Patent Publication Number: US-6910750-B2

Title: Low-profile ink head cartridge with integrated movement mechanism and service station

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. patent application Ser. No. 09/872,345, filed Jun. 1, 2001, now abandoned, which claims the benefit of U.S. Provisional Patent Application No. 60/208,759, filed Jun. 2, 2000. This application is also related to U.S. Pat. No. 6,264,295, issued Jul. 24, 2001. These applications and patent are incorporated herein by reference in their entirety for all purposes. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to printing systems and methods for printing with the same. More particularly, the present invention relates to printing systems with cartridges that are configured to radially print onto a media that rotates in relation to a printing assembly. 
   Conventional printing systems typically utilize rectangular based bitmaps. In general, a conventional printing system prints onto a standard size rectangular-shaped media along a horizontal axis, for example, and the media is moved along a vertical axis. Typically, after the paper advances to a desired vertical location under a head assembly, the printing assembly moves across the paper to print an image onto the paper while the paper is held stationary. In sum, conventional printing systems generally implement movements within a rectangular coordinate system for printing onto media having standard sizes and shapes. 
   To facilitate discussion,  FIG. 1  depicts a conventional printing system  10  in the form of a typical ink jet printer. As shown, the printing system  10  includes a print head  102 , a roller  106 , an actuator  108 , and an ink head service and capping area  120 . The print head  102  is configured for dispensing ink onto a print media  100 , representing, for example, a rectangular sheet of paper. The actuator  108  is configured for moving the print head  102  across the print media  100 . The roller  106  is configured for moving the print media  100  under the print head  102 . 
   Typically, the roller  106  moves the print media  100  perpendicularly to the movement of the print head  102 . That is, the media  100  travels under the print head  102  along a y-axis  110 , and the print head moves over the media  100  along an x-axis  112 . Periodically to service the ink jet nozzles, the print head  102  is moved past the paper edge along an x-axis to the service station  120 , where it clears, wipes  126  and caps  124  the nozzles. 
   Although conventional printing systems such as those described above are suitable for certain applications, they also have certain disadvantages. The print head cartridge in conventional ink jet printers, for example, as disclosed in U.S. Pat. No. 4,872,026, are typically optimized for printing rectangular objects like paper using x-y axis coordinate system printers, and are inherently not optimized for printing along radial axis. 
     FIG. 2  illustrates a radial print system  200 , as disclosed in U.S. Pat. No. 6,264,295, issued Jul. 24, 2001. In the radial printing system  200 , the head assemble  210  in one embodiment of this invention consists of a conventional ink jet cartridge that also has print head  102  that moves radially and tangentially to the spinning media underneath in contrast to the conventional printing system  10  of  FIG. 1 , which moves print head  102  in the x-axis direction across the media  100  under print while the media  100  gradually advances along the y-axis. Where on the one hand, the spatial resolution of the ink object resolution is normally constant across the conventional printing system  10  media, on the other hand, the spatial resolution of the radial print system printing ink objects increases as the radial position of the ink jet cartridge increases with respect to the circular CD-R media. 
   The ink jet cartridges designed for use in conventional printing system are inherently not optimized to place ink object for radial printing.  FIGS. 3   a  and  3   b  illustrate the bottom view of a conventional cartridge  300  that has nozzles  320  with orientation, firing order, and firing rates optimized for rectangular printing in the orthogonal or Cartesian reference coordinate system. However, this same cartridge print head and nozzles produce non-optimal results when used to print radially in the polar reference coordinate system. For example, in a conventional printing system cartridge  300 , nozzles  320  are usually arranged along a parallel vertical lines offset  334  from the centerline  330  of the print head  310 . While this design may be optimal for rectangular printing, in contrast during radial printing this orientation causes distortion due in part to the misalignment of the nozzle axes  320  relative to the radial centerline  330 . To partially correct for this, the each respective nozzle axis,  320   a  and  320   b , must be laterally translated in motion an offset distance  334  so as to be centered over the radial centerline  330  prior to printing. This extra translation requirement causes extra steps to be added to the radial printing system operation and reduces overall print speed and performance. 
   Another limitation associated with using conventional rectangular-optimized cartridges  300  in the radial print system  200  is the way conventional print head nozzles  320  are designed to operate. In conventional printer operations, the firing order of each nozzle is typically addressed electronically using a grid-like, row-column technique, to more easily enable the nozzles in conventional cartridges to fire at the appropriate time optimized for the rectangular media printing environment or to simplify the electronics interface. Since the conventional print head nozzles  320  are typically arranged to be fired optimally in column order instead of azimuthal  340  or radial order, printing is inherently slower for radial printing and print speed diminishes due to missed printing opportunities. For example, because conventional cartridge nozzles  310  usually are fired in column order, the target zone where to place an ink object may pass by before the next addressed nozzle is ready to fire, necessitating the target to pass repeatedly underneath the print head nozzles  320 . In this case until it is ready to fire, the print head  310  must linger over the spinning media, awaiting the target zone for a much longer period of time than is optimal in order to ensure complete ink object coverage. Another aspect of these design limitations of conventional print heads  310  causes the column addressing modes to constrain and restrict the firing order during radial printing operation, to the extent that the next radial dot position is missed, because the firing order cannot be configured flexibly enough or fast enough to allow for optimal azimuthal  340  print coverage. 
   Yet another disadvantage of ink jet cartridges  300  used in conventional rectangular printers is that their vertical height is too tall for particular printing applications. Conventional ink jet cartridges are usually not designed to limit physical height, but rather are so designed to be as tall as practical for larger ink reservoir capacity. 
   Another disadvantage of conventional printing systems using ink jet technology is the necessity for a separate print head service device. Referring back to  FIG. 1 , the conventional design of a print head  102  necessitates it being serviced frequently to maintain optimal performance of the print head, so a separate service station  120  is required to wipe  126  and clear the print head  102  nozzles during printing and cap  124  the print head for storage while not in use. This service station is often a separate device  120  inline with the x-axis  112  direction of the print head  102  movement, beyond the placement of the media  100 . However, for a radial print system, a separate service station may occupy substantial portions of the space available in a radial printing system. In addition, a separate service station  120  can inherently slow down printing due to the need to add extra motion steps outside the normal radial positioning motion during the radial printing operations. 
   In view of the foregoing, there is a need for an improved printing system cartridge for radial printing that efficiently implements simple movements, inherently reduces distortion while minimizing the amount of space taken by such cartridge within a radial printing system. 
   SUMMARY 
   In general terms, the present invention provides an ink cartridge that includes therein a print head for dispensing ink onto a media, a movement mechanism for enabling movement of the print head, and/or an ink service station. In one embodiment, the cartridge is designed to be inserted into a receptacle so that the cartridge and receptacle form a radial printing system. The receptacle may also include a motion actuator for engaging with the movement mechanism of the cartridge to thereby move the print head of the cartridge. The movement mechanism of the cartridge works in conjunction with the actuator of the receptacle to thereby move the print head with respect to the cartridge, e.g., moving into and out of the cartridge, and with respect to a rotating media to enable ink to be dispensed by the print head along a radius of a rotating circular media. In a specific implementation, the cartridge remains fixed with respect to the media. In an example application, the radial print system may be used to print a label on the top surface of a recordable circular media, such as a recordable compact disc (CD-R). 
   In one aspect, the cartridge and receptacle are sized into a slim form factor. In one exemplary embodiment of this invention, the cartridge and receptacle together serve as an ink jet printing system. Accordingly, the cartridge includes one or more ink storage mechanisms, such as ink storage bladders, a mechanism to enable print head positioning, and a mechanism to perform print head servicing, including nozzle clean-out, nozzle wiping, and nozzle capping for storage. When this cartridge is inserted into a radial printing system receptacle, mating receptacle components, such as a communication bus coupled with a processor, externally activate the cartridge to enable printing. These mating receptacle components also actuate internal cartridge motion mechanisms to achieve movement of the print head. 
   In a preferred embodiment, the cartridge is operable to enable printing onto spinning CD-R media while mounted and positioned over or integrated with a standard slimline-height CD-R drive. More particularly, some of the particular embodiments of the present invention provide a printing ink jet “print head” cartridge that fits into a printing receptacle, and the combination of the cartridge and printing receptacle are positioned adjacent to or integrated with a standard slimline-height CD-R drive. Consequently, the cartridge and printing receptacle are designed so that a combination of the cartridge, printing receptacle and CD-R drive substantially fits within a standard ½-height computer bay or in a externally mounted computer peripheral device or bay of existing computer systems. In a specific implementation, the cartridge is designed to have a height that is less than or equal to a slimline-height CD-R drive (currently sized to be 20.7 mm or less in height). Most preferably, the cartridge has a height less than or equal to the size of an opening for receiving CD-ROMS (currently sized to be about 14 mm or less in height). Additionally, the cartridge preferably has a width and length that are less than or equal to a slimline CD-R drive (currently sized to 146 mm or less in width and 203 mm or less in length, respectively). 
   Some of the specific cartridge embodiments are removable from and insertable into a printing assembly that is mounted in a computer bay. A removable cartridge may contain replaceable and disposable portions that may be inserted or removed, permitting new features or extensions in function. Accordingly, users may freely and easily swap printing cartridges, as one might now do with floppy disks. For example, this enables repetitively swapping out specialty printing cartridges with alternate colors or other featured coatings to layer onto the same target CD-R under print. 
   In one embodiment, a printing cartridge for radially printing onto a rotating circular media is disclosed. The cartridge includes an ink print head having a plurality of nozzles operable to dispense ink onto the rotating circular media and a motion mechanism coupled with the ink print head to allow radial movement of the print head over the rotating circular media. 
   In a specific implementation, the motion mechanism is designed to be engagable with an actuator of a receptacle when the cartridge is coupled with the receptacle, and the actuator is operable to move the print head via the motion mechanism. In a further aspect, the motion mechanism is a cam wheel having a groove for receiving a pin coupled to the print head. The cam wheel is engagable with the actuator of the receptacle when the cartridge is coupled with the receptacle, and the actuator is operable to rotate the cam wheel and move the print head via the pin moving along the groove. In yet a further aspect, the motion mechanism further includes a bladder assembly for supporting an ink reservoir coupled to the print head, and the bladder assembly is also coupled with the print head. In yet another embodiment, the bladder assembly includes two pivots on two opposing sides of the bladder assembly, and the pivots are positioned to slidably and pivotably engage with two rails of an inside surface of the cartridge. 
   In one aspect, the groove is configured to allow vertical and horizontal movement of the print head when the cam wheel rotates. In a specific implementation, the cam wheel includes a service station for maintaining the print head. For example, the service station includes a spit, a wipe, and a cap device. In a further aspect, the groove is further configured to rotate the print head over the service station. 
   In another implementation, the cartridge and the receptacle are arranged together so that the cartridge remains in a fixed position with respect to the rotating media when the print head is moving over the media. 
   In an alternative embodiment, the motion mechanism includes an attachment mechanism coupled with the print head, and the attachment mechanism is engagable with the actuator of the receptacle when the cartridge is coupled with the receptacle. The actuator is operable to move the print head via the attachment mechanism. In one aspect, the actuator includes a motor coupled with a lever arm which is engageable with the attachment mechanism when the cartridge is inserted within the receptacle. In yet another aspect, the motion mechanism includes a second attachment mechanism coupled with a service platform, and wherein the attachment mechanism is engagable with a second actuator of the receptacle when the cartridge is coupled with the receptacle, and the second actuator is operable to move the service platform with respect to the print head via the second attachment mechanism. 
   In a further embodiment, the cartridge is sized to couple with a printer receptacle, wherein the printer receptacle is positioned adjacent to or integrated with a standard slimline CD-R device, so that a combination of the cartridge, the printer receptacle and the standard slimline CD-R device substantially fit within a standard ½ height computer bay. 
   In a further implementation, the cartridge includes a print service component configured to service the print head by cleaning and/or capping the nozzles of the print head. In one aspect, the cartridge is has a similar size as a slimline type CD-R drive bay. 
   In another embodiment, the invention pertains to a method of radially printing onto a rotating media using a cartridge having an ink print head having a plurality of nozzles operable to dispense ink onto the rotating circular media and a motion mechanism coupled with the ink print head to allow radial movement of the print head over the rotating circular media. The motion mechanism of the cartridge is engaged to thereby move the print head over the rotating circular media, and ink is dispensed onto the rotating circular media. In one aspect, the engaging operation includes activation of a servicing operation on the print head. In one application, the cartridge is inserted into a slimline printer system to activate engagement of the motion mechanism of the cartridge. In another application the cartridge is inserted into a combination compact disc recorder and printer system which is sized to fit within a standard height computer bay to activate engagement of the motion mechanism of the cartridge. 
   In yet another embodiment, a radial printing and compact disc recording (CD-R) system is disclosed. The system includes a CD-R drive for recording on a rotating media, the CD-R drive having a standard slimline size and a radial printing receptacle arranged to receive a cartridge. The radial printing receptacle is positioned adjacent to or integrated with the CD-R drive, and the radial printing receptacle and cartridge are operable to print onto the rotating media. The radial printing receptacle and cartridge are sized such that a combination of the radial printing receptacle, cartridge, and CD-R drive substantially fit within a standard ½ height computer bay. 
   In a specific implementation, the cartridge includes an ink print head having a plurality of nozzles operable to dispense ink onto the rotating media and a motion mechanism coupled with the ink print head to allow radial movement of the print head over the rotating media. The radial movement is defined with respect to a circular motion of the rotating media. In a further aspect, the motion mechanism is designed to be engagable with an actuator of a receptacle when the cartridge is coupled with the receptacle, the actuator being operable to move the print head via the motion mechanism. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which: 
       FIG. 1  represents a conventional printing system. 
       FIG. 2  is a diagrammatic representation of a radial printing system. 
       FIG. 3   a  is a diagrammatic representation of the bottom nozzle surface pattern of a conventional ink jet cartridge assembly typically used in FIG.  1 . 
       FIG. 3   b  is a diagrammatic representation of the nozzle pattern of a conventional cartridge assembly overlaid onto radial polar coordinate lines as representative in a radial printing system. 
       FIG. 4   a  is a diagrammatic representation of the radial print head of a radial cartridge assembly with its nozzles positioned over and substantially along the radius of a CD-R media, in accordance with one embodiment of the present invention. 
       FIG. 4   b  is a diagrammatic representation of the optimal placement of the radial nozzle pattern of a radial cartridge print head with respect to the radial coordinate lines over spinning media in a radial printing system, in accordance with one embodiment of the present invention. 
       FIG. 5  is a diagrammatic representation of a combination device consisting of a slimline CD-R drive and radial printing system in accordance with one embodiment of the present invention. 
       FIG. 6   a  is diagrammatic representation perspective view of the cartridge of  FIG. 5  in accordance with one embodiment of the present invention. 
       FIG. 6   b  is diagrammatic representation side view of the cartridge of  FIG. 5  in accordance with one embodiment of the present invention. 
       FIG. 6   c  is a diagrammatic top view representation of the cam wheel of the cartridge of  FIGS. 6   a  and  6   b  in accordance with one embodiment of the present invention. 
       FIG. 6   d  is a diagrammatic perspective end view representation of the cam wheel of the cartridge  FIGS. 6   a  and  6   b  in a partially closed position as the print head retracts in accordance with one embodiment of the present invention. 
       FIGS. 7   a ˜ 7   e  are diagrammatic top view representations of the cam wheel and print head positioned in relation to the cartridge and media  220  at various stages within the print and maintenance cycle in accordance with one embodiment of the present invention. 
       FIG. 7   f  is a diagrammatic side view representation of the cartridge and cam shutter wheel rotated with the print head fully retracted in the capped position and the cam shutter in the closed position in accordance with one embodiment of the present invention. 
       FIGS. 8   a  and  8   b  are illustrations of two charts representative of the relative vertical and horizontal positions, respectively, of the print head with respect to the CD-R media and cartridge housing in accordance with one embodiment of the present invention. 
       FIGS. 9   a  and  9   b  are diagrammatic perspective view and side view representations, respectively, of an extended ink supply cartridge used for CD-R radial printing in accordance with an alternative embodiment of the present invention. 
       FIG. 10  is a diagrammatic representation of a radial printing system in which the cartridge of the present invention may be implemented. 
       FIG. 11  is a block diagram of the on-board cartridge control circuitry of  FIG. 6   b  in accordance with one embodiment of the present invention. 
       FIG. 12  is a diagrammatic perspective view representation a cartridge having motion mechanisms which use linear actuators in accordance with an alternative embodiment of the present invention. 
       FIG. 13  is a diagrammatic representation of the side view of the linear actuators of  FIG. 12 , illustrating the relative vertical movement of internal components of the cartridge and the print head. 
       FIG. 14  is a diagrammatic representation of the top view of the linear actuators of FIG.  12 . 
       FIG. 15  is a diagrammatic representation of the side view of the linear actuators of  FIG. 12 , illustrating the relative vertical arrangement of significant internal components of the cartridge, with the print head shown in a capped position. 
   

   DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
   Reference will now be made in detail to a specific embodiment of the invention. An example of this embodiment is illustrated in the accompanying drawings. While the invention will be described in conjunction with this specific embodiment, it will be understood that it is not intended to limit the invention to one embodiment. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention. 
   The present invention relates to circular recording media, such as an optical disc, such as a recordable compact disc (CD-R). For the scope of this invention, the terms “CD-R” and “CD” are intended to mean all varieties of recordable circular media (e.g., CD-R, CD-RW, DVD-R, DVD+R, DVD-RAM, DVD-RW, DVD+RW and the like.). 
   Several of the features of the present invention may be used in conjunction with the printing system features illustrated in FIG.  1  and described further in U.S. Pat. No. 6,264,295, issued Jul. 24, 2001, which patent is incorporated herein by reference in its entirety. That is, the system features disclosed in this patent may be easily integrated with the cartridge or printing system of the present invention. 
     FIG. 5  illustrates a combination CD-R device or drive and radial printing system  500  in accordance with one embodiment of the present invention. The combination system  500  includes a low-profile radial printer system  520  having a cartridge system  530  that is designed to physically mate with, substantially mount directly over or adjacent to, and/or may be manufactured in combination with a standard slimline CD-R device  510 , such as Teac model CD-W216E and the like, which CD devices are often used in present-day computer laptops and are well known to those familiar with the art. Preferably, the combined standard slimline CD-R device  510  and cartridge system  530  substantially fit within a standard ½ height computer bay. 
   As described further below, the system  500  includes a receptacle for receiving the cartridge, as well as for providing other printing operations. In one illustrated embodiment, the receptacle may include one or more of the following components: an interlocking mechanisms (e.g.  524 ) for coupling with and ejecting of the cartridge, one or more actuators for facilitating movement of a print head within the cartridge (e.g.  604  and  606  of  FIG. 6   a  or  1212 ,  1210 ,  1214 , and  1216  of FIG.  14 ), and hardware and/or software components for enabling printing (e.g.,  660 ). 
   During use, the user may press or snap the cartridge  530  into an interlocking mechanism  524  in the printer system  520  and thereby place the cartridge  530  substantially horizontally into position over the media  220 . Through means either independent of the radial printer system or under control of the radial printer system, the user may insert or remove the media  220  via the CD-R tray mechanism  514 . During the CD-R printing operation, the cartridge  530  is activated from the radial printer mechanism  520 , which engages the cartridge  530  to move the print head  410  into position over the CD-R media  220 . 
   The interlocking mechanism is in the form of any suitable device for providing active restraint of the cartridge. By way of examples, the interlocking mechanism may be in the form of a positive detent or clasp. The interlocking mechanism may be operable to grab the cartridge as it is inserted within the tray  514  and then pull and lock the cartridge into the printing system  520 . The interlocking mechanism may be similar to a ZIP drive&#39;s locking mechanism. The interlocking mechanism is also operable to eject the cartridge from the printing system. For example, the interlocking mechanism may be coupled with a processor, which is configured to activate an ejection (e.g., via activation of a solenoid) when printing is complete. The interlocking mechanism may also include a user selectable eject mechanism which the user may activate to eject the cartridge. This user selectable ejection mechanism may also be controlled by a processor to prevent the cartridge from being ejected during printing or to query whether the user really wants to eject prior to activating ejection of the cartridge. 
   The design of the print head  410  is preferably of a type, a technology and a form or adapted for use with radial printing from a variation on a form of those widely known and extensively covered under prior art and well understood by those familiar with the art. For example, the print head could be designed using thermal ink jet or piezoelectric technologies commonly used in the art. Mounting or coupling this print head to the ink supply could use techniques widely known in the art.  FIG. 4   a  shows the radial print head  410  of  FIG. 5  with nozzles  412  aligned along the radial centerline  414  in accordance with a preferred embodiment of the present invention. A print head designed for radial printing in this fashion and thus aligned over the radial axis enables printing successive concentric annual print position lines  336  as the media  220  passes under the nozzles  412 , and thus align directly with nozzle positions without the need for further lateral translation, minimizing distortions. This is also shown in a perspective view in  FIG. 4   b , illustrating the placement of the radial print head  410  in relation to the media  220  and the radial print centerline  330 , offset by azimuthal angle  340  from a reference origin radial line  342 . In this configuration, radial print head nozzles  412  ideally fire in time so as to place ink objects substantially on the radial centerline  330  as the media  220  spins underneath. In sum, the print head designed for radial printing in this fashion, optimizes placement of ink objects directly along the radial axis, minimizing print distortion. 
   The cartridge also includes a motion mechanism that enables movement of the print head  410  with respect to the media. The motion mechanism is coupled with the print head and arranged to also be engagable with an external actuator so that the external actuator activates the motion mechanism to thereby move the print head. In one embodiment, activation of the motion mechanism causes the print head  410  to be physically translated over any portion of the radial axis  330  of the rotating media  220  (e.g., over the rear  414  portion or the front  914  portion of the media, as shown in  FIGS. 5 and 9   a , respectively). 
     FIGS. 6   a ˜ 6   b  are more detailed diagrammatic representations of the cartridge  530  of  FIG. 5 , in accordance with one embodiment of the invention.  FIG. 6   a  is a perspective view of a portion of the cartridge  530  internal components discussed in  FIG. 5 , as shown engaged with an external actuator in accordance with one embodiment of the present invention.  FIG. 6   b  is a detailed side view of the cartridge  530  described in  FIG. 5  engaged with an external actuator in accordance with one embodiment of the present invention. 
   The cartridge includes any suitable number and type of motion mechanism(s). In the illustrated embodiment as shown in  FIGS. 6   a  and  6   b , the cartridge includes a cam shutter wheel  610 , which may be activated by an external actuator. The cam wheel  610  is coupled with the print head through a bladder assembly  620 , which holds one or more ink bladders  630  which are coupled to ink pathways  632  which are coupled with print head  410 . Movement of the cam wheel  610  substantially causes the print head to move in concert with the bladder assembly. 
   As shown in  FIGS. 6   a  and  6   b , the cam wheel  610  is positioned underneath the bladder assembly  620 , providing support to the bladder assembly  620  via the tracking pin  650  affixed to the bottom of the bladder assembly  620 .  FIG. 6   c  is a perspective top view of the cam wheel  610  in accordance with one embodiment of the present invention. Spring  612  ( FIG. 6   b ) applies pressure to keep the track tracking pin  650  in the irregular-shaped, raised and/or recessed cam guide track  710  as fashioned in the cam shutter wheel  610  as shown in  FIG. 6   c . Of course, the cam wheel may be alternately positioned over the bladder assembly. 
   In the illustrated embodiment, the external actuator may be in the form of a print motor  606 , pinion gear  604 , and servo actuator ( 1060  of FIG.  10 ). The print motor  606  ( FIG. 6   a ), pinion gear  604 , and servo actuator  1060  ( FIG. 10 ) rotate the cam wheel  610  to position the print head  410  for printing and servicing. In this mode, the pinion gear  604  meshes with gears on the cam wheel  610  to thereby rotate the cam wheel  610 . As the cam wheel  610  rotates, the cam guide track  710  generates a print head vertical and horizontal positioning profile, shown in graphical form in  FIGS. 8   a  and  8   b , respectively. As the cam wheel rotates, the bladder assembly  620  also pivots  624  and slides on side rail guide grooves  636  ( FIG. 6   a ) located on the inside sides of the cartridge  530  housing. The bladder assembly  620 , containing ink bladders  630 , ink pathways  632  and print head  410 , all pivot together around pivots  624  on either side (see  FIG. 6   b ), allowing the entire bladder assembly  620  to move in concert. In a preferred embodiment, a one-piece, rigid bladder assembly potentially reduces ink leak or seal problems and lowers manufacturing costs. Of course, the bladder assembly  620  may be formed from a plurality of parts. However, a single piece assembly  620  is more cost effective to manufacture and maintain. The ink pathways  632  may be capillaries or a capillary sponge material as used in the art, to allow ink to properly flow to the print head. An ink well (not shown) may be located at the capillary end near the print head on the bladder assembly. Also while the print head-bladder assembly  620  is lowered during printing, the slightly downward slope of the pivoted assembly may aid ink flow. 
     FIG. 6   c  is a diagrammatic top view of the cam wheel  610  of  FIGS. 6   a  and  6   b  in accordance with one embodiment of the present invention. As described above, the cam wheel  610  includes a guide track  710  for receiving the tracking pin  650  affixed to the bottom of the bladder assembly  620 . The guide track  710  may be embossed, machined, milled, molded, stamped, or otherwise fashioned into or attached onto the cam shutter wheel  610  of the print head positioning mechanism. This guide track  710  is so shaped as to accurately profile the complete movement cycle to substantially support all necessary print head positioning, printing and servicing operations. 
     FIGS. 7   a ˜ 7   e  are diagrammatic top view representations and  FIG. 7   f  is a side view representation of the cam wheel  610  and print head  410  positioned in relation to the cartridge  520  and media  220  at various stages within the print and maintenance cycle in accordance with one embodiment of the present invention. When printing, the print head  410  end of the print head-bladder assembly  620  is forced out of the cartridge  520  via the guide pin  650  following track  710  by rotating the cam shutter wheel  610  to a maximum extension, position  740  on the cam, so as to be over the edge of the target media  220  ( FIG. 7   a ). During the initial extension, the shutter  720  portion of the cam shutter wheel  610  opens as the cam wheel rotates and the print head  410  extends. In the present embodiment, during printing the print head  410  gradually moves radially along path  734  towards the radial center of the media  220  ( FIG. 7   a ) along track  710  through consecutive positions towards the other edge of the media  220 , starting at position  740 , then on to position  741  approximately halfway through printing ( FIG. 7   b ) towards the inner edge of the media  220  at position  742  ( FIG. 7   c ) on the cam shutter wheel  610 . However the direction of movement along the media  220  need not exclusively move from outer to inner portion of the media. For example, in an alternate embodiment ( FIG. 9   a ), using a similar cam shutter wheel to guide the print head path, the print head  410  conversely moves in a path  914  from the inner edge to the outer edge of the media  220 . 
   When finished printing, the print head  410  continues radially  734  into the service area of the wheel, following the relative path  720 , as guided along by the cam wheel track, starting at position  744  to spit  716  ( FIG. 7   d ), through the wipe blade  714  and function, and eventually into the cap  712  in cam wheel track position  746  ( FIG. 7   e ). The print cycle may then either begin once more, or alternately prepare for cartridge ejection. During this final phase where the print head is reentering the cartridge for service in direction  734 , the shutter  720  closes while rotating  732  over the cartridge opening, as shown in  FIG. 6   d , a diagrammatic end view of the cam wheel of the cartridge in a partially closed position in accordance with one embodiment of the present invention. 
   Referring to the print head relative vertical and horizontal positions in  FIG. 8   b , graph  820  illustrates the horizontal extension position of the print head  410  as a function of degrees rotation of the cam wheel  610 , starting with 0 degrees in the stow position, illustrating the print head at various relative lateral positions as the guide pin  650  follows the lateral contours of the guide track  710  about the circuitous track  710  while the cam wheel  610  rotates. As shown, the print head  410  first extends all the way out to the starting edge of the CD-R, then gradually moves to the other edge of the CD-R, finally ending up in the service areas  644  and  646  and finally in the pen cap  648  stow position  814 , in the process of cycling through graph regions  806 ,  810 ,  812  and  814 , respectively, ready to repeat the cycle once more again. Similarly,  FIG. 8   a  shows the vertical height of the print head profile, illustrating the print head at various relative heights as the guide pin  650  simultaneously follows the vertical contours of the guiding circuitous track  710  while the cam wheel  610  rotates. The stow-position  814  also prepares the cartridge  530  for ejection and removal. The stow-position  814  caps the print head  410  to prevent drying and damage from shock or inadvertent handling. When in this stow position, the cartridge cam shutter  720  ( FIGS. 6   c  and  6   d ) is also in closed position, protecting the cartridge internals from damage and intrusive objects that may damage the mechanism and rupture the ink bladders. 
   Similar to the aforementioned cartridge,  FIGS. 9   a  and  9   b  are diagrammatic perspective view and side view representations, respectively, of an extended ink supply cartridge  930  for inserting into a CD-R printing system ( 510  and  520 ) in accordance with an alternative embodiment of the present invention. The cartridge  930  is similar to the cartridge of FIGS.  5 ˜ 8   b , except it includes a relatively large ink reservoir  932  which extends outside the printer assembly  520 . The ink reservoir  932  may be coupled to the print head via flexible ink channels  934  or via a combination of ink channels  934  and additional ink reservoirs within the bladder assembly  630 . The CD tray  514  of the CD-R device  510  may also be formed to extend out flush with the end of the reservoir housing  930  (not shown) to allow greater clearance. Additionally, the extended ink reservoir may be detachable from the rest of the cartridge  530  to allow easy replacement of the ink reservoir. For example, the ink reservoir may include nozzles  934  to attach to and remove from the cartridge at point  524 . 
   Activation of the cartridge  530  may be accomplished through a series of commands to printer mechanism  520  from a hosting computer system or any combination of hardware and/or software. Printer assembly  520  attaches with and routes command signals and power through connector  664  ( FIG. 6   b ) to the control circuitry  660  located in the panhandle  656  of the cartridge  530 . The overall print operation is controlled by the printer mechanism  520  shown in  FIG. 5 , which receives, processes and ejects the print cartridge  530  from the host computer. 
     FIG. 10  is a diagrammatic representation of a radial printing and CD-R system  1000  in which the cartridge print system of the present invention may be implemented. As shown, the CD-R and radial print system  1000  includes the printer assembly  520  having a cartridge (not shown) as described above. The print head  410  extends out of the cartridge and moves along a radial path  414  by an actuator, while the media  100  spins  214  underneath the print head  410 , which fires in along a trajectory  430  to place ink on the disc at a specific target location, also referred to as the print zone  440 . 
   The Pen control system  1050  controls the positioning and firing of the pen  410 . Images from the imaging algorithms  1072  are prepared by the imaging system  202  and synchronized with the synchronization system  204  with the rotational information from the encoder  1040  and in conjunction with the rotation motor  208  and servo  206 . The pen  410  thereby synchronously prints radially to place ink objects at the target print zone  440 . Mechanisms for enabling radial printing are further described in co-pending (1) U.S. patent application Ser. No. 10/125,681, filed 18 Apr. 2002, (2) U.S. patent application Ser. No. 09/815,064, filed 21 Mar. 2001, and (3) U.S. Pat. No. 6,264,295, issued 24 Jul. 2001, which applications and patent are incorporated herein by reference in their entirety. 
     FIG. 11  is a block diagram of the on-board cartridge control circuitry  660  of  FIG. 6   b  in accordance with one embodiment of the present invention. The components of the control circuitry  660  may be implemented within any suitable combination of hardware and/or software. As shown, the control circuitry includes an input/output interface  1110  for interfacing with the cartridge and may also include an encryption decoder  1112  for decoding an authentication code from the cartridge (e.g., via a cartridge serial number  1152 ). The control circuitry also may include a mechanism for determining whether the authentication code indicate invalid access by an invalid cartridge ( 1118 ). If the access is valid, an ink counter located within the printing assembly and/or cartridge  1150  may be updated or reset. Otherwise, access may be denied ( 1116 ) and the cartridge is unable to be used. This access mechanism may be implemented to ensure use of only a particular type of cartridge having an authentic serial number. 
   The control circuitry  660  may also include a mechanism for determining whether the cartridge  1150  has run out of ink ( 1122 ). If there is no more ink, a report ( 1120 ) may be generated to thereby deny access ( 1116 ) via the cartridge and discontinue printing. If there is enough ink, print head  410  firing may then be enabled ( 1124 ). 
   In another alternative printer assembly and cartridge embodiment (not shown), the print mechanism motor  606  and pinion gear  604  may also serve to pull in and eject the cartridge  530 , when mating teeth are fashioned on the outer cartridge sidewall, and the pinion drive gear  604  mates with and moves the cartridge horizontally into position over the CD-R media. 
   In yet another alternative embodiment (not shown), an interlocking hook is used to mate to and engage with a recess in the outer cartridge sidewall, so that when the user partially inserts the cartridge, the cartridge thereafter automatically is moved horizontally into position over the CD-R media  220 . 
   In another alternative embodiment, the cartridge  530  may couple to a lever arm through the front panhandle end  656  or front cartridge door  654  ( FIGS. 6   b  and  6   d ), which positions the print head inward and outward along the radial centerline  330 . In this embodiment, the print head bladder assembly  620 , when activated by the level arm rather than pinion gear, would follow a modified track groove  636  on the inside of the cartridge  530  housing, profiling the vertical position  800  ( FIGS. 8   a  and  8   b ) only of the print head position, while the print head service functions are still performed by the cam-shutter wheel. In yet another alternative embodiment (not shown), the print head service function may be performed instead by a sliding lever arm mechanism installed in place of the cam-shutter wheel. 
     FIG. 12  is a diagrammatic perspective view representation of a cartridge having motion mechanisms which use linear actuators in accordance with an alternative embodiment of the present invention.  FIG. 13  is a diagrammatic representation of the side view of the linear actuators of  FIG. 12 , illustrating the relative vertical movement of internal components of the cartridge and the print head.  FIG. 14  is a diagrammatic representation of the top view of the linear actuators of linear actuators of FIG.  12 . As shown in  FIGS. 12 and 13 , the cartridge includes motion mechanisms in the form of two attachment mechanisms  1220  and  1314  for engaging with two external lever arms  1212  and  1216 , respectively, which are in turn coupled with two motors  1210  and  1214 , respectively. The lever arms and motors form part of the printer assembly (not shown). When the cartridge  530  is inserted within the printing assembly, the lever arms insert into the cartridge  530  to engage with the attachment mechanisms. 
   One attachment mechanism  1220  is coupled with the bladder assembly  620 , and the other attachment mechanism  1314  is attached to a movable service platform  1320 . When the lever arm  1212  is engaged with attachment mechanism  1220 , the bladder assembly and print head  410  may be moved in direction  734  to thereby move the print head radially over the media  220 . The bladder assembly  620  also rest within track  1310  via pin  650 . Spring  612  provides pressure against the bladder assembly so the bladder assembly remains in track  1310 . 
   The track provides a vertical profile  656  for positioning of the print head  410 . As the print head is moved out of the cartridge to a position over the media, the track  1310  serves to lower the print head. As the print head is retracted into the cartridge, the track  1310  serves to raise the print head.  FIG. 15  is a diagrammatic representation of the side view of the linear actuators of  FIG. 12 , illustrating the relative vertical arrangement of significant internal components of the cartridge, with the print head shown in a capped position. The bladder assembly  620  include pivot points  624  which pivot and slide along side rail guide grooves  636  ( FIG. 6   b ). 
   When the lever arm  1216  is engaged with attachment mechanism  1314 , the movable service platform  1320  rotates clockwise  714  around pivot  1316  to thereby sequentially move a spit  644 , wipe  646 , and cap  648  under the print head  410  (see FIG.  14 ). The service station platform  1320  may have any suitable shape which allows maintenance of the print head, while not interfering with printing operations. As shown in  FIG. 14 , the service station platform  1320  may have a semi-circular shape. 
   In the preferred embodiment of this particular invention, the motion in the radial printer mechanism  520  is actuated by a “rack and pinion” gear. However, the motion could be actuated by a suitable actuator  1066  and motor  1060  ( FIG. 10 ) in any suitable form for radially moving the print head  410  across the media  220 . For example, the actuator  1066  and translational motor  1060  may be in the form of, among others, a screw drive and stepper motor, a voice coil, linear drive with feedback position, a band actuator and stepper motor, or a scissor joint attached to a gear or a linear actuator. A pinion gear  604  ( FIG. 6   c ) driven by a motor  606  is mounted in the printer&#39;s housing  520  and the rack  616  is fashioned as gear teeth  616  on the outer circumference  614  of the cam shutter  610 . As the cartridge  530  is inserted, the pinion  604  engages the rack  616  and the system synchronizes with print head position. During operations, the pinion gear  604  actuates the print head position profiles, illustrated in FIG.  8 . The upper graph  800  ( FIG. 8   a ) illustrates the vertical position throughout the 360-degree rotation of the cam shutter wheel  614 . As shown therein, the print head  410  begins motion from a higher stow position  814  and moves to a lower print position  806 , hovering over the CD-R media  220  surface while printing. When returning to the service areas  810  and  812 , the print head  410  then moves back up, eventually ending in the stow position  814  ready to repeat the cycle one more. 
   In an alternative embodiment, the cam shutter wheel  610  may use a plurality of spirals instead of a single track  710  to move the print head  410  along the radius  330  of the CD-R media surface  220 . In this alternative embodiment, the print head  410  is made to move more gradually, thereby increasing the effective radial resolution and precision to the radial motion with each additional rotation along the spiral track in the cam shutter wheel  610 . 
   In sum, the cartridge  530  may be configured for activation of printing or forming a desired pattern of any type of media. The cartridge  530  may be configured for insertion and for internal or external actuation of the internal print head  410  and internal service station components  664 ,  646 , and  648  ( FIG. 6 ) in any form that is suitable for the implemented shape of the cartridge and radial printer assembly, whether as represented, for example, in  500  or  900  ( FIG. 9 ) or any other suitable shape and configuration. 
   Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. For example, the cam shutter is optional and may be excluded from the cartridge design. Additionally, the cartridge may easily be configured to move the print head initially from the outer edge of the media to the inner edge, rather that from the inner to outer edge. By way of another example, a multiple piece print head-ink bladder may be used. Therefore, the described embodiments should be taken as illustrative and not restrictive, and the invention should not be limited to the details given herein but should be defined by the following claims and their full scope of equivalents.