Patent Abstract:
A printhead assembly includes an elongate printhead mounted along a spine. A conductive film is provided in electrical contact along the printhead. Power and data from a flexible circuit bearer are conveyed to the conductive film, and hence the printhead, by pressing the flexible circuit bearer against the film. The flexible circuit bearer is forced against the film by an angled member arranged to bias the flexible circuit bearer towards the spine thereby pressing the intermediately located flexible circuit bearer into abutment with the conductive film.

Full Description:
[0001]     This is a Continuation of Ser. No. 10/040,472 filed on Jan. 9, 2002 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The following invention relates to a hand-held computing device, of the type commonly referred to as a personal digital assistant, with an internal printer. More particularly, though not exclusively, the invention relates to a personal digital assistant having a pagewidth drop-on-demand printhead and a source of print media located in the personal digital assistant.  
         [0003]     A personal digital assistant, such as the type commonly known under the trade mark Palm Pilot, is typically a hand-held portable electronic device having a fold down display screen and a control panel. The display screen is typically of a touch screen type that reacts to touches made by a user controlling a pixel pen. Alternatively user inputs are provided to the digital assistant through a keypad or in-built curser ball.  
         [0004]     Personal digital assistants provide a user with the convenience to be able to store diaries, address books, meeting schedules etc in a compact, transportable form as well as to be able to instantly add new entries such as meeting notes, new addresses etc..  
         [0005]     Much of the benefit of such portable prior art personal digital assistants is lost however if a print-out of any stored information is required. To print information, prior art digital assistants must be connected to a print device compatible with the digital assistant which requires additional cabling to be carried thus reducing the portability of the digital assistant. Alternatively the digital storage medium that stores the images within the digital assistant must be transferred to another computer having compatible software for reading the storage medium and which is connected to a printer. Each of the above alternatives can only be implemented if these other computing devices are readily at hand. The prior art personal digital assistants are thus yet to reach their maximum potential as a functional medium for storing and transporting information. With the advent of mobile communications technologies potentially allowing electronic commerce to be conducted through one&#39;s digital assistant, it is becoming essential that digital assistants have more suitable print capabilities for printing hard copies of the information stored in the digital assistant.  
         [0006]     However, presently, printer technology has not been suitable for incorporating into personal digital assistants without a significant compromise in the size and portability of such devices.  
       OBJECTS OF THE INVENTION  
       [0007]     It is an object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.  
         [0008]     It is another object of the present invention to provide a personal digital assistant having an in-built printer.  
         [0009]     It is a further object of the invention to provide a personal digital assistant having an in-built printer without significantly increasing the size over prior art digital assistants.  
         [0010]     It is a further object of the present invention to provide a personal digital assistant from which stored information can be printed without connecting the digital assistant to additional computing or printing devices.  
       DISCLOSURE OF THE INVENTION  
       [0011]     There is disclosed herein a hand held personal digital assistant including information storage means, display means, in-built printer means, control means allowing a user to selectively retrieve and display information from said storage means on said display means and to print said information using said printer means and means allowing a user to enter and store new information in said information storage means.  
         [0012]     Preferably the personal digital assistant includes a body section connected to said display means through a hinge joint, said body section housing said information storage means and said control means, wherein at least a portion of said printer means is disposed in said hinge joint.  
         [0013]     Preferably the printer means includes a supply of print media located within said personal digital assistant.  
         [0014]     Preferably said supply of print media is located substantially within said hinge.  
         [0015]     Preferably a printhead of the printer is a monolithic pagewidth printhead.  
         [0016]     Preferably the printhead is an ink jet printhead.  
         [0017]     Preferably the body or hinge includes a releasable cover portion through which a portion of the printer including the print media and/or an ink cartridge can be removed.  
         [0018]     Accordingly, the present invention provides a hand held personal digital assistant comprising an information storage device; a display; a printer comprising a pagewidth printhead wherein said printhead is an inkjet printhead; and a user interface allowing a user to selectively retrieve and display information from said storage device on said display; print said information using said printer; and enter and store new information in said information storage device. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     The invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which:  
         [0020]      FIG. 1  shows a three dimensional view of a print engine, including components in accordance with the invention;  
         [0021]      FIG. 2  shows a three dimensional, exploded view of the print engine;  
         [0022]      FIG. 3  shows a three dimensional view of the print engine with a removable print cartridge used with the print engine removed;  
         [0023]      FIG. 4  shows a three dimensional, rear view of the print engine with the print cartridge shown in dotted lines;  
         [0024]      FIG. 5  shows a three dimensional, sectional view of the print engine;  
         [0025]      FIG. 6  shows a three dimensional, exploded view of a printhead sub-assembly of the print engine;  
         [0026]      FIG. 7  shows a partly cutaway view of the printhead sub-assembly;  
         [0027]      FIG. 8  shows a sectional end view of the printhead sub-assembly with a capping mechanism in a capping position;  
         [0028]      FIG. 9  shows the printhead sub-assembly with the capping mechanism in its uncapped position;  
         [0029]      FIG. 10  shows an exploded, three dimensional view of an air supply arrangement of the print engine;  
         [0030]      FIG. 11  shows a personal digital assistant having a built in printer;  
         [0031]      FIG. 12  shows the internal components of a personal digital assistant having a built in printer;  
         [0032]      FIG. 13  shows a personal digital assistant with a releasable cover portion; and  
         [0033]      FIG. 14  is a schematic block diagram of components incorporated into a personal digital assistant having a built-in printer. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]     In FIGS.  1  to  10  of the accompanying drawings, reference numeral  500  generally designates a print engine, in accordance with the invention. The print engine  500  includes a print engine assembly  502  on which a print roll cartridge  504  is removably mountable.  
         [0035]     The print cartridge  504  is described in greater detail in our co-pending applications U.S. Ser. No. 09/607,993 and U.S. Ser. No. 09/607,251, the contents of that disclosure being specifically incorporated herein by reference.  
         [0036]     The print engine assembly  502  comprises a first sub-assembly  506  and a second, printhead sub-assembly  508 .  
         [0037]     The sub-assembly  506  includes chassis  510 . The chassis  510  comprises a first molding  512  in which ink supply channels  514  are molded. The ink supply channels  514  supply inks from the print cartridge  504  to a printhead  516  (FIGS.  5  to  7 ) of the printhead sub-assembly  508 . The printhead  516  prints in four colors or three colors plus ink which is visible in the infra-red light spectrum only (hereinafter referred to as ‘infra-red ink’). Accordingly, four ink supply channels  514  are defined in the molding  512  together with an air supply channel  518 . The air supply channel  518  supplies air to the printhead  516  to inhibit the build up of foreign particles on a nozzle guard of the printhead  516 .  
         [0038]     The chassis  510  further includes a cover molding  520 . The cover molding  520  supports a pump  522  thereon. The pump  522  is a suction pump, which draws air through an air filter in the print cartridge  504  via an air inlet pin  524  and an air inlet opening  526 . Air is expelled through an outlet opening  528  into the air supply channel  518  of the chassis  510 .  
         [0039]     The chassis  510  further supports a first drive motor in the form of a stepper motor  530 . The stepper motor  530  drives the pump  522  via a first gear train  532 . The stepper motor  530  is also connected to a drive roller  534  ( FIG. 5 ) of a roller assembly  536  of the print cartridge  504  via a second gear train  538 . The gear train  538  engages an engageable element  540  ( FIG. 2 ) carried at an end of the drive roller  534 . The stepper motor  530  thus controls the feed of print media  542  to the printhead  516  of the sub-assembly  508  to enable an image to be printed on the print media  542  as it passes beneath the printhead  516 . It also to be noted that, as the stepper motor  530  is only operated to advance the print media  542 , the pump  522  is only operational to blow air over the printhead  516  when printing takes place on the print media  542 .  
         [0040]     The molding  512  of the chassis  510  also supports a plurality of ink supply conduits in the form of pins  544  which are in communication with the ink supply channels  514 . The ink supply pins  544  are received through an elastomeric collar assembly  546  of the print cartridge  504  for drawing ink from ink chambers or reservoirs  548  ( FIG. 5 ) in the print cartridge  504  to be supplied to the printhead  516 .  
         [0041]     A second motor  550 , which is a DC motor, is supported on the cover molding  520  of the chassis  510  via clips  552 . The motor  550  is provided to drive a separating means in the form of a cutter arm assembly  554  to part a piece of the print media  542 , after an image has been printed thereon, from a remainder of the print media. The motor  550  carries a beveled gear  556  on an output shaft thereof. The beveled gear  556  meshes with a beveled gear  558  carried on a worm gear  560  of the cutter assembly  554 . The worm gear  560  is rotatably supported via bearings  562  in a chassis base plate  564  of the printhead sub-assembly  508 .  
         [0042]     The cutter assembly  554  includes a cutter wheel  566 , which is supported on a resiliently flexible arm  568  on a mounting block  570 . The worm gear  560  passes through the mounting block  570  such that, when the worm gear  560  is rotated, the mounting block  570  and the cutter wheel  566  traverse the chassis base plate  564 . The mounting block  570  bears against a lip  572  of the base plate  564  to inhibit rotation of the mounting block  570  relative to the worm gear  560 . Further, to effect cutting of the print media  542 , the cutter wheel  566  bears against an upper housing or cap portion  574  of the printhead sub-assembly  508 . This cap portion  574  is a metal portion. Hence, as the cutter wheel  566  traverses the capped portion  574 , a scissors-like cutting action is imparted to the print media to separate that part of the print media  542  on which the image has been printed.  
         [0043]     The sub-assembly  506  includes an ejector mechanism  576 . The ejector mechanism  576  is carried on the chassis  510  and has a collar  578  having clips  580 , which clip and affix the ejector mechanism  576  to the chassis  510 . The collar  578  supports an insert  582  of an elastomeric material therein. The elastomeric insert  582  defines a plurality of openings  584 . The openings  584  close off inlet openings of the pins  544  to inhibit the ingress of foreign particles into the pins  544  and, in so doing, into the channels  514  and the printhead  516 . In addition, the insert  584  defines a land or platform  586  which closes off an inlet opening of the air inlet pin  524  for the same purposes.  
         [0044]     A coil spring  588  is arranged between the chassis  510  and the collar  578  to urge the collar  578  to a spaced position relative to the chassis  510  when the cartridge  504  is removed from the print engine  500 , as shown in greater detail in  FIG. 3  of the drawings. The ejector mechanism  576  is shown in its retracted position in  FIG. 4  of the drawings.  
         [0045]     The printhead sub-assembly  508  includes, as described above, the base plate  564 . A capping mechanism  590  is supported displaceably on the base plate  564  to be displaceable towards and away from the printhead  516 . The capping mechanism  590  includes an elongate rib  592  arranged on a carrier  593 . The carrier is supported by a displacement mechanism  594 , which displaces the rib  592  into abutment with the printhead  516  when the printhead  516  is inoperative. Conversely, when the printhead  516  is operational, the displacement mechanism  594  is operable to retract the rib  592  out of abutment with the printhead  516 .  
         [0046]     The printhead sub-assembly  508  includes a printhead support molding  596  on which the printhead  516  is mounted. The molding  596 , together with an insert  599  arranged in the molding  596 , defines a passage  598  through which the print media  542  passes when an image is to be printed thereon. A groove  700  is defined in the molding  596  through which the capping mechanism  590  projects when the capping mechanism  590  is in its capping position.  
         [0047]     An ink feed arrangement  702  is supported by the insert  599  beneath the cap portion  574 . The ink feed arrangement  702  comprises a spine portion  704  and a casing  706  mounted on the spine portion  704 . The spine portion  704  and the casing  706 , between them, define ink feed galleries  708  which are in communication with the ink supply channels  514  in the chassis  510  for feeding ink via passages  710  ( FIG. 7 ) to the printhead  516 .  
         [0048]     An air supply channel  711  ( FIG. 8 ) is defined in the spine portion  704 , alongside the printhead  516 .  
         [0049]     Electrical signals are provided to the printhead  516  via a TAB film  712  which is held captive between the insert  599  and the ink feed arrangement  702 .  
         [0050]     The molding  596  includes an angled wing portion  714 . A flexible printed circuit board (PCB)  716  is supported on and secured to the wing portion  714 . The flex PCB  716  makes electrical contact with the TAB film  712  by being urged into engagement with the TAB film  712  via a rib  718  of the insert  599 . The flex PCB  716  supports busbars  720  thereon. The busbars  720  provide power to the printhead  516  and to the other powered components of the print engine  500 . Further, a camera print engine control chip  721  is supported on the flex PCB  716  together with a QA chip (not shown) which authenticates that the cartridge  504  is compatible and compliant with the print engine  500 . For this purpose, the PCB  716  includes contacts  723 , which engage contacts  725  in the print cartridge  504 .  
         [0051]     As illustrated more clearly in  FIG. 7  of the drawings, the printhead itself includes a nozzle guard  722  arranged on a silicon wafer  724 . The ink is supplied to a nozzle array (not shown) of the printhead  516  via an ink supply member  726 . The ink supply member  726  communicates with outlets of the passages  710  of the ink feed arrangement  702  for feeding ink to the array of nozzles of the printhead  516 , on demand.  
         [0052]     In  FIG. 10 , the air supply path for supplying air to the printhead  516  is shown in greater detail. As illustrated, the pump  522  includes an impeller  728  closed off by an end cap  730 . The cover molding  520  of the chassis forms a receptacle  732  for the impeller  728 . The cover molding  520  has the air inlet opening  734  and the air outlet opening  736 . The air inlet opening  734  communicates with the pin  524 . The air outlet opening  736  feeds air to the air supply channel  518  which, in  FIG. 10 , is shown as a solid black line. The air fed from the air supply channel  518  is blown into the printhead  516  to effect cleaning of the printhead. The air drawn in via the pump  522  is filtered by an air filter  738 , which is accommodated in the print cartridge  504 . The air filter  738  has a filter element  740  which may be paper based or made of some other suitable filtering media. The filter element  740  is housed in a canister, having a base  742  and a lid  744 . The lid  744  has an opening  746  defined therein. The opening  746  is closed off by a film  748  which is pierced by the pin  524 . The advantage of having the air filter  738  in the print cartridge  504  is that the air filter  738  is replaced when the print cartridge  504  is replaced.  
         [0053]     It is an advantage of the invention that an air pump  522  is driven by the stepper motor  530 , which also controls feed of the print media to the printhead  516 . In so doing, fewer components are required for the print engine  500  rendering it more compact. In addition, as the same motor  530  is used for operating the air pump  522  and for feeding the print media  542  to the printhead  516 , fewer power consuming components are included in the print engine  500  rendering it more compact and cheaper to produce.  
         [0054]     It is also to be noted that, in-order to make the print engine  500  more compact, the size of the print engine assembly  502  is such that most of the components of the assembly  502  are received within a footprint of an end of the print cartridge  504 .  
         [0055]     In  FIG. 11  there is depicted a personal digital assistant having an internal printer. The digital assistant  901  includes a body section  902  housing the main circuitry of the digital assistant including a digital storage medium. A display screen  904  is pivotably connected to the body section  902  about a hinge joint  905 . The screen  904  pivots between a closed position ( FIG. 12 ) where the screen lies adjacent the body section  902  thus allowing safe transport, and an open position ( FIG. 11 ) where the screen  904  is visible to a user.  
         [0056]     The body section  902  includes a control panel  906  on an upper surface thereof that includes all buttons required to operate the functions of the digital assistant including the functions of the printer. Using this control panel, a user can selectively view any stored information and make any new entries or amendments. The control panel also includes keys allowing the user to selectively print any of the stored information. A slot  910  in the front edge of the body is used for ejecting printed media  911 .  
         [0057]     The display screen is of a known touch screen type allowing a user to control the digital assistant using a compatible pixel pen (not shown) through which the user selects items on a displayed menu. In addition the digital assistant may include known pattern recognition software that allows a user to enter information by writing on the screen whereafter the user&#39;s input is analysed and converted into text.  
         [0058]     In  FIG. 14  there is schematically depicted in block diagram form the key internal components of a personal digital assistant having an internal printer. The printer would typically utilize a monolithic printhead  814  which could be the same as described above with reference to FIGS.  1  to  10 , but could alternatively be another compact printhead capable of printing on suitably sized print media. Print data from the memory  909  of the digital assistant or a display screen dump  904  is fed to a print engine controller  813  which controls the printhead  814 .  
         [0059]     A micro-controller  807  associated with the print engine controller controls a motor driver  809  which in turn drives a media transport device  810 . This might be the same as stepper motor  530  described earlier.  
         [0060]     The micro-controller  807  also controls a motor driver  811  which in turn controls a guillotine motor  812  to sever a printed sheet from an in-built roll of print media after an image is printed. A sheet being driven by media transport device  810  is shown at  911  in  FIG. 11 . The guillotine might be of the form of cutter wheel  566  described earlier.  
         [0061]     When ready, printer control buttons on the control panel can be depressed to activate the print engine controller to print stored information either from memory or as a screen dump from the display screen. This would in turn activate the micro-controller  807  to activate the media transport  810  and guillotine  812 .  
         [0062]      FIG. 12  shows an internal view of the personal digital assistant in its closed position. The printer engine  500  described previously is disposed within the body section  902  with the removable print media cartridge  504  being disposed in the hinge joint  905  linking the body section  902  with the display screen  904 . Printed media ejected from the print media passage  548  of the print engine travels substantially along the inner surface of the bottom panel of the body section  902  and exits the digital assistant at ejector slot  910 . Because the print roll  504  is disposed within the hinge joint  905 , the personal digital assistant of the present invention can be made substantially the same size as prior art digital assistants.  
         [0063]     The body section  902  and hinge  905  include a releasable portion  912  pivotably connected through a hinge  913  and secured in a closed position by a catch  914 . Opening of this portion ( FIG. 13 ) allows the ink containing print roll cartridge  504  to be removed and replaced. Further details of a removable print roll cartridge are described in our co-pending application IN/PCT/2002/02045/CHE mentioned earlier.  
         [0064]     While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. It will further be understood that any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates.

Technology Classification (CPC): 1