Abstract:
Apparatus and method for visibly changing the appearance of a single serve hot beverage cartridge pod to identify its having been previously brewed, along, where desired, together with or independently visualizing previously hidden message content embedded within the cartridge pod construction itself.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Provisional patent applications covering the invention described herein were filed on Jan. 27, 2015, (assigned Ser. No. 62/108,085), and on Feb. 21, 2015, (assigned Ser. No. 62/119,140). 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Research and development of this invention and Application have not been federally sponsored, and no rights are given under any Federal program. 
       REFERENCE TO A MICROFICHE APPENDIX 
       [0003]    NOT APPLICABLE 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    This invention relates to single serve hot beverage cartridges, in general, and to a manner of visibly changing the appearance of the cartridge as an indication of its being previously brewed, in particular. 
         [0006]    2. Description of the Related Art 
         [0007]    Single serve hot beverage cartridges such as the Keurig Green Mountain Company&#39;s K-CUPS are meant to be brewed only one time. This is because subsequent brewing with the same cartridge will yield a weaker then optimal beverage. To avoid a second brewing the single serve brewing machine instructs the operator to replace the cartridge each time brewing is completed. However if an operator opens and closes the brewing cartridge receptacle but forgets to replace the cartridge, the brewing apparatus has no way to detect the presence of a previously brewed cartridge. Additionally when the operator opens the brewing apparatus cartridge receptacle, he or she has no convenient way to positively identify a previously brewed cartridge. The operator can check the cartridge brew status only by feeling the surface to check for residual heat from a recent brewing or by removing the cartridge and looking for signs of water on or in the cartridge. These are inconvenient checks and they are not available to the user after enough time passes for the heat to dissipate and for the water to evaporate. These brewing cartridges typically have printed labels with logos on a visible surface that can be designed to drive brand interest, brand loyalty and brand recognition. These printed logos and messages are small and don&#39;t maximize interest because the purposeful comprehension of the details within does not provide potential benefit to the beverage consumer. 
       OBJECTS OF THE INVENTION 
       [0008]    Objects of the present invention include a manner of visibly changing the appearance of the beverage cartridge as a result of the brewing process itself; and in an additional manner of accomplishing this in a way to focus the consumer&#39;s interest to its cartridge labelling for a variety of beneficial purposes and reasons. 
       SUMMARY OF THE INVENTION 
       [0009]    As will become apparent from the following description, the invention demonstrates an approach of marking or labeling a prepackaged single serve beverage container to allow a visible change in the cartridge appearance in response to heat during the hot beverage brewing process. This appearance change will make it visibly obvious to the consumer when a beverage cartridge has been previously brewed. This provides the advantage of allowing the consumer to easily identify a previously brewed cartridge by observing a noticeable label or appearance change. The company who produces the cartridge will also be able to simultaneously design this appearance change to inform, educate, amuse, entertain and reward the consumer. Additionally the label change can be designed to convey information about the cartridges compatibility, brewing requirements and contents to the brewing apparatus. As will also become clear, these advantages follow from the use of a thermochromic medium on the cartridge to change color, transparency, shading or appearance in response to the heat generated by the brewing apparatus or brewing water. And, as will be understood by those skilled in the art, these advantages follow whether the brewing process is employed for coffees, teas, cocoa, cappuccinos or other like hot beverage varieties. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    These and other features of the invention will be more clearly understood from the following description, taken in conjunction with the accompanying drawings, in which: 
           [0011]      FIG. 1  illustrates a dot Indicator implementation of the invention in providing a visual change at a top surface of a typically employed beverage cartridge pod; 
           [0012]      FIG. 2  shows similar implementation of the invention for use with an alternate beverage cartridge pod construction. 
           [0013]      FIG. 3A  shows a hidden message implementation of the invention. 
           [0014]      FIG. 3B  shows a hidden message implementation of the invention after the change occurs. 
           [0015]      FIG. 4A  shows a trivia question implementation of the invention. 
           [0016]      FIG. 4B  depicts the answer to the trivia question implementation of the invention after heat is applied. 
           [0017]      FIG. 5A  shows a hidden words of wisdom implementation of the invention. 
           [0018]      FIG. 5B  shows the hidden words of wisdom sample words after an appearance change. 
           [0019]      FIG. 6A  shows a changing graphics implementation of the invention. 
           [0020]      FIG. 6B  shows the changing graphics implementation of the invention after an appearance change. 
           [0021]      FIG. 7A  shows the hidden symbol implementation of the invention. 
           [0022]      FIG. 7B  shows the hidden symbol implementation of the invention after an appearance change. 
           [0023]      FIG. 8A  shows the hidden code implementation of the invention. 
           [0024]      FIG. 8B  shows the hidden code implementation of the invention after an appearance change. 
           [0025]      FIG. 9A  shows the store redeemable prize version of the invention. 
           [0026]      FIG. 9B  shows the store redeemable prize version of the invention after an appearance change. 
           [0027]      FIG. 10A  shows a vanishing color implementation of the invention. 
           [0028]      FIG. 10B  shows a vanishing color implementation after selective color vanishes. 
           [0029]      FIG. 11A  shows a thermometer implementation of the invention. 
           [0030]      FIG. 11B  shows a thermometer implementation of the invention after temperature is applied. 
           [0031]      FIG. 12A  shows a pod compatibility implementation of the invention. 
           [0032]      FIG. 12B  shows a pod compatibility implementation of the invention after heat changes the color. 
           [0033]      FIG. 13A  shows a hidden logo implementation of the invention. 
           [0034]      FIG. 13B  shows a hidden logo implementation of the invention after heat changes the color. 
           [0035]      FIG. 14A  shows a form altering version of the invention. 
           [0036]      FIG. 14B  shows a form altering version of the invention after heat changes the appearance. 
           [0037]      FIG. 15  illustrates an alternative packaging configuration to protect, preserve and enhance the instrument of the invention. 
           [0038]      FIG. 16  illustrates an alternative position for the instrument of the invention. 
           [0039]      FIG. 17  illustrates a brewing apparatus with a dedicated heat transducer or thermal print head for creating the thermochromic changes and an optional light or color sensor for interpreting appearance changes. 
           [0040]      FIG. 18  illustrates an injection molded implementation of the thermochromic messaging system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]    One embodiment of the coffee pod indicator and messaging system is illustrated in  FIG. 1  (Dot Indicator). Item  104  is the base cup of a typical Keurig Green Mountain Company or similar single serve coffee pod cartridge. Item  102  is the typical aluminum, metallic, polymer, paper, membrane, plastic or functionally similar cover on the single serve coffee filter pod. Item  106  is an irreversible thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye that will develop an externally visible change in color, transparency, shading or appearance in response to temperature elevations. 
         [0042]    In operation, the  FIG. 1  coffee pod embodiment is inserted into a conventional Keurig Green Mountain Company style single serve brewing machine as any common single serve coffee pod cartridge. During the brewing process the brewing machine creates a hole in cover  102  and base cup  104 . The brewing apparatus will direct heated brewing water to pass through the hole created in cover  102 . The heated water will then matriculate through the brewing product and a filter medium internal to base cup  104 . The heated brewing water then exits through the hole in base cup  104  and is directed to a coffee vessel for distribution or consumption. During the process the heated water will elevate the temperature of cover  102  and base cup  104  as it passes through the coffee pod. Thermochromic ink  106  is positioned in a visible area on the top surface of cover  102 . Thermochromic ink  106  is formed from a thin medium that is printed, sprayed, painted, coated, laminated, rolled, pressed, taped or otherwise bonded to the top surface of cover  102 . Thermochromic ink  106  will irreversibly change color, transparency, shading or appearance in response to the heat from the brewing water. The thermochromic ink  106  appearance change will serve as an easily noticeable indicator of the completed brewing process. Thus the user and brewing apparatus sensors can now instantly identify a pod that was previously brewed. This will prevent users from accidentally brewing pods a second time. If a user is unsure of the brewing status of a pod within the apparatus, they will now be able to objectively confirm just by looking at the indicator. Without this type of indicator they would have had to remove the pod from the brewer to inspect for elevated temperatures or residual signs of water. 
         [0043]    The  FIG. 2  (Alternate Pod) embodiment depicts an alternate style single serve brewing pod cartridge. Item  202  is a typical aluminum, metallic, polymer, paper, membrane, plastic or functionally similar cover on the single serve coffee pod. Item  204  is a typical pod frame produced from plastic, aluminum, wood or paper based recyclable or compostable material. Item  206  is a filter medium for the coffee product. Cover  202  and filter  206  are supported by frame  204 . Item  208  is a thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye area that will develop an externally visible change in color, transparency, shading or appearance in response to temperature elevations. 
         [0044]    The  FIG. 2  coffee pod operates in Keurig Green Mountain Company style single serve brewers like any conventional single serve coffee pod cartridge. Heat from the brewing water passing through the pod will create a color, transparency, shading or appearance change in thermochromic ink  208 . The thermochromic ink  208  appearance change will serve as an easily noticeable indicator of the completed brewing process. 
         [0045]    The  FIG. 3A  and  FIG. 3B  (Message) embodiments depict a conventional style single serve coffee pod cartridge with a hidden message formed with a thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye. Item  302  is the thermochromic marking medium ink or coating deposited in such a way that it is indistinguishable from the background color. Item  304  in  FIG. 3B  shows the shape or form of the thermochromic ink  302  deposits and how they will appear to the naked eye after heat from the brewing process changes the appearance. 
         [0046]    In this messaging example the message word “DONE” in  FIG. 3B  is distinguishable from the background only after heat from the brewing water or the brewing apparatus changes the color, transparency, shading or appearance of the thermochromic ink  302  deposits. Depositing the thermochromic marking medium in the shape of or to reveal symbols, letters or words allows the appearance changes to be more noticeable. It also helps convey messages more specifically. 
         [0047]    The  FIG. 4A  and  FIG. 4B  (Brain Teaser) embodiments depict a conventional style single serve coffee pod cartridge. Item  404  is a printed entertaining question or brain teaser on the cover  102 . Item  402  is an area where the hidden answer to brain teaser  404  is obscured or deposited with irreversible or reversible thermochromic marking medium coatings or inks such as a leuco dye matrix or a wax melt dye. Item  406  is the form of the answer that would become visible after a brewing process increases the temperature of thermochromic ink  402 . 
         [0048]    In  FIG. 4A  the answer to the brain teaser  404  would not become visible until after the brewing heat changed the appearance of thermochromic ink  402 . The user&#39;s interest in the correct answer would drive them to check the pod immediately after brewing. This would drive immediate attention to the brew pod after brewing. This attention would increase the likelihood that the brewing apparatus operator would remove their own pod. This is because they would be incentivized to open the brewer and inspect the pod after each cycle. A pod that is removed and discarded after brewing is unlikely to accidentally get brewed a second time. Additionally the brewing status would become obvious as complete if irreversible thermochromic ink  402  is used to form the answer that is revealed by heat from the brewing process. 
         [0049]    The  FIGS. 5A and 5B  (Words of Wisdom) embodiment depicts a conventional style single serve coffee pod cartridge. Item  502  is an area where an entertaining word of wisdom, fortune, joke or fact will be deposited, obscured or formed with irreversible or reversible thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye. Item  504  is the same thermochromic ink revealing the form of a word of wisdom, fortune, joke or fact after it is exposed to the brewing heat and changes color, transparency, shading or appearance. 
         [0050]    In  FIG. 5B  the  504  thermochromic ink word of wisdom would not become visibly distinguishable until the heat from the brewing process or brewer converts the appearance. Heat from the brewing process would alter the color, shading transparency or appearance of the  504  thermochromic ink word of wisdom making it distinguishable. The appearance change would make it obvious to the user that the pod had been brewed previously. The immediate appearance would incentivize the user to open the pod cartridge tray to inspect the thermochromic ink  504  message after brewing. This would promote a timely discarding of the used pod. This timely discarding would prevent pods from being used a second time. 
         [0051]    The  FIGS. 6A and 6B  (Graphic Altering) embodiment depicts a conventional style single serve coffee pod cartridge. Item  602  is a graphic printed on cover  102 . Item  604  is a graphic area where thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye has been deposited that will compliment and add meaning to graphic  602  after heat from brewing alters the appearance. 
         [0052]    In  FIG. 6B  thermochromic ink  604  will change color, transparency, shading or appearance in response to heat from the brewer or the brewing process. The shape or form of thermochromic ink  604  can be deposited on or near graphic  602  with the intent of conveying specific final messages to the user. These messages could be based on the relationships between graphic  602  and the appearance change after heat reveals or forms additional graphics from thermochromic ink  604 . 
         [0053]    The  FIGS. 7A and 7B  (Promotional Art) embodiment depicts a conventional style single serve coffee pod cartridge. Item  702  is thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye graphic printed, deposited or placed on cover  102  in such a way that it blends with and is indistinguishable from the surface of cover  102 . Item  704  is the shape or form of the thermochromic ink  702  graphic as it appears after heat from the brewing water or brewing apparatus changes its appearance. 
         [0054]    In  FIG. 7B  the thermochromic ink  702  graphic becomes distinguishable from the background color only after brewing water or heat from the brew apparatus elevates and changes the color, transparency, shading or appearance of the thermochromic area. Promotional graphics can be used to promote interest in a company, group or cause. The appearance of the promotional graphic would also indicate to the user that the pod had been previously brewed. The appearance of the thermochromic  704  graphic would make it easy to identify a previously brewed pod. The appearance of the thermochromic ink  704  graphic would also allow the pod manufacture to promote a company, group or cause to consumers. 
         [0055]    The  FIGS. 8A and 8B  (Lottery) embodiment depicts a conventional style single serve coffee pod. Item  802  is an area where a thermochromic marking medium ink or coating, such as a leuco dye matrix or a wax melt dye would be deposited in the form of a code or number or obscuring a code or number printed on cover  102 . Item  804  is written or printed instructions that explain how to use the thermochromic ink  802  code. Item  806  is the code after being revealed as a result of heat acting on the thermochromic medium. 
         [0056]    In  FIG. 8B  heat from the brewing process or brewing water creates a color, transparency, shading or appearance change to the thermochromic medium. This appearance change reveals code or number  806 . The  806  code or number could be a lottery style sequence that can be submitted to a website or at a store to determine if it is a winning combination. The appearance of this code would allow the user to instantly recognize a pod that has been previously brewed. It would also create user interest in the pod after brewing which would promote immediate pod removal. It could also be used to drive pod consumer traffic to a store or website. 
         [0057]    The  FIGS. 9A and 9B  (Store Prize) embodiment depicts a conventional style single serve coffee pod cartridge. Item  902  is printed instructions for redeeming a prize. Item  904  is a hidden message formed or obscured with a thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye that is indistinguishable until heat is applied. Item  906  is the form or shape of the revealed hidden message  904  after heat from the brewer or brewing process alters the appearance. 
         [0058]    In  FIG. 9B  the thermochromic ink revealed  906  message forms a visible prize that can be redeemed as per instruction  902 . For example thermochromic ink  906  message conveys the winning of a free “Grande Hot Beverage”. Alternatively the message of thermochromic ink  906  could instruct a pod consumer that no prize was won or to try again. The appearance of this prize message would allow the user to instantly recognize a pod that had been previously brewed. It would also create user interest in the pod after brewing. This would promote the user to regularly remove pods from the brewer after brewing. Additionally it would allow the pod company to incentivize winning customers to visit specific company outlets or stores to redeem prizes. 
         [0059]    The  FIGS. 10A and 10B  (Vanishing Color) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1002  is a graphic, word or symbol printed with standard ink and thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye. Item  1004  depicts the form of graphic  1002  after heat is applied transforming the color, transparency, shading or appearance of the thermochromic ink medium in graphic  1002 . 
         [0060]    In  FIG. 10B  graphic  1004  is the left over form of graphic  1002  after heat from brewing changes the thermochromic component of graphic  1002  to a different color, transparency, shading or appearance. The change in appearance would allow the pod user to instantly identify a pod that has already been brewed. This change would also allow the pod company to convey or highlight a message or symbol of specific meaning to the consumer. 
         [0061]    The  FIGS. 11A and 11B  (Temperature Indicator) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1102  is a printed thermometer graphic strategically filled or obscured with thermochromic marking medium ink or coatings, such as liquid crystals, leuco dye matrices or wax melt dyes that are formulated to change color, transparency, shading or appearance at graduated temperature intervals illustrated by the thermometer graphic  1104 . Item  1106  is revealed after the thermochromic component is exposed to elevated temperatures above the transition level for the deposited portion of the thermometer. Item  1104  are printed graduated temperature ranges that would correlate with transition temperatures of thermochromic ink in each region of thermometer graphic  1102 . 
         [0062]    In  FIG. 11B  thermochromic component  1106  is formulated to change colors when the pod temperature reaches above the temperatures indicated on the thermometer graphic  1102 . The change in appearance could be used to indicate and inform the brewing temperature of the brewing water. This change in appearance would allow the consumer to easily identify a pod that had been previously brewed. It would also have the advantage of informing the consumer about the actual range of temperatures of the brewing water used. 
         [0063]    The  FIGS. 12A and 12B  (Pod Compatibility) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1202  is an annular area covered with thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye that is positioned and sized to have the same appearance at any radius and angle from the center of the pod. Item  1204  depicts the thermochromic area  1202  after heat from brewing alters its color transparency, shading or appearance. 
         [0064]    In  FIG. 12B  the thermochromic area  1204  experiences a color, transparency, shading or appearance change in response to heat from the brewing apparatus or brewing water. The annular shape of the thermochromic area  1204  allows the appearance change to be identical from any radial angle from the center of the pod. This annular positioning is symmetrical allowing a light or color sensor in the brew apparatus to sense the appearance change regardless of the pod&#39;s rotational indexing in the brewing apparatus. The appearance changes of this annular area after brewing would make the pod brew status obvious to the user after brewing. The annular shape would facilitate a convenient and flexible positioning of a light or color sensitive sensor in the brewing apparatus without a need for specific pod indexing. The brew apparatus color or light sensor could recognize the appearance change and could prevent brewing of pods that were previously brewed or that were incompatible with the brewing apparatus. When the appearance change is created with irreversible thermochromic mediums it would also become impossible to re-use a pod lid on a non-compatible pod to circumvent a pod compatibility check. 
         [0065]    The  FIGS. 13A and 13B  (Logo) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1302  is an area on cover  102  where a thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye is deposited in the form of or obscuring a logo so that it is indistinguishable with the naked eye. Item  1304  is the visible shape or form of the logo after heat from the brewing process or water changes the color, transparency, shading or appearance of the thermochromic component. 
         [0066]    In  FIG. 13B  logo  1304  becomes noticeable or enhanced as a result of heat from the brewing process. This change allows the user to instantly identify a pod that has been previously brewed. The change or enhancement of the thermochromic component  1302  allows the coffee pod company to highlight and therefore drive the user&#39;s attention to their logo. 
         [0067]    The  FIGS. 14A and 14B  (Form Altering) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1402  is a graphic shape or form that is printed with both standard ink and thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye. The  1402  graphic is created to solicit interest in the thermochromic changes after brewing. Item  1404  depicts the graphic changes of thermochromic component  1402  after changes in color, transparency, shading or appearance as a result of heat from the brewing process. 
         [0068]    In  FIG. 14B  the thermochromic changes are stylized to change the smiling face of thermochromic component  1402  to the winking face of graphic  1404 . The combination of standard and thermochromic ink will allow a designer, artist or cartoonist to create unexpected outcomes and changes to the standard cover  102  graphics. These changes will entertain and promote interest in inspecting the pod after brewing. The changes will make it obvious to the user that the pod had been previously brewed. 
         [0069]    The  FIG. 15  (Clear Coating) embodiment shows the side-view of a conventional single serve coffee pod cartridge. Item  1502  is a clear coating, laminate or sticker to protect the thermochromic medium. This cover can be applied by a waxing, painting, spraying, laminating, deposition, printing, rolling, pressing, dipping or similar applicator processes. 
         [0070]    In  FIG. 15  the clear coating  1502  covers protects and prevents the thermochromic marking medium from getting damaged and from migrating and contaminating the coffee product, brewing apparatus or brewing water. 
         [0071]    The  FIG. 16  (Alternate Position) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1602  is an alternative position for the deposition of a standard ink, thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye as described by this disclosure in  FIG. 1  through  FIG. 14  and all such potential combinations and ramifications across these figures. Item  1604  is an optional clear coating as described in  FIG. 15  but applied to this alternate position. 
         [0072]    In  FIG. 16  alternate position  1602  shows an external area of the plastic base cup  104  where standard ink and a thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye can be deposited. The positioning, shape or form of the thermochromic medium would be used similarly as in  FIG. 1  through  FIG. 14  of this disclosure to indicate brew pod status or compatibility to a user or brewing apparatus. 
         [0073]    The  FIG. 17  (Heat Transducer) embodiment depicts a conventional style single serve coffee pod cartridge. Item  1702  is a cover with thermochromic marking medium ink or coating, such as a leuco dye matrix or wax melt dye on its top surface. Item  1704  is a heat transducer or thermal print head that is part of the brewing apparatus. Item  1706  is an optional color or light sensor in the brewing apparatus that would detect changes in the color or appearance of the top surface of cover  1702 . 
         [0074]    In  FIG. 17  the surface coating on cover  1702  is formulated to change appearance or color at or above the maximum brewing water temperature. Heat transducer  1704  will use radiation, convection or conduction to apply heat energy towards cover  1702  during or before the brewing process. This energy will change the color, transparency, shading or appearance of the surface of cover  1702 . The appearance change could be a simple color change or a more complex graphic, symbol or letter arrangement as created by a thermal print head. Light sensor  1706  would be used to detect the expected appearance or color change. The detection of the expected appearance change would allow the brewing apparatus to confirm that a compatible pod was being used in the brewing apparatus. An incompatible pod could be detected by the lack of color changes observed by light sensor  1706  during brewing process steps. With the detection of an incompatible pod, the brewing apparatus of the invention could halt the brewing process and could warn the user through a user interface of the compatibility concern. The appearance or color change in cover  1702  would make it obvious to the user and the brewing apparatus that the pod had been previously brewed. Such halting or lock-outs of a non-conforming pod also nullifies the approach of removing the original Keurig Green Mountain Company K-CUP lids and re-attaching to non-conforming pods to circumvent the brewing apparatus compatibility checks. A brewer that can sense a previously brewed pod can be programmed to prevent a second brewing on a used pod. 
         [0075]    The  FIG. 18  (Injected Plastic) embodiment depicts a conventional style single serve coffee pod. Item  1802  is a molded polymeric or plastic cover that has thermochromic ink or pellets injected into the plastic during the molding or forming process. These thermochromic pellets can also be injected into cup  104  or into frame  204  of  FIG. 2  during the plastic molding process. 
         [0076]    In  FIG. 18  cover  1802  will change color in response to heat delivered by the brewer or brewing water during brewing. This color change will make it obvious to a user or to a sensor in the brewing apparatus that the pod had been previously brewed. 
         [0077]    Thermochromic medium inks and coatings are commercially available at a variety of outlets. LCR Hallcrest LLC in Glenview, Ill. is one of many companies that manufactures and distributes thermochromic ink and marking mediums in a variety of chemistries and with transition temperatures from 84 F to over 500 F with several colors available. Chromax K60-NH is one of many standard options that is an off white color flexo ink that transitions to magenta at above 140 F. Paper Thermometer Company in Manchester, N.H. is another company that manufactures and distributes thermochromic marking and indicating products. Paper Thermometer has a standard Thermolabel product that will transition from white to black at predetermined temperatures. Thermolabels are available in temperature ranges from 90 F to 500 F. 
         [0078]    Additionally coatings commonly applied to thermal paper such as those used in point of sale machines are suitable for the temperature transition levels of around 180 F common in the coffee brewing process. Leuco dyes such as triaryl methane phthalide dyes, flouran dyes and crystal violet lactone a commonly used for transitions in these temperature ranges. Leuco dyes when heated and melted in conjunction with organic acids as developers will provide visible color changes. Common organic acids include Bisphenol and Bisphenol-S. Other suitable acids such as sulfonyl ureas and Pergafast 201 are also used as developers. Zinc salts such as zinc di-tert-butylsalicylate also can be used as developers. To optimize leuco dyes and developer color changes and to facilitate mixing, a chemical sensitizer can be added to the layer. Sensitizers are commonly simple ether molecules such as 1,2-bis-(3-methylphenoxy)ethane or 2-benzyloxynapthalene. Stabilizers can be added to prevent color reversal when exposed to extended heat or humidity. Stabilizers are typically multifunctional phenols that inhibit recrystallization of dye and developer. 
         [0079]    As will be readily understood by the skilled artisan, each of these single serve hot beverage cartridges, consist of a plastic cup or frame, a cover, and a filter, filled with coffee grounds, tea leaves, cocoa and cappuccino powder, etc., and in which hot water is directed through the cartridge, passing through the grounds leaves etc., and through the filter. And as will be appreciated, the heat sensitive thermochromic medium can be produced from known thermochromic marking mediums, inks, dyes or coatings. Common thermochromic mediums include leuco dyes, liquid crystals, organic and inorganic thermochromic inks, micro-encapsulated dyes, wax melt dyes and thermal paper. Irreversible and reversible thermochromic mediums can be selected to control the longevity of the change. Message deposition or ink deposition can be accomplished with a variety of printing techniques including planographics, relief, instaglio, porous and thermal printing processes. Message development or color changes can be accomplished with heat from the brewing water or a heat transducer or a thermal print head in the brewing apparatus. This thus allows for the added benefit from the brewing water heat, besides helping with the pod compatibility check. 
         [0080]    While my above description contains many specifics, these should not be construed as limitations on the scope, but rather as an exemplification of several embodiments. Many other combinations and variations are obviously possible by cross combining any feature within every embodiment disclosed within and using the concept of known thermochromic indicating materials to reveal a message at the point of brewing completion, and to allow hidden messages to appear to the users as a result of the brewing process to entertain, instruct, educate, amuse, advertise and reward the consumer with redeemable prizes, all besides permitting the brewing apparatus to recognize a predetermined cartridge feature and to adjust accordingly. And, as will be equally understood, this usage of the thermochromic indicating materials in these manners serve to yield both an apparatus to improve upon existing single serve beverage cartridge pods as an indicator and messaging system, and a method for displaying the hidden message content while providing the indication of prior cartridge pod brewing at one and the same time. Accordingly, the scope should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents, in which by the term “thermochromic medium”, the conveyor of the change in color, transparency, shading or appearance and of the “hidden message” in accordance with the invention includes the inks, dyes, matrices and coatings noted above. And, at the same time, applicable even to thermochromic mediums which change color in the presence of rising temperatures as well as to those which change transparency to reveal or obscure printed background printed messages as described previously.