Abstract:
Apparatus for printing and memory tag application onto a base medium is described. The apparatus includes a print head for printing onto the base medium, and a memory tag dispenser movable relative to the base medium for applying memory tags to the base medium. The print head may also be moveable relative to the base medium.  
     A method of printing onto a base medium and applying a memory tag to the base medium is also described. It comprises the steps of:  
     i) feeding the base medium along a first axis past a print head;  
     ii) printing onto the base medium;  
     iii) feeding the base medium past a memory tag dispenser; and  
     iv) moving the memory tag dispenser relative to the base medium and applying a memory tag to the base medium at a desired location.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to printing apparatus, and in particular to such apparatus which in addition to printing can apply memory tags to the paper or other base medium being printed onto, and to a method of doing so.  
         BACKGROUND OF THE INVENTION  
         [0002]    Memory tags in the form of Radio Frequency Identification (RFID) tags are well known in the prior art, and the technology is well established (see for example: RFID Handbook, Klaus Finkenzeller, 1999, John Wiley &amp; Sons). RFID tags come in many forms but all comprise an integrated circuit with information stored on it and a coil which enables it to be interrogated by a reader which also powers it by means of an inductive (wireless) link. Until recently RFID tags have been quite large, due to the frequency they operate at (13.56 MHz) and the size of coil they thus require, and have had very small storage capacities. Such RFID tags have tended to be used in quite simple applications, such as for file tracking within offices or in place of or in addition to bar codes for product identification and supply chain management.  
           [0003]    Much smaller RFID tags have also been developed, operating at various frequencies. For example Hitachi-Maxell have developed “coil-on-chip” technology in which the coil required for the inductive link is on the chip rather than attached to it. This results in a memory tag in the form of a chip of 2.5 mm square, which operates at 13.56 MHz. In addition Hitachi has developed a memory tag they call a “mu-chip” which is a chip of 0.4 mm square and operates at 2.45 GHz.  
           [0004]    These smaller memory tags can be used in a variety of different applications. Some are even available for the tagging of pets by implantation.  
           [0005]    There are however many further uses to which such memory tags may be put. For example in EP 1 076 316 A2 an application is described whereby a memory tag is attached to a print of a photograph and contains data about the print concerned.  
         SUMMARY OF THE INVENTION  
         [0006]    According to a first aspect of the present invention there is provided apparatus for printing and memory tag application onto a base medium, the apparatus having a print head for printing onto the base medium, and a memory tag dispenser movable relative to the base medium for applying memory tags to the base medium at a desired location.  
           [0007]    The invention provides the ability to apply one or more memory tags to a base medium at selected locations, and to co-ordinate this with printing also applied to the base medium. This means that documents can be produced with memory tags in various locations with stored on them data to supplement the printed information.  
           [0008]    The print head may also be moveable relative to the base medium.  
           [0009]    Preferably the base medium is moved along a first axis through or past the apparatus and the print head if moveable moves back and forth along a second axis and the memory tag dispenser moves back and forth along a third axis, the second and third axes being substantially perpendicular to the first axis.  
           [0010]    The print head and memory tag dispenser may be connected together and move in unison along the second and third axes.  
           [0011]    Preferably the memory tag dispenser includes a supply of memory tags on a flexible substrate and a substrate guide path which takes the substrate past a memory tag application station where memory tags are removed from the substrate and applied to the base medium as required.  
           [0012]    The memory tag application station may include a reciprocating member adapted to apply pressure to the substrate opposite the location of a memory tag pushing the memory tag onto the base medium, thus transferring the memory tag from the substrate to the base medium.  
           [0013]    The memory tag dispenser further may further include a data writing station where data is written to the memory tags and which is located such that the substrate passes it shortly before passing the memory tag application station.  
           [0014]    The data writing station may also read the memory tags after writing to them to check that the data has written correctly. Alternatively the memory tag dispenser further includes a data check station which the memory tags pass after the data write station and where the memory tags are read and the data checked with that written at the data write station.  
           [0015]    Preferably the base medium passes the print head before passing the memory tag dispenser.  
           [0016]    The apparatus may be adapted to handle base medium in sheet form which passes through the apparatus, and in particular to handle sheets of paper or like material.  
           [0017]    Preferably the base medium passes through the apparatus with a surface towards the print head and the memory tag dispenser, and the printing and the memory tag are applied to that surface.  
           [0018]    According to a second aspect of the invention there is provided a method of printing onto a base medium and applying a memory tag to the base medium comprising the steps of:  
           [0019]    i) feeding the base medium along a first axis past a print head;  
           [0020]    ii) printing onto the base medium;  
           [0021]    iii) feeding the base medium past a memory tag dispenser, and  
           [0022]    iv) moving the memory tag dispenser along a third axis substantially perpendicular to the first axis and applying a memory tag to the base medium at a desired location.  
           [0023]    The method may further comprise the step of moving the print head relative to the base medium. Such movement may be along a second axis substantially perpendicular to the first axis.  
           [0024]    The movement of the memory tag dispenser may be along a third axis substantially perpendicular to the first axis.  
           [0025]    Preferably the method further comprises the step of writing data to the memory tag, prior to applying it to the base medium.  
           [0026]    Conveniently the method also comprises the step of reading the data on the memory tag and checking it against the data written to it.  
           [0027]    The memory tag may be applied to the base medium at a location printed with a preselected icon.  
           [0028]    The method may be used such that a plurality of memory tags are applied to the base medium. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    Embodiments of apparatus according to the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:  
         [0030]    [0030]FIG. 1 is a schematic of the main elements of a first embodiment of apparatus according to the invention from the side;  
         [0031]    [0031]FIG. 2 is a schematic of the apparatus of FIG. 1 from above;  
         [0032]    [0032]FIG. 3 is a block diagram of the control of the apparatus according to the invention;  
         [0033]    [0033]FIG. 4 is a schematic of the main elements of a second embodiment of apparatus according to the invention from the side;  
         [0034]    [0034]FIG. 5 is a schematic of the main elements of a third embodiment of apparatus according to the invention from the side; and  
         [0035]    [0035]FIG. 6 is a schematic of a memory tag and data write device as incorporated in any embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    Referring to FIGS. 1 and 2 apparatus  10  for printing and memory tag placement onto a base medium, in this case sheet paper  12 , is illustrated. For simplicity only those parts of the apparatus  10  which need to be shown to describe the invention are illustrated.  
         [0037]    The apparatus  10  includes much known technology from the prior art of printers which is not described here. However, the apparatus  10  includes paper feed rollers  14  which are driven to rotate as indicated by arrows R 1  to feed the paper sheets  12  through the apparatus  10  along a first axis in the direction indicated by arrows A 1 .  
         [0038]    The apparatus  10  further includes a print head  16 , which in this example is of ink jet form, mounted on a print head carriage  18  which extends across the apparatus  10  substantially perpendicular to the axis A 1 . The print head  16  is moveable back and forth along the print head carriage  18 , in known manner. Thus the print head  16  is moveable back and forth along a second axis indicated by arrows A 2 , substantially perpendicular to the axis A 1 , to enable the print head  16  to access most of the upper surface  12   a  of the paper sheet  12  as it moves through the apparatus  10 , and thus to print anywhere on that accessible area of surface  12   a  as required.  
         [0039]    The apparatus  10  also includes a memory tag dispenser  20  which in this embodiment is connected to the print head  16  for movement back and forth along the print head carriage  18  with the print head  16 . Thus the memory tag dispenser  20  is moveable back and forth along a third axis indicated by arrows A 3 , substantially perpendicular to the axis A 1 , and parallel to the axis A 2 , to enable the memory tag dispenser  20  to apply memory tags to anywhere on the accessible area of surface  12   a , as will be described further below.  
         [0040]    The memory tag dispenser  20  includes a supply  22  of memory tags  24  removably secured to a substrate  26  by appropriate adhesive, the memory tags  24  having further adhesive on the faces opposite the substrate  26 . A substrate guide path comprising rollers  28 ,  30 ,  32 ,  34  and  36  guides the substrate  26  and thus the memory tags  24  through the dispenser  20 . Roller  36  is driven to rotate in the direction of arrow R 2  to pull the substrate  26  along the guide path from the supply  22  on roller  28 . The memory tag dispenser  20  further includes a data write station  38  and a memory tag application station  40  located adjacent to the substrate guide path such that the substrate  26  passes between the data write station  38  and the memory tag application station  40  and the paper sheet  12 .  
         [0041]    The data writing station  38  is used to write data to the memory tags  24 , in known manner, whilst they are still on the substrate  26 , shortly before they are applied to the paper sheet  12 . Then, at the memory tag application station  40  a reciprocating member (not shown) can on command push the substrate  26 , behind the location of a memory tag  24  to be applied to the paper sheet  12 , downwards and thus apply the memory tag  24 , by means of the adhesive on it&#39;s face opposite the substrate  26 , to the paper sheet  12 . The empty substrate  26 , following the removal of the memory tags  24 , is wound onto roller  36  for later disposal when a fresh supply  22  is loaded into the memory tag dispenser  20  if appropriate, or replacement of the whole memory tag dispenser  20  if it is a disposable unit as for the toner cartridges in most printers.  
         [0042]    The method of operation of the apparatus  10  will now be described, with reference also to FIG. 3. The apparatus  10  includes a main processor  42  which receives instruction signals from a host computer  44 , including the details of what to print, where to print it, what data to write to the memory tag or tags  24  to be applied to the paper sheet  12 , and where on the paper sheet  12  the memory tag or tags  24  are to be applied. The main processor  42  sends command signals as required to the mechanics controller  46 , which controls all the mechanical operations of the apparatus, (i.e. the paper feed rollers  14 , the movement of the print head  16  and memory tag dispenser  20  along the print head carriage  18  and the operation of memory tag dispenser  20 ), to the print head  16  and to the data write station  38 . Thus the paper sheet  12  is fed through the apparatus  10  and has the required information printed on it&#39;s upper surface  12   a . At the same time the required memory tags  24  have the necessary data written to them at the data write station  38  prior to being moved to the tag application station  40  where they are applied to the upper surface  12   a  of the paper sheet  12  in the required location(s).  
         [0043]    The manner of co-ordination of the printing, data writing and tag application processes will depend on a number of factors. If, for example, the memory tags  24  are only to be applied adjacent the top and/or bottom of the paper sheet  12  then the data writing and tag application processes can take place before and/or after the printing. This would avoid the necessity for the printing process to be interrupted, and would make the co-ordination simpler. Further, when implemented with an inkjet printer, which in general requires a pause, after printing has been completed before the paper sheet is ejected, to allow the ink to dry, the data writing and tag application processes could conveniently take place during this pause for memory tags applied adjacent the bottom of the paper sheet.  
         [0044]    It is likely that the memory tags  24  will be read in future both by further apparatus which can scan the paper sheet  12  to locate the memory tags  24  and by hand held readers. Thus in order to assist users in the future to locate the memory tags  24  on the paper sheet  12  the memory tags  24  may be applied to the paper sheet  12  on top of printed icons which can be readily identified by users.  
         [0045]    Referring now to FIG. 6 the basic operation of the memory tags  24  and of the data write station  38  will be described. The memory tag  24  includes an antenna coil L 1  and a capacitor C 1  connected in parallel therewith to form a resonant circuit. It further includes a memory M and processing and power circuit P 1 . The data write station  38  includes an antenna coil L 2  and a capacitor C 2  in parallel therewith to form a resonant circuit, and a processing and signal generating circuit P 2 .  
         [0046]    A signal generator with in P 2  generates a signal at the chosen frequency, such as 2.45 GHz, this is applied to the antenna coil L 2  and thus generates an electromagnetic field which, provided the memory tag  24  is sufficiently close to the data write device  38 , penetrates the antenna coil L 1  of the memory tag  24 . By induction a voltage is thus generated in the antenna coil L 1 , this is rectified in circuit P 1  and used to power the memory tag  24 . The capacitance of the capacitors C 1  and C 2  is selected such that the resonant circuits are both resonant at the frequency generated by the signal generator, in order to maximise transmitted signal strength and received signal.  
         [0047]    When data is to be written to the memory tag  24  by the data write device  38  the radio frequency signal generated in P 2  is modulated, e.g. amplitude modulated, with the data before being applied to the antenna coil L 2  and transmitted. The signal received by the memory tag  24  by inductive coupling thus both powers the memory tag  24  and communicates with it, the circuit P 1  separating the data signal from the carrier and passing data for storage to the memory M.  
         [0048]    Similarly, if data is to be read from the memory tag  24  the circuit P 1  applies a signal indicative of the data to the antenna coil L 1  which is detected, as a result of the inductive coupling, by antenna coil L 2  and deciphered in circuit P 2  before being passed from the data write device  38  to main processor  42  of the apparatus  10 . This signal may for example be transmitted using load modulation. In RFID systems such as this the power consumed by the memory tag  24  can be measured as a drop in voltage across the internal resistance of the antenna coil L 2  of the data write device  38 . A load resistance within the circuit P 1  may be switched on and off, thus altering the power consumed by the memory tag  24  which is then detected as an amplitude modulation of the voltage across the antenna coil L 2  of the data write device  38 .  
         [0049]    The apparatus  10  has been described as appropriate for use with paper sheets  12 . However, embodiments of the invention may also be constructed for use with other base media, for example paper in fan fold or roll form, other sheet material, or indeed boxes or other packages passing underneath, rather than through the apparatus  10 , on some kind of conveyor.  
         [0050]    The data write station  38  may, in addition to writing the data to the memory tags  24 , also conduct a read operation to check that the data has written successfully before the memory tag  24  is applied to the base medium. Alternatively, particularly if the apparatus  10 ′ is operating at high speed, a separate data check station  50  may be included in apparatus  10 ′, this would be conveniently located between the data write station  38  and the memory tag application station  40 , within the memory tag dispenser  20 ′ as shown in FIG. 4 (where parts common to the apparatus  10  of FIG. 1 are like referenced).  
         [0051]    A further alternative, for some very limited applications, is for the supply  22  of memory tags  24  to be pre-written with data when loaded into the apparatus  10 . Clearly in such embodiments there would be no requirement for the inclusion of the data write station  38  within the memory tag dispenser  20 ″ of the apparatus, and such a simplified apparatus  10 ″ is shown in FIG. 5 (where parts common to the apparatus  10  of FIG. 1 are like referenced).  
         [0052]    Although the print head  16  is described as being of ink jet form, the invention can be implemented with many different forms of print head and indeed many different forms of printer. For some forms of printer with moveable print heads it may be appropriate for the tag dispenser to be moveable independently of the print head, rather than these units being connected together for movement as one. The invention may also be implemented in printers in which the print head is not movable, such as laser printers. All such embodiments still fall within the scope of this invention.  
         [0053]    The apparatus of the invention provides a significant advantage over the prior art in that more than one memory tag can be applied to a single base medium, and they can be applied to a large area of the base medium, i.e. that which is accessible to the memory tag dispenser. With the movement of the base medium through the apparatus and the movement of the tag dispenser within the apparatus the accessible area of the base medium is generally most of the area of the base medium, with just the boundaries not being accessible as for most printers.