Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of copending International Application No. PCT/GB99/03544, filed Oct. 26, 1999. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a multi-functional printer. 
     BACKGROUND OF THE INVENTION 
     In the state of the art, a number of printers capable of “direct” printing are known. Direct printing in the context of the present invention means that the printer is placed on the image receiving medium, usually manually, and the printing means of the printer or the entire printer then scans over the image receiving medium in the printing operation. Thus, the medium is not fed through the printer—as in most office printers—but the printer moves over the medium. 
     Such a printer is known from ER 564297 A. The printer is manually positioned on an image receiving medium and has an ink jet print head which scans in two orthogonal directions over the image receiving medium. The printer is connected to a computer and capable, for example, of printing addresses onto envelopes, but can also be used separately from the computer for printing data downloaded from the computer to the printer. 
     Another ink jet printer that is placed on a printing medium is disclosed in U.S. Pat. No. 5,634,730. This printer is provided with a keyboard for inputting data, but can also print images downloaded from a computer. The print head scans over the image receiving medium along a special path, e.g., helically or like a pendulum. 
     DE 3142937 A refers to a so-called hand stamp which is placed manually on the image receiving medium. It can print data downloaded from an accounting machine, or images consisting of user-selected fixed phrases. The hand stamp has a thermal print head and an ink ribbon for printing. 
     The direct printers known in the prior art are thus capable of printing an image onto an image receiving medium, and make use of a scanning print head. Thus, they can only perform one function, which is printing. On the other hand, a number of purposes for a scanning device can be imagined, for which such a device could be used, as well. 
     Thus, the object of the present invention is to provide a printer of the type having a scanning print head, which allows for use of the printer for printing and for purposes different than printing. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided a printer having a housing and a scanning means provided in the housing. The scanning means is arranged to move in two different directions within the housing. The printer also includes a mounting means for releasably mounting a print head to the scanning means, and an aperture provided within the housing. The aperture is arranged to be placed on, or adjacent to, a medium such that the print head, when mounted, is operable to print onto the medium through the aperture. The mounting means is arranged to accommodate a holding means which holds a machining device for machining the medium. 
     The proposed solution is to use the mounting means for fixing a holding unit to the scanning means instead of, or in addition, to the print head being fixed to the scanning means. The holding unit holds a machining device for machining the image receiving medium. Thus, the printer can be used for printing, when the print head is mounted to the mounting means, and alternatively or additionally, for machining a medium on which it is mounted. The scanning means then moves the machining device over the medium which is being machined. 
     An advantage of the invention is that the printer is not only suitable for printing, but can be used for another purpose, as well. This second purpose is to machine a medium. 
     In particular, the machining device can be a cutting blade, a rotating milling cutter, or a rotating drill. Since these tools normally have to be rotated when the medium is machined, the printer, or more particularly, the holding means which can be released from the printer and holds the machining device, is provided with rotating means for rotating the machining device with respect to the machined medium. In particular, the holding means can be provided with a motor for rotating the machining device, whereby the motor is electrically connected to a controlling unit of the printer via a connector which is normally connected to the print head of the printer. Thus, the electrical connection for the print head also serves for providing the motor of the holding means with electrical power. The machining device is preferably releasably connected to the holding means. 
     The medium which is machined by the machining device is preferably a stencil. Thus, the user can place the printer—to which the machining device is mounted—upon a blank stencil material, and, by machining, engrave a desired image or pattern into the stencil material. This machined material can then be mounted onto a stamp apparatus. It should be noticed that instead of a stencil material, also other materials can be machined. For example, glass or metal plates could be engraved. 
     The machining device is held by the holding means, which is accommodated in the mounting means instead of the print head—or, in another embodiment of the invention, additionally to the print head. 
     According to a second aspect of the invention, there is provided a printer having a housing, a scanning means, a mounting means, and an aperture. The scanning means is provided in the housing and arranged to move within the housing. The mounting means mounts an ink jet print head provided with an ink supply to the scanning means. The aperture is provided within the housing and arranged to be placed on, or adjacent to, an image receiving medium such that the print head, when mounted, is operable to print onto the image receiving medium through the aperture. The ink supply preferably contain a security ink. 
     Additionally, there is provided a method of printing security images onto an image receiving medium, including the steps of providing a printer with a housing and a scanning means in the housing, mounting an ink jet print head provided with an ink supply containing security ink to the scanning means, providing an aperture within the housing, placing the aperture on, or adjacent to, the image receiving medium such that the print head can print onto the image receiving medium through the aperture, and scanning the print head with the scanning means within the housing and thereby spitting the security ink according to a desired pattern onto the image receiving medium. 
     In the prior art, it is known to use normal rubber stamps for providing entry receipts onto the hand or forearm of a visitor of a concert event, discotheque, or other event. Such rubber stamps can be used in combination with security inks, which, for example, are only visible when illuminated with ultraviolet light. A disadvantage of the prior art is that the rubber stamps are easily counterfeited, while the security ink can be easily obtained in the market. Thus, the security of these entry receipts is quite low. 
     The second aspect of the invention proposes to replace the rubber stamps with a direct printer, i.e., a printer with an ink jet head scanning over the image receiving medium and spitting a security ink onto the medium, according to a desired pattern. Thus, the security, for example, of entry receipts printed onto the hand or forearm of a user is significantly improved, since the printed image can be altered electronically, and thus with a high frequency (as for example daily), such that it will hardly be possible to make a rubber stamp copy of it before the user of the printer has already chosen a new pattern to be printed as an entry receipt. Furthermore, the printing resolution will normally be much better than any details which can be produced with a rubber stamp. 
     The security ink is preferably provided in a special ink cartridge. The cartridge can contain the printing nozzles, or be connected to a separate printing unit having nozzles. 
     Further, the security ink can be of any number of types. One such type is chemical marker ink, i.e., invisible ink which can be made visible by means of a pencil containing a developer liquid, as disclosed in DE 19646156 A, U.S. Pat. No. 5,660,925, or U.S. Pat. No. 5,534,587, the contents of which are incorporated herein by reference. Another type of security ink is ink containing a luminescent substance, which transmits light with a different wavelength compared with the wavelength of the light which the ink is illuminated, as disclosed in EP 680411 A, the contents of are incorporated herein by reference. Another type of security ink is UV fluorescent ink, which fluoresces under UV light, as disclosed in ER 730250 A, ER 267215 A, or EP 3187 A, the contents of which are incorporated herein by reference. Yet another type of security ink that can be used with the present invention is magnetic ink, which contains magnetic particles, which can be detected by means of a special detector making use of polarization of light provided by the magnetic particles, as disclosed in ER 632398 A, the contents of which is incorporated herein by reference. Another type of security ink is phosphorescent ink, which still phosphoresces after it has been illuminated, as disclosed in ER 770969 A or ER 766198 A, the contents of which are incorporated herein by reference. Another type of security ink for use with the present invention are photo chromic inks, which alter their optical appearance under illumination, as disclosed in ER 716387 A, the contents of which is incorporated herein by reference. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention and to demonstrate how the same may be carried into effect, reference will now be made to the accompanying drawings in which: 
     FIG. 1 is a plan view showing a printer, a base station and a computer; 
     FIG. 2 is a view of a cutter mechanism which is usable instead of the print head of the printer; 
     FIG. 3 is a view of a printer using a special security ink; 
     FIG. 4 is a view of a mechanism for fixing the print head in the printer; 
     FIG. 5 illustrates the operation mode of the print head; 
     FIG. 6 is a view of a print head with an alignment feature; and 
     FIG. 7 is a view of the printer mounted on another base station. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a printing system consisting of a computer  10 , a computer controlled display  12 , which is in the described embodiment of the invention a CRT, a keyboard  14  linked to the computer  10  by means of a cable  16 , and another cable  18 , connecting the computer  10  with a base station  20 . The base station  20  is connected to a printer  24  by means of a cable  22 . Thus, the printer  24  is linked to the computer  10  via the cables  18 ,  22  and the base station  20 . 
     As known in the prior art, the computer  10  comprises a processor on which software is running, comprising an operating system, a printer driver to enable printing with the printer  24  from the operating system, and a software application by which data can be created, selected and formatted on the PC, for defining image patterns to be printed by the printer  24 . The software application can be activated in a number of ways. For instance, the software application can be selected by the user at startup or from the desktop. The user can place the software application in the start up directory or create an icon on the desktop. From within another application, the user may invoke the software application from a button (displayed on the display  12 ) in the toolbar of another software application. From a handheld printer  24  itself, if the application is not running, the user may press a print button  34  on the hand held printer  24 , which will automatically invoke the software application in the first instance. 
     Another possibility to activate the software application on the computer  10  for controlling the printer  24  is to lift the printer  24  off the base station  20 . A switch  32  is provided in the base station  24  sensing the presence or absence of the printer  24  by means of a pin  30 . When the printer  24  is placed upon the base station, the pin  30  is depressed, and the switch  32  is closed. In the case that the printer  24  is removed from the base station  20 , the pin  30 , which is biased in the vertical direction, moves upwardly and the switch  32  opens. The switch is connected via some electronic circuits to the computer  18  and activates the software application for printing. 
     The base station  20  is connected to the computer  10  by means of the cable  18 , which can be a parallel or a USB cable. Electric power is supplied to the base station  20  by a separate mains transformer, but could also be supplied from the computer via the cable  18 , preferably when the cable  18  is a USB cable. The cable  18  can be hard wired to the base station  20 , or connected to a socket of the base station, which is preferably provided at the rear thereof. When the printer  24  is not in use, the handheld printer may be placed in the base station  20 . The base station  20  will ensure that the ink jet print head of the printer  24  is protected when not in use by a capping device that will be automatically triggered whenever the printer is inserted into the base station  20 . The base station  20  will also cause the print head of the printer  24  to eject ink into a reservoir and mechanically clean the surface of the print head. These measures are necessary to maintain optimum print quality. 
     The umbilical cable  22  connects the base station  20  to the hand held printer  24 , providing both power and data. An LED on the printer will indicate that power is on. The printer  24  is removed from the base station  24  and positioned on the surface to be printed. The length of the cable  22  limits the distance of travel from the base station. 
     In another embodiment of the invention, the printer is arranged to be disconnected from the base station by unplugging the umbilical cable  22  and moved to another location where printing of the contents of onboard memory, i.e., downloaded image data, can be effected. The user will employ scroll buttons on the printer to select the required print data, which appear in a small LCD. Once a selection has been made, pressing the print button  34  will activate printing. Having selected the data to print using the software application (or the scroll buttons on the printer), the user will activate printing from the print button  34  on the hand held printer  24  itself. 
     Print alignment is achieved visually through a transparent window  36  in the printer casing. This window  36  can also be opened for inserting an ink cartridge into the printer  24  before use. The cartridge is then clamped in a carriage of the printer  24 . The window  36  must be closed before printing. The user can choose from a range of colored and special inks. Changing a cartridge is achieved by lifting a retaining lever and extracting the cartridge in use and replacing this with a new or different color cartridge in the way described above. If the removed cartridge still contains ink and is to be reused, it must be capped to avoid the ink drying out. 
     The printer  24  contains a print mechanism with the ink jet print head having a number of print nozzles, and an ink supply. The print head is moved by means of motor driven scanning means within the housing in two (generally orthogonal) directions such that a rectangular area can be imprinted through an aperture of the printer  24  at the bottom of its housing. Thus, the printer  24  is placed manually on an image receiving medium and—when the print button  34  is depressed—the print head scans over the medium and imprints it by spitting ink droplets onto it. The print button has to be held on for a predetermined time, e.g., at least two seconds, to initiate printing (in order to prevent accidental printing). 
     FIG. 1 shows the printer  24 , base station  20  and computer  10  linked by cables. In an embodiment, it is possible to replace one or all of these links by a wireless link such as a low power RF link or an infra red link. FIG. 1 also shows the presence of a “Smart Card” reader  28  in the base station  20 . Smart cards  26 , i.e., memory cards, may be used for storing data or images or as a substitute for additional RAM in the base station. Spare cards may be stored within the base station where a storage compartment is provided (not shown). 
     In the case that the printer  24  is powered only by batteries, rather than having the cable  22  transmitting power from the base station  20 , the amount of charge remaining in the batteries may be monitored and displayed on a display of the printer  24 , and/or on the display  12  of the computer  10 . If rechargeable batteries are used, the battery monitoring system could also be used to control the charge/discharge cycle of the battery pack to maximize battery life. This could also enable rapid recharging of the batteries. Such a battery management system could also indicate that there was sufficient energy remaining in the battery pack to complete the current task. 
     As described above, the printer  24  is based on a two dimensional movement of the print head over the image receiving medium. Additional features may be provided to this X-Y motion to perform a range of other functions. For example, the print cartridge could be replaced with a cutter mechanism and then be used for cutting out stencils. This is indicated in FIG. 2. A holder  40  is provided which has the same measurements as an ink jet print head cartridge, such that it can be mounted in the printer  24  instead of a print cartridge. On the bottom of the holder  40 , a blade  46  is provided which is mounted to a brick shaped blade holder  42 , and the blade holder  42  is connected with the holder  40  via a shaft  44 . Since the holder  40  scans in two orthogonal directions over the medium  48 , the blade  46  can also be moved over the medium, which is in the embodiment shown in FIG. 2 a stencil material, in order to cut a desired pattern out of it. 
     Due to the fact that cutting has to be performed along different cutting directions, it is necessary to rotate the cutting blade around an axis  50  lying in a plane defined by the direction of motion of the holder  40 . Thus, the blade holder  42  needs to be rotated with respect to the holder  40  around the axis of the shaft  44 . This is performed by means of a motor provided in the holder  40 . The motor (not shown) is arranged to rotate the shaft  44 , via an intermediate gear. The power required by the motor is provided by the printer, via the connections to which the print head is normally connected. Hence, the holder  40  contains a motor connected to the electronics of the printer  24 , and controlled by the printer&#39;s software. Instead of a blade, a milling cutter or a drill can be mounted to the blade holder  42 , among other tools, preferably interchangeable by means of an appropriate releasable connection. 
     FIG. 3 illustrates another use of the described printer  24 . By insertion of a special ink cartridge, a further use of the printer would be possible. The ink is a security ink, such as a chemical marker ink, an ink containing a luminescent substance, a UV fluorescent ink, a magnetic ink, a phosphorescent ink, or a photo chromic ink. Thus, the printer  24  can be used for printing entry receipts  54  on the backs of the hands  52  of a visitor of a concert, a discotheque, or other events, as shown in FIG.  3 . 
     It should be noted that other possible printing uses include postal franking and printing data onto the reverse of business cards. In this case, the printer would preferably be arranged to remain in the base station and an envelope or a business card is inserted into an appropriate one of a number of molded guides. Typically the user would use a guide which positions an envelope for franking. An appropriate software application would be running on the computer  10 , assuring that the postage is paid (e.g., via downloading a franking image from the Internet upon payment via a credit card number), before a franking stamp is printed. The information printed onto the reverse of a business card would have some connection to the person mentioned on the front of this card. 
     FIG. 4 illustrates how a print cartridge  72  is mounted in the printer  24 . A metal (or plastic) base plate  60  is mounted for scanning motion along the direction indicated by arrow A. The necessary mechanism for scanning in this direction is not shown in FIG. 4, for the sake of clarity. On the base plate  60 , a first guide rail  62  is provided, and a second guide rail  64 . Both guide rails  62 ,  64  extend in a direction which is orthogonal to the direction of movement of the plate  60 . Additionally, two wheels  78  are provided, around which a drive belt  66  is located. The drive belt  66  is preferably toothed and extends parallel to the guide rails  62 ,  64 . Further, a pin  70  is provided on a pin holder  68 , the latter being fixed to the drive belt  66 . The print cartridge  72  is provided with an ink supply and nozzles for spitting the ink onto an image receiving medium. Print cartridge  72  is also provided with four snap-on bearings  80 ,  82 ,  84  (the fourth one cannot be seen in FIG.  4 —since it is hidden behind the cartridge  72 —but is in the same plane as bearing  84  and fits onto guide rail  64 ). The bearings  80  and  82  are arranged to be snapped (or clipped) into the first guide rail  62 , and the bearing  84  plus the hidden bearing are arranged to be snapped into the second guide rail  64 . Thus, the cartridge  72  can be slidably fixed to the guide rails  62 ,  64  and travel along the longitudinal axis of the guide rails. The pin  70  engages in a hole  86  of the cartridge, such that a driving connection between the drive belt  66  and the cartridge  72  is established. When the belt is driven (by means of a corresponding motor, not shown in FIG. 4 for the sake of clarity, but it could drive the belt  66  through the rectangular window in the base plate  60 ), the cartridge  72  travels along the guide rails  62 ,  64 . In order to control the print head of the cartridge  72 , the printer&#39;s control electronics requires an information on the position of the print head. Thus, a pin wheel  74  engaging the printed medium is provided on the cartridge. The pin wheel rotates  74  when the cartridge  72  moves along the guide rails  62 ,  64  and its rotation is detected by means of a motion detector  76 . The pin  70  also carries the electrical connections (not shown) to both the print head and the motion detector  76 . Pin wheel  74  is used to detect whether or not the printer is sufficiently close to the substrate to print accurately. If the wheel loses contact with the substrate, it stops revolving and the output signal from the motion detector  76  (which can employ a light barrier detecting the pins of the pin wheel  74 ) changes and printing is interrupted. 
     The base plate  60 , the pins on which the wheels  78  are mounted, and the guide rails  62 ,  64  are unitary. Thus, the base plate  60  is produced as a unitary unit, e.g., by die casting, in order to simplify construction and minimize component cost. It should be noted that a movement along the direction indicated by the arrow A is not necessary when the cartridge  72  contains a print head having a width sufficient to print the entire image receiving medium in one scan. 
     FIG. 5 illustrates how scanning is performed over the image receiving medium. Most inkjet printers known in the prior art accelerate the print cartridge from rest to normal printing speed prior to firing the ink droplets. This simplifies the control of ink droplet spacing, but the additional space required to accelerate the print cartridge increases the overall size of the product. The printer described here is hand held and thus requires that the overall dimensions be minimized. The control system of the print cartridge  72  thus provides the ability to print as the print cartridge assembly is accelerating—during printing of the left margin  90  of the image receiving medium  48 ′—and decelerating—during printing of the right margin  90 , of the image receiving medium  48 ′—at the start and finish of each sweep of the mechanism thus enabling the product dimensions to be minimized for a given size of the print area on the image receiving medium. 
     In FIG. 6, it is shown how features can be added to the cartridge  94  or the housing  92  of the cartridge  94  (i.e., a holder in which the cartridge is accommodated) to aid alignment of the printer to the print area. These take the form of a pointer  98  or an indicator  96  attached to the print cartridge  94  or to the holder  92 . The print cartridge may then be moved around the print area to indicate the maximum printable area. 
     FIG. 7 illustrates the printer  24  when placed on an alternative or modified base station  20 ′. The base station  20 ′ contains a supply  100  of labels  102  for printing upon. In order to prevent the ink cartridge from drying out should the printer  24  not be returned to the base station  24 , a sealing lid  108  is attachable to the printer to close the print aperture in the base of the printer. A hermetically sealable compartment is also provided in the base station  20 ′(not shown). This provides storage for a partially used cartridge to prevent it from drying out, for example, if different color cartridges are used. The printer  24  of FIG. 7 has some features for making alignment on the image receiving medium easier: on the top of the housing of the printer, two small windows  104  are located, which allow viewing of and aligning the image receiving medium with respect to the printer (or the other way around). 
     It should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention accordingly is to be defined as set forth in the appended claims.

Technology Category: 7