at any particular time for at a regular price or at a 
temporarily reduced price, a new trend has emerged: reliance on the 
product identification itself, rather than any such indicia to determine 
the momentarily applicable price to be paid by the purchaser at the 
checkout counter for each particular item. Inasmuch as there are literally 
thousands upon thousands of different items being offered for sale even in 
any medium-size grocery store, for instance, and the prices of tens or 
possibly hundreds of them may change if not on a daily basis then from one 
week to the next one, it cannot and should not be expected from the store 
personnel to accurately remember or recall the momentarily applicable 
prices of all of such items. This is why the retail industry is heavily 
relying, more so than on, or even to the exclusion of, any price 
information that may be provided on the product itself or its packaging, 
on the so-called Universal Product Code (UPC) designation and particularly 
on the so-called UPC symbol that is a graphic representation of the UPC 
designation. 
As is well known by now, this symbol in its simplest form consists of a 
series of bars and intervening spaces that differ from one another in 
their optical properties, with the bar regions being more light-absorptive 
than the intervening space regions and these widths and distribution of 
the bars corresponding to the numerical values to be represented thereby. 
The main if not only reason for presenting the UPC symbol in this form is 
that it is easily machine-readable, that is, it can be scanned by a simple 
scanner that passes a light beam (usually in the red or infrared range of 
the spectrum) over the symbol and converts the varying-intensity of the 
light returning to it after being redirected back from the bar code zone 
into electrical signals that represent, after possible further processing 
in the electric domain, the numeric or alphanumeric expression of the UPC. 
This expression of the UPC is then presented to the computer/database 
circuitry that looks up the price of the item on the basis of such 
expression and returns such price to the cash register for further 
processing thereat. 
As useful as all of the aforementioned information associated with the 
product is either to the retail store owners or to the customers or to 
both, there is still one area that is not addressed by it, or at least not 
properly or reliably: namely, the history of the product between the time 
it was produced or put into the channels of commerce and the time that it 
is being purchased. Now, during such period, the product may have been 
subjected to certain conditions or factors that may have adversely 
affected its quality or wholesomeness or may have even made the product 
hazardous to the customer's health or well-being. This, coupled with the 
possibility that the purchaser may fail to check or notice the expiration 
date accompanying the product in one way or another if the product is of a 
perishable nature, as many processed and unprocessed foodstuffs are, 
results in a situation that the product may be purchased, without 
knowledge on the part of the purchaser and in most cases even the store 
owner or personnel, even though its integrity or other properties may have 
been impaired by intervening events. 
OBJECTS OF THE INVENTION 
Accordingly, it is a general object of the present invention to avoid the 
disadvantages of the prior art. 
More particularly, it is an object of the present invention to provide a 
method of providing a prospective purchaser of perishable goods with 
important information, which method does not possess the shortcomings of 
the known methods of this type. 
Still another object of the present invention is to devise an arrangement 
for performing the method of the present invention that is capable of 
alerting a potential purchaser of such goods about past events in the 
history of the product about to be purchased that may have adversely 
affected the quality of the product. 
It is still another object of the present invention to develop the 
arrangement of the type here under consideration in such a manner as to be 
usable to record the occurrence of one or more of intervening events. 
It is yet another object of the present invention to design the above 
arrangement in such a manner as to be essentially tamper-proof. 
A concomitant object of the present invention is so to construct the 
arrangement of the above type as to be relatively simple in construction, 
inexpensive to manufacture, easy to use, and yet reliable in operation. 
SUMMARY OF THE INVENTION 
In keeping with the above objects and others which will become apparent 
hereafter, one feature of the present invention resides in a method of 
protecting retail establishment customers from unwittingly purchasing 
perishable items that may have been adversely affected by being subjected 
to at least one predetermined factor. This method involves providing an 
identification object with an initially machine-scannable bar code of such 
a character that its scannability is at least gravely impaired when the 
identification object is subjected to the at least one predetermined 
factor, and securing the identification object to the respective item for 
both of them to be subsequently exposed to the same conditions such that a 
failed scan of the bar code occurring at the time of purchase alerts the 
customer to a previous occurrence among such conditions of the at least 
one predetermined factor that may have adversely affected the item being 
purchased. A particular advantage of the method as described so far is 
that its use alerts the customer to the fact that the product to be 
purchased may have encountered the aforementioned "factor" in the past and 
may have suffered because of such encounter. 
Many conditions qualify as such factor, from mere passage of time to 
exposure of the product to temperatures that are either too high or too 
low for that particular product, to variations or fluctuations in the 
temperature to which the product has been exposed, to exposure of the 
product to various kinds of radiation including light, especially light in 
the part of the spectrum that is not normally encountered at the location 
at which the product is on display in the store or on its route to that 
destination, exposure of the product to certain chemicals, etc. In 
accordance with the present invention, exactly what detrimental factor is 
to be looked for plays an important role in the decision how to perform 
the method in order to achieve the desired failure in scanning the bar 
code after the occurrence of the aforementioned predetermined factor. 
In accordance with an advantageous facet of the present invention, the 
method includes forming on an exposed surface of the identification object 
a layer capable of accepting the bar code, and applying to the layer a 
pattern of bars and intervening spaces of different optical properties in 
correspondence with the applicable bar code in the form of an ink that 
cooperates with the layer in such a manner as to present an image of the 
pattern that is initially distinct but deteriorates when subjected to the 
at least one predetermined factor. The method then further includes 
choosing the layer and the ink in such a manner as to achieve sensibility 
to the factor to be watched out for. It is further advantageous when the 
inventive method includes providing in the layer a pattern of latent image 
regions corresponding in size and spatial distribution to the bar code and 
distinguished from surrounding and intervening regions of the layer by 
their capability of accepting the ink, and depositing the ink on the layer 
in such a manner as to permeate the latent image regions. 
The present invention is also concerned with an arrangement for use in 
conjunction with an optical scanning device for protecting retail 
establishment customers from unwittingly purchasing perishable items that 
may have been adversely affected by being subjected to at least one 
predetermined factor. According to the present invention, such an 
arrangement includes an identification object securely attached to the 
respective item for both of them to be exposed to the same conditions 
subsequently to such attachment, and item identification means on the 
identification object, including a bar code being of such a character as 
to be initially scannable by the scanner but with its scannability being 
at least gravely impaired when the identification object is subjected to 
the at least one predetermined factor for a failure of a scan of the bar 
code performed by the scanner at the time of purchase to alert the 
customer to a previous occurrence among the aforementioned conditions of 
the at least one predetermined factor that may have adversely affected the 
item being purchased. 
The aforementioned item identification means advantageously includes a 
layer on an exposed surface of the identification object capable of 
accepting the bar code, and a pattern of bars and intervening spaces of 
different optical properties in correspondence to the applicable bar code 
applied to the layer in the form of an ink that cooperates with the layer 
in such a manner as to present an image of the pattern that is initially 
distinct but deteriorates when subjected to the at least one predetermined 
factor. 
It is also particularly advantageous in this respect when the 
aforementioned layer incorporates a pattern of latent image regions 
corresponding in size and spatial distribution to the bar code and 
distinguished from surrounding and intervening regions of the layer by 
their capability of accepting the ink for the latter to permeate the 
latent image regions on the layer. Of course, in this context as well, it 
is advantageous and proposed by the present invention to choose the 
material of the aforementioned layer and that of the ink in such a manner 
as to achieve the desired sensitivity to the condition event or, generally 
speaking, factor, the pre-purchase occurrence of which is to be tracked. 
In another aspect, rather than impairing the scannability of the bar code, 
another feature of the present invention relates to affirmatively advising 
the customer that the product has encountered the aforementioned "factor" 
. For example, the identification object may be provided with a second bar 
code or indicia, in either machine--or human--readable form, that is only 
rendered readable to the machine or the customer when the identification 
object and the product to be purchased have experienced said factor, i.e., 
the passage of time or temperature minimum or maximum. This second indicia 
may be provided alongside or overlay the first bar code. There may be 
different types of the second indicia, each corresponding to a different 
factor. These different types may be applied on the identification object 
in advance, and then, if the object has experienced a particular factor, 
then only the corresponding type of the second indicia is rendered 
readable. If the indicia type is rendered visible to the customer, then 
the customer will have a positive, unambiguous warning or message that the 
product to be purchased has experienced a specific adverse condition. If 
the indicia type is rendered readable to a machine, then the machine can 
use this data to consult a look-up table stored either locally or in a 
remote location, retrieve the corresponding condition, and alert the 
customer or checkout operator at the point-of-sale site of the existence 
of said condition. This positive "diagnosis" of the condition of the 
product helps the customer make an informed decision about purchasing, and 
more usually, about not purchasing the product. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As already alluded to before, the present invention generally relates to a 
system for using optical scanners for protecting customers by alerting 
them to certain pre-existing conditions in the history of a product that 
may have adversely affected the quality of the product. More particularly, 
this invention proposes the use of a bar-code scanner situated at a point 
of sale in a retail setting, whose primary if not only purpose in the past 
was to provide the cashier (or, to be more precise, the cash register) 
with information about the prices of the items being purchased, to 
prevent, or at least to alert the prospective purchaser of each particular 
item of the possibility of, an impending sale of a product that has 
already been scanned at least once before, whose expiration date has 
expired, that has been tampered with or adulterated in one way or another, 
that has been exposed to potentially harmful temperatures or temperature 
variations, or to harmful radiation, or to certain chemicals, etc. 
As also mentioned before, many industries, possibly foremost among them the 
food processing industry and food distribution establishments such as 
grocery stores, supermarkets and the like, use a unique code (the 
aforementioned UPC designation and the corresponding symbol) for 
identifying the various products being ultimately offered for sale to the 
general public. The UPC symbol, as is well known, which is provided on or 
otherwise secured to the product itself or to its packaging, is 
characterized by a series or succession of bars and intervening spaces 
(hence the frequent reference to it as the "bar code"), with the bars 
having different widths and/or distributions depending on what numeric or 
alphanumeric values are to be represented by them, and optical properties 
differing from those of the intervening spaces and/or the surrounding 
regions. 
Within the context of the present disclosure, the term "optical properties" 
will be used to denote solely the light absorptivity/reflectivity of the 
particular affected zone or region, be it the bar region of the space 
region, at least in the spectral range of interest for the scanning 
purposes, that is usually in the far red/near infrared range. While the 
absorptivity in the range of interest is all that matters as the scanning 
of the bar code is concerned, that is ordinarily not the only range in 
which the light absorptivity of the bars differs from that of the 
intervening spaces; as a matter of fact, the colors of (i.e. the 
intensities of light reflected or scattered at various wavelengths 
throughout the visible range of the visible spectrum from) the bars and 
spaces are typically different from one another, thus making the bar code 
visible even to a human observer, rather than just to the scanner. For 
maximum contrast between the bars and the intervening spaces, black ink 
(minimum light reflection) is currently preferred for the bars, printed or 
otherwise deposited on a white background (minimum light absorption). 
When the particular item is to be checked out of the retail store or 
similar establishment equipped with the requisite scanning devices, a 
cashier positions or moves the item relative to the scanner (with either 
the item or the scanner performing the actual relative movement) in such a 
manner that a scanning beam generated by the scanner can sweep over the 
bar code. With the scanner activated, the intensity of the light reflected 
or scattered back to the scanner and detected thereat varies in dependence 
on whether it is a bar or an intervening space that is hit by the scanning 
beam at any particular time. This function that varies with the region 
illuminated by the scanning beam at any particular time and hence with the 
amount of time elapsed from the beginning of the particular scanning 
operation is then further processed in the electrical domain in that at 
least one photosensitive element intercepts such returning light and 
converts its varying intensity into a corresponding electrical signal that 
is then further processed and/or forwarded to a computer and/or an 
electronic database where a stored price for the product identified by 
such signal is retrieved and returned to the checkout counter or, to be 
more precise, to a cash register or computer terminal located thereat. 
Of course, for this scanning process to work properly, it is imperative, 
among other things, that the bars and intervening spaces be, on the one 
hand, "visible" to the scanner in the first place, and on the other hand, 
that their respective optical properties within the operating range of the 
scanner differ from one another sufficiently for the scanner to be able to 
"tell the difference" between such bars and the intervening spaces. It is 
this requirement that is being utilized in accordance with the present 
invention to alert the customer, as well as the cashier and other store 
personnel, to the existence of a potential problem in the past history of 
the item being scanned at that particular time. 
This is accomplished in accordance with the present invention by changing 
the characteristic optical properties of the bar code symbol or of at 
least one type of its constituent elements (bars or intervening spaces) as 
a function of something that is being referred to throughout this 
specification as a factor. Briefly stated, a "factor" is any condition 
which, if the product were subjected or exposed to it, would result in the 
deterioration in the quality of the product, possibly even to the point of 
spoilage when the product or item is perishable. The change taking place 
in such optical properties is of such a character as to tend to obliterate 
the differences between what the bars and the intervening spaces "look 
like" to the scanner, thus either fully negating the readability of the 
bar code to the scanner or at least so greatly impairing it that several 
scanning operations, that is several passes of the item by the scanner (or 
vice versa) would be required before the item would "register". 
This failure to detect the bar code during the first scanning pass then 
constitutes an indication that would or should alert the consumer and also 
the store personnel that something is amiss with that particular item, and 
at least send them on a path of inquiry of what may have gone wrong with 
the product in the past. Of course, the mere fact that this event, i.e. 
the failure to properly scan the bar code of the particular product, had 
occurred gives no assurance that it will raise any alarm flags if the 
customer is unaware of its significance and if the store personnel, either 
out of ignorance or carelessness or with deceptive intent, discounts such 
significance or conceals it from the customer; moreover, even if it does, 
there is still no assurance that the customer or the checkout clerk will 
act on this information, i.e. investigate the reason why the scan had 
failed. Be it as it may, though, at least the customer is provided with an 
additional piece of useful information that was not provided prior to the 
present invention, and gets an opportunity to act on such information. 
The present invention may be implemented, for example, by using a 
proprietary reusable paper and ink system marketed by the 3M Corporation 
under the name DATRIM.RTM. for the label, tag, layer, or, generally 
speaking, any substrate that is supposed to carry the bar code or UPC 
symbol. In this particular system, a latent image corresponding to the 
location of the bars is formed in the substrate. This latent image has 
affinity for at least certain liquids whereas the surrounding and 
intervening regions of the substrate do not, so that when a liquid 
substance referred to herein as ink is applied to the substrate, it will 
permeate the latent image regions and stay away from the intervening 
regions. 
Now, the ink changes the appearance or color of the affected regions, 
because it fills microvoids present in such regions thus defeating the 
opacity previously provided by such microvoid and thus reveals the dark 
pigment or similar mineral substance that was previously concealed by such 
microvoids. The ink has a certain degree of volatility so that it will 
leave the substrate after a period of time the length of which can be 
chosen by selecting a substance with the requisite degree of volatility 
for the ink and by taking other measures, such as by applying an overcoat 
exhibiting low or non-existent vapor permeability, to range between just a 
few seconds and several years. While neither one of these extremes is 
usable or practical in the application proposed by the present invention, 
certain values in between ranging from several days to several months are 
well suited for the purposes of the present invention. 
No matter what substance is chosen for the ink, the fact remains that at 
the beginning, right after the application of the ink to the substrate, 
there is revealed a sharp and crisp image of the desired pattern (bar 
code), but that the image will fade over time until a point is reached 
that the scanner is unable to read the bar code, this point corresponding 
to the predetermined expiration date for such product. However, the 
evaporation rate of the ink in this known system is or can be (by choosing 
an appropriate liquid substance for the ink) accelerated by the 
application to the product and thus to the substrate of temperatures that 
are elevated relative to that at which the particular product is supposed 
to be stored. This may be used to advantage with products such as 
prepackaged red meat, poultry, fish or the like that are supposed to be 
maintained in a frozen state until sold. Under these circumstances, the 
accelerated rate of evaporation of the ink and thus disappearance of the 
UPC symbol can be made to correspond to the rate at which the product 
would spoil at such elevated temperatures. Hence, relatively short 
exposure to such elevated temperature such as when a customer takes out 
the package to examine the meat or the like would hardly shorten the 
expiration period, whereas overnight electric blackout at the store might 
render the bar code illegible by the morning if that's all that it takes 
for the package contents to spoil. 
In another currently contemplated embodiment of the present invention, the 
impingement of the scanning or laser beam on the symbol as it is being 
scanned for sale of the associated product to a customer is used as the 
factor rendering the UPC symbol unreadable to the scanner afterwards. In 
this instance, the ink is composed of a material which, when exposed to 
light at the operating wavelength of the scanning laser beam, changes its 
light absorptivity, self-destructs, flows or becomes otherwise invisible 
thus making the bars indistinguishable (at least at the operating 
wavelength of the scanner) from their surroundings and hence the symbol 
unreadable. Thus, in the event that it was attempted to pass the very same 
product through the checkout equipment again, be it because the product 
was already previously purchased by another customer and then returned, or 
because the store clerk had made a mistake and tried to scan the very same 
item a second time in the course of the same checkout operation, the 
unreadability of the code would once more alert both the customer and the 
store personnel to the existence of this factor or preexisting condition 
and make it possible for them to decide how to handle the situation. Thus, 
in the case a tamperer had tampered with the particular product, the next 
time an unsuspecting customer would attempt to buy the very same product, 
the latter would be stopped at the cash register. Also, by preventing 
another sale of a previously scanned (and hence presumably already charged 
for) product, it is avoided that an inattentive retail clerk could check 
such product through the checkout line more than once, thus again serving 
as a boon to consumers. 
The factor the occurrence of which renders the bar code unreadable need not 
be the laser beam as such; rather, it may be any external condition to 
which the ink or the substrate, film or layer incorporating such ink is 
sensitive, for instance the elapse of a predetermined period of time as 
mentioned before. In this case, the ink may incorporate, or the regions of 
the substrate originally permeated by such ink may be overlaid with, a 
material which will change the optical properties of the symbol and 
especially its bar regions upon the elapse of a time interval from the 
application of the code that ideally extends all the way up to but does 
not continue beyond the stated expiration date of the product except when 
such product is subjected to abnormal temperatures or temperature 
excursions (whether they be above or below the desired temperature range 
at which the product is supposed to be stored), as also already mentioned 
before. 
In this case, a rather slow polymerizing chemical can be employed either in 
the ink itself or in the material of the overlay; in the first instance, 
the polymerization may render the ink-permeated regions virtually 
indistinguishable from their surroundings in the end. In the second 
instance, the polymerized or almost completely polymerized material of, or 
incorporated in, the overlay may totally obstruct the view of the bar 
regions and/or of the adjacent space regions, thus once more making such 
regions optically indistinguishable from one another, at least as far as 
the scanning equipment is concerned. Other factors that can be detected is 
exposure of the product to humidity, to certain chemicals, its position or 
orientation during storage, handling and store display, or other 
mishandling of the product prior to being picked up by the purchaser. 
Not only the optical properties of the ink, but also those of the 
background or matrix on which the ink is deposited and against which it is 
visible can be changed. The ink could be caused by the respective factor 
to be less absorptive, or the matrix less reflective, or both. Also, as 
alluded to before, not only the ink-containing regions (the bars of the 
symbol) but also the background or matrix (constituting the intervening 
spaces and surroundings of the bars) may be covered by an overlay that is 
sensitive to the predetermined factor and changes its optical properties 
in response to its occurrence such as to obscure both the ink regions and 
the matrix regions. The overlay may advantageously be constituted by an 
initially light-transmissive and preferably transparent film, sheet, strip 
or label that is applied over the symbol, with the material of such 
overlay changing its light absorptive/reflective properties when exposed 
or subjected to the aforementioned factor. Thus, for instance, heat may be 
applied to the overlay under some circumstances to render the overlay 
opaque either accidentally or by design. 
Thus, it may be seen that the invention in its broadest sense, as depicted 
in FIG. 1 is directed to changing the spectral response (optical 
properties) of the bar code symbol imprinted on a matrix or substrate, be 
it the product itself, its packaging, or a label or tag secured to the 
product, so as to render the bar code unreadable to scanners after the 
product (and hence the bar code) has been exposed to at least one factor 
that may have adversely affected the integrity or quality of the product. 
The consumer, if heeding the warning, is thus protected from buying 
tampered-with products, resold products, expired products, improperly 
stored products or the like, all that by using various means for rendering 
the UPC symbols accompanying the products unreadable, particularly to bar 
code laser scanning point-of-sale equipment or systems. 
In another sense, rather than impairing the scannability of the bar code, 
another feature of the present invention relates to affirmatively advising 
the customer that the product has encountered the aforementioned "factor" 
. For example, the identification object may be provided with a second bar 
code symbol or indicia, in either machine--or human--readable form, that 
is only rendered readable to the machine or the customer when the 
identification object and the product to be purchased have experienced 
said factor, i.e., the passage of time or temperature minimum or maximum. 
This second indicia may be provided alongside or overlay the first bar 
code. There may be different types of the second indicia, each 
corresponding to a different factor. These different types may be applied 
on the identification object in advance, and then, if the object has 
experienced a particular factor, then only the corresponding type of the 
second indicia is rendered readable. 
If the indicia type is rendered visible to the customer, then the customer 
will have a positive, unambiguous warning or message that the product to 
be purchased has experienced a specific adverse condition. If the indicia 
type is rendered readable to a machine, then the machine can use this data 
to consult a look-up table stored either locally or in a remote location, 
retrieve the corresponding condition, and alert the customer or checkout 
operator at the point-of-sale site of the existence of said condition. 
This positive "diagnosis" of the condition of the product helps the 
customer make an informed decision about purchasing, and more usually, 
about not purchasing the product. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the type described above. 
While the present invention has been described and illustrated herein as 
embodied in some specific constructions of an arrangement for alerting 
customers to the past occurrence of certain conditions that may have had 
an adverse influence on the product, it is not limited to the details of 
this particular construction, since various modifications and structural 
changes may be made without departing from the spirit of the present 
invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention and, 
therefore, such adaptations should and are intended to be comprehended 
within the meaning and range of equivalence of the following claims.