Abstract:
A printer has a substrate carrier that is a planar membrane driven through the printer solely by friction drives. The planar membrane is completely removable from the printer, and can be adapted to support a substrate of desired configuration and held against locating surfaces while it is being driven through the printer by the friction drive. The friction drive comprises at least one set of rollers including a drive roller on one side of the carrier and a resiliently mounted roller on the other, and also includes a rotating resilient platen that is resiliently urged against a printhead for providing a reaction force for the friction drive while printing occurs.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a Continuation-in-part of U.S. patent application Ser. No. 09/326,041 now U.S. Pat. No. 6,148,722 , Filed Jun. 4, 1999, for COMPACT DISC AND RECORDABLE COMPACT DISC THERMAL TRANSFER PRINTER, incorporated herein by reference, which in turn claims priority to Provisional Application Ser. No. 60/088,397, filed Jun. 8, 1998, and entitled COMPACT DISC (CD) AND RECORDABLE COMPACT DISC (CD-R) THERMAL TRANSFER PRINTER. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a printer that will print from a carrier ribbon, film or web to a substrate carried on a flexible support that is planar and is driven directly by rollers or drives. The substrate carrier can be removed from the printer to be changed, and/or for other manipulation, such as loading it into another device for a related operation on the substrate. A removed carrier can be driven back into the printer. A cartridge carrying the printhead is also provided. 
     Thermal printing technology for substrates, such as compact discs (CDs) and recordable compact discs (CD-Rs) and also identification cards incorporate pivotally mounted heads and linear platens with resilient surfaces and carriers that have clamping mechanisms for the substrate. The carriers are generally separately driven. 
     Current technology for printing onto plastic substrates uses expensive head actuating and force modifying mechanisms. The printhead is moved on pivotally mounted arms that extend substantially beyond the envelope of the printhead, with a linearly driven carriage that has to hold the disc over an expensive, flat resilient surface with a clamping device that moves with the carriage. Threading the ribbon through the printhead and mounting ports of the presently available printers is a tedious job which includes taping the ribbon to the carriage, then taping the ribbon after the carriage is driven into the printer. This leads to large, high-cost printers for plastic substrates such as CD&#39;s, CD-R&#39;s and digital videodiscs. It is desirable to substantially reduce the printer size in order to take less space for the CD printers, as well as reducing manufacturing costs and user interaction. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a substrate carrier or tray and printhead cartridge that mount into a frame for reliably printing on flat substrates of various shapes, such as a rectangular ID card, CDs, CD-Rs, DVDs and irregular shapes. A substrate carrier or tray is substantially planar and is removable from the printer for loading. Friction drives that engage the planar carrier, such as one or more spring-loaded rollers are used. The substrate on the carrier is urged against stops by drive rollers, for positive positioning. The drive rollers shown act on a flexible or semi-flexible planar support that will move the substrate into the installed print cartridge. 
     A platen roller is mounted so that it and the carrier for the substrate can be moved against a printhead under a controlled spring force. The platen roller, in one form of the invention, can be slidably mounted, and can be urged toward the printhead with springs that can be varied in force. In another form of the invention, the platen, the substrate carrier and the substrate are mounted on a pivoting frame and urged up against the printhead where the force is reacted by the printhead for contact printing. 
     The pivoting frame mounts not only the platen, but also drive rollers for the substrate carrier. The force with which the platen, carrier and/or substrate are urged against the printhead during the loading and printing operation is controlled by a cam that acts on a cam follower connected to the platen frame by springs so that the frame pivots toward the printhead under spring load. One drive roller for the substrate tray or carrier is on the pivoting frame and rests against a spring-loaded pinch roller. The printhead cartridge also carries the printhead and a second pinch roller. The platen is spring-loaded and resilient to load the cartridge and the substrate against the printhead, which is held in a fixed position. A second drive roller is provided on the printer housing and cooperates with the second pinch roller, so the carrier is driven by rollers after it has passed through an inlet opening. 
     According to another aspect of the invention, a printhead cartridge contains the printhead, as well as the ribbon, film or web supply and take-up rollers. The cartridge permits easy loading of the ribbon since the ribbon does not have to be threaded through pairs of rollers or openings, and does not require special “lead-in” tapes or the like. Also, the printer provides easy front loading of both the printhead cartridge and the substrate carrier. The outer printer housing fits within a PC box or other container. 
     The flexible or semi-flexible planar substrate carrier or tray is moved in and out with motors or drives that are synchronized for printing and for insertion and removal. The carrier for the substrate can be adapted to a wide range of shapes, because the substrate is seated by being held against edges or stops on the carrier by the action of the five rollers. Alternatively, the carrier can have a recess formed to the peripheral shape of the substrate to provide for positioning the substrate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic representation of one form of the present invention; 
     FIG. 2 is a front view of the form of the invention shown in FIG. 1; 
     FIG. 3 is a schematic side-elevational view of the device of FIG. 1, again schematically illustrated; 
     FIG. 4 is a perspective view of a housing or cabinet showing a printhead cartridge on which the printhead is located about to be inserted into the cabinet; 
     FIG. 5 is a side elevational view of the form of the invention shown in FIG. 4; 
     FIG. 6 is a horizontal sectional view of the device shown in FIG. 5 taken generally along line  6 — 6  in FIG. 4; 
     FIG. 6A is a side view similar to FIG. 6 with the cartridge carrying the printhead and ribbons partially installed and about to be latched; 
     FIG. 6B is a view similar to FIG. 6A with the printhead fully in place and the cartridge carrying a substrate to be printed on the exterior of the main cabinet; 
     FIG. 7 is an enlarged sectional view of a portion circled in FIG. 6; 
     FIG. 7A is a sectional view similar to FIG. 7 with the portion enlarged circled in FIG. 6A; 
     FIG. 7B is an enlarged view of the portion of the circle in FIG. 6B; 
     FIG. 8 is a sectional view similar to that shown in FIG. 6 with the printhead and cartridge in working position, and printing about to start on a circular substrate or disc; 
     FIG. 9 is an enlarged fragmentary view of a portion of the assembly shown circled in FIG. 8; 
     FIG. 10 is an enlarged sectional view of the portion shown in FIG. 9 with printing about to commence; 
     FIG. 11 is a sectional view similar to that shown in FIG. 10, with the printing about a third of the way through, where a maximum chordal length of the print area on the circular substrate is encountered near the center opening of a CD; 
     FIG. 12 is a sectional view similar to FIG. 8, when the platen frame is lowered, after printing is done to allow the print ribbon to advance and the substrate and carrier to be moved back for another pass; 
     FIG. 13 is an enlarged sectional view of the circled portion in FIG. 12; 
     FIG. 14 is a top plan view of the printer with the platen frame in position in cross section, with the printhead cartridge removed for sake of clarity; 
     FIG. 15 is an enlarged sectional view of a portion circled in FIG. 14; 
     FIG. 16 is a sectional view taken generally along line  16 — 16  in FIG. 14; 
     FIG. 17 is an enlarged view of a printing shaft support and a cam follower plate with parts of a side wall of a platen frame broken away; 
     FIG. 18 is a top plan view similar to FIG. 14, illustrating a modified form of the substrate, in the form of an identification card carried on the carriers; 
     FIG. 19 is a sectional view of a typical character taken on line  19 — 19  in FIG. 18; 
     FIG. 20 is a top plan view of a further modified tray or carrier for carrying an irregularly shaped substrate on which printing is to be placed; 
     FIG. 21 is a sectional view taken on line  21 — 21  in FIG. 20; 
     FIG. 22 is a top view of a tray or carrier with a recess for holding a substrate; and 
     FIG. 23 is a sectional view taken on line  23 — 23  in FIG.  22 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 through 3 show a schematic view of a printer  10  embodying the principles of the present invention and in the illustrated embodiment includes a printhead  12  that has a series of very small heat elements (resistors) that transfer a base coating or an imaging compound, wax, resin or resin composites or sublimation dyes from a carrier ribbon, film or web  13 , to a substrate  14 . The substrate  14  may be an identification card of rectangular or irregular shape, a circular compact disc, a recordable compact disc, a DVD disc or other desired substrate that is to receive printing. The platen  15  is used to force the substrate  14  against the ribbon  13  and create intimate contact between the printhead, ribbon and substrate. The substrate is carried on a generally planar, flexible or semi-flexible support tray or carrier  17 . The carrier can be used with other types of printers such as ink jet printers, or with other devices that perform one of a series of operations in a process, such as a device that records data on CD&#39;s. The platen  15  will be controlled to push the carrier  17  and the substrate thereon toward the printhead so the substrate is urged against the printhead  12  with the desired amount of force for printing images. 
     Images are created in the form disclosed through control of the heat elements on the thermal transfer printhead to selectively apply imaging compound from the web or ribbon  13  to specific areas of the substrate. Colors can optionally be created with multiple passes using a panelled ribbon, combined with dithering techniques to create several perceived colors, as is known. 
     The platen roller  15 , which is driven by a stepper motor  15 A, can be controlled so as to control the speed of driving the carrier  17  and the substrate  14 , as it is held against the printhead  12  under a fixed spring load. The carrier is rigid enough so that it can support the weight of the substrate when it is fully extended out from the printer, as will be shown in subsequent drawings, in a position linearly horizontal to the plane of the tray or carrier as the substrate is being printed, and yet will have some “give” or flexibility as the platen roller  15  urges the carrier  17  and the disc  14  on the carrier against the printhead and as the rollers  16  feed the carrier through the printer. The force with which the platen roller engages the carrier  17  and thus the force with which the disc is urged against the printhead is controlled by springs  27 . 
     Brackets  18  are used for mounting the platen relative to the printhead as shown schematically, and the platen roller  15  can be moved out of the way, so that a frame that contains the printhead and ribbon can be removed from the printer easily. 
     Power supplies generally are those of a PC, and the printer can be driven from a personal computer. The platen roller is mounted in such a way that it is held against the carrier or support tray  17  in a floating manner without a pivotally mounted frame, such as by providing slots for guiding the carrier. The platen roller  15  is clamped to the printhead frame through intermediate brackets  18  and  19 A which can be unclamped and allow the platen roller to drop away from the printhead. By unclamping and moving the platen roller out of the way, the ribbon can be installed in a straightforward fashion. 
     The clamping brackets  18  and  19 A can be actuated fairly easily through a cam system mounted just above the printhead. This system saves space and allows for electronic control of the head force. The substrate and membrane or carrier are held by the pinch rollers  16  of the roller sets. The pinch rollers are the upper rollers and will first roll along the upper surface of the carrier  17 . When the leading edge of the substrate comes against the upper pinch roller it will slide along the surfaces of the carrier, the force of the pinch roller  16  will locate the substrate on the membrane by forcing or urging it up against a reference edge or stop  19  on the carrier when first being engaged. The reference edge or stop  19  and the squeezing action of the rollers  16  serve to position and then clamp and hold the substrate in a controlled, known position throughout the printing process. No separate clamping of the substrate is needed. 
     The chassis of the printer has a moveable portion  20  that allows the platen roller  15  to move vertically while maintaining the fixed horizontal position of the platen roller. The vertical movement is accomplished through a camshaft  21  mounted through the top portion of the chassis (which is fixed and non-moveable). The camshaft  21  is driven by a stepper motor  22  and has two springs  27  which are attached to a shaft or bracket  19 A which is driven by the camshaft on one end and pivotally attached to the moveable portion  20  of the chassis on the other so it tilts. By incrementally moving the camshaft  21  by actuating the stepper motor,  22 , the roller  15  can be raised or lowered under spring force, thus creating the pressure upon the support tray or carrier  17 . This allows the platen roller  15  to act as a pinch roller in the sense that as it is raised, it pinches the support tray or carrier  17  and the substrate between itself, the printhead and the ribbon. The pinching action creates pressure that is applied to the substrate as it passes under the printhead, depending on the position of the camshaft. 
     The springs  27  act on the platen to move it up in a desired manner, toward the planar carrier  17  to act against the printhead  12 . 
     In FIGS. 4 through 20, a further illustrative embodiment is shown. Referring first to FIG. 4, a main cabinet  30  forms a housing that has side walls  31 , and a top wall  32  as well as a bottom wall  34 , (see FIG. 6, and other Figures for example). A printhead cartridge assembly  36  that is a unitary assembly has a top wall  38 , and depending side walls  40 . The side walls  40  are made to fit between the side walls  31  of the main housing. The side walls  31  have an outer panel  31 A and an inner panel  31 B (FIGS.  6  and  16 ). It can be seen that the side walls  40  of the printer head cartridge include a latch recess  42  on each side that will be used for holding the printhead cartridge assembly  36  in position when it is fully inserted into the housing  30 . Also, as can be seen in FIG. 6, a cutout portion  29  of the inner panel  31 B of wall  31  has a support edge  29 A that will support the printhead cartridge  36  in proper position. As shown in FIG. 14, the ends of shafts  23 D and  24 D will slide on edges  29 A on each side of the housing. 
     The printhead cartridge  36  has a front wall  44  that includes a recess  46  that will permit the substrate support or carrier  17  and substrate  14  such as a CD, CD-R, DVD, ID card or the like to be on the exterior of the housing for loading, and then driven into the housing  30  for printing. 
     In FIG. 6, it can be seen that the supply roll  23  for the ribbon film or web  13  and the take-up roll  24  for the ribbon, film or web are mounted onto the side walls  40  of the printhead cartridge. The slots  23 A and  24 A shown in FIGS. 4 and 5 mount the shafts  23 D and  24 D for these supply and take-up rollers and hold the shafts in off-set notches. The thermal printhead  12  is mounted to the side walls  40  of the printhead cartridge assembly  36 , and is fixed in position. The print supply and take-up rollers  23  and  24  can be easily installed by moving the shafts  23 D and  24 D up from the bottom of the cartridge in slots  23 A and  24 A in the side walls  40  of the cartridge, without the need for threading the film or ribbon through particular rollers or slots. The ribbon will be passed over the printhead without threading it through any openings. The ribbon is thus simply laid over the exposed edge of the printhead when the rolls  23  and  24  are installed. Effortless loading of the ribbon is possible with the printhead cartridge removed from the housing. 
     A suitable sensor  12 A can be used for sensing the ribbon  13  for various controls. A motor  23 B can be used for driving the ribbon or web supply roll  23 . The ribbon take-up roller  24  will be driven from a motor  24 B through a gear train  24 C that includes a spur gear  24 F on a shaft on the housing side wall that will drivably mate with a spur gear  24 G when the printhead cartridge assembly is moved into position in the housing  30 . The gear  24 G is mounted on a pin or shaft  24 H. 
     A spring loaded pinch roller  48  is mounted on the printhead cartridge assembly  36 , and will cooperate with drive rollers, as will be explained, for driving the carrier  17  and the disc  14  across the printhead for printing. 
     In FIG. 6, the housing  30  is also shown in cross section. The carrier  17  is mounted for movement with a drive roller  50  at an input end of the housing that cooperates with a spring loaded pinch roller  52  to engage the tray or carrier  17  and drive it in direction as indicated by the arrow  54  (or in reverse). A platen and carrier support frame  56  has a top plate  60  and a pair of side walls or arms  58 ,  58  to form an inverted channel. The drive roller  50  and pinch roller  52  are carried on shafts extending between the arms  58 . The carrier  17  moves over the top plate  60 , which is supported on the arms  58  that are pivotally mounted on the axis of a shaft  61  of a drive roller  62 . The arms  58  and top plate  60  extend toward the input end of the housing  30 . The frame  56  is in a lowered position in FIG.  6 . 
     The platen support top plate  60  joins the side arms or walls  58 . The drive roller  50  and platen roller carry and drive the carrier  17  and substrate  14  into printing position after the cartridge  36  is in place, as will be shown. The shaft  61  and roller  62  are suitably driven with stepper motor  61 A, and will drive the carrier  17  during the printing process. After the printhead cartridge has been moved into place, the drive roller  62  will also cooperate with the pinch roller  48  on the printhead cartridge for providing a driving force when the printing has commenced, and the tray or carrier  17  is being moved in direction indicated by arrow  54   
     As can be seen in FIG. 7, which is an enlarged cross section view, the side arms or walls  58  of the platen support frame  56  are to the side of triangular plates  69  that are pivoted on shaft  61  adjacent the housing side walls as well. There is a plate  69  on each side of the platen support frame  56 . Plates  69  rotatably mount a cross shaft  66  on which a pair of cam rollers  68  are mounted. The cam rollers  68  are also shown in FIG.  16 . The cam shaft  66  is driven by stepper motor  66 A under control from controller  96  and the platen roller stepper motor  15 A is also controlled by controller  96  so the platen drive motor and camshaft drive motor can be controlled under common control. 
     Upstanding ears  70  are part of plates  69 , which are independent of the side arms  58 , and these ears  70  hold a cross shaft  72  in position, (see FIG. 17 as well). The ends of the shaft  72  extend through slots  74  in the side walls  31  of the housing, so that there can be some movement of the shaft  72  to permit the printhead cartridge  36  to be inserted into the housing  30  and latched in place using shaft  72 . Shaft  72  has bearing hubs  76  at its ends, again as shown in FIGS. 15 and 16, and the receptacles  42  on the side walls  40  of the printhead cartridge are of size to receive these hubs  76  as the printhead cartridge assembly  36  is inserted into place. The receptacles  42  are formed with a guide edge or a lead-in edge  42 A that will slip under the hubs  76  and lift the shaft  72  so that the hubs  76  on the shaft  72  can slip into the receptacles  42 , and detent in place in recesses  42 B. When the printhead cartridge is moved into this position, the ends of shafts on the cartridge, including shaft  24 H mounting gear  24 G, protrude outwardly from the side walls  40  sufficiently to slide into open-ended slots  78  (see FIG. 6 for example) so that the printhead cartridge  36  is held from unwanted movement relative to the housing  30 , and the drive gear from gear train  24 C meshes with gear  24 G, the takeup rollers thus driven by the motor  24 B. 
     Cam rollers  68  carried on shaft  72  act against a pivoting cam follower plate  80  which has side arms  82  on opposite sides of the housing  30  pivoted on shaft  61  as well (see FIG.  17 ). When rotated, the cam rollers  68  will change the pivoted position of plate  80 . Springs  81  carried on the edge of plate  80  are used to apply a load to the frame  56  through a cross member  83  that mounts on walls  58  and on which end of springs  81  are hooked. When the printhead cartridge  36  is inserted, shaft  72  is lifted to enter the receptacles  42 , which lifts the frame  56  to its loaded and operating position as shown in FIG.  6 B. The frame  56  also can be moved a limited amount by moving cam rollers  18  to exert or remove lifting forces. When the substrate engages the printhead, the force by which the platen urges the substrate against the printhead can be increased by moving the cam rollers  68  to increase the tension in springs  81 . The cams can be moved to a lowered position to slightly space the platen, and substrate from the printhead for ribbon removal or fast ribbon feed. 
     The platen roller  15  is driven by stepper motor  15 A. The tray or carrier  17  and the substrate  14  are also driven through the printing cycle under the printhead  12 , and force from the springs  81  urges the platen roller  15  upwardly to act as a pinch roller that drives the carrier  17  and substrate  14  across the printhead. The platen  15  also has an outer resilient covering  86  as shown, and the tray or carrier is flexible so it will conform to some irregularities in the substrate or components. 
     Positioning the printhead cartridge assembly  36  for sliding into the housing  30  is illustrated schematically in FIG. 6, where the printhead cartridge is disengaged. The printhead cartridge assembly  36  is entering the provided opening in the front of the housing  30  for insertion. It can be seen in FIGS. 6A and 6B, that the side members  40  of the cartridge assembly  36  are approaching the shaft  72  that has the hubs  76  (FIG. 15) for retaining the cartridge when it latches in place. In the view in FIGS. 6A and 7A, it can be seen that the receptacles  42  and guide edge  42 A on each side are approaching the shaft  72 . This is also shown enlarged in FIG.  7 A. The print ribbon  13  from the supply roller  23  and take-up roller  24  is under the printhead  12 , and then the printhead cartridge assembly  36  will be slid into place as shown in FIG. 6B held by the shaft receptacles  42 , and the slots  78  at one end. When the printhead cartridge is fully inserted, as shown in FIG. 6B, the frame  56  and the tray or carrier  17  are lifted and the outer end is aligned with the end opening or recess  46  of the housing so the carrier can be moved out of the housing and loaded or it can be completely removed, and a carrier already loaded with a different shape substrate or the same shape inserted. 
     In FIG. 6B, the substrate carrier  17  is shown in its loading position, having been driven there by the drive rollers  50  and pinch roller  52  outwardly under control of a controller  96 . The signal to drive the carrier  17  out of the housing can be manual or programmed. The substrate  14  can be put onto the carrier and located against edge or stop  19 . This is also shown in FIG.  14 . 
     The drive roller  50  can then be driven from a suitable stepper motor  50 A under control of central controller  96  to move the carrier  17  and substrate  14  in the direction indicated by the arrow  54  and so that the leading end  14 A of the substrate  14  first engages the pinch roller  52  which is against the top surface of the carrier  17  and will exert a force moving the back edge of the substrate against stop  19 . The carrier and substrate are then moved by the drive under the printhead. 
     While, for simplicity, this description has shown individual stepper motors for platen roller  15  and rollers  50  and  62 , these rollers can be driven together with gears (or timing belts) using only one stepper motor, such as motor  61 A. 
     The start of the printing cycle is shown in FIG. 10, where the leading end  14 A of substrate or disc  14  is immediately under the printhead  12 , which has the resistors forming heating elements  12 B to provide print heat. The platen roller  15  is urged up by the cam rollers  68  acting through the plate  80  and springs  81  to provide a force to urge platen support frame  56  and the platen roller  15  about the pivot axis up against the carrier  17 . A standard, uniform force can be used to urge the substrate  14  against the printhead  12 . 
     FIG. 11 illustrates the positioning of the substrate  14  when it has been fed approximately ⅓ of the way through the printhead by the drive rollers  50  and  52  and by drive roller  62 . 
     The printhead opposes the force from platen  15 . The cartridge is held in position by slots  78 . Shaft  72 , which seats in receptacles  42 , and the cam shaft  66 , are both mounted on plates  69 , as can be seen in FIG.  17 . Thus the forces on the platen and printhead from spring  81  are contained within the plates  69 . 
     In FIGS. 12 and 13, the substrate has been moved from under the printhead  12 , and the print ribbon  13  is being advanced. The cams move so the platen support frame  56  pivots down slightly and platen roller  15  is permitted to move away from the printhead  12 , to permit the ribbon, film or web  13  to be advanced so that the next color can be printed. If multi colors are to be printed, the tray or carrier  17  and the substrate  14  would be reversed in direction and another layer printed over the same region. The substrate  14  is indexed appropriately using suitable sensors such as the sensor shown at  88  in FIG.  12 . The signal from the sensor will be used to coordinate the position of the substrate  14  with the ribbon, film or web  13  and a particular color panel that is on that film. 
     When printing is done, the tray or carrier  17  is lowered or released from the printhead by moving cam  68  and then the tray or carrier is backed out of the housing and the printed substrate  14  removed. A new substrate is put onto the carrier  17  and the printing is repeated anew. If desired, a new carrier  17  can be inserted, since the carrier  17  is held only by the drive and pinch rollers and can be moved completely out of the rollers  50  and  52 . 
     FIG. 18 illustrates the printer of the present invention, with the same designations on the printer as before, but a substrate carrier illustrated at  17 M is modified to carry a substrate  114  that is rectangularly shaped, and which is held in position on the upper surface  115  of the carrier  17 M with suitable stop members  116 , along the sides, and  118  along the trailing edge. The substrate  114  is thus positioned laterally, and will be urged against the stops  118  when the pinch roller and drive roller  50  and  52  that drive the leading end of the carrier and engage the end of the substrate. 
     The leading end of the carrier is positioned about to enter the roller set  50  and  52 , as previously described and because the pinch roller  52  will ride on the surface  115  initially, it will tend to slide the substrate  114  along the carrier when the leading end  114 A is engaged by the pinch roller. Before the pinch roller lifts to engage the substrate it will tend to push the substrate back against the stops  118 , to positively seat the substrate  114  in position for printing the same. 
     As illustrated in FIG. 19, the tray or carrier  17 M can be made of a suitable plastic material, such as a polycarbonate, or other plastics that can be molded, and will have wall  120  with I shaped edge flanges  122  to provide some rigidity along the edges. the frame  56  supports wall  120  as shown, and the flanges  122  fit outside of the arm  58  as shown schematically. The platen roller and the drive rollers fit up against the wall  120 . The carrier  17 M is sufficiently flexible so that slight irregularities would not cause gaps in the printing. The force from platen  15  makes the carrier wall  120  conform to slight irregularities because of the resilient platen roller and the spring mounting, and the flexibility in transverse direction of wall  120 . 
     Various other types of carriers  17 M can be advanced, but the carrier is generally planar so that it can be driven by a drive roller on one side and a pinch roller on the other side, or some other type of reaction member such as the fixed printhead, for moving it through the printer. 
     FIG. 20 illustrates a further modified carrier  17 N, which has an irregularly shaped substrate  130  mounted thereon using suitable side guides  132 , and at least one trailing end guide  134 . The carrier  17 N would be made as previously shown, except it has a wall  135  that has grooves  137  extending in longitudinal direction to provide lateral flexibility for bending or conforming to lateral irregularities, and the guide and pinch rollers would exert a force as indicated by the arrow  136  to seat the substrate against the rear guide  134 . 
     FIGS. 22 and 23 show a modified planar carrier or tray  150  made for carrying a recessed substrate such as a name tag or card  152  to be printed upon that is fed between the drive and pinch rollers  50  and  52 . The flat carrier  150 , and an irregular shaped substrate  152 , which as shown is a representation of Lake Michigan can be used for an identification badge or card for convention delegates. 
     The planar carrier or tray is of sufficient thickness so that the defining line  154  of the badge or substrate  152  can be milled as a recess  156  in the carrier or tray  150 . The substrate recess  156  is milled to leave a thickness of material of the carrier below the recess. The badge  152  can be cut out as separate items. The cut peripheral edge of the badge will fit within the defining line  154  on the carrier  150 , and fit down into the recess. 
     The planar carrier  150  can be made of two flat panels, including a base panel and an upper panel with the upper panel cut to form an opening of the shape desired. The opening could be closed on its bottom by bonding the base panel to the panel with the cut out. 
     The badges are held and located properly in the recess formed in the carrier. The carrier can have longitudinal grooves  160  to permit more lateral flexibility. The cutting of recesses of irregular shapes, or even rectangular shapes or ornamental designs, in the surface of a carrier or tray used with a printer increase the versatility of the printer. 
     It also can be seen in FIGS. 6A and 12 that electrical connections for the motors on the printhead cartridge assembly can be made with the connector shown at  90 , which includes a portion  90 A on the housing  30 , and a second portion  90 B on the printhead cartridge  36 . When the printhead cartridge  36  moves to its home position, as latched with the receptacle  42 , connection will be made for the power. 
     The controller shown at  96  will coordinate all functions, including the movement of the cam shaft  66  and the platen roller  15 , through the stepper motors  66 A and  15 A, and the position of cam shaft  66  can be changed so that the cam rollers  68  will move to lower the platen  15  as needed. The printing can be preprogrammed into the controller. 
     The term substrate is intended to include objects that have a surface which is to have printed material applied and which will fit onto a carrier or tray. In addition to the items previously described, the term substrate can include credit cards, playing cards, labels, name tags, sign of various types and similar flat surface objects. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.