Patent Publication Number: US-2021170768-A1

Title: Portable Printer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent arises from a continuation of U.S. patent application Ser. No. 16/039,977, filed Jul. 19, 2018, which is a continuation of U.S. patent application Ser. No. 15/347,564, filed Nov. 9, 2016, now U.S. Pat. No. 10,052,895, which is a continuation of U.S. patent application Ser. No. 14/548,742, filed Nov. 20, 2014, now U.S. Pat. No. 9,550,371, which is a continuation of U.S. patent application Ser. No. 13/706,690, filed on Dec. 6, 2012, which is a continuation of U.S. patent application Ser. No. 12/488,138, filed on Jun. 19, 2009, now U.S. Pat. No. 8,342,763, which claims the benefit of U.S. Provisional patent Application Ser. No. 61/073,815, filed on Jun. 19, 2008. U.S. patent application Ser. Nos. 15/347,564, 14/548,742, 13/706,690, and 12/488,138 and U.S. Provisional patent Application Ser. No. 61/073,815 are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     In some applications, it is beneficial to provide a portable printer. For example, portable printers may be beneficial for retail stores. These stores often provide all incoming goods with labels for inventory purposes. It is often easier to relocate a printer than the merchandise. In addition to portability, the stores often desire that the printer be able to produce quality prints and be acquired at an affordable price. Meeting all of these requirements presents several obstacles that printer manufacturers may have to overcome in order to produce a marketable product. Stores may also be interested in labeling shelves or inventory locations with prices or customer information, or possibly more permanent information, such as location. Some of those shelves and inventory locations may be outside, inside a cooler, or near a window or special lighting source. These conditions create additional requirements for the printer and the printed output that manufacturers must overcome. 
     Beyond stores, other labeling and tracking applications may also require a portable printer. Labeling large items, such as oil field equipment, furniture, or utility fixtures is often best done without moving the item to be labeled. Military supplies, and their containers, are often labeled at remote locations or while in transit. Materials that are hazardous, explosive, or fragile are often labeled without being moved. Items delivered by truck, rail, air, sea container, and even bicycle may need to be labeled in the field. These applications require high quality, durable labels, tags, wristbands, or receipts from a portable printer. Depending on the application, the diverse user of the printer may be a young retail associate, a U.S. Marine, or an oil field worker. The printer could be used in a refrigerated warehouse, an air conditioned department store, an urban delivery route, or a desert war zone. This variety of uses, users, and locations also create additional requirements for the printer and the printed output. 
     Applicant has identified a number of deficiencies and problems associated with the manufacture, operation, and use of portable printers. Through applied effort, ingenuity, and innovation, Applicant has solved many of these identified problems by developing a solution that is embodied by the present invention, which is described in detail below. 
     BRIEF SUMMARY OF THE INVENTION 
     Systems and methods are therefore provided for printing indicia onto media and encoding one or more RFID tags associated with the media. In an exemplary embodiment, the printer comprises a housing defining a ribbon receiving area configured to receive a ribbon cartridge. The printer further comprises a ribbon cover configured to move between a closed ribbon position and an opened ribbon position, and a ribbon cartridge retaining feature configured to engage at least part of the ribbon cartridge. The ribbon cartridge retaining feature is configured to move the ribbon cartridge to an installed position when the ribbon cover is moved to the closed ribbon position, and to move the ribbon cartridge to an accessible position when the ribbon cover is moved to the opened ribbon position. 
     In some embodiments, the ribbon cartridge retaining feature comprises a lifting portion configured to support at least a part of the ribbon cartridge, and a securing portion configured to maintain the ribbon cartridge in the installed position when the ribbon cartridge retaining feature is in the operational position. The lifting portion and the securing portion may generally define a U-shape. In addition, the lifting portion may be configured to at least partially move the ribbon cartridge between the installed position and the accessible position as the ribbon cartridge retaining feature is moved between the operational position and the retrieval position. The securing portion may comprise contact areas configured to engage the ribbon cartridge to secure the ribbon cartridge in the installed position when the ribbon cartridge retaining feature is in the operational position, and the contact areas may comprise ridges. 
     The housing of the printer may define a media receiving area configured to receive a supply of media, and the printer may further comprise a media cover configured to move between a closed media position and an opened media position. The media cover may comprise an electromagnetic shield, and the media cover may be configured such that when the media cover is in the closed media position, the electromagnetic shield is positioned between the media receiving area and the ribbon receiving area. In some cases, the media cover may be blocked from moving to the closed media position when the ribbon cartridge retaining feature is in the retrieval position. 
     In some embodiments, the printer may further comprise a linkage connecting the ribbon cover to the ribbon cartridge retaining feature. Movement of the ribbon cover from the closed ribbon position to the opened ribbon position may be transmitted through the linkage to move the ribbon cartridge retaining feature from the operational position to the retrieval position. 
     The printer may also include a ribbon cover button configured to facilitate movement of the ribbon cover from the closed ribbon position to the opened ribbon position, and a media cover button configured to facilitate movement of the media cover from the closed media position to the opened media position. The media cover button may be located generally proximate the ribbon cover button. In some cases, the ribbon cover button may only be accessible by a user when the media cover is in the opened media position. 
     The linkage may comprise a sliding component defining a first end and a second end, and a rotating component defining a first leg and a second leg. The first end of the sliding component may be hingedly connected to the ribbon cover, and the second end of the sliding component may be slidingly engaged with the first leg of the rotating component. The second leg of the rotating component may further comprise a slot configured to receive an extension defined by the ribbon cartridge retaining feature, such that movement of the ribbon cover between the closed ribbon position and the opened ribbon position slides the second end of the sliding component along the first leg of the rotating component and rotates the rotating component with respect to the housing, thereby moving the ribbon cartridge retaining feature between the operational position and the retrieval position, respectively, via the extension. The ribbon cover and the ribbon cartridge retaining feature are configured to move substantially simultaneously. 
     In other embodiments, a printing mechanism is provided comprising a printhead, a platen configured to oppose the printhead during printing operations, and a printhead support configured to receive the printhead, wherein the printhead support defines a pocket configured to receive an RFID coupler. The printing mechanism may further comprise a ribbon cartridge comprising a supply spool and a take-up spool, where the ribbon extends between the supply spool and the take-up spool, and where the printhead support is positioned between the supply spool and the take-up spool. The printhead support may also define a bracket portion configured to receive the ribbon guide. 
     In some cases, the platen may also be positioned on a media cover that is configured to move between an opened media position and a closed media position such that the platen is configured to operationally engage the printhead when the media cover is in the closed media position. 
     In still other embodiments, the printer comprises a housing defining a ribbon receiving area, and a printhead support extending from the housing for receiving a printhead. The ribbon receiving area may be configured to receive a ribbon cartridge comprising a cartridge frame structured to support a supply spool, a take-up spool, and a ribbon extending between the supply spool and the take-up spool, and the printhead support may define first and second channels disposed on opposite sides of the printhead, where each of the first and second channels is structured to receive at least part of the cartridge frame. In some cases, the printhead may be positioned between the supply spool and the take-up spool. 
     The ribbon cartridge in some cases is movable between an installed position during printing operations and an accessible position to facilitate replacement. The ribbon cartridge may define a first orientation relative to the printhead support when disposed in the installed position and a second orientation relative to the printhead support when disposed in the accessible position. Furthermore, the cartridge frame of the ribbon cartridge may be substantially aligned with a top surface of the printhead support when the ribbon cartridge is disposed in the installed position, and the cartridge frame of the ribbon cartridge may extend at least partially beyond the top surface of the printhead support when the ribbon cartridge is disposed in the accessible position. 
     In addition, the cartridge frame of the ribbon cartridge may define gripping portions, wherein the gripping portions are disposed below a top surface of the printhead support when the ribbon cartridge is disposed in the installed position, and wherein the gripping portions are disposed above the top surface of the printhead support when the ribbon cartridge is disposed in the accessible position. 
     The printer may further comprise a ribbon cartridge retaining feature movable between an operational position and a retrieval position. The ribbon cartridge retaining feature may secure the ribbon cartridge in the installed position when disposed in the operational position, and the ribbon cartridge retaining feature may support the ribbon cartridge in the accessible position when disposed in the retrieval position. The ribbon cartridge retaining feature may define a securing portion configured to engage and secure the ribbon cartridge in the installed position when the ribbon cartridge retaining feature is disposed in the operational position, and the ribbon cartridge retaining feature may define a lifting portion configured to lift and support the ribbon cartridge in the accessible position when the ribbon cartridge retaining feature is disposed in the retrieval position. 
     In still other embodiments, a printer is provided that is adapted to print to a media having opposite ends, where the media is adapted to transition from a laterally strong condition to a laterally weak condition. The printer may comprise a housing defining a media receiving area configured to receive the media, two media support arms extending from the housing proximate the media receiving area for engaging opposite ends of the media, and a media cover configured to move between a closed position and an open position, the media cover comprising a second locking element. At least one of the media support arms may be biased to slidably translate along the housing to provide a holding force to opposite sides of the media, and the at least one of the media support arm may define a first locking element. The first locking element of the at least one of the media support arms may be configured to engage the second locking element of the media cover when the media cover is in the closed position. 
     The first locking element may be movable within the media support arm and may be biased towards engagement with the second locking element. In addition, the first locking element may include a spring configured to move the first locking element into engagement with the second locking element when the media cover is closed, thereby stabilizing the at least one of the media support arms during printing operations. In some cases, the second locking element may be configured to slope towards a center of the second locking element. 
     In still other embodiments, a printer is provided that comprises a ribbon cover configured to move between an opened ribbon position for providing access to the ribbon supply and a closed ribbon position, and a media cover configured to move between an opened media position for providing access to a media supply and a closed media position. One of the ribbon cover and the media cover may comprise a slidable opening mechanism. 
     In some cases, the printer defines a top surface, a front surface, and a bottom surface. The ribbon cover and the media cover may each form at least part of the front surface, and the slidable opening mechanism may be biased upwardly along a slide direction generally away from the bottom surface. The slidable opening mechanism may be configured to retain the respective cover in the respective opened position. 
     Furthermore, the other of the ribbon cover and the media cover may comprise a clamshell opening mechanism. The printer further comprises a first button for triggering the clamshell opening mechanism and/or a second button for triggering the slidable opening mechanism, wherein the second button is positioned generally adjacent to the first button. The printer may further comprise a seam defined between the ribbon cover and the media cover, wherein the first button and the second button are generally positioned proximate the seam. 
     In addition, the printer may define a top surface, a front surface, and a bottom surface, and the ribbon cover and the media cover may each form at least part of the front surface. The slidable opening mechanism may be biased upwardly along a slide direction generally away from the bottom surface, and the clamshell opening mechanism may be structured to pivot downwardly generally away from the top surface. Furthermore, the ribbon cover may comprise the slidable opening mechanism, and the media cover may comprise the clamshell opening mechanism. 
     In still other embodiments, a ribbon cartridge is provided that includes a supply spool, a take-up spool, and a cartridge frame. The cartridge frame comprises a first portion structured to support the supply spool and a second portion structured to support the take-up spool. A retrieval assist angle may be defined between the first portion and the second portion, and a gripping portion may be defined proximate the retrieval assist angle. The gripping portion may include ridges defined in the cartridge frame that facilitate grasping of the ribbon cartridge by a user. In addition, the ribbon cartridge may be adapted to be received in a printer, such that the gripping portion is exposed for grasping by a user when the ribbon cartridge is disposed in an accessible position, and not exposed for grasping by the user when the ribbon cartridge is disposed in an installed position. In some cases, the take-up spool may define an RFID tag configured to hold information regarding the ribbon cartridge. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  illustrates a printer according to an exemplary embodiment; 
         FIG. 2  is a bottom view of the printer of  FIG. 1 ; 
         FIG. 3  illustrates a top view of the printer of  FIG. 1  with a media cover in the opened media position and a ribbon cover in the closed ribbon position; 
         FIG. 4  shows the printer of  FIG. 1  with the media cover in the opened media position and the ribbon cover in the opened ribbon position; 
         FIG. 5  is a cross-sectional representation of a printing mechanism of the printer of  FIG. 1 , showing the ribbon and media paths during printing, according to an exemplary embodiment; 
         FIG. 6  is a schematic block diagram of an apparatus for load control according to an exemplary embodiment; 
         FIG. 7  is a flowchart according to a method for load control according to an exemplary embodiment; 
         FIG. 8  is a diagram representing a relationship between a state of charge value, a state of charge low threshold, a state of charge high threshold, and a charge control signal according to an exemplary embodiment; 
         FIG. 9  is a schematic block diagram of an apparatus for battery charge control according to an exemplary embodiment; 
         FIG. 10  is a flowchart according to a method for battery charge control according to an exemplary embodiment; 
         FIG. 11  shows a partial view of the printer of  FIG. 1  with the ribbon cover in a closed ribbon position; 
         FIG. 12  shows a partial view of the printer of  FIG. 1  with the ribbon cover in an opened ribbon position; 
         FIG. 13  illustrates a partial view of a printer housing, with a ribbon cartridge removed from the printer housing, according to an exemplary embodiment; 
         FIG. 14  shows a portion of the printer housing of  FIG. 13  with a first locating feature and a portion of the ribbon cartridge having a first corresponding locating feature; 
         FIG. 15  shows the first locating feature of  FIG. 14  of the printer housing engaged with the first corresponding locating feature of the ribbon cartridge; 
         FIG. 16  is a cross-sectional view of a portion of the printer with the ribbon cartridge received into the printer housing of  FIG. 13 ; 
         FIG. 16A  is a detail view of the inside surface of the securing portion of the ribbon cartridge retaining feature of  FIG. 16 ; 
         FIG. 17  shows the media cover of the printer of  FIG. 1  engaged with a ribbon cartridge according to an exemplary embodiment; 
         FIG. 18  is a side view of the ribbon cartridge of  FIGS. 13-17  showing the forces exerted by the locating features of the printer; 
         FIG. 19  shows a ribbon guide of a printer according to an exemplary embodiment; 
         FIG. 20  shows the top view of the ribbon guide of  FIG. 19 ; 
         FIG. 21  is a cross-sectional representation of the printer of  FIG. 1 , showing shielding of an RFID coupler during printing, according to an exemplary embodiment; 
         FIG. 22  illustrates the mounting of the RFID coupler of  FIG. 21  in the printer according to an exemplary embodiment; 
         FIG. 23  illustrates a locking element connecting to both a media support arm and the media cover according to an exemplary embodiment; 
         FIG. 24  shows the locking element of  FIG. 23  connected to the media cover; 
         FIG. 25  shows the media support arms of  FIG. 23  engaged with a supply of media; 
         FIG. 26  is a top view of a printer including alignment marks according to one embodiment; 
         FIG. 27  shows a printer including an alignment feature according to another embodiment; 
         FIG. 28  is a top view of a portion of a printer including an alignment feature according to another embodiment; 
         FIG. 29  is a top view of a portion of a printer including an alignment feature according to another embodiment; and 
         FIG. 30  shows a printer including an alignment feature according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, embodiments of these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Further, the term “exemplary” as used herein is defined to indicate an example, and should not be construed to indicate a qualitative assessment. 
     The devices, systems, and methods of the present invention may be used by manufacturers and distributors for printing needs, such as printing shipping labels or product label tags. The devices, systems, and methods described provide an ability to quickly and easily manage supplies and products, store information on product labels, and aid in product shipping. The devices, systems, and methods may be stand alone applications, or they may communicate with other devices to help facilitate management of products or supplies. 
     One such application is that of a printer  10 , as seen in  FIG. 1 . For the purposes of explanation, the printer  10  will be described in terms of a portable thermal transfer printer, although it is understood that the devices, systems, and methods of embodiments of the present invention may be used for any printer or device with similar components, including direct thermal printers. The printer  10  is typically used for encoding and reading RFID tags, as well as printing labels. 
     An embodiment of the printer  10  may be useful in a fast-paced moving environment due to its portability. The relatively small, lightweight design of the printer  10  allows the printer to be easily picked up and carried. The printer  10  may define one or more attachment openings  90 , as seen in  FIG. 2 . The attachment openings  90  are configured to engage a latching mechanism for connection to and/or the support of a cradle or other device or support. To further allow for portability, the printer  10  may include one or more batteries, e.g., a smart battery  95 , as a power source. In this way, the printer  10  may be quickly moved to convenient locations without regard for the location of power outlets. In some cases, the battery may be external to the printer, as in the case when a separate battery is provided on a cart, or when the battery in a vehicle is used to provide power for the printer. 
     Referring again to  FIG. 1 , the printer  10  may include a ribbon cover  20  and a media cover  30 . According to the illustrated embodiment, the media cover  30  can be opened using the media cover button  35 . As seen in  FIG. 3 , the media cover  30  encloses a media receiving area  40 , such as a cavity, which stores media  45 , such as shipping labels. The media  45  can be inserted into the media support arms  80  and locked into place with the locking element  85  when the media cover  30  is closed. The ribbon cover  20  can be opened by pushing the ribbon cover button  25 . The ribbon cover  20  encloses the ribbon receiving area  50 , which stores the ribbon cartridge  52 , as shown in  FIG. 4 . 
       FIG. 4  also shows that the printer  10  may include one or more input data ports for importing data from or exporting data to an external source. Data imported could include printing commands, status requests, e-mail, printer settings, executable computer code, definitions for formatting data, fonts, graphics, passwords, or maintenance data. The data could be provided from a data storage medium, such as a computer, web site, portable data terminal, mobile phone, bar code reader, RFID reader, weigh scale, truck radio, or even another printer. Communication could be via a Universal Serial Bus (USB), Ethernet stack, wireless radio, or the like. These data ports can be located under the data port cover  100  and can allow for data to be input to communicate with the printer  10  during typical operation to help facilitate tasks like storing information or printing certain labels. Data could also be exported from these ports to help with product information storing and shipment tracking. Data exported could include the response to status requests, e-mail, network messages, printer status or settings, stored customer data, passwords, maintenance data, printer alert conditions, information read from RFID tags on the ribbon or supplies, battery status, external battery conditions, or information derived from sensors within the printer such as power conditions, supply measurements, temperature, or printhead conditions. 
     Various embodiments of the printer  10  may also utilize wired and/or wireless communications techniques and/or protocols for communications with, and control of, the printer  10  via the data ports described above. These communications techniques and/or protocols may allow for tethered and/or untethered operation of the printer  10 . In this regard, the printer may include a communications interface that may be controlled by various means, including one or more processors. The one or more processors may be software and/or hardware configured and may control various communications hardware that may be used to implement communications with a remote device (e.g., a host device). The processor(s) may be configured to communicate using various wired and wireless communications techniques and/or protocols including serial and parallel communications and printing protocols, USB techniques, transmission control protocol/internet protocol (TCP/IP), radio frequency (RF), infrared (IrDA), or any of a number of different wireless networking techniques, including WLAN techniques such as, IEEE 802.11 (e.g., 802.11a, 802.11b, 802.11g, 802.11n, etc.), world interoperability for microwave access (WiMAX) techniques such as IEEE 802.16, and/or wireless Personal Area Network (WPAN) techniques such as IEEE 802.15, Bluetooth (BT), ultra wideband (UWB) and/or the like. The printer  10  may implement these and other communications techniques and/or protocols directly with a host device in a point-to-point manner, or indirectly through an intermediate device such as an access point or other network entity. Various host devices that may be used to communicate with and/or control the operation of printer  10  may include computers, mobile computers, cameras, scales, global positioning system (GPS) devices, radios, mobile terminals, media players, or the like. 
     As seen in  FIG. 5 , when the printer  10  is closed and in typical operation, the media  45  passes over an RFID coupler  60  for encoding and reading of an RFID tag that may be encoded in the media  45 . When a ribbon  55  is used (such as in thermal transfer printing), the media  45  then contacts the ribbon  55  and the platen roller  75  for the printing of the label, as illustrated in  FIG. 5 . In printing applications where no ribbon is used (such as in direct thermal printing), the media would contact the thermal printhead  70  and the platen roller  75 . Referring again to  FIG. 1 , once the label has been printed, the media exits the printer via the media exit slot  105 . In embodiments, the printer  10  may include an optional peeler that functions to separate the printed media (e.g., the printed label) from a liner. In these cases, the peeled label may be discharged from the printer via the media exit slot  105 , and the liner may be separately discharged via the liner exit slot  110 . 
     The printer  10  can include many different features that may combine to help meet various printing needs. Several of the features that may be included are described below with reference to the figures. 
     Load Control Feature 
       FIG. 6  depicts an apparatus  120  for load control according to an exemplary embodiment. The apparatus  120  and, in particular, the processor  125  and the memory device  126 , may be configured to perform load control as described below with respect to  FIGS. 6 and 7 . The apparatus  120  may be embodied as, or utilized in combination with, any battery operated electronic device, such as a printer (e.g., the printer  10 ), computer, portable data terminal, scanner, RFID reader, portable device (e.g., music player, mobile telephone, digital camera, global positioning system (GPS) device), external battery (e.g., cart battery, forklift, vehicle), or the like. The apparatus  120  may include, control, and/or be in communication with a memory device  126 , a processor  125 , a smart battery  95 , a load controller  130 , and a load  135 . 
     The memory device  126  may include, for example, volatile and/or non-volatile memory. The memory device  126  may be configured to store information, data, applications, instructions, or the like for enabling the apparatus to carry out various functions in accordance with exemplary embodiments. For example, the memory device  126  could be configured to buffer input data for processing by the processor  125 . Additionally or alternatively, the memory device  126  may be configured to store instructions for execution by the processor  125 . In some cases, the memory device  126  may be external to the load control apparatus  120 , such as when the memory device  126  resides on a computer in communication with the apparatus  120 . 
     The processor  125  may be embodied in a number of different ways. For example, the processor  125  may be embodied as a microprocessor, a coprocessor, a controller, or various other processing means or elements including integrated circuits such as, for example, an ASIC (application specific integrated circuit) or FPGA (field programmable gate array). In an exemplary embodiment, the processor  125  may be configured to execute instructions stored in the memory device  126  or otherwise accessible to the processor  125 . 
     The load controller  130  may be any type of controllable switching device that may be used to interrupt and reestablish the flow of current from the smart battery  95  to the load  135 . In this regard, the load controller  130  may be a switching relay, a transistor, a controllable switch, or the like. The load controller  130  may include an input that may receive a control signal and in response generate an open or closed circuit condition. 
     Further, the load  135  of the apparatus  120  may be any type of electrical load. In this regard the electrical load may be a printer, a printhead, an RFID encoder, a computer, a portable device (e.g., a music player, a mobile telephone, a digital camera, a global positioning system (GPS) device), or the like, as described above. The load  135  in  FIG. 6  is powered by the smart battery  95 . 
     The smart battery  95  may be a battery equipped with specialized hardware and/or software for monitoring a battery and transmitting information regarding the battery. In this regard, the smart battery  95  may include a battery  140  and a state of charge generator  145 . The battery  140  may be any rechargeable, or non-rechargeable, power source and may include any type and number of battery cells. In some embodiments, the battery cells of the battery  140  may be lithium-ion, lithium-cobalt, lithium-polymer, nickel cadmium, nickel metal hydride, or the like. Similar non-battery rechargeable, or non-rechargeable, power sources may include fuel cells, capacitors, pressurized air tanks, radioactive decay devices, or microelectromechanical systems (MEMS) vibration cells. In some exemplary embodiments, the smart battery  140  may be removable from apparatus  120  and replaceable. 
     The state of charge generator  145  may be any electronic device that may be configured to monitor the battery  140  to determine the state of charge of the battery  140  and transmit communications with respect to the state of charge. In this regard, the state of charge of a battery may be an indication and/or prediction of the remaining battery capacity. Unlike voltage levels associated with a battery, a state of charge value for a battery need not respond to, or indicate, sudden changes in load (e.g., powering up a printer, powering up a thermal printhead in preparation for printing on a media, or the like). In this regard, the state of charge value may be substantially immune to sudden changes in load, unlike voltages, which may experience significant transient fluctuations when load is introduced or removed from a circuit. 
     In some embodiments, the state of charge value may provide a representation of a percentage of the maximum capacity of a fully charged battery. For example, a fully charged battery may have a state of charge value representing 100%. Similarly, a battery that is half charged, may have a state of charge value representing 50%. In this regard, over the life of a battery, the power output of the battery may degrade. As such, in some exemplary embodiments, the state of charge value may be determined relative to a fully charged battery experiencing a degraded power output. Additionally, in some exemplary embodiments, the state of charge value need not be determined relative to a fully charged battery, but rather a predetermined set point. As a result, in these embodiments, the state of charge value may represent a percentage above 100% or below 0%. Additionally, in some exemplary embodiments, information about the age of a battery, date of manufacture, manufacturing lot, design, part number, maintenance history, sales history, or usage history of the battery may also be used in determining the state of charge or its suitability for operation under certain conditions. 
     In this regard, the state of charge generator  145  may be configured to receive a request for a state of charge value and return (i.e., transmit) the state of charge value to the requesting entity (e.g., the processor  125 ) or another entity. Further, in some exemplary embodiments, the state of charge generator  145  may be configured to transmit a state of charge value at a regular interval (i.e., based on a timer). In some exemplary embodiments, the state of charger generator  145  may be configured to transmit a state of charge value at irregular intervals, such as, for example when the state of charge reaches one or more predetermined break points (e.g., 75%, 50%, 25%, 10%, 5%, or the like). Transmission of a state of charge value may be performed by providing the information in an analog signal or in a digital signal, such as a data packet. 
     In some exemplary embodiments, the processor  125  of the apparatus  120  may be configured to provide for transmission of a request to the smart battery  95  and, in turn, the state of charge generator  145 . The request may be any type of communication that causes the state of charge generator to respond by providing a representation of a state of charge value to the processor  125 . In some exemplary embodiments, the processor may be configured to provide for transmission of a request, where the request is a smart battery message as described in Smart Battery Data Specifications, such as,  Smart Battery Data Specification , Rev. 1.1, Dec. 11, 1998, which is hereby incorporated by reference in its entirety. The smart battery message may be a RelativeStateOfCharge( ) message or an AbsoluteStateOfCharge( ) message. 
     In some embodiments, the smart battery  95  may be configured to transmit, receive, and or store various types of data regarding the state of the battery. Such data may include the number of cycles that the battery has experienced, the date the battery was first used, the theoretical capacity of a new battery, the theoretical voltage of a new battery, the predicted battery capacity when the battery is fully charged, the relative health of the battery (e.g., “good,” “replace,” or “poor”) based on the number of times the battery has cycled, the date the battery was manufactured, the predicted remaining battery capacity, the serial number of the battery, and/or the internal temperature of the battery. 
     The processor  125  may also be configured to receive a representation of the state of charge. The processor  125  may receive the representation of the state of charge from the state of charge generator  145  based on the state of charge generator&#39;s monitoring of the battery  140 . In this regard, the representation of the state of charge may be received as an analog or digital signal. In some exemplary embodiments, the representation of the state of charge may be received as a data packet. The representation of the state of charge value may be a converted, encoded, translated, etc. version of the state of charge value. In some exemplary embodiments, receiving the representation of the state of charge value may also include converting, decoding, translating, etc. the representation of the state of charge value into the state of charge value. 
     The processor  125  may be further configured to compare the state of charge value with a state of charge load control threshold. The state of charge load control threshold may be a predetermined value that may be compared to the state of charge value. In some exemplary embodiments, the state of charge load control threshold may be set at a battery capacity where power from the battery  140  to the load  135  may be interrupted. For example, the state of charge load control threshold may be set at 5%, and, as a result, when the state of charge value reaches or falls below 5%, actions may be implemented to interrupt power from the battery to the load, so as not to completely discharge the battery. The state of charge load control threshold may be stored in, for example, the memory device  126 , and the processor  125  may be configured to retrieve the state of charge load control threshold from the memory device  126  for comparison. 
     In some exemplary embodiments, the state of charge value may be averaged with one or more previously received state of charge values to determine an average state of charge value. In this regard, the average state of charge value may be used in the comparison with the state of charge load control threshold. As such, the processor  125  may be configured to receive and store a plurality of state of charge values. The plurality of state of charge values may be stored in memory device  126 . Accordingly, the processor  125  may be configured to average the stored state of charge values. The plurality of received state of charge values may be received over a predetermined period of time. For example, an average may be determined for all values received over a period of 1 second. Further, in some exemplary embodiments, an average state of charge value may be determined based on some predetermined number of received state of charge values. For example, the average state of charge value may be determined based on the last six received state of charge values. In this example, a first-in first-out algorithm may be utilized for the state of charge values such that when a new state of charge value is received, the oldest state of charge value may be discarded. The processor  125  may therefore be configured to determine the average of the stored state of charge values, the variation in those values, or the trend of those values with respect to time or other operating conditions of the printer. 
     In this regard, the processor  125  may be configured to provide for transmission of a power down signal, or a modification of a power down signal, in response to the state of charge value, or the average state of charge value, surpassing the state of charge load control threshold. The term surpassing, and variations of the term (i.e., surpass, surpassed, or the like), may be defined to mean reaching, exceeding, falling below, or the like. Further, the power down signal may be any signal output by the processor that may indicate that the state of charge value, or the average state of charge value, has surpassed the state of charge load control threshold. In some exemplary embodiments, the modification of a signal (e.g., the power down signal) may be a change in a power or voltage level of the signal. Further, in some exemplary embodiments, in response to the state of charge signal falling below the state of charge load control threshold, the processor  125  may transmit a power down signal, or a modification of a power down signal, to the load controller  130  causing the load controller  130  to interrupt power to the load  135 . Similarly, in some exemplary embodiments, in response to the state of charge signal reaching or exceeding the state of charge load control threshold (i.e., due to charging of the battery), the processor  125  may transmit a power down signal, or a modification of a power down signal, to the load controller  130  causing the load controller  130  to cease interruption of power (i.e., allow power to flow) to the load. 
       FIG. 7  illustrates a method for performing load control according to various exemplary embodiments of the present invention. The exemplary method of  FIG. 7  may be implemented by the apparatus  120  or the processor  125 . Various steps or operations of the exemplary method of  FIG. 7  may be omitted, and various orderings of the steps or operations are contemplated. 
     The exemplary method of  FIG. 7  may include providing for transmission of a request for a state of charge value at  150 . The exemplary method may also include receiving a representation of the state of charge value at  152 . At  154 , the exemplary method may include comparing the state of charge value with a state of charge load control threshold. In some exemplary embodiments, comparing the state of charge value with a state of charge load control threshold may include comparing a state of charge value that is an average state of charge value to the state of charge load control threshold. At  156 , the exemplary method may also include providing for transmission of a power down signal, or a modification of a power down signal, in response to the state of charge value surpassing the state of charge load control threshold. 
     Battery Charge Control Feature 
       FIGS. 8, 9, and 10  describe exemplary embodiments that may perform battery charge control, such as charge control of the printer  10 . The exemplary embodiments describing aspects of  FIGS. 8, 9, and 10  may, but need not, be combined with the other aspects of the present invention as described herein. 
     Exemplary embodiments may include a state of charge low threshold and a state of charge high threshold. In this regard, the state of charge low threshold may be set such that when a state of charge value of a battery falls below the state of charge low threshold, charging of the battery may be initiated. Further, when the state of charge value of a battery rises to, or exceeds, the state of charge high threshold, battery charging may be interrupted. 
     By setting a state of charge high threshold, charging of a battery may be discontinued before the battery achieves a maximum charge. In some instances, charging a battery to a maximum charge may be detrimental to the operation of the battery over the lifetime of the battery. Further, by setting a state of charge low threshold, a battery need not experience continuous recharging cycles when the state of charge of the battery falls below the state of charge high threshold. These continuous recharging cycles may also be detrimental to battery operation over the lifetime of the battery. Rather the state of charge low threshold may provide for a discharge region between the state of charge low threshold and the state of charge high threshold where the battery need not be re-charged to the state of charge high threshold until the state of charge of the battery falls to the state of low threshold. By implementing the thresholds in this manner, continuous re-charging of the battery may be avoided when the battery is connected to a charger and the state of charge of the battery falls below the state of charge high threshold. 
     With regard to battery charge control, the signal diagram of  FIG. 8  provides an exemplary scenario. In this regard, embodiments may receive a state of charge value and control the charging of a battery based on the state of charge value. The state of charge value may be compared to a state of charge low threshold and a state of charge high threshold. 
     In the exemplary scenario of  FIG. 8 , at  160  the state of charge value is between the state of charge low threshold and the state of charge high threshold. At  160 , the battery may be connected to a charging power supply capable of charging the battery through battery charging control circuitry (e.g., a battery charge controller). However, since the state of charge value is above the state of charge low threshold, charging of the battery is not initiated and the charge control signal remains at a level such that the battery is not charged. 
     At  162 , the battery begins to discharge and the state of charge value falls to the state of charge low threshold at  164 . In response to the state of charge falling to the state of charge low threshold, the charge control signal may be modified such that charging is initiated at  164 , since the battery is connected to a charging power supply. Charging may continue until the state of charge value reaches the state of charge high threshold at  166 . In response to the state of charge reaching the state of charge high threshold the charge control signal may be modified such that charging is interrupted at  166 . In the exemplary scenario of  FIG. 8 , the charging power supply may be disconnected from the battery charge control circuitry, and, in turn, the battery, possibly for mobile operation of the device being powered by the battery sometime after  166  and before  168 . 
     From  166  to  168 , the state of charge value may fall while the battery is discharging, for example, due to the operation of a device powered by the battery. At  168 , the state of charge value again reaches the state of charge low threshold, and the charge control signal may be modified again such that charging may be initiated at  168 . However, since the charging power supply is no longer connected to the battery charge control circuitry, charging of the battery may not commence. At  169 , the charging power source may be connected to the battery control circuitry, and since the charge control signal has been modified to allow for charging of the battery, battery charging may commence. 
       FIG. 9  depicts an additional exemplary apparatus  170  for performing battery charge control according to various exemplary embodiments of the present invention. The apparatus  170  and, in particular, the processor  125  and the memory device  126  may be configured to perform various aspects of battery charge control as described with respect to  FIGS. 8, 9, and 10 , in addition to, or in lieu of, being configured to perform various aspects of load control as described with respect to  FIGS. 6 and 7 . The apparatus  170  may be embodied as scenario  160  of  FIG. 8  and may include some or all of the components of apparatus  120 , such as the smart battery  95  (including the battery  140  and the state of charge generator  145 ), the load controller  130 , and the load  135 , which may be embodied and/or operate as described above. Additionally, the apparatus  170  may include a charging controller  172  and a charging power supply  174 . 
     The charging controller  172  may be any type of controllable switching device that may be used to interrupt and reestablish the flow of current from the charging power source  174  to the battery  140 . In this regard, the charging controller  172  may be a switching relay, a transistor, a controllable switch, or the like. The charging controller  172  may include an input that may receive a control signal and in response generate an open or closed circuit condition. 
     The charging power supply  174  may be any type of power source that may be used to charge the battery  140 . In this regard, the charging power supply  174  may originate from, for example, a wall outlet, a generator, an alternator, another battery, or the like. In some exemplary embodiments, the charging power supply  174  may be external to the apparatus  170  and/or may be removable from the charging controller  172  and/or the battery  140 . In these embodiments, when the charging power supply  174  is removed, the charging power supply  174  may be unable to charge the battery  140 . In some exemplary embodiments, the charging controller  172  may also be removable with the charging power supply  174 . 
     The processor  125  may be configured to receive a state of charge value as described above. The processor  125  may also be configured to compare the state of charge value, or an average state of charge value, to a state of charge low threshold and a state of charge high threshold. The state of charge low threshold and the state of charge high threshold may be stored in, for example, the memory device  126 , and the processor  125  may be configured to retrieve the state of charge low threshold and the state of charge high threshold from the memory device  126  for comparison. 
     The processor  125  may also be configured to provide for transmission of a charge control signal, or a modification to a charge control signal, in response to the state of charge value being less than the state of charge low threshold. In this regard, the charge control signal, or the modification of a charge control signal may initiate charging of a battery. For example, the processor  125  may provide the charge control signal, or modification thereof, to charging controller  172 , and in response, the charging controller  172  may generate a closed circuit between the charging power supply  174  and the battery  140 , thereby charging the battery  140 . In instances where the charging power supply  174  is removed, the processor  125  may provide the charge control signal, or modification thereof, to the charging controller  172 , and the charging controller  172  may respond; however, charging may not initiate until the charging power supply  174  is connected to the charging controller  172  and/or the battery  140 . 
     The processor  125  may also be configured to provide for transmission of a charge control signal, or a modification to a charge control signal, in response to the state of charge value being greater than or equal to the state of charge low threshold. In this regard, the charge control signal, or the modification of a charge control signal may interrupt charging of a battery. For example, the processor  125  may provide the charge control signal, or modification thereof, to the charging controller  172 , and in response, the charging controller  172  may generate an open circuit between the charging power supply  174  and the battery  140 , thereby interrupting the charging of the battery  140 . 
       FIG. 10  illustrates a method for performing battery charge control according to various exemplary embodiments. The exemplary method of  FIG. 10  may be implemented by the apparatus  170  or the processor  125 . Various steps or operations of the exemplary method of  FIG. 10  may be omitted, and various orderings of the steps or operations are contemplated. 
     The exemplary method of  FIG. 10  may include receiving a representation of the state of charge value at  180 . In this regard, the exemplary method may also include providing for transmission of a request for a state of charge value, and receiving the representation of the state of charge value in response to the request. At  182 , the exemplary method may include providing for transmission of a battery charge signal, or a modification of a battery charge signal, to thereby charge a battery in response to the state of charge value being less than a state of charge low threshold. At  184 , the exemplary method may include providing for transmission of a battery charge signal, or a modification of a battery charge signal, to thereby interrupt battery charging in response to the state of charge value being greater than or equal to a state of charge high threshold. In some exemplary embodiments, an average state of charge value may be used as the state of charge value in  182  and/or  184 . 
     With or without these approaches, information about the battery, its state of charge, its current condition, or its usage history could be used to moderate operation of the printer, display instructions to users, or alert external systems via the external communication systems. For instance, in some applications, printing may be sped up or print darkness may be reduced as the battery discharges in order to maximize the amount of printing from the available charge. A warning could be printed out, printing could be delayed, or a message could be rendered on the user display to warn of low charge conditions. This could be particularly valuable if enough power remains for basic communicating or printing a single label, but there is insufficient power for printing a full batch of labels or for downloading a large data update. Radio communication or RFID encoding could also be temporarily suspended to conserve power. 
       FIGS. 7 and 10  are flowcharts of systems, methods, and program products according to exemplary embodiments of the invention. It will be understood that each block, step, or operation of the flowcharts, and combinations of blocks, steps or operations in the flowcharts, can be implemented by various means, such as hardware, firmware, and/or software including one or more computer program code portions, program instructions, or executable program code portions. For example, one or more of the procedures described above may be embodied by computer program code instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by a memory device of the apparatus and executed by a processor in the apparatus. As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (i.e., hardware) to produce a machine, such that the instructions which execute on the computer or other programmable apparatus create means for implementing the functions specified in the flowcharts block(s), step(s), or operation(s). These computer program instructions may also be stored in a computer-readable memory that can direct a computer, a processor, or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowcharts block(s), step(s), or operation(s). The computer program instructions may also be loaded onto a computer, processor, or other programmable apparatus to cause a series of operational steps to be performed on the computer, processor, or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer, processor, or other programmable apparatus provide steps for implementing the functions specified in the flowcharts block(s), step(s), or operation(s). 
     Accordingly, blocks, steps, or operations of the flowcharts support combinations of means for performing the specified functions, combinations of steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that one or more blocks, steps, or operations of the flowcharts, and combinations of blocks, steps, or operations in the flowcharts, can be implemented by special purpose hardware-based computer systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions. 
     Ribbon Cartridge Insertion Feature 
     Another feature that may be included in a portable printer according to an exemplary embodiment is a ribbon cartridge insertion feature. The ribbon cartridge insertion feature provides a user with access to a ribbon receiving area  50  (shown in  FIG. 4 ), which may include one or more cavities, for example, to allow a user to remove an old ribbon cartridge and/or to allow a user to install a new ribbon cartridge. More specifically, the ribbon cartridge insertion feature allows the user to access the ribbon cartridge without requiring removal of the media. In this way, as described below, the user may replace or install a ribbon cartridge without having to first remove the media from the media receiving area. 
     Referring to  FIG. 1 , when the ribbon cover  20  and the media cover  30  of the printer  10  are closed, a user can depress the media cover button  35  to open the media cover  30 . The media cover button  35  may be located in any location that is accessible to the user when the ribbon and media covers  20 ,  30  are closed, such as on a side of the printer  10 . The media cover button  35  may engage an internal portion of the media cover  30  in the closed media position such that depressing the button  35  releases the media cover  30  so that it may be opened by a user to expose the media  45  and/or the media receiving area  40 , as shown in  FIG. 3 . For example, depressing the media cover button  35  may release a spring-loaded tab  36  located on a shield housing  64  that is integral to or otherwise attached to the media cover  30 . Disengagement of the spring-loaded tab  36  may also serve to urge the media cover  30  away from the rest of the printer housing, towards the opened media position illustrated in  FIG. 3 . 
     In the depicted embodiments, opening of the media cover  30  exposes a ribbon cover button  25 , which is configured to provide access to the ribbon cartridge. Depressing the ribbon cover button  25  allows the ribbon cover  20  to move to an opened ribbon position and substantially simultaneously raises an installed ribbon cartridge  52  away from the printer housing  12  such that the ribbon cartridge  52  is disposed in an accessible position. In the accessible position, the ribbon cartridge  52  may be grasped and removed by the user, as shown in  FIG. 4  and described below. Likewise, a new ribbon cartridge  52  may be installed by placing the ribbon cartridge  52  in the ribbon receiving area  50  and closing the ribbon cover  20  to urge the ribbon cartridge  52  into an installed position for printing. 
       FIG. 11  shows a cut-away partial view of the top of the printer  10  with the ribbon cover  20  in the closed ribbon position, and  FIG. 12  shows a similar view with the ribbon cover  20  in the opened ribbon position. The ribbon cover  20  may be generally spring-loaded or otherwise biased to the opened ribbon position and may be held in the closed ribbon position at least in part by the ribbon cover button  25 . In this way, depressing the ribbon cover button  25  releases the ribbon cover  20  and facilitates movement of the ribbon cover  20  away from the ribbon receiving area  50  to the opened ribbon position. The ribbon cover  20  may be configured to move to the opened ribbon position in various ways. For example, in  FIGS. 11 and 12 , the ribbon cover  20  remains engaged with the printer housing  12  along two sides of the ribbon cover  20  and slides away from the media cover  30  (shown in  FIG. 4 ) following a cam surface  14  on each side of the printer housing  12 . 
     The ribbon cartridge  52  (shown separately in  FIG. 13 ) is configured to fit within the ribbon receiving area  50  with the supply spool  56  being received by a ribbon cartridge retaining feature  58 . The ribbon cartridge retaining feature may be a tray, as shown in the depicted embodiment, or one or more clips configured to engage at least a portion of the ribbon cartridge. The ribbon cartridge retaining feature  58  may include a lifting portion  354  configured to support at least part of the ribbon cartridge  52 , and a securing portion  54  configured to maintain the ribbon cartridge  52  in the installed position when the ribbon cartridge retaining feature  58  is in an operational position. The ribbon cartridge retaining feature  58  may have, for example, a “U” shape such that the supply spool  56  rests in the trough of the “U” and is supported by the lifting portion  354 . When the ribbon cover  20  is in the closed ribbon position, as seen in  FIG. 11 , the ribbon cartridge retaining feature  58  may be configured to move to the operational position, wherein the securing portion  54  (i.e., one leg of the “U” shape) covers the supply spool  56 , separating the ribbon receiving area  50  from the media receiving area  40  and holding the ribbon cartridge  52  within the ribbon receiving area  50 . In this regard, the securing portion  54  may include contact areas configured to engage the ribbon cartridge  52  to secure the ribbon cartridge  52  in the installed position when the ribbon cartridge retaining feature  58  is in the operational position. As shown in  FIGS. 16 and 16A , for example, the contact areas may include tabs  454  and/or ridges  455  configured to contact the ribbon cartridge  52  and urge it into the installed position for printing operations. 
     When the ribbon cover  20  moves from the closed ribbon position to the opened ribbon position, illustrated in  FIG. 12 , the ribbon cartridge retaining feature  58  is rotated towards the media receiving area  40  (i.e., in the clockwise direction in  FIGS. 11 and 12 ) from the operational position to the retrieval position, thereby raising the supply spool  56  out of the ribbon receiving area  50  and moving the ribbon cartridge  52  from the installed position to the accessible position. In this regard, the ribbon cartridge retaining feature  58  may be connected to the printer housing  12  via a ribbon cartridge hinge  62 , such that ribbon cartridge retaining feature  58  is able to rotate about the ribbon cartridge hinge  62  when the ribbon cover  20  moves between the closed and opened ribbon positions. 
     The ribbon cover  20  is connected to the ribbon cartridge retaining feature  58  via a linkage  44 , as shown in  FIGS. 11 and 12 . The linkage  44  may include a sliding component  66  that connects to the ribbon cover  20  and a rotating component  68  that connects to the ribbon cartridge retaining feature  58 . A first end  47  of the sliding component  66  may be connected to the ribbon cover  20  by a hinge pin  67  (shown in  FIG. 12 ) such that as the ribbon cover  20  moves between the closed and open positions the sliding component  66  is able to rotate with respect to the ribbon cover  20  about the hinge pin  67 . 
     The rotating component  68  may have an “L” shape, with a first leg  69  of the rotating component  68  engaging a second end  51  of the sliding component  66  and a second leg  71  of the rotating component  68  connecting to the ribbon cartridge retaining feature  58 . In this regard, the first leg  69  of the rotating component  68  may include a hollow portion that is configured to receive the second end  51  of the sliding component  66  such that the second end  51  of the sliding component  66  is able to slide along at least a portion of the length of the first leg  69 . 
     The area of the printer housing  12  proximate the second leg  71  of the rotating component  68  may include a slot  63  through which an extension  61  of the ribbon cartridge retaining feature  58  passes to engage the second leg  71  of the rotating component  68 . Thus, the second leg  71  may include a hole  59  that is configured to receive the extension  61  of the ribbon cartridge retaining feature  58 . The hole  59  may be circular or slightly oblong to provide additional tolerance for receiving the extension  61 . The second leg  71  may have various configurations. For example, the second leg  71  may incorporate a sector gear, as shown in  FIGS. 11 and 12 , that is configured to engage an optional damper (not shown) to slow down the motion of the ribbon cover  20  when the ribbon cover  20  is moved from the closed position to the open position. 
     The first and second legs  69 ,  71  of the rotating component  68  may be substantially perpendicular to each other, as shown in the figures, or may join at some other angle suitable to allow the movement of the linkage  44  and other components. The legs  69 ,  71  may define an aperture  57  at their juncture that is configured to receive a protrusion  53  of the printer housing  12 , thereby forming a pivot point. In this way, the rotating component  68  is able to rotate about the protrusion  53 , as described below. 
     Referring now to  FIG. 11 , when the ribbon cover  20  is in the closed ribbon position, the second end  51  of the sliding component  66  is received within the hollow portion of the first leg  69  of the rotating component  68  such that the second end is in a position proximate the protrusion of the printer housing  12 . In the closed ribbon position of this example, the first leg  69  of the rotating component  68  is substantially perpendicular to the plane of the ribbon cover  20 . The second leg  71  of the rotating component  68  is positioned such that the extension  61  of the ribbon cartridge retaining feature  58  is held at one end of the slot  63  corresponding to a retracted ribbon cartridge retaining feature  58 . Thus, when the ribbon cover  20  is in the closed ribbon position, the securing portion  54  of the ribbon cartridge retaining feature  58  substantially covers the supply spool  56  and limits access to the ribbon cartridge  52 . 
     Upon actuation of the ribbon cover button  25 , the ribbon cover  20  moves from the closed ribbon position ( FIG. 11 ) to the opened ribbon position ( FIG. 12 ). As the ribbon cover  20  moves from the closed ribbon position to the opened ribbon position, the sliding component  66  pivots about the hinge pin  67  and slides within the hollow portion of the first leg  69  of the rotating component  68 , moving the second end  51  of the sliding component  66  away from the protrusion  53  of the printer housing  12 . As the sliding component  66  pivots and slides within the first leg  69 , the rotating component  68  is rotated about the protrusion  53 , and the extension  61  of the ribbon cartridge retaining feature  58  is moved along the slot  63  by the second leg  71  of the rotating component  68 . In addition, as the rotating component  68  rotates, the extension  61  is moved along an arcuate path via the slot  63 , which serves to rotate the ribbon cartridge retaining feature  58  from the operational position ( FIG. 11 ) to the retrieval position ( FIG. 12 ), thereby presenting the ribbon cartridge  52  to the user. For example, the extension  61  may be an extension of the lifting portion  354  (shown in  FIG. 16 ) of the ribbon cartridge retaining feature  58 . Thus, as the extension  61  is rotated to a raised position via the rotating component  68 , the ribbon cartridge retaining feature  58  likewise moves towards the retrieval position described above. 
     When the user has accessed the ribbon cartridge  52 , such as to remove the old cartridge and install a new cartridge, the user may close the ribbon cover  20 , for example, by manually moving the cover  20  from the opened ribbon position of  FIG. 12  to the closed ribbon position of  FIG. 11 . Closing the ribbon cover  20  serves to push the sliding component  66  back into the hollow portion of the rotating component  68 , rotating the rotating component  68  towards the closed position, moving the extension  61  of the ribbon cartridge retaining feature  58  via the slot  63 , and moving the ribbon cartridge retaining feature  58  to the operational position so that the ribbon cartridge  52  is ready for printing. As the ribbon cover  20  reaches the closed ribbon position shown in  FIG. 11 , the cover  20  may engage the ribbon cover button  25  (directly or indirectly) such that the ribbon cover  20  is held in the closed ribbon position and the ribbon cover button  25  is ready to open the ribbon cover  20  upon its next actuation. Furthermore, once the ribbon cover  20  has been closed and the ribbon cartridge  52  is in the operational position, there is adequate clearance for moving the media cover  30  into the closed media position (see  FIG. 1 ) such that the printer  10  may be used for printing operations. In other words, the media cover  30  may be blocked from moving to the closed media position when the ribbon cartridge retaining feature  58  is in the retrieval position, requiring that the ribbon cover  20  be closed before the media cover  30  can be closed. 
     In some embodiments (for example, embodiments in which the portable printer is carried on a user&#39;s person), the printer defines a top surface  300 , a front surface  305 , and a bottom surface  310 , shown in  FIG. 1 . The ribbon cover  20  and the media cover  30  may form at least part of the front surface  305 . The ribbon cover  20  may include a slidable opening mechanism  320  (shown in  FIG. 12 ) including the linkage  44 , the cam surfaces  14 , and/or biasing springs (not shown), and the media cover  30  may include a clamshell opening mechanism  325  including a media cover hinge  114  (shown in  FIG. 3 ) and/or biasing springs (not shown). Alternatively, in some embodiments (not shown), the media cover  30  may include the slidable opening mechanism, and the ribbon cover  20  may include the clamshell opening mechanism. 
     A first button, such as the media cover button  35 , may be used to trigger the clamshell opening mechanism  325 , and a second button, such as the ribbon cover button  25  may be used to trigger the slidable opening mechanism  320 . Due to the orientation of the portable printer  10  on the user&#39;s person, the slidable opening mechanism  320  may be spring biased upwardly along a slide direction A (shown in  FIG. 4 ) generally away from the bottom surface  310  of the printer. Similarly, the clamshell opening mechanism  25  may be structured to pivot downwardly (arrow B in  FIG. 4 ) generally away from the top surface  300 . For example, the force of gravity may act on the media cover  35 , in the case of the media cover  30  including the clamshell opening mechanism  325 , such that when actuation of the media cover button  35  releases the media cover  30  from the printer housing, gravity assists the media cover  30  in pivoting about the media cover hinge  114  away from the top surface  300  of the printer  10 , to the opened media position. In addition, a spring may be provided to facilitate or drive the media cover  30  to the opened media position. In contrast, in such embodiments, the slidable opening mechanism is biased (e.g., spring-biased, etc.) to move upwardly against the force of gravity. 
     In the depicted embodiment, the media cover button is located generally proximate the ribbon cover button. For example, as shown in  FIG. 3 , the media cover button  35  and the ribbon cover button  25  may be located on the same side of the printer in order to facilitate one-handed opening of both covers. In this way, a user may be able to open the media cover and/or the ribbon cover, replace the media supply and/or the ribbon supply, and close the media cover and/or the ribbon cover using only one hand. 
     Ribbon Cartridge Locating Features 
     In addition to the features described above, the printer  10  may be configured to receive and position a ribbon cartridge  52  for printing operations via locating features of the printer housing  12 . As described below, the locating features of the printer housing  12  are configured to engage corresponding features on the ribbon cartridge  52  such that the cartridge  52  may be properly received in the ribbon receiving area  50  to produce correct ribbon path alignment for printing without requiring the cartridge  52  to have precise design tolerances. In this way, the ribbon cartridge  52  may include a frame  352  that is manufactured using a grade of plastic or other material that is semi-flexible and may thus be less expensive than more rigid types of plastic. Such lower grade plastics (which are typically less rigid and less expensive than higher grade plastics) may include polystyrene (PS) and acrylonitrile butadiene styrene (ABS). In contrast, higher grade plastics may include polycarbonate (PC) and PolyEtherEtherKetone (PEEK). An exemplary embodiment may use a ribbon cartridge  52  made of ABS. Use of a semi-flexible material such as ABS may allow the cartridge  52  to flex into alignment as it is installed in the ribbon receiving area  50 , in which case the locating features may hold the ribbon cartridge  52  in place once installed to prevent unwanted flexing during printing, which could result in misalignment of the ribbon path. 
     With reference to  FIG. 13 , various surfaces and edges of the printer housing  12  and printer components may include locating features  21 ,  23 ,  27  that are configured to engage corresponding features  21 ′,  23 ′,  27 ′ on the ribbon cartridge  52  to hold the ribbon cartridge in place during operation and maintain proper ribbon alignment. For example, the printer housing  12  may include a first locating feature  21  defined by two opposing inner walls  13  of the printer housing  12 , as shown in  FIG. 13 . The first locating feature  21  of  FIG. 13  is a parabolic groove cut out of each wall  13  that is sized and shaped to receive a first corresponding feature of the ribbon cartridge frame  352  (which, in this case, is a circular protrusion  21 ′). The first locating feature  21  of the printer housing may be cut at an angle, as shown, such that when the ribbon cartridge is first inserted into the ribbon receiving area  50 , the protrusion  21 ′ rests on the edge of the outer wall  13  proximate the first locating feature  21  but not in the trough of first locating feature  21 , as shown in  FIG. 14 . When the ribbon cover  20  is subsequently moved from the opened ribbon position to the closed ribbon position and the supply spool  56  of the ribbon cartridge  52  is lowered into the ribbon receiving area  20  via movement of the ribbon cartridge retaining feature  58  (see  FIGS. 11 and 12  and the corresponding description above), the protrusion  21 ′ is moved into engagement with the trough of the first locating feature  21 , as shown in  FIG. 14 . Once engaged, the protrusion  21 ′ is surrounded on three sides by the wall  13 , thereby restricting movement of the ribbon cartridge  52 , as shown in  FIG. 15 . 
     Referring again to  FIG. 13 , a second locating feature  23  may be located on the inner surface of the printer frame  12 . The second locating feature  23  may, for example, be on a portion of the inner surface of the printer frame  12  opposite the ribbon cartridge retaining feature  58  and adjacent the supply spool  56  when the supply spool  56  is installed. In this way, the second locating feature  23  may be positioned to engage a second corresponding feature of the ribbon cartridge  52  when the cartridge  52  is installed and the ribbon cover  20  is closed. Referring to  FIG. 16 , for example, the corresponding feature may be a tab  23 ′ on the ribbon cartridge frame  352  proximate the supply spool  56 . Thus, as the ribbon cartridge  52  is lowered into the ribbon receiving area  50  via the ribbon cartridge retaining feature  58  (i.e., as the ribbon cover is closed), the tab  23 ′ may come to rest against the inner surface of the printer frame  12  in the area of the second locating feature  23 . 
     A third locating feature may be a fin  27  located in the media cover  30  that is integrally molded or otherwise attached to an inside surface of the media cover  30 , as shown in  FIG. 17 . For example, a shield housing  64  of the media cover  30  (discussed below) may define the fin  27  on each end wall  26 . The location of the fin  27  may be such that when the ribbon cartridge  52  is installed and lowered into the ribbon receiving area  50  and the media cover  30  is closed, the fin  27  engages the third corresponding feature, which may be a notch  27 ′ defined by the ribbon cartridge frame  352 , thereby restricting the ribbon cartridge  52  from moving toward the media cover  30 . 
     The combination of the three locating features  21 ,  23 ,  27  described above can thus maintain the ribbon cartridge  52  in position during printing operations by resisting lateral and rotation forces that may be applied to the cartridge during printing.  FIG. 18  shows the reactive forces that may be applied by the corresponding features  21 ′,  23 ′,  27 ′ to stabilize the ribbon cartridge  52  and maintain proper alignment of the ribbon path. 
     As mentioned above and shown in  FIG. 18 , the ribbon cartridge  52  may include a supply spool  56 , a take-up spool  49 , and a ribbon cartridge frame  352 . The ribbon cartridge frame  352  may include a first portion  351  structured to support the supply spool  56  and a second portion  353  structured to support the take-up spool. A retrieval assist angle α may be defined between the first portion  351  and the second portion  353 . In addition, one or more gripping portions  450  may be defined proximate the retrieval assist angle α to facilitate grasping of the ribbon cartridge. Thus, the gripping portions  450  may assist a user in handling the ribbon cartridge  52  when retrieving the cartridge  52  from the ribbon receiving area  50  or inserting the cartridge  52  into the ribbon receiving area  50 , as shown in  FIGS. 16 and 18 . 
     In this regard, the retrieval assist angle α may be any angle between 50° and 150°. For example, the retrieval assist angle α may be in the range of 90°-120°. The ribbon cartridge  352  may be adapted to be received in a printer, as described above, such that the gripping portions  450  are exposed for grasping by a user when the ribbon cartridge is disposed in the accessible portion and not exposed for grasping by the user when the ribbon cartridge is disposed in the installed position. Furthermore, the gripping portions  450  may include ridges or extended surfaces or points defined on the frame  352  that provide an area for the user to grasp the cartridge  52  when retrieving the cartridge from the ribbon receiving area  50 . In this regard, the gripping portions  450  may be configured to sit above the rest of the cartridge  52  with respect to the plane of the front surface  305  of the printer when the ribbon cartridge retaining feature  58  is in the retrieval position. 
     Referring to  FIGS. 5 and 16 , the printhead support  410  may define a top surface  471 , and the gripping portions  450  may be disposed below the top surface  471  when the ribbon cartridge  52  is in the installed position. Similarly, the gripping portions  450  may be disposed above the top surface  471  of the printhead support  410  when the ribbon cartridge  52  is in the accessible position. Thus, when the ribbon cartridge retaining feature  58  is lowered into the operational position, the gripping portions  450  may sink into the ribbon receiving area  50  such that the gripping portions  450  are no longer accessible and the ribbon cover door  20  may be closed. In addition, the gripping portions  450  may include a rough texture or other non-smooth surface to help the user grip the cartridge frame  352  when loading and unloading the printer. 
     In some embodiments, the take-up spool  49  may define an RFID tag configured to hold information regarding the ribbon cartridge. For example, the RFID tag may include information such as the type of ribbon cartridge, the manufacturer, and the date of manufacture that can be read by an RFID reader disposed on a corresponding portion of the printer housing (such as within the ribbon cartridge receiving area). 
     Ribbon Guiding Feature 
     Another feature that may be included to improve printing quality in a printer is a ribbon guiding feature. The ribbon guiding feature comprises a ribbon guide  72 , shown in  FIGS. 5 and 19 , that is configured to contact and guide the ribbon  55  along the ribbon path as the ribbon  55  extends between the supply spool  56  and the printhead  70 . As the ribbon  55  passes over the ribbon guide  72 , the ribbon guide  72  is able to adjust and align itself with respect to the ribbon  55  such that the ribbon guide  72  can remain in contact with the width of the ribbon  55 . In this way, the tension in the ribbon  55  may be generally equalized, reducing the incidence of wrinkles in the ribbon  55  and improving print quality without requiring the use of a highly precise guiding surface. 
       FIG. 5  shows a printing mechanism  400  in accordance with some embodiments of the invention. The printing mechanism  400  includes a printhead  70  defining a printing surface  470 , a platen  75  configured to oppose the printing surface  470  during printing operations, a ribbon guide  72  configured to guide a portion of ribbon  55  over the printing surface  470  of the printhead  70 , and a printhead support  410  defining a printhead receiving portion  415  and a ribbon guide receiving portion  185 . The printhead receiving portion  415  is thus configured to attach to the printhead  70 , and the ribbon receiving portion  185  is configured to attach to the ribbon guide  72 , as described below. Furthermore, the platen  75  may be included in the media cover  30 , such that when the media cover  30  is moved from the opened media position to the closed media position, the platen is moved into place to operationally engage the printhead  70  at the printing surface  470 . 
     Referring to  FIG. 19 , the ribbon guide  72  includes a guide portion  72  and an attachment portion  74 . The guide portion  73  has a guide surface  76 , across which the ribbon  55  travels as fresh ribbon is supplied by the supply spool  56  and consumed ribbon is taken up by the take-up spool  49  (shown in  FIG. 5 ). The guide portion  73 , as well as other parts of the ribbon guide  72 , may be made of any material capable of providing a smooth surface that allows the ribbon  55  to be drawn across the guide surface  76  without being hindered, torn, or otherwise damaged. For example, the guide portion  73  may be made of an injection-molded plastic. In some cases, the guide portion  73  includes a carbon-fiber filling that promotes the dissipation of static electricity from the ribbon. Static electricity may be generated on the ribbon  55  due to the friction created as the ribbon  55  is pulled across the guide surface  76 . Static may also be generated as a result of unrolling the ribbon  55  from the supply spool  56 . If left undissipated, the static electricity may build to a level that can damage the thermal printhead  70  or other electronics downstream, disrupt the normal operations of the electronic systems, or at least impair the quality of the printing operation. 
     Referring again to  FIG. 19 , the guide portion  73  is affixed to the attachment portion  74  and is substantially perpendicular to the attachment portion  74 . For example, the guide portion  72  and the attachment portion  74  may form a “T” shape when viewed in cross-section, as shown in  FIG. 5 . The guide portion  73  and the attachment portion  74  may be joined to each other using an adhesive, or the two portions  73 ,  74  may be integrally molded to form a unitary ribbon guide  72 . In any case, the guide portion  73  is configured such that the width x 1  of the guide portion  73  increases from each end of the guide portion  73  to the center area of the guide portion  73  (i.e., along they-axis), as illustrated in  FIG. 20 , creating a ribbon guide pivot point  77  on the guide portion  73  at the area of increased width, as described below. Similarly, the attachment portion  74  may be configured such that the edge of the attachment portion  74  farthest from the guide portion  73  may be bowed out in the center area, corresponding to the area of increased width of the guide portion  73 . Thus, the width of the ribbon guide  72  proximate each end of the ribbon guide is less than the width proximate a central portion of the ribbon guide. In this way, additional clearance x 2  may be provided at the ends of the attachment portion  74  to allow the ribbon guide  72  to pivot once installed, as described below. 
     With reference to  FIG. 5 , the attachment portion  74  is configured to be mounted to the printer housing  12  via the ribbon guide receiving portion  185  of the printhead support  410  (which is described in conjunction with the RFID coupler mounting feature below). The printhead support  410  may be, for example, one or more aluminum extrusions and may include a bracket portion  78  configured to receive the attachment portion  74  of the ribbon guide  72 . For example, the bracket portion  78  may have a “C” shape in cross-section, as shown in  FIG. 5 . The ends of the “C” may be separated by a distance that corresponds to the thickness of the attachment portion  74  such that the attachment portion  74  may fit within and be supported by the bracket portion  78 . 
     In this regard, the attachment portion  74  may include a guide tab  79 , depicted in  FIGS. 19 and 20 , located on the edge of the attachment portion  74  farthest from the guide portion  73  and proximate the ribbon guide pivot point  77  in the central portion of the ribbon guide. The guide tab  79  may be configured to maintain the attachment portion  74  in engagement with the bracket portion  78  of the ribbon guide receiving portion  185  while at the same time allowing the ribbon guide  72  to pivot about the ribbon guide pivot point  77  in the direction of the arrows shown in  FIG. 19 . 
     Once in place within the bracket portion  78  shown in  FIG. 5 , the shape of the guide portion  73  and corresponding shape of the attachment portion  74  allow the ribbon guide  72  to pivot about the ribbon guide pivot point  77  (shown in  FIG. 20 ). This is because the edge of the guide portion  73  proximate the ribbon guide pivot point  77  maintains contact with the outer surface  81  of the bracket portion  78  while the edge of the guide portion  73  at each end of the guide portion  73  is free to move with respect to the outer surface  81  of the bracket portion  78 . The corresponding shape of the attachment portion  74  provides clearance at the ends of the attachment portion  74  to move within the bracket portion  78  in response to the pivoting. 
     Referring to  FIG. 5 , the ribbon guide  72  is supported by the ribbon guide receiving portion  185  in a position along the path of the ribbon  55  between the supply spool  56  and the thermal printhead  70 . As the ribbon  55  is unwound from the supply spool  56  and moves towards the take-up spool  49 , part of the ribbon  55  may experience more tension than the rest of the ribbon  55 . For example, one edge of the ribbon  55  may be stretched more tautly between the supply spool  56  and the thermal printhead  70 /platen roller  75 , leaving the opposite edge of the ribbon  55  to hang more loosely. As a result, the ribbon guide  72  in this case pivots about the ribbon guide pivot point  77  in the direction of increased tension. In other words, the increased tension in the ribbon  55  moves the guide portion  73  towards the bracket portion  78  of the ribbon guide receiving portion  185  in the high-tension area while the opposite end of the guide portion  73  is moved away from the bracket portion  78 . Some of the tension in the high-tension area of the ribbon  55  is thereby be relieved, and a corresponding portion of the tension in the other areas of the ribbon  55  is increased proportionally while maintaining contact of the guide surface  76  with the ribbon  55  across the width of the ribbon. In this way, the tension across the width of the ribbon  55  may be continually equalized during printing without interrupting the printing operation. 
     RFID Coupler Mounting Feature 
     Another feature that may be included in a printer  10  according to an exemplary embodiment is an RFID coupler mounting feature.  FIG. 5  shows that this feature allows an RFID coupler  60  to be mounted in a printer  10  for reading, encoding, or otherwise communicating with RFID tags. 
     The RFID coupler mounting feature may be useful for quickly encoding and reading data for product labels. For example, this feature may help with printing needs on or near an assembly line, in distribution centers or warehouses where on-demand RFID encoding and reading is required, and in a variety of other applications. Although this feature is disclosed here in a specific embodiment for use within a portable thermal transfer printer  10 , it may also be used with any type of RFID encoding or reading device or other types of printers using other printing technologies. 
     The RFID coupler mounting feature provides for a relatively small and compact configuration for the combination of the RFID coupler and the printhead. Typically, in conventional printers, when combining an RFID coupler with a printhead for use in one printer, a greater distance is necessary to achieve proper printing results. Moreover, conventional combination printers often require the printer to back-up or stop and read or encode the RFID tag, and then proceed forward to print with the printhead  70 . This system, however, allows for near continuous motion of the media  45  and even smaller media label sizes since the RFID coupler  60  and printhead  70  are placed so close together. 
     Due to the close proximity of the RFID coupler  60  to the media  45 , however, the energy radiated by the RFID coupler  60  may engage multiple media  45  or, more specifically, multiple RFID tags associated with the media  45 . In this regard, the RFID coupler mounting feature may include one or more shielding elements to prevent or reduce the likelihood of multiple activations of RFID tags at the same time. 
       FIG. 21  illustrates an exemplary embodiment of this mounting feature. More specifically, the printer includes a printhead support  410 , described above, for securing the RFID coupler  60  within the printer or relative to the printhead. The printhead support  410  may be one piece, or, according to the exemplary embodiment shown in  FIG. 5 , may include a printhead receiving portion  415  that is formed separately and is fastened to the rest of the printhead support  410 , as shown. For example, the printhead support  410  may be connected to the printhead  70  with a printhead screw  189  or other fastener. At least part of the printhead support  410 , such as the ribbon guide receiving portion  185 , may be an aluminum extrusion element that functions as a mounting point for the coupler and as an electromagnetic shield. With regard to the shield function, the printhead support  410  may define a cavity or pocket  191  with one open end disposed proximate the printhead  70  such that at least part of the printhead support  410  shields the coupler in all directions other than the open end which faces a particular media  45  or, more specifically, the RFID tag associated with the particular media, that the coupler is intended to read or encode. Thus, the printhead support  410  maintains proper shielding while allowing for the printhead  70  and RFID coupler  60  to be placed in close proximity to each other. Moreover, as seen in  FIG. 5 , the printhead support  410  may be shaped to correspond with the ribbon cartridge  52  and platen roller  75  to allow the ribbon  55  to pass over the printhead  70  for effective thermal transfer printing. 
     As can be seen from  FIGS. 4 and 12 , the printhead support  410  may be configured such that, when received in a printer housing, a first end  480  and a second end  481  of the printhead  70  define channels  490  on opposite sides of the printhead  70  (e.g., between the respective end and the printer housing) that are configured to receive at least a portion of the ribbon cartridge frame  352  installed in the ribbon receiving area  50 . Thus, when installed, the printhead  70  is positioned between the supply spool  56  and the take-up spool  49  of the ribbon cartridge  52 , as illustrated in  FIG. 5 . When the ribbon cartridge retaining feature  58  is moved from retrieval position ( FIG. 12 ) to the operational position ( FIG. 11 ), the ribbon cartridge frame  352  is thus further received by the channels  490  at each end  480 ,  481  of the printhead  70 , thereby allowing the ribbon cover  20  to close. The “peninsular” orientation of the printing mechanism  400  within the printer therefore allows a more compact configuration of the printing mechanism  400 , ribbon cartridge  52 , and printer housing, providing for a smaller and more efficiently design portable printer  10 . 
     As previously stated, according to the illustrated embodiment, the printhead support  410  may be an aluminum extrusion element. However, in other embodiments, the printhead support  410  may be made of any conductive material or combination of conductive materials, such as copper, aluminum, or the like. Moreover, in other embodiments, the printhead support  410  may be manufactured through a method other than an extrusion method. For example, the printhead support  410  may be made through a deep drawing method, a casting method, or other manufacturing method or combination thereof. Furthermore, at least part of the printhead support  410 , such as the printhead receiving portion  415 , may act as a heat sink to dissipate heat generated by the printhead  70  during printing operations. 
     Referring back to  FIG. 21 , in instances such as the illustrated embodiment, in which providing shielding of the coupler is desirable, the printer may further include a separate (i.e., not part of the printhead support  410 ) electromagnetic shield  193  to further block energy radiated by the RFID coupler  60 . According to the illustrated embodiment, the media cover  30  of the printer  10  may include an electromagnetic shield. For example, the media cover  30  may define a protrusion, termed the shield housing  64 , that stores the electromagnetic shield  193 . When the media cover  30  is closed, the electromagnetic shield  193  blocks the stored media  45  from being read or encoded by the RFID coupler  60 . The electromagnetic shield  193  can be made of any conductive material, such as aluminum. As shown, when the media cover  30  is closed, the shield housing  64  is strategically positioned between the RFID coupler  60  and the roll of media  45 . Since each media has an associated RFID tag, the roll of media  45  is also a roll of RFID tags which may be at risk of unintentional activation but for the shield housing  64  being positioned between the roll of RFID tags and the RFID coupler  60 . 
     In addition to shielding, the range of the radiated energy from the RFID coupler  60  may be controlled, so that only the desired RFID tag is read or encoded. A short range RFID coupler  60  reduces the chance that additional RFID tags will be engaged when in typical operation. In such embodiments, printhead support  410  may be configured to mount the coupler but not specifically configured for shielding. For example, the printhead support  410  may define a frame-like element that is configured to hold the RFID coupler but not necessarily to provide shielding for each side of the RFID coupler except one. 
     Thus, the printhead support  410 , electromagnetic shield  193 , and the RFID coupler  60  combine to create an environment where the RFID coupler  60  reads or encodes the desired RFID tag and minimizes the likelihood of unintentional activation of multiple RFID tags at the same time. In some embodiments, the RFID coupler  60  may be further configured to have a limited range for reading and/or encoding, as described in U.S. Patent Publication No. 2007-0262873 entitled “RFID UHF Stripline Antenna-Coupler,” which is hereby incorporated by reference in its entirety. 
       FIG. 22  illustrates the RFID coupler  60  being mounted inside the pocket  191  of the printhead support  410 . As an example and as illustrated, the RFID coupler  60  may be connected directly to the printhead support  410  with two coupler screws  195 . The RFID coupler  60  may be connected with the smaller end  187  facing the media  45  for encoding or reading. This mounting enables the RFID coupler  60  to be shielded by the printhead support  410  while still maintaining close proximity to the printhead  70 . 
     Media Guide Locking Feature 
     Another feature that may be included in the printer according to an embodiment is a media guide locking feature. The locking feature may be configured to secure the media  45  when the media cover  30  is in the closed media position, stopping or hindering the media  45  from shifting when the printer  10  is moved. 
       FIG. 23  shows an example of the locking system, which is comprised of three main parts: at least one media support arm  80 ; a first locking element  85  of the media support arm  80 ; and at least one second locking element on the media cover, such as a media cover rib  96 . The locking system utilizes a first locking element  85  located in each support arm  80  to engage with media cover ribs  96  attached to the media cover  30 . This system engages once the media cover  30  is closed and locks the media  45  in a position, as shown in  FIG. 24 . When the media cover  30  is opened, the system disengages allowing the media  45  to move easily for loading purposes. 
     Such a locking system provides several benefits. For example, coreless media has been recognized by the inventors as presenting unique challenges when the media is consumed to a point at which the “core” (i.e., the portion of media at the center of the supply) is almost exhausted and can no longer act as a stable “core” due to the lack of rigidity inherent in the media itself. In other words, the media  45  is adapted to transition from a laterally strong condition (e.g., when the roll is full) to a laterally weak condition (e.g., when the roll is nearly empty). By providing the locking system described below, however, coreless media can be stabilized via the locking system throughout the life of the media (i.e., from the time a full roll of media is installed until the media is consumed). Thus, the media can continue to be used for printing operations without negatively impacting the quality of printing as the media supply approaches empty, allowing for more efficient use of resources. 
     According to the illustrated embodiment, at least one of the media support arms  80  is biased to slidably translate along the housing to provide a holding force C to opposite sides of the media  45  (shown in  FIG. 25 ). At least one of the media support arms  80  may define a first locking element  85 , which may include a locking element pivot point  98 , a locking element tab  102 , a locking element snap  104  and a locking element spring  106 .  FIG. 23  shows how the first locking element  85  may be inserted into a support arm pocket  108  incorporated into the media support arm  80 . The first locking element  85  is inserted into the support arm pocket  108  through an aperture  112  via the locking element snap  104 , which holds the first locking element  85  within the pocket  108  and keeps the first locking element  85  from falling out of the pocket  108  once it has been inserted. In other words, as the first locking element  85  is being inserted, the locking element snap  104  is movable towards the body of the first locking element  85  to allow the first locking element  85  to clear the aperture  112  and be inserted into the pocket  108 . Once the first locking element  85  (and, more specifically, the locking element snap  104 ) has cleared the aperture  112 , the locking element snap  104  moves back to its original position and maintains the first locking element  85  within the pocket  108 . A support arm  80  with the first locking element  85  in position within the pocket  108  is shown in  FIG. 25 . 
     Once inserted, features on the first locking element  85  operate in conjunction with the support arm pocket  108  to ensure that the locking element tab  102  is forced through the support arm aperture  112 . In this regard, the locking element spring  106  pushes against the back of the media support pocket  108 , shown in  FIG. 23 , causing the first locking element  85  to pivot about the locking element pivot point  98 . This pivoting in turn causes the locking element tab  102  to be forced out the support arm aperture  112 . The locking element snap  104  (shown in  FIG. 23 ) can be located in a manner that creates a default position in which the first locking element  85  stays within the support element pocket  108  while allowing the locking element tab  102  to extend out the support arm aperture  112 . As will be discussed in greater detail later, the locking element spring  106  and locking element pivot point  98  allow external forces to push the locking element tab  102  into the pocket  108  and also allow the first locking element  85  to return to the default position once the force is removed. 
     The second locking element, or, in this example, the media cover ribs  96 , can attach to the shield housing  64  portion of the media cover  30 .  FIG. 24  shows that near the end opposite the media cover hinge  114 , a portion of the media cover  30  making up the shield housing  64  extends away from the outer covering back into the media receiving area  40 . ( FIG. 24  illustrates a portion of the media cover  30  and a first locking element  85  without a media support arm  80  to better illustrate the interaction between the first locking element  85  and a media cover rib  96  of the media cover  30 .) The media cover ribs  96  may be located on the shield housing  64  such that the media cover ribs  96  face towards the media and the media cover hinge  114 . The media cover ribs  96  may in some cases span the width of the shield housing  64 . In other cases, the middle portion of the shielding housing  64  may not include media cover ribs  96 , such as in the example shown in  FIG. 24 . 
     The locking element tabs  102  engage with the media cover ribs  96  when the media cover  30  is in closed media position. The locking element tabs  102  are configured to fit around or otherwise engage the media cover ribs  96 . For example, referring to  FIG. 23 , each locking element tab  102  may have a first protrusion  116  and a second protrusion  118  on either side of a groove. Once a media cover rib  96  is engaged with the locking element tab  102  groove, the media support arm  80  is fixed and the media  45  is locked in position. Although each locking element tab  102  independently may be sufficient to lock the media  45  in place, using a first locking element  85  in each media support arm  80  allows for redundancy. 
     The locking feature may also be configured to self-adjust. The pivoting feature in the first locking element  85  allows the media cover  30  to close easily regardless of the location of the first locking element  85 . The pivoting feature will then adjust the first locking element  85  if necessary to engage the media cover ribs  96  while the media cover  30  is in the closed position. This self-adjust system can work as follows. If a media cover rib  96  lines up with the locking element tab  102  groove, then no adjustment is necessary because the media cover rib  96  slides into the groove unobstructed. Once the groove engages with the media cover rib  96 , the media  45  is locked into place. If a media cover rib  96  is aligned so that it hits one of the protrusions  116  or  118  and not the groove, the locking element tab  102  pivots through the support arm aperture  112  into the media support arm pocket  108  allowing the media cover  30  to close unobstructed. The locking element spring  106  continues applying force pushing the locking element tab  102  towards the support arm aperture  112  out the media support arm pocket  108 . This ensures that when the media  45  is shifted, the locking element tab  102  will spring out the support arm aperture  112  once the groove becomes aligned with a media cover rib  96 . Once the locking element tab  102  groove is engaged with the media cover rib  96 , the media  45  is locked in place. Sloping the media cover ribs  96  and locking element tab  102  grooves may allow the media cover ribs  96  to align with the locking element tabs  102  more often. Also, sloping the media cover ribs  96  and locking element tab  102  groove may allow the locking system to engage after less shifting of the media  45  if the locking element tab  102  groove is not aligned with a media cover rib  96  when the media cover  30  is closed. 
     The locking feature may also provide an additional function. When the system is engaged, the locking element spring  106  pushes against both the media cover ribs  96  and the back of the media support pocket  108 . This forces the media support arms  80  away from shield housing  64 , which helps to stabilize the media support arms  80  and increases the overall printing quality. 
     Media Alignment Feature 
     A media alignment feature may also be included in embodiments of the printer  10  in order to allow a user to properly align media with the printhead when installing the supply of media. The media alignment feature may be provided in various forms, including alignment marks, alignment ribs, and edge guides, each of which is described below. 
     Referring to  FIG. 26 , the printer  10  in some embodiments may include alignment marks  205  on the outside surface of the ribbon cover  20  for aligning the edges of the media. In this regard, when the media  45  is inserted into the media receiving area  40  (see  FIG. 3 ), the user can extend the leading end  207  of the media  45  (shown in  FIG. 5 ) across the outside surface of the ribbon cover  20 , with the media cover  30  still open, and adjust the alignment of the media  45  by aligning the edges of the media  45  with corresponding alignment marks  205 . Media  45  having different widths may be accommodated by choosing the pair of alignment marks  205  that are best positioned to match the width of the particular media  45 . For example, wider media may be aligned using the outermost alignment marks  205 , while media having a narrower width may be aligned with the innermost alignment marks  205 . 
     The alignment marks  205  may be provided on the outside surface of the ribbon cover  20  in several ways. For example, the alignment marks  205  may be printed or etched directly on the ribbon cover  20 . Alternatively, the alignment marks  205  may be pre-printed on a label, for example along with a product logo or other design, and the label may then be adhered or otherwise affixed to the ribbon cover  20  in the appropriate location. 
     Once the edges of the media  45  have been aligned with the appropriate alignment marks  205 , the media cover  30  may be closed to hold the media in place. The alignment can then be double checked (for example, to ensure that the media  45  was not shifted as the media cover  30  was closed) by extending the leading end  207  of the media roll  45  across the surface of the closed media cover  30 . Alignment ribs  209  are provided on the media cover  30  of  FIG. 26  for aligning the edges of the media  45  once the media cover  30  is in the closed media position, i.e., the edges of the media as it exits the media exit slot may be compared against the alignment ribs  209 . As with the alignment marks  205 , several alignment ribs  209  may be provided to allow for different widths of media  45 . If the media  45  is not aligned with the corresponding alignment ribs  209 , the media cover  30  may be opened to allow the user to re-adjust the media  45  using the alignment marks  205  as described above. The alignment ribs may be integrally molded with the media cover  30 , or they may be manufactured separately and adhered or otherwise affixed to the surface of the media cover  30 . 
     Referring now to  FIG. 27 , another form of the media alignment feature may include adjustable edge guides  211  on the ribbon cover  20  that can be used to guide the edges of the media  45  as it exits the media exit slot  105 . Each edge guide  211  may be movable within a guide slot  213  to accommodate media  45  of various widths. In this regard, the edge guides  211  may be connected by guide linkage (not shown) within the ribbon cover  20  such that movement of one of the edge guides  211  results in movement of the other edge guide  211  in the opposite direction. 
     For example, upon extending the leading end  207  of the media  45  across the ribbon cover  20 , prior to closing the media cover  30 , the user may manually adjust one of the edge guides  211 , thereby moving both edge guides  211  to fit the width of the media  45 . In other words, if the edge guides  211  are spaced too far apart and do not contact the edges of the media  45 , the user may push one of the edge guides  211  towards the edge of the media  45  until the edge guide  211  contacts the media  45 . As the edge guide  211  is moved towards the edge of the media  45  on one side, the other edge guide  211  is also moved into contact with the opposite edge of the media  45  via the guide linkage. Conversely, if the edge guides  211  are spaced too close to each other and do not fit the width of the media  45 , they may be moved apart in much the same way. By linking the two edge guides  211  in this manner, the media  45  may be generally centered within the media exit slot  105  during the alignment process. Once the media  45  has been aligned, the media cover  30  may be closed, and the alignment of the media  45  may be double-checked using alignment ribs  209  or other alignment features as described above. 
     Instead of moving the edge guides  211  directly (i.e., by pushing or pulling on the edge guide  211  itself),  FIG. 28  depicts a form of the media alignment feature that includes edge guides  211  that are movable via a lever  217 . Similarly, the edge guides  211  of  FIG. 29  are movable via a dial  219 , and in  FIG. 30  the edge guides  211  are movable via a slider  221  that slides along a slot  223  formed by the media cover  30 . In  FIGS. 28, 29, and 30 , the edge guides  211  are movable within guide slots  213  located on the media cover  30 , proximate the media exit slot  105 . In this way, the leading end of the media  45  need not be extended across the outside surface of the ribbon cover  20  for purposes of alignment. 
     Referring to  FIG. 28 , the user may align the edges of the media  45  with two edge guides  211  by pushing on the lever  217 . With reference to  FIG. 28 , the position of the lever  217  farthest from the media exit slot  105  may correspond to the outermost position of the edge guides  211  (i.e., to accommodate the widest media), as shown. When the user in this example wishes to accommodate smaller media widths, the user may push the lever  217  towards the media exit slot  105 , which serves to gradually move the edge guides  211  closer to each other. Other embodiments may provide for the opposite motions of the edge guides  211  with movement of the lever  217 . Similarly, in  FIG. 29 , the user may rotate a dial  219  to move the edge guides  211 . For example, rotating the dial  219  towards the media exit slot  105  may move the edge guides  211  closer together, while rotating the dial  219  away from the media exit slot  105  may move the edge guides  211  farther apart, or vice versa. In  FIG. 30 , the user may move the slider  221  from one end of the slot  223  to the other end to adjust the position of the edge guides  211 . Regardless, the coordinated movement of the edge guides  211  allows the user to align the edges of the media  45  with the two edge guides  211  while maintaining a particular position within the media exit slot  105  (for example, while keeping the media centered as it is outputted from the media exit slot  105 ). 
     In addition to facilitating the alignment of the media, any of these embodiments may also be used to provide a simple measurement to the user as to the width of the loaded media. This measurement may be used to recalibrate the printer for the supply currently loaded. For instance, if the printer, or the host system, was configured to print 2-inch wide labels, and the printer is now loaded with 4-inch wide labels, the user may wish to simply modify the position of printing on the labels along the new left edge. Determining the measurement and entering it into the printer via the front panel or from a device in communication with the printer would allow the printer to make the necessary calculations for repositioning printed information in the proper location. 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.