INTERACTIVE PRINTER PROVIDER

Abstract: An on-demand computer based system is provided for allowing a user to obtain interactive printed information from a remote source. The system includes a printer module that is provided by a first party to the user for interfacing the user with the source. The module is responsive to the user requesting first information from the source for generating a first printed page that displays to the user the first information together with advertising that is derived from an advertiser. The module includes an identifier means for applying an identifier to the first page such that designation of the identifier by the user results in the module generating a second printed page that displays to the user further advertising. In some embodiments, use is made of an account server that is responsive to the module for determining a payment to be made by the advertiser to the first party. In other embodiments, the account server determines a payment made by the advertiser to another party and then a second payment from that other party to the first party.

Description: INTERACTIVE PRINTER PROVIDER FIELD OF INVENTION The present invention relates to generally to systems, apparatus, devices and methods for interacting with computers and in particular to a system and method for providing to a user printed information The ιn\entιon has been developed primarily to allow a large number of distributed users to interact with networked information via printed matter and optical sensors, thereby to obtain interactive printed matter on demand via high-speed networked color printers Although the invention will largely be described herein with reference to this use, it will be appreciated that the invention is not limited to use in this fieid CO-PENDING APPLICATIONS Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application- PCT/AUOO/00518, PCT/AUOO/0051 , PCT/AU00/00520, PCT/AU00/00521 , PCT/AUOO/00523, PCT/AUOO/00524, PCT/AU00/00525, PCT/AU00/00526, PCT/AU00/00527, PCT/AU00/OO528, PCT/AUOO/00529, PCT/AU00/00530. PCT/AUOO/00531 , PCT/AU00/00532, PCT/AUOO/00533, PCT/AUOO/00534, PCT/AU00/00535, PCT/AUOO/00536, PCT/AU00/00537, PCT/AUOO/00538, PCT/AUOO'00539, PCT/AU00/00540, PCT/AU00/00541 , PCT/AU00/00542, PCT/AU00/00543, PCT/AU00/00544, PCT/AU00/00545, PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AU00/00556, PCT/AU00/00557, PCT/AU00/00558, PCT/AU00/00559, PCT/AUOO/00560, PCT/AU00/00561 , PCT/AU00/00562, PCT/AU00/00563, PCT/AU00/00564, PCT/AU00/00566, PCT/AUOO/00567, PCT/AU00/00568, PCT/AU00/00569, PCT/AUOO/00570, PCT/AU00/00571 , PCT/AU00/00572, PCT/AU00/00573, PCT/AU00/00574, PCT/AUOO/00575, PCT/AU00/00576, PCT/AU00/00577, PCT/AUOO/00578, PCT/AU00/00579, PCT/AU00/00581 , PCT/AU00/00580, PCT/AU00 00582, PCT/AU00/00587, PCT/AU00/00588, PCT/AUOO/00589, PCT/AU00/00583, PCT/AU00/ 00593, PCT/AUOO/00590, PCT/AU00/00591 , PCT/AU00/00592, PCT/AU00/00594, PCT/AU00 00595, PCT/AU00/00596, PCT/AU00/00597. PCT/AU00/00598, PCT/AUOO/00516, and PCT/AU00.00517 The disclosures of these co-pending applications are incoφorated herein by cross-reference BACKGROUND Paper is widely used to display and record information Printed information is easier to read than information displayed on a computer screen Hand-drawing and handwriting afford greater richness of expression than input via a computer keyboard and mouse Moreover, paper doesn't run on batteries, can be read in bright light, more robustly accepts coffee spills, and is portable and disposable Online publication has many advantages over traditional paper-based publication From a consumer's point of view, information is available on demand, information can be navigated via hypertext links, searched and automatically personalized From the publisher ' s point of view, the costs of printing and physical distribution are eliminated, and the publication becomes more attractive to the advertisers w ho pay for it because it can be targeted to specific demographics and linked to product sites - 1a - Onhne publication also has disadvantages. Computer screens are inferior to paper. At the same quality as a magazine page, an SVGA computer screen displays only about a fifth as much information. Both CRTs and LCDs have bπghtness and contrast problems, particularly when ambient light is strong, while ink on paper, being reflective rather than emissive, is both bright and sharp in ambient light. SUMMARY OF INVENTION It is an object of the present invention, at least in the preferred embodiments, to overcome or substantially ameliorate one or more of these disadvantages of the prior art, or at least to provide a useful alternative. According to a first aspect of the invention there is provided a system for providing to a user pπnted information obtained from a remote source, the svstem including a user module that is provided by a first party to the user for interlacing the user with the source, the module being responsive to the user requestmg first information from the source for generating a first pπnted medium that displavs to the user the first information together with second information deπved from a second party; identifier means for applying an identifier to the first pπnted medium such that designation of the identifier bv the user results in the module generating a second prmted medium that displays to the user third information, and calculation means being responsive to the module for determining a payment to be made by the second party to the first partv Preferablv, the svstem mcludes a plurality of modules associated with corresponding users wherein the calculation means is responsive to the number of pπnted media generated that display one of the first information, the second information, and the third information More preferablv, the calculation means is responsive to the number of pπnted media generated that display two or more of the first information, the second information, and the third information Preferably also, the svstem mcludes account means for receiving the pavment from the second party and for providing the payment to the first party More preferably, the payment from the second party is a fixed amount for a predetermined peπod In a preferred form, the second party is a supplier of goods and/or services and the second information or the third information allows the user to purchase those goods and/or services at respective predetermined purchase pπces. More preferablv, the calculation means is responsive to the monetary value of the purchases completed by the users for determining the payment Even more preferablv, the payment is one or a combination of a flat fee for each purchase; a fixed proportion of the purchase pnce for the goods and/or services that are purchased, and a proportion of the purchased pπce of the goods and or services that are purchased, where that proportion is different for particular goods and or services Preferablv, there are a plurality of second parties and the quantum of their respective payments is contingent upon one or more ol the tollowing characteπstics of the second party geographic location, quantitv of purchases completed in a given time peπod. and relative geographic location with respect to the user Preferablv also, the identifier is a tag More preterablv, however, the identifier is a plurality of tags spaced apart on the respective pπnted medium In alternative embodiments, however, the identifier is a character string that the user provides to the module to obtain the third information Preferablv, the string mcludes a sequence of numbers that are manually keyed into the module In other embodiments, the stπng is scanned bv sensor means that are manually operated bv the user In a preferred torm. the account means generates a disable signal if the pavment calculated as payable by the second partv is not paid within a predetermined time, the generation ot the disable signal preventing the module obtaining the first or the second information Preferably, the second information is advertising lor the goods and/or services and the identifier is related to that mlormation such that designation bv the user ot the second information results in designation of the identifier which, in turn, ensures that the third information mcludes either or both of further mlormation about the goods and/or services or instructions as to how the user should proceed to effect a purchase ot those goods and/or services Preferablv also the second partv obtains an indication ot the success of the advertising bv monitoring one or more of the following the number ot times that the user designates the second mlormation. the number and/or value of sales that are achieved through the user designating the second information, and the cost savings gained through the use of on-lme selling over that of shop front retailing In a prelerred torm. the second information is a link to a third party and the identifier is related to that information such that designation bv the user of the second information results m designation of the identifier which, m turn, ensures that the third mlormation includes either or both of further information about the goods and/or services bemg offered tor use and/or sale bv the third partv or instructions as to how the user should proceed to effect that use and/or a purchase of those goods and or services of the third partv More preterablv, the second party obtains an indication of the success of the link bv monitoring one or more of the number or proportion of users selecting the click- through, and the number or proportion of users purchasing or making use of the goods and/or services of the third party Preferablv also, the monitoring allows the second party to accurately estimate the cost/benefit achieved by the advertising Preferablv, the first information includes advertising deπved from a third partv wherem the calculation means determines the quantum of a pavment that is made bv the third party to the first partv The advertising is, m some embodiments solicited bv the user while in other embodiments it is unsolicited In a preferred torm, the first party, as the printer provider, gams an income stream through the preferential display ot the advertising to the user Preferablv, the user module includes a pπnter unit for generating the pπnted medium Alternatively, the printed medium are selectively generated at a remote pπnter and subsequently provided to the user for viewing. According to a second aspect ol the invention there is provided a svstem tor providing to a user pπnted information obtained from a remote computer source, the svstem including a user pπnter module that is provided bv a first party to the user for interfacing the user with the source, the module being responsive to the user requesting first information from the source for generating a first prmted medium that displavs to the user the first mtormation together with second information deπved from a second partv, an identifier device for applying an identifier to the first pnnted medium such that designation of the identifier bv the user results in the module generating a second pπnted medium that displavs to the user third information, and an account computer being responsive to the module and or the remote computer source tor determining a pavment to be made bv the second partv to the first partv Preferablv, the user pπnter module and the identifier device are contained within a single housing More preferablv, the identifier device applies the identifier to the surface ot a medium as it is being produced bv the pπnter module Preferablv also, the identifier is pnnted on the medium Preferablv. the identifier is pπnted with ink that does not substantially retlect light in the visible spectrum According to a third aspect ot the invention there is provided a method tor providing to a user pπnted information obtained from a remote source, the method including the steps of interfacing the user with the source via a user module that ts provided bv a first partv to the user, the module bemg responsive to the user requesting first mtormation trom the source for generating a first pπnted medium that displavs to the user the first mtormation together with second mlormation deπved trom a second partv applying an identifier to the first prmted medium with identifier means such that designation ot the identifier bv the user results in the module generating a second pπnted medium that displays to the user third lnlormation. and being responsive to the module with calculation means tor determining a pavment to be made bv the second partv to the first partv Preferablv, the method includes employmg a plurality of modules associated with corresponding users mcluding the further step of the calculation means bemg responsive to the number of pπnted medium generated that displav one of: the first information: the second information, and the third information. Accordmg to another aspect of the invention there is provided a method for providing to a user printed information obtained from a remote computer source, the method including the steps of. interfacing the user with the source via a user pπnter module that is provided to the user by a first party, the module being responsive to the user requestmg first mlormation from the source for generating a first pπnted medium that displavs to the user the first information together with second information deπved from a second party, applying an identifier to the first pπnted medium with an identifier device such that designation of the identifier by the user results in the module generatmg a second prmted medium that displays to the user third mformation; and bemg responsive to the module and/or the remote computer source with an account computer for determining a payment to be made by the second party to the first party BRIEF DESCRIPTION OF DRAWINGS Preferred and other embodiments of the invention will now be descnbed, bv wav of non-limiting example only, with reference to the accompanying drawings, in which. Figure 1 is a schematic of a the relationship between a sample pnnted netpage and its online page descπption; Figure 2 is a schematic view of a interaction between a netpage pen, a netpage pπnter, a netpage page server, and a netpage application server, Figure 3 illustrates a collection of netpage servers and pπnters interconnected via a network. Figure 4 is a schematic view of a high-level structure of a pπnted netpage and its online page descπption, Figure 5 is a plan view showing a structure of a netpage tag; Figure 6 is a plan view showing a relationship between a set of the tags shown in Figure 5 and a field of view of a netpage sensmg device in the form of a netpage pen. Figure 7 is a flowchart of a tag image processing and decoding algoπthm. Figure 8 is a perspective view ot a netpage pen and its associated tag-sensing field-of-view cone. Figure 9 is a perspective exploded view ot the netpage pen shown in Figure 8. Figure 10 is a schematic block diagram of a pen controller for the netpage pen shown in Figures 8 and 9, Figure 1 1 is a perspective view of a wall-mounted netpage pπnter, Figure 12 is a section through the length of the netpage pπnter of Figure 1 1 , Figure 12a is an enlarged portion of Figure 12 showing a section of the duplexed pπnt engines and glue wheel assembly, Figure 13 is a detailed view of the ink cartπdge, ink. air and glue paths, and pπnt engines of the netpage printer of Figures 1 1 and 12. Figure 14 is a schematic block diagram of a pπnter controller for the netpage pπnter shown in Figures 1 1 and 12; Figure 15 is a schematic block diagram of duplexed pnnt engine controllers and Memjet™ pnntheads associated with the printer controller shown in Figure 14. Figure 16 is a schematic block diagram of the pnnt engine controller shown in Figures 14 and 15. Figure 17 is a perspective view of a single Memjet™ pπntmg element, as used in. for example, the netpage pπnter of Figures 10 to 12. Figure 18 is a perspective view of a small part of an arrav of Meπ et™ pnnting elements. Figure 19 is a senes ot perspective views illustrating the operating cvcle ot the Meπηet™ pnnting element shown in Fiεure 13. - 5 - Figure 20 is a perspective view of a short segment of a pagewidth Memiet™ pπnthead. Figure 21 is a schematic view of a user class diagram. Figure 22 is a schematic view ot a pπnter class diagram, Figure 23 is a schematic view of a pen class diagram, Figure 24 is a schematic view ot an application class diagram. Figure 25 is a schematic view ot a document and page descnption class diagram. Figure 26 is a schematic view of a document and page ownership class diagram, Figure 27 is a schematic view ot a terminal element specialization class diagram, Figure 28 is a schematic view ot a static element specialization class diagram, Figure 29 is a schematic view of a hyperlink element class diagram, Figure 30 is a schematic view of a hyperlink element specialization class diagram. Figure 31 is a schematic view of a hvperlinked group class diagram, Figure 32 is a schematic view of a form class diagram, Figure 33 is a schematic view of a digital ink class diagram, Figure 34 is a schematic view of a field element specialization class diagram, Figure 35 is a schematic view of a checkbox field class diagram, Figure 36 is a schematic view of a text field class diagram, Figure 37 is a schematic view of a signature field class diagram, Figure 38 is a flowchart of an mput processmg algoπthm, Figure 38a s a detailed flowchart of one step of the flowchart of Figure 38. Figure 39 is a schematic view of a page server command element class diagram, Figure 40 is a schematic view of a resource descπption class diagram, Figure 41 is a schematic view of a favontes list class diagram, Figure 42 is a schematic view of a history list class diagram. Figure 43 is a schematic view ot a subscπption delivery protocol. Figure 44 is a schematic view of a hyperlink request class diagram. Figure 45 is a schematic view ot a hvperlmk activation protocol. Figure 46 is a schematic view of a form submission protocol, Figure 47 is a schematic view ot a commission pavment protocol. Figure 48 is a schematic view of an advertising fee pavment protocol. Figure 49 is a schematic view ot a click-through fee payment protocol, Figure 50 is a schematic view ot a sales commission pavment protocol. Figure 51 is a schematic view ol an advertising tee commission pavment protocol. Figure 52 is a schematic view of a click-through fee commission pavment protocol, and Figure 53 is a schematic view ot a sales commission commission pavment protocol DETAILED DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS Note Memjet™ is a trade mark ot Silverbrook Research Ptv Ltd. Australia In the preferred embodiment, the invention is configured to work with the netpage networked computer svstem a detailed overview ot which tollows It will be appreciated that not even, implementation will necessaπlv embodv all or even most of the specific details and extensions discussed below in relation to the basic svstem However, the sv stem is descnbed in its most complete torm to reduce the need for external reference when attempting to understand the context in which the preferred embodiments and aspects ot the present invention operate In bπef summary, the preferred form of the netpage system employs a computer interface in the form of a mapped surface, that is, a physical surface which contams references to a map of the surface maintained m a computer system. The map references can be quened by an appropπate sensmg device. Depending upon the specific implementation, the map references may be encoded visibly or invisibly, and defined in such a way that a local query on the mapped surface vields an unambiguous map reference both within the map and among different maps The computer system can contain mformation about features on the mapped surface, and such mformation can be retπeved based on map references supplied bv a sensing device used with the mapped surface. The information thus retπeved can take the form of actions which are initiated bv the computer system on behalf of the operator in response to the operator's mteraction with the surface features In its preferred form, the netpage system relies on the production of, and human interaction with, netpages. These are pages of text, graphics and images pπnted on ordinary paper, but which work like interactive web pages. Information is encoded on each page using ink which is substantially invisible to the unaided human eye. The ink, however, and thereby the coded data, can be sensed by an opticallv imagmg pen and transmitted to the netpage system. In the preferred form, active buttons and hyperlinks on each page can be clicked with the pen to request information from the network or to signal preferences to a network server. In one embodiment, text ritten by hand on a netpage is automatically recognized and converted to computer text m the netpage system, allowing forms to be filled in. In other embodiments, signatures recorded on a netpage are automatically venfied, allowing e-commerce transactions to be securely authorized As illustrated in Figure 1 , a pnnted netpage 1 can represent a interactive form which can be filled m by the user both phvsically, on the pnnted page, and "electronically", via communication between the pen and the netpage system. The example shows a "'Request" form containing name and address fields and a submit button. The netpage consists of graphic data 2 pπnted using visible ink, and coded data 3 pπnted as a collection of tags 4 usmg invisible ink. The corresponding page descnption 5, stored on the netpage network, descnbes the individual elements of the netpage. In particular it descnbes the type and spatial extent (zone) of each interactive element (l e text field or button m the example), to allow the netpage svstem to coπectlv interpret input via the netpage The submit button 6, for example, has a zone 7 hich corresponds to the spatial extent of the coπesponding graphic 8 As illustrated in Figure 2. the netpage pen 101 , a prefeπed form of which is shown in Figures 8 and 9 and descnbed in more detail below, works in conjunction with a netpage pπnter 601. an Internet-connected printing appliance for home, office or mobile use The pen is wireless and communicates securely with the netpage pπnter via a short-range radio link 9 The netpage printer 601. a prefeπed form of which is shown in Figures 1 1 to 13 and descnbed m more detail below, is able to deliver, peπodicallv or on demand, personalized newspapers, magazines, catalogs, brochures and other publications, all pnnted at high quality as interactive netpages. Unlike a personal computer, the netpage pπnter is an appliance which can be. for example, wall-mounted adjacent to an area where the mommg news is first consumed, such as in a user s kitchen, near a breakfast table, or near the household ' s point of departure tor the dav It also comes in tabletop. desktop, portable and miniature versions Netpages pnnted at their point of consumption combine the ease-ot-use of paper v\ ith the timeliness and interactivity of an interactive medium As shown in Figure 2. the netpage pen 101 interacts with the coded data on a pnnted netpage 1 and communicates, via a short-range radio link 9. the mteraction to a netpage pπnter The pπnter 601 sends the interaction to the relevant netpage page server 10 lor interpretation In appropπate circumstances, the page server sends a corresponding message to application computer software running on a netpage application server 13 The application - 7 - server mav m turn send a response which is pnnted on the onginating printer The netpage svstem is made considerably more convenient m the prefeπed embodiment by bemg used m conjunction with high-speed microelectromechamcal system (MEMS) based Inkjet (Memjet™) printers In the preferred form of this technology, relatively high-speed and high-qualitv printing is made more affordable to consumers. In its prefeπed form, a netpage publication has the physical charactenstics ot a traditional newsmagazme, such as a set of letter-size glossv pages pπnted in full color on both sides, bound together for easy navigation and comfortable handling. The netpage pπnter exploits the growing availability ot broadband Internet access. Cable service is available to 95% ot households in the United States, and cable modem service offenng broadband Internet access is alreadv available to 20% ot these Fhe netpage pπnter can also operate with slower connections, but with longer delivery times and lower image quality Indeed, the netpage system can be enabled using existing consumer Inkjet and laser pπnters. although the svstem will operate more slowly and will therefore be less acceptable from a consumer's pomt of view In other embodiments, the netpage svstem is hosted on a pnvate intranet In still other embodiments, the netpage svstem is hosted on a single computer or computer-enabled device, such as a printer Netpage publication servers 14 on the netpage network are configured to deliver pπnt-quality publications to netpage pπnters Peπodical publications are delivered automatically to subscnbmg netpage pπnters via pointcasting and multicasting Internet protocols Personalized publications are filtered and formatted according to individual user profiles A netpage pπnter can be configured to support any number of pens, and a pen can work with any number of netpage pnnters hi the preteπed implementation, each netpage pen has a unique identifier A household may have a collection of colored netpage pens, one assigned to each member of the family This allows each user to maintain a distinct profile with respect to a netpage publication server or application server A netpage pen can also be registered with a netpage registration server 1 1 and linked to one or more payment card accounts This allows e-commerce payments to be securely authoπzed using the netpage pen The netpage registration server compares the signature captured by the netpage pen with a previously registered signature, allowing it to authenticate the user s identity to an e-commerce server Other biometrics con also be used to veπfv identity A version ot the netpage pen includes fingerprint scanning, venfied in a similar vvav bv the netpage registration server Although a netpage pπnter mav deliver penodicals such as the morning newspaper without user intervention, it can be configured never to deliver unsolicited junk mail hi its preleπed form, it only delivers penodicals from subscπbed or otherwise authoπzed sources In this respect, the netpage pπnter is unlike a tax machine or e-mail account hich is visible to any junk mailer who knows the telephone number or email address 1 NETPAGE SYSTEM ARCHITECTURE Each ob)ect model in the svstem is descnbed usmg a Unified Modeling Language UML) class diagram. A class diagram consists ot a set of object classes connected bv relationships, and two kinds of relationships are of interest here associations and generalizations An association represents some kind of relationship between objects, l e between instances of classes A generalization relates actual classes, and can be understood in the following vvav if a class is thought of as the set of all obieets of that class, and class A is a generalization ot class B, then B is simply a subset of A The UML does not directlv support second-order modelling - 1 e classes ot classes Each class is drawn as a rectangle labelled with the name of the class It contains a list of the attπbutes of the class, separated from the name bv a horizontal line, and a list ot the operations ot the class, separated from the αttπbute list bv a hoπzontal line In the class diagrams which follow, however, operations are never modelled Λn association is drawn as a line loining two classes, optionally labelled at either end with the multiplicity of the association The default multiplicity is one An astensk (*) indicates a multiplicity ot many '. I e zero or more - 8 - Each association is optionally labelled with its name, and is also optionally labelled at either end with the role of the correspondmg class An open diamond indicates an aggregation association ("is-part-of '), and is drawn at the aggregator end of the association line A generalization relationship ("ls-a") is drawn as a solid line joining two classes, with an arrow (in the form ol an open tnangle) at the generalization end When a class diagram is broken up mto multiple diagrams, any class which is duplicated is shown with a dashed outline m all but the main diagram which defines it It is shown with attπbutes onlv where it is defined 1.1 NETPAGES Netpages are the foundation on which a netpage network is built They provide a paper-based user interface to published information and interactive services A netpage consists of a pπnted page (or other surface region) invisibly tagged with references to an online descπption of the page The onlme page descπption is mamtained persistently by a netpage page server The page descπption descnbes the visible layout and content of the page, including text, graphics and images It also descnbes the input elements on the page, including buttons, hyperlinks, and mput fields A netpage allows markings made with a netpage pen on its surface to be simultaneously captured and processed bv the netpage svstem Multiple netpages can share the same page descπption However, to allow input through otherwise identical pages to be distinguished, each netpage is assigned a unique page identifier This page ID has sufficient precision to distinguish between a very large number of netpages Each reference to the page descπption is encoded in a pnnted tag The tag identifies the unique page on which it appears, and thereby indirectly identifies the page descπption The tag also identifies its own position on the page Charactenstics of the tags are descnbed in more detail below Tags are pπnted in infrared-absorptive ink on any substrate which is infrared-reflective, such as ordinary paper Near-infrared wavelengths are invisible to the human eve but are easily sensed by a solid-state image sensor with an appropπate filter A tag is sensed bv an area image sensor in the netpage pen, and the tag data is transmitted to the netpage svstem via the nearest netpage pπnter The pen is wireless and communicates with the netpage pπnter via a short-range radio link Tags are sufficiently small and densely aπanged that the pen can rehablv image at least one tag even on a smgle click on the page It is important that the pen recognize the page ID and position on every interaction with the page, since the mteraction is stateless Tags are error-coπectablv encoded to make them pαrtialiv tolerant to surface damage The netpage page server maintains a unique page instance for each pnnted netpage, allowing it to maintain a distinct set ol user-supplied values tor input fields in the page descnption lor each pπnted netpage The relationship between the page descnption. the page instance, and the pπnted netpage is shown m Figure 4 The page instance is associated with both the netpage pπnter which pπnted it and, if known, the netpage user who requested it 1.2 NETPAGE TAGS 1.2.1 Tag Data Content In a preferred torm. each tag identities the region in which it appears, and the location ot that tag within the region A tag mav also contain flags which relate to the region as a whole or to the tag One or more flag bits mav, for example, signal a tag sensing device to provide feedback indicative of a function associated with the immediate area of the tag without the sensing device having to refer to α descπption ot the region A netpage pen mav . tor example, illuminate an active area " LED when in the zone ot α hvperlink - 9 - As will be more clearlv explamed below, m a prefeπed embodiment, each tag contams an easily recognized mvaπant structure which aids initial detection, and which assists m minimizing the effect of anv warp mduced by the surface or bv the sensmg process The tags preferably tile the entire page, and are sulficiently small and densely arranged that the pen can reliably image at least one tag even on a s gle click on the page. It is important that the pen recognize the page ED and position on every mteraction with the page, since the mteraction is stateless In a preleπed embodiment, the region to which a tag refers coincides with an entire page, and the region ID encoded m the tag is therefore synonymous with the page ID of the page on which the tag appears In other embodiments, the region to which a tag refers can be an arbitrary subregion of a page or other surface For example, it can coincide with the zone of an interactive element, in which case the region ID can directly identify the interactive element Table 1 - Tag data Each tag contams 120 bits ol " information, typically allocated as shown m Table 1 Assuming a maximum tag density of 64 per square inch, a 16-bit tag ID supports a region size of up to 1024 square inches Larger regions can be mapped continuously without increasing the tag ID precision simply bv using abutting regions and maps The 100-bit region ID allows 2 100 (~10 30 or a million tnllion tπllion) different regions to be uniquely identified 1.2.2 Tag Data Encoding The 120 bits of tag data are redundantlv encoded using a (15, 5) Reed-Solomon code This yields 360 encoded bits consisting of 6 codewords of 15 4-bit symbols each The (15. 5) code allows up to 5 symbol eπors to be coπected per codeword, I e it is tolerant ot a svmbol eπor rate of up to 33% per codeword Each 4-bit svmbol is represented in a spatially coherent av in the tag, and the symbols of the six codewords are interleaved spatiallv within the tag This ensures that a burst eπor (an eπor affecting multiple spatially adjacent bits) damages a minimum number ot symbols overall and a minimum number of symbols in anv one codeword, thus maximising the likelihood that the burst eπor can be fullv coπected 1.2.3 Physical Tag Structure The physical representation ot the tag, shown m Figure 5. includes fixed target structures 15, 16, 17 and vanable data areas 18 The fixed target structures allow a sensing device such as the netpage pen to detect the tag and infer its three-dimensional oπentation relative to the sensor The data areas contain representations of the individual bits of the encoded tag data To achieve proper tag reproduction the tag is rendered at α resolution ot 256x256 dots When pnnted at 1600 dots per inch this vields a tag with a diameter of about 4 mm At this resolution the tag is designed to be surrounded bv a 'quiet area" of radius 16 dots Since the quiet area is also contπbuted bv ad j acent tags, it onlv adds 16 dots to the effective diameter of the tag The tag mcludes six target structures A detection πng 15 allows the sensing device to initially detect the tag The rmg is easv to detect because it is rotationallv invaπant and because α simple coπection ot its aspect ratio removes most ot the effects of perspectiv e distortion An oπentation axis 16 allows the sensing device to determine the approximate planar oπentation of the tag due to the yaw ot the sensor The oπentation axis is skewed to vield a unique - 10 - onentation. Four perspective targets 17 allow the sensing device to infer an accurate two-dimensional perspective transform of the tag and hence an accurate three-dimensional position and oπentation of the tag relative to the sensor. All target structures are redundantly large to improve their immunity to noise. The overall tag shape is circular This supports, amongst other things, optimal tag packing on an irregular tπangular gnd In combination with the circular detection ring, this makes a circular aπangement of data bits within the tag optimal To maximise its size, each data bit is represented bv a radial wedge m the form of an area bounded by two radial lines and two concentnc circular arcs Each wedge has a minimum dimension of 8 dots at 1600 dpi and is designed so that its base (its inner arc), is at least equal to this minimum dimension. The height of the wedge in the radial direction is always equal to the minimum dimension Each 4-bit data symbol is represented by an aπay of 2x2 wedges The 15 4-bit data symbols of each of the six codewords are allocated to the four concentnc svmbol πngs 18a to 18d in interleaved fashion Symbols are allocated alternately in circular progression around the tag. The interleaving is designed to maximise the average spatial distance between anv two symbols of the same codeword In order to support "single-click" interaction with a tagged region via a sensmg device, the sensmg device must be able to see at least one entire tag m its field of view no matter where m the region or at what oπentation it is positioned The required diameter of the field of view of the sensmg device is therefore a function of the size and spacmg of the tags Assuming a circular tag shape, the minimum diameter of the sensor field of view is obtained when the tags are tiled on a equilateral tπangular gnd, as shown m Figure 6 1.2.4 Tag Image Processing and Decoding The tag image processing and decodmg performed by a sensmg device such as the netpage pen is shown m Figure 7 While a captured image is bemg acquired from the image sensor, the dynamic range of the image is determined (at 20) The center of the range is then chosen as the binary threshold for the image 21 The image is then thresholded and segmented into connected pixel regions (I e shapes 231 (at 22) Shapes which are too small to represent tag target structures are discarded The size and centroid ot each shape is also computed Binary shape moments 25 are then computed (at 24) for each shape, and these provide the basis for subsequently locating target structures Central shape moments are bv their nature invaπant of position, and can be easilv made invaπant of scale, aspect ratio and rotation The rmg target structure 15 is the first to be located (at 26) A nng has the advantage of bemg very well behaved when perspective-distorted Matching proceeds bv aspect-normalizing and rotation-normalizing each shape's moments Once its second-order moments are normalized the nng is easy to recognize even if the perspective distortion was significant The πng ' s oπgmal aspect and rotation 27 together provide a useful approximation of the perspective transform The axis target structure 16 is the next to be located (at 28) Matching proceeds bv applymg the ring's normalizations to each shape s moments, and rotation-normalizing the resulting moments Once its second-order moments are normalized the axis target is easilv recognized Note that one third order moment is required to disambiguate the two possible onentations ot the axis The shape is deliberately skewed to one side to make this possible Note also that it is only possible to rotation-normalize the axis target after it has had the nng s normalizations applied, since the perspective distortion can hide the axis target s axis The axis target's oπgmal rotation provides a useful approximation of the tag s rotation due to pen aw 29 The four perspective target structures 17 ore the last to be located (at 301 Good estimates of their positions - 1 1 - are computed based on their known spatial relationships to the nng and axis targets, the aspect and rotation of the ring, and the rotation of the axis Matching proceeds by applying the ring ' s normalizations to each shape ' s moments. Once their second-order moments are normalized the circular perspective targets are easy to recogmze. and the target closest to each estimated position is taken as a match. The ongmal centroids of the four perspective targets are then taken to be the perspective-distorted corners 31 of a square of known size in tag space, and an eight-degree-of-freedom perspective transform 33 is infeπed (at 32) based on solving the well-understood equations relating the four tag-space and image- space point pairs (see Heckbert, P , Fundamentals of Texture Mapping and Image Warping, Masters Thesis, Dept. of EECS, U of California at Berkeley, Technical Report No UCB/CSD 89/516, June 1989, the contents of which are herem incorporated by cross-reference) The infeπed tag-space to image-space perspective transform is used to project (at 36) each known data bit position in tag space into image space where the real-valued position is used to bilmearly interpolate (at 36) the four relevant adjacent pixels in the input image. The previously computed image threshold 21 is used to threshold the result to produce the final bit value 37 Once all 360 data bits 37 have been obtained in this way. each of the six 60-bit Reed-Solomon codewords is decoded (at 38) to yield 20 decoded bits 39, or 120 decoded bits in total Note that the codeword symbols are sampled in codeword order, so that codewords are implicitly de-interleaved during the sampling process. The nng target 15 is only sought m a subarea of the image whose relationship to the image guarantees that the rmg, if found, is part of a complete tag If a complete tag is not found and successfully decoded, then no pen position is recorded for the current frame Given adequate processing power and ideally a non-minimal field of view 193, an alternative strategy involves seeking another tag m the current image The obtained tag data mdicates the identity of the region containing the tag and the position of the tag within the region. An accurate position 35 of the pen mb m the region, as well as the overall onentation 35 of the pen, is then mfeπed (at 34) from the perspective transform 33 observed on the tag and the known spatial relationship between the pen ' s physical axis and the pen ' s optical axis. 1.2.5 Tag Map Decoding a tag results in a region ID, a tag ID, and a tag-relative pen transform Before the tag ID and the tag-relative pen location can be translated mto an absolute location within the tagged region, the location of the tag within the region must be known Fhis is given by a tag map, a function which maps each tag ID in a tagged region to a corresponding location The tag map class diagram is shown in Figure 22. as part ot the netpage pnnter class diagram. A tag map reflects the scheme used to tile the surface region with tags, and this can vary according to surface tvpe When multiple tagged regions share the same tiling scheme and the same tag numbenng scheme, they can also share the same tag map The tag map for a region must be retπevable via the region ED Thus, given a region ID. a tag ED and a pen transform, the tag map can be retneved. the tag ED can be translated into an absolute tag location within the region, and the tag-relative pen location can be added to the tag location to yield an absolute pen location within the region 1.2.6 Tagging Schemes Two distmct surface coding schemes are of interest, both of which use the tag structure descnbed earlier m this section The prefeπed coding scheme uses "location-indicating" tags as already discussed An alternative codmg scheme uses object-indicating tags A location-indicating tag contains a tag ID which, when translated through the tag map associated with the tagged region, vields a unique tag location within the region The tag-relative location of the pen is added to this tag location to weld the location of the pen within the region This in turn is used to determine the location of the pen - 12 - relative to a user mterface element in the page descnption associated with the region Not only is the user mterface element itself identified, but a location relative to the user mterface element is identified Location-indicating tags therefore tπvially support the capture of an absolute pen path in the zone of a particular user interface element. An object-mdicating tag contains a tag ID which directly identifies a user mterface element m the page descπption associated with the region. All the tags m the zone of the user interface element identify the user mterface element, making them all identical and therefore indistinguishable. Object-indicating tags do not, therefore, support the capture of an absolute pen path. They do, however, support the capture of a relative pen path. So long as the position sampling frequency exceeds twice the encountered tag frequency, the displacement from one sampled pen position to the next within a stroke can be unambiguouslv determined. With either tagging scheme, the tags function in cooperation with associated visual elements on the netpage as user interactive elements in that a user can interact with the pnnted page using an appropnate sensmg device in order for tag data to be read by the sensing device and for an appropπate response to be generated m the netpage system. 1.3 DOCUMENT AND PAGE DESCRIPTIONS A prefeπed embodiment of a document and page descnption class diagram is shown m Figures 25 and 26. In the netpage system a document is descnbed at three levels. At the most abstract level the document 836 has a hierarchical structure whose terminal elements 839 are associated with content objects 840 such as text objects, text style objects, image objects, etc. Once the document is pnnted on a pnnter with a particular page size and according to a particular user ' s scale factor preference, the document is pagmated and otherwise formatted Formatted terminal elements 835 will m some cases be associated with content objects which are different from those associated with their coπesponding terminal elements, particularly where the content objects are style-related. Each pnnted instance of a document and page is also descnbed separately, to allow mput captured through a particular page instance 830 to be recorded separately from mput captured through other instances of the same page descπption. The presence of the most abstract document descπption on the page server allows a user to request a copy of a document without bemg forced to accept the source document ' s specific format. The user may be requestmg a copy through a pnnter with a different page size, for example Conversely, the presence of the formatted document descnption on the page server allows the page server to efficiently interpret user actions on a particular pπnted page. A formatted document 834 consists of a set of formatted page descnptions 5. each of which consists of a set of formatted terminal elements 835. Each formatted element has a spatial extent or zone 58 on the page. This defines the active area of input elements such as hvper nks and input fields. A document instance 831 coπesponds to a formatted document 834 It consists of a set of page instances 830. each of which coπesponds to a page descnption 5 of the formatted document Each page instance 830 descnbes a smgle unique pnnted netpage 1 , and records the page ID 50 of the netpage. A page instance is not part of a document instance if it represents a copy of a page requested in isolation. A page instance consists of a set of terminal element instances 832 An element instance onlv exists if it records instance-specific information Thus, a hyperlink instance exists for a hyperlink element because it records a transaction ID 55 which is specific to the page instance, and a field instance exists for a field element because it records mput specific to the page instance An element instance does not exist, however, for static elements such as textflows A terminal element can be a static element 843. a hvperlmk element 844. a field element 845 or a page server command element 846 as shown m Figure 27 A static element 843 can be a stvle element 847 with an associated stvle object 854, a textflow element 848 with an associated stv led text object 855. an image element 849 with an associated image element 856. a graphic element 850 with an associated graphic object 857. a video clip element 851 with an associated video clip object 858. an audio clip element 852 with an associated audio clip object 859. or a scπpt - 13 - element 853 with an associated scπpt object 860, as shown m Figure 28 A page instance has a background field 833 which is used to record anv digital ink captured on the page which does not apply to a specific input element In the preferred form of the invention, a tag map 81 1 is associated with each page instance to allow tags on the page to be translated into locations on the page 1.4 THE NETPAGE NETWORK In a preferred embodiment, a netpage network consists of a distributed set of netpage page servers 10, netpage registration servers 11 , netpage ED servers 12, netpage application servers 13, netpage publication servers 14, and netpage pπnters 601 connected via a network 19 such as the Internet, as shown m Figure 3 The netpage registration server 11 is a server which records relationships between users, pens, pπnters, applications and publications, and thereby authonzes vaπous network activities. It authenticates users and acts as a sigmng proxv on behalf of authenticated users in application transactions It also provides handwπtmg recognition services As descnbed above, a netpage page server 10 mamtams persistent information about page descπptions and page instances The netpage network mcludes anv number ot page servers, each handling a subset of page instances. Since a page server also mamtams user mput values for each page instance, clients such as netpage pπnters send netpage input directly to the appropnate page server The page server interprets any such mput relative to the descπption of the coπesponding page A netpage ID server 12 allocates document IDs 51 on demand, and provides load-balancing of page servers via its ID allocation scheme. A netpage pnnter uses the Internet Distπbuted Name Svstem (DNS), or similar, to resolve a netpage page ID 50 mto the network address of the netpage page server handling the coπesponding page instance. A netpage application server 13 is a server which hosts mteractive netpage applications A netpage publication server 14 is an application server which publishes netpage documents to netpage pπnters They are descnbed m detail m Section 2 Netpage servers can be hosted on a vanety of network server platforms from manufacturers such as IBM, Hewlett-Packard, and Sun Multiple netpage servers can run concurrentlv on a single host, and a single server can be distributed over a number of hosts Some or all of the functionality provided bv netpage servers, and in particular the functionality provided bv the ID server and the page server, can also be provided directly in a netpage appliance such as a netpage pnnter, m a computer workstation, or on a local network 1.5 THE NETPAGE PRINTER The netpage pnnter 601 is an appliance which is registered with the netpage svstem and prints netpage documents on demand and via subscπption Each pnnter has a unique pπnter ED 62, and is connected to the netpage network via a network such as the Internet, ideally via a broadband connection Apart from identity and security settings m non-volatile memory, the netpage pnnter contams no persistent storage As far as a user is concerned, "'the network is the computer" Netpages function interactively across space and time with the help of the distπbuted netpage page servers 10. independently of particular netpage pπnters The netpage pπnter receives subscπbed netpage documents from netpage publication servers 14 Each document is distπbuted m two parts the page lavouts. and the actual text and image objects which populate the pages Because ot personalization, page lavouts are tvpicallv specific to a particular subscnber and so are pointcast to the subscnber ' s pπnter via the appropπate page server Text and image objects, on the other hand, are tvpicallv shared with other subscπbers, and so are multicast to all subscnbers pnnters and the appropnate page servers The netpage publication server optimizes the segmentation of document content into pointcasts and - 14 - multicasts After receiving the pointcast ot a document's page lavouts, the pπnter knows which multicasts, if any, to listen to Once the pπnter has received the complete page lavouts and objects that define the document to be pπnted, it can pnnt the document The pnnter rastenzes and pnnts odd and even pages simultaneously on both sides of the sheet It contams duplexed pπnt engme controllers 760 and pπnt engmes utilizing Memjet™ pπntheads 350 for this purpose The printing process consists of " two decoupled stages rasterization of page descnptions, and expansion and pnnting of page images The raster image processor (RIP) consists of one or more standard DSPs 757 running m parallel The duplexed pπnt engine controllers consist of custom processors which expand, dither and pπnt page images m real time, synchronized with the operation of the pπntheads in the pnnt engmes Pnnters not enabled for ER printing have the option to pnnt tags using ER-absorptive black ink, although this restπcts tags to otherwise empty areas of the page Although such pages have more limited functionality than IR-pπnted pages, they are still classed as netpages A normal netpage pnnter pnnts netpages on sheets ot paper More specialised netpage pπnters may pπnt onto more specialised surfaces, such as globes Each pπnter supports at least one surface type, and supports at least one tag tiling scheme, and hence tag map, for each surface type The tag map 81 1 which descnbes the tag tiling scheme actually used to pπnt a document becomes associated with that document so that the document's tags can be correctly interpreted Figure 2 shows the netpage pπnter class diagram, reflecting pπnter-related information maintained by a registration server 1 1 on the netpage network A prefeπed embodiment of the netpage pnnter is descnbed m greater detail in Section 6 below, with reference to Figures 11 to 16 1.5.1 Memjet™ Printheads The netpage svstem can operate using pnnters made with a wide range of digital pnnting technologies, mcluding thermal inkjet, piezoelectπc Inkjet, laser electrophotographic, and others However, tor wide consumer acceptance, it is desirable that a netpage pnnter have the following chαractenstics photographic qualitv color printing high quality text printing high reliabihtv • low pnnter cost low ink cost low paper cost simple operation nearly silent pnnting • high pnnting speed simultaneous double sided pπntmg compact form factor low power consumption No commerciallv available pnnting technology has all of these chαracteπstics To enable to production of pnnters with these characteπstics the present applicant has invented a new pnnt technologv reteπed to as Memiet™ technolo v Memiet™ is a drop-on-demand inkiet technology that incorporates pagewidth pnntheads tabncated usmg microelectromechamcal systems ( MEMS) technology Figure 17 shows a smgle - 15 - pπnting element 300 of a Memjet™ prmthead. Ehe netpage wallpnnter incorporates 168960 pnnting elements 300 to form a 1600 dpi pagewidth duplex pnnter This pπnter simultaneously pnnts cvan, magenta, yellow, black, and infrared inks as well as paper conditioner and ink fixative The pnnting element 300 is approximately 1 10 microns long by 32 microns wide Arrays of these pnntmg elements are formed on a silicon substrate 301 that mcorporates CMOS logic, data transler. tuning, and dπve circuits (not shown) Major elements ot the pnntmg element 300 are the nozzle 302, the nozzle nm 303, the nozzle chamber 304, the fluidic seal 305, the ink channel nm 306, the lever arm 307, the active actuator beam pair 308, the passive actuator beam pair 309, the active actuator anchor 310, the passive actuator anchor 311 , and the ink inlet 312 The active actuator beam pair 308 is mechanically joined to the passive actuator beam parr 309 at the join 319. Both beams pairs are anchored at their respective anchor points 310 and 311 The combination of elements 308, 309, 310, 31 1, and 319 form a cantilevered electrothermal bend actuator 320. Figure 18 shows a small part of an array of printing elements 300, mcluding a cross section 315 of a pnnting element 300 The cross section 315 is shown without mk, to clearlv show the ink inlet 312 that passes through the silicon water 301 Figures 1 (a), 1 (b) and 19(c) show the operating cycle of a Memjet™ pnnting element 300 Figure 1 (a) shows the quiescent position of the ink memscus 316 pnor to pnnting an ink droplet. Ink is retained in the nozzle chamber bv surface tension at the ink memscus 316 and at the fluidic seal 305 formed between the nozzle chamber 304 and the ink channel nm 306 While pnnting, the pπnthead CMOS circuitry distπbutes data from the pπnt engine controller to the correct pnntmg element, latches the data, and buffers the data to dnve the electrodes 318 of the active actuator beam pair 308. This causes an electπcal cuπent to pass through the beam pair 308 for about one microsecond, resulting m Joule heating. The temperature increase resulting from Joule heating causes the beam pair 308 to expand As the passive actuator beam pair 309 is not heated, it does not expand, resulting m a stress difference between the two beam pairs This stress difference is partially resolved by the cantilevered end of the electrothermal bend actuator 320 bendmg towards the substrate 301 The lever arm 307 transmits this movement to the nozzle chamber 304 The nozzle chamber 304 moves about two microns to the position shown in Figure 1 (b) This increases the ink pressure, lorcing ink 321 out of the nozzle 302. and causing the ink memscus 316 to bulge. The nozzle nm 303 prevents the ink meniscus 316 from spreading across the surface of the nozzle chamber 304 As the temperature of the beam parrs 308 and 309 equalizes, the actuator 320 returns to its oπgmal position This aids in the break-off of the ink droplet 317 from the ink 321 in the nozzle chamber, as shown in Figure 19(c) The nozzle chamber is refilled bv the action ol " the surface tension at the meniscus 316 Figure 20 shows a segment of a prmthead 350 In a netpage pπnter, the length ol " the prmthead is the fiill width of the paper (tvpicallv 210 mm) in the direction 351 The segment shown is ϋ 4 mm long (about 0 2% of a complete pnnthead) When pnnting. the paper is moved past the fixed pπnthead m the direction 352 The pπnthead has 6 rows of interdigitated pnnting elements 300, pnntmg the six colors or tvpes of ink supplied bv the ink inlets 312 To protect the fragile surface of the pπnthead during operation, a nozzle guard wafer 330 is attached to the pπnthead substrate 301 For each nozzle 302 there is a coπesponding nozzle guard hole 331 through which the nk droplets are fired To prevent the nozzle guard holes 331 from becoming blocked bv paper fibers or other debπs. filtered air is pumped through the air inlets 332 and out of the nozzle guard holes duπng pnntmg To prevent ink 321 from drying, the nozzle guard is sealed hile the pπnter is idle - 16 - 1.6 The Netpage Pen The active sensmg device of the netpage system is typically a pen 101 , which, using its embedded controller 134, is able to capture and decode IR position tags from a page via an image sensor The image sensor is a solid-state device provided with an appropπate filter to permit sensmg at onlv near-infrared wavelengths. As descnbed m more detail below, the svstem is able to sense when the mb is m contact with the surface, and the pen is able to sense tags at a sufficient rate to capture human handwπting (l e at 200 dpi or greater and 100 Hz or faster) Information captured by the pen is encrypted and wirelessly transmitted to the pπnter (or base station), the pπnter or base station interpreting the data with respect to the (known) page structure The prefeπed embodiment of the netpage pen operates both as a normal markmg ink pen and as a non- markmg stylus. The markmg aspect, however, is not necessary for using the netpage system as a browsmg system, such as when it is used as an Internet interface Each netpage pen is registered with the netpage system and has a umque pen ID 61 Figure 23 shows the netpage pen class diagram, reflectmg pen-related information maintamed by a registration server 11 on the netpage network When either mb is m contact with a netpage, the pen determines its position and oπentation relative to the page The mb is attached to a torce sensor, and the force on the nib is interpreted relative to a threshold to indicate whether the pen is "up" or 'down" This allows a interactive element on the page to be 'clicked' by pressing with the pen mb, in order to request, say, mformation from a network. Furthermore, the force is captured as a continuous value to allow, say, the full dynamics of a signature to be veπfied The pen determines the position and onentation of its mb on the netpage by imaging, m the infrared spectrum, an area 193 of the page m the vicinity of the mb It decodes the nearest tag and computes the position of the mb relative to the tag from the observed perspective distortion on the imaged tag and the known geometry of the pen optics Although the position resolution of the tag mav be low, because the tag density on the page is inversely proportional to the tag size, the adjusted position resolution is quite high, exceeding the minimum resolution required for accurate handwnting recognition Pen actions relative to a netpage are captured as a seπes of strokes A stroke consists of a sequence of time- stamped pen positions on the page, initiated bv a pen-down event and completed bv the subsequent pen-up event. A stroke is also tagged with the page ED 50 ot the netpage whenever the page ED changes, which, under normal circumstances, is at the commencement ot the stroke Each netpage pen has a current selection 826 associated with it, allowing the user to perform copy and paste operations etc The selection is timestamped to allow the svstem to discard it after a defined time penod The cuπent selection descnbes a region of a page instance It consists of the most recent digital ink stroke captured through the pen relative to the background area of the page It is interpreted in an application-specific manner once it is submitted to an application via a selection hyperlink activation Each pen has a cuπent nib 824 Tins is the mb last notified bv the pen to the svstem In the case of the default netpage pen descnbed above, either the marking black ink mb or the non-marking stylus mb is cuπent Each pen also has a cuπent mb stvle 825 This is the nib stvle last associated with the pen bv an application, e g m response to the user selecting a color trom a palette The default mb stvle is the mb style associated with the current mb Strokes captured through a pen are tagged with the current nib stvle When the strokes are subsequently reproduced, thev are reproduced m the mb stvle with which thev are tagged Whenever the pen is within range ot α pnnter with which it can communicate, the pen slowly flashes its onlme LED When the pen tails to decode a stroke relative to the page, it momentanlv activates its eπor ' LED When the pen succeeds in decoding α stroke relative to the page, it momentanlv activates its "ok" LED - 17 - A sequence of captured strokes is referred to as digital ink Digital ink forms the basis for the digital exchange of drawings and handwriting, for onlme recognition of handwriting, and for onlme venfication of signatures The pen is wireless and transmits digital ink to the netpage pnnter via a short-range radio link. The transmitted digital ink is encrypted for pnvacy and secuπty and packetized for efficient transmission, but is always flushed on a pen-up event to ensure timely handling m the pπnter When the pen is out-of-range of a pπnter it buffers digital ink m internal memory, which has a capacity of over ten minutes of contmuous handwriting When the pen is once agam within range of a pnnter, it fransfers any buffered digital ink A pen can be registered with anv number of pnnters, but because all state data resides in netpages both on paper and on the network, it is largely mmatenal which pπnter a pen is communicating with at any particular time A preferred embodiment of the pen is descnbed in greater detail m Section 6 below, with reference to Figures 8 to 10 1.7 NETPAGE INTERACTION The netpage pnnter 601 receives data relating to a stroke from the pen 101 when the pen is used to interact with a netpage 1 The coded data 3 of the tags 4 is read by the pen when it is used to execute a movement, such as a stroke The data allows the identity of the particular page and associated mteractive element to be determined and an indication of the relative positioning of the pen relative to the page to be obtained The indicating data is transmitted to the pπnter, where it resolves, via the DNS, the page ED 50 of the stroke into the network address of the netpage page server 10 which mamtams the coπespondmg page instance 830 It then transmits the stroke to the page server If the page was recently identified m an earlier stroke, then the pπnter may already have the address of the relevant page server in its cache Each netpage consists of " a compact page layout mamtained persistently by a netpage page server (see below) The page lavout refers to objects such as images, fonts and pieces of text, typically stored elsewhere on the netpage network When the page server receives the stroke from the pen, it retrieves the page descπption to which the stroke applies, and determines which element of the page descπption the stroke intersects It is then able to interpret the stroke m the context of the type of the relevant element A "click" is a stroke where the distance and time between the pen down position and the subsequent pen up position are both less than some small maximum An object which is activated bv a click typically requires a click to be activated, and accordingly, a longer stroke is ignored The failure of a pen action, such as a "'sloppy ' click, to register is mdicated by the lack of response from the pen's "ok" LED There are two kinds ot input elements m a netpage page descπption hyperlinks and form fields Input through a form field can also tngger the activation of an associated hyperlink 1.7.1 Hyperlinks A hyperlink is a means ol sendmg a message to a remote application, and tvpicallv elicits a pπnted response in the netpage svstem A hyperlink element 844 identities the application 71 which handles activation of the hyperlink, a link ID 54 which identifies the hyperlink to the application, an "alias required" flag which asks the system to include the user's application alias ED 65 m the hyperlink activation, and a descπption which is used when the hyperlink is recorded as a favonte or appears in the user s historv The hyperlink element class diagram is shown in Figure 29 When a hyperlink is activated, the page server sends a request to an application somewhere on the network The application is identified bv an application ID 64 and the application ED is resolved m the normal vvav via the DNS There are three types of hyperlinks general hyperlinks 863, torm hyperlinks 865. and selection hyperlinks 864, as - 18 - shown m Figure 30 A general hyperlmk can implement a request for a linked document, or may simply signal a preference to a server A form hyperlink submits the coπespondmg form to the application A selection hyperlink submits the current selection to the application If the current selection contams a smgle-word piece of text, for example, the application may return a s gle-page document givmg the word ' s meaning within the context in which it appears, or a translation into a different language Each hyperlink type is characterized bv what information is submitted to the application The coπespondmg hyperlink instance 862 records a transaction ED 55 which can be specific to the page instance on which the hyperlink instance appears The transaction ED can identify user-specific data to the application, for example a "shopping cart" of pending purchases maintained bv a purchasing application on behalf of the user. The system mcludes the pen's current selection 826 in a selection hyperlmk activation The system mcludes the content of the associated form instance 868 m a form hyperlink activation, although if the hyperlink has its "submit delta" attπbute set, only mput since the last form submission is mcluded The svstem includes an effective return path in all hyperlmk activations A hyperlinked group 866 is a group element 838 which has an associated hyperlmk, as shown in Figure 31 When input occurs through anv field element in the group, the hyperlink 844 associated with the group is activated A hyperlinked group can be used to associate hyperlink behavior with a field such as a checkbox. It can also be used, in conjunction with the "submit delta" attπbute of a form hyperlink, to provide continuous mput to an application It can therefore be used to support a "blackboard" interaction model, l e where mput is captured and therefore shared as soon as it occurs 1.7.2 Forms A form defines a collection of related mput fields used to capture a related set of inputs through a pnnted netpage A form allows a user to submit one or more parameters to an application software program running on a server A form 867 is a group element 838 m the document hierarchy It ultimately contams a set of terminal field elements 839 A form instance 868 represents a pπnted instance of a form It consists of a set of field instances 870 which coπespond to the field elements 845 of the form Each field instance has an associated value 871 , whose type depends on the type of the coπesponding field element Each field value records input through a particular pπnted form instance, I e through one or more prmted netpages The form class diagram is shown in Figure 32 Each form instance has a status 872 which indicates whether the form is active, frozen, submitted, void or expired A form is active when first pπnted A form becomes frozen once it is signed A form becomes submitted once one of its submission hyperlinks has been activated, unless the hyperlink has its "'submit delta"' attnbute set A form becomes void when the user mvokes a void form, reset form or duplicate form page command A form expires when the time the torm has been active exceeds the form s specified lifetime While the torm is active, form mput is allowed Input through a form which is not active is instead captured in the background field 833 of the relevant page instance When the torm is active or frozen, torm submission is allowed Anv attempt to submit a torm when the form is not active or trozen is rejected, and mstead elicits an torm status report Each form instance is associated (at 59) with anv torm instances deπved from it, thus providing a version history This allows all but the latest version of a form m a particular time peπod to be excluded from a search All mput is captured as digital ink Digital ink 873 consists of a set of timestamped stroke groups 874, each of which consists of a set of stvled strokes 875 Edch stroke consists ot d set ot timestamped pen positions 876, each of which also includes pen onentation and mb force The digital ink class diagram is shown in Figure 33 A field element 845 can be a checkbox field 877, α text field 878 α drawing field 879 or a signature field 880 The field element class diagram is shown m Figure 34 Anv digital ink captured in a field's zone 58 is assigned to - 19 - the field A checkbox field has an associated boolean value 881 , as shown m Figure 35 Any mark (a tick, a cross, a stroke, a fill zigzag, etc ) captured m a checkbox field's zone causes a true value to be assigned to the field's value A text field has an associated text value 882, as shown in Figure 36 Any digital ink captured m a text field's zone is automatically converted to text via onlme handwπtmg recognition, and the text is assigned to the field's value Onlme handwriting recognition is well-understood (see, tor example, Tappert, C , C Y Suen and T Wakahara, "The State ot the Art in On-Line Handwriting Recognition", EEEE Transactions on Pattern Analysis and Machine Intelligence, Vol 12. No 8, August 1990, the contents of which are herem incorporated by cross-reference) A signature field has an associated digital signature value 883, as shown in Figure 37 Anv digital ink captured in a signature field's zone is automaficallv veπfied with respect to the identity of the owner of the pen, and a digital signature ot the content of the form of which the field is part is generated and assigned to the field's value The digital signature is generated using the pen user's pnvate signature kev specific to the application which owns the form Onlme signature venfication is well-understood (see, lor example, Plamondon, R and G Lorette. "Automatic Signature Venfication and Wnter Identification - The State ot the Art", Pattern Recognition, Vol 22, No 2, 1989, the contents of which are herem incorporated bv cross-relerence) A field element is hidden if its "hidden" attnbute is set A hidden field element does not have an mput zone on a page and does not accept input It can have an associated field value which is included in the form data when the form containing the field is submitted "Editing ' commands, such as stπke-throughs indicating deletion, can also be recognized in torm fields Because the handwπtmg recognition algoπthm works "onlme ' (l e with access to the dynamics of the pen movement), rather than Offline" (1 e with access only to a bitmap ol pen markings), it can recognize run-on discretely- wntten characters with relatively high accuracy, without a wπter-dependent framing phase A wπter-dependent model of handwπting is automatically generated over time, however, and can be generated up-front it necessary, Digital ink. as already stated, consists of a sequence of strokes Anv stroke which starts m a particular element s zone is appended to that element s digital ink stream, readv for interpretation Anv stroke not appended to an object s digital ink stream is appended to the background field s digital ink stream Digital ink captured in the background field is interpreted as α selection gesture Circumscnption of one or more objects is generally interpreted as a selection of the circumscnbed objects, although the actual interpretation is application-specific Table 2 summanses these vanous pen mteractions with a netpage Table 2 - Summary of pen interactions with a netpage ■ 20 . The system mamtams a current selection for each pen The selection consists simply of the most recent stroke captured in the background field The selection is cleared after an inactivity timeout to ensure predictable behavior The raw digital ink captured m every field is retained on the netpage page server and is optionally transmitted with the form data when the form is submitted to the application This allows the application to mterrogate the raw digital ink should it suspect the ongmal conversion, such as the conversion of handwritten text This can, for example, involve human intervention at the application level for forms which fail certain application-specific consistency checks As an extension to this, the entire background area of a form can be designated as a drawing field The application can then decide, on the basis of the presence of digital ink outside the explicit fields of the form, to route the lorm to a human operator on the assumption that the user mav have indicated amendments to the filled-m fields outside ot those fields Figure 38 shows a flowchart ot the process ot handling pen mput relative to a netpage The process consists ot receiving (at 8841 a stroke from the pen identifying (at 885) the page instance 830 to which the page ED 50 m the stroke refers, retπevmg (at 886) the page descnption 5 identifying (at 887) a formatted element 839 whose zone 58 the stroke mtersects determining (at 888) whether the formatted element coπesponds to a field element, and if so appending (at 892) the received stroke to the digital ink ot the field value 871, interpreting (at 893) the accumulated digital ink ot the field, and determining (at 894) whether the field is part of a hyperlinked group 866 and if so activating (at 895) the associated hyperlink, alternatively determining (at 889) whether the formatted element coπesponds to a hyperlink element and if so activating (at 895) the correspondmg hyperlink, alternatively, m the absence of an input field or hyperlink, appending (at 890) the received stroke to the digital ink of the background field 833, and copying (at 891 ) the received stroke to the current selection 826 of the current pen as maintained by the registration server Figure 38a shows a detailed flowchart of step 893 m the process shown m Figure 38, where the accumulated digital ink ot a field is interpreted according to the tvpe of the field The process consists ot determining (at 896) whether the field is a checkbox and (at 897) whether the digital ink represents a checkmark, and if so assigning (at 898) a true value to the field value alternatively determining (at 899) whether the field is a text field and if so converting (at 900) the digital ink to computer text, with the help of the appropπate registration server, and assigning (at 901) the converted computer text to the field value, alternatively determining (at 902) whether the field is a signature field and if so veπfvmg (at 903) the digital ink as the signature ot the pen s owner, with the help of the appropπate registration server creating (at 904) a digital signature ot the contents ot the correspondmg form, also with the help of the registration server and using the pen owner s pπvate signature kev relating to the coπesponding application, and assigning (at 905) the digital signature to the field value 1.7.3 Page Server Commands A page serv er command is a command which is handled locallv by the page server It operates directly on form, page and document instances A page ser er command 907 can be a void form command 908 a duplicate torm command 909 a reset form command 910 a get torm status command 911 a duplicate page command 912 a reset page command 913 a get page status command 914 a duplicate document command 915 a reset document command 916 or a get document status command 917 as shown in Figure 39 A void torm command voids the coπesponding form instance A duplicate form command voids the coπespondmg torm instance and then produces an active pπnted copv ot the current torm instance with field values - 21 - preserved The copv contams the same hvperlmk transaction IDs as the oπgmal, and so is mdistmgmshable from the onginal to an application A reset form command voids the coπespondmg form mstance and then produces an active pnnted copv ot the torm mstance with field values discarded A get lorm status command produces a pnnted report on the status of the coπesponding form mstance, mcludmg who published it, when it was pnnted, for whom it was pπnted, and the form status ol the form instance Smce a torm hyperlink mstance contams a transaction ID, the application has to be involved in producing a new form mstance A button requesting a new torm mstance is therefore typically implemented as a hyperlink A duplicate page command produces a pπnted copy ot the correspondmg page instance with the background field value preserved If the page contams a lorm or is part of a form, then the duplicate page command is interpreted as a duplicate torm command A reset page command produces a pπnted copy ot the coπespondmg page mstance with the background field value discarded If the page contams a form or is part of a form, then the reset page command is interpreted as a reset form command A get page status command produces a pπnted report on the status of the coπespondmg page instance, mcludmg who published it, when it was pnnted, for whom it was prmted, and the status of anv forms it contams or is part ot The netpage logo which appears on every netpage is usually associated with a duplicate page element When a page mstance is duplicated with field values preserved, field values are pnnted in their native form, l e a checkmark appears as a standard checkmark graphic, and text appears as typeset text Only drawings and signatures appear in their oπgmal form, with a signature accompanied bv a standard graphic indicating successful signature venfication A duplicate document command produces a pπnted copy of the correspondmg document instance with background field values preserved If the document contains any forms, then the duplicate document command duplicates the forms in the same ay a duplicate torm command does A reset document command produces a pπnted copy of the coπespondmg document mstance with background field values discarded If the document contams any forms, then the reset document command resets the forms m the same wav a reset form command does A get document status command produces a pπnted report on the status ot the coπesponding document mstance, mcludmg who published it, when it was pnnted, tor whom it was pnnted and the status ot anv forms it contams If the page server command s on selected αttπbute is set, then the command operates on the page identified bv the pen s cuπent selection rather than on the page containing the command This allows a menu of page server commands to be pnnted If the target page doesn t contain a page server command element for the designated page server command then the command is ignored An application can provide application-specific handling bv embedding the relevant page server command element m a hyperlinked group The page server activates the hyperlink associated with the hyperlinked group rather than executing the page server command A page server command element is hidden it its hidden αttπbute is set A hidden command element does not have an input zone on a page and so cannot be activated directly by a user It can, however, be activated via a page server command embedded in a different page, it that page server command has its on selected attπbute set 1.8 STANDARD FEATURES OF NETPAGES In the preteπed torm, each netpage is pnnted with the netpage logo at the bottom to mdicate that it is a netpage and therefore has interactive properties The logo also acts as a copv button In most cases pressing the logo produces a copv ot the page In the case ot a torm the button produces a copv ol the entire lorm And in the case ot a secure document such as a ticket or coupon the button elicits an explanatory note or advertising page The default single-page copv function is handled directly bv the relevant netpage page server Special copy - 22 - functions are handled by linking the logo button to an application 1.9 USER HELP SYSTEM In a prefeπed embodiment, the netpage pnnter has a single button labelled "Help" When pressed it elicits a smgle page of information, mcludmg status of pπnter connection status of pnnter consumables top-level help menu document function menu top-level netpage network directory The help menu provides a hierarchical manual on how to use the netpage system The document function menu includes the following functions • pπnt a copy of a document • pπnt a clean copy of a form • pnnt the status of a document A document function is initiated bv simply pressing the button and then touching anv page of the document The status of a document mdicates who published it and when, to whom it was delivered, and to whom and when it was subsequently submitted as a form. The netpage network directory allows the user to navigate the hierarchy of publications and services on the network As an alternative, the user can call the netpage network "900" number "yellow pages" and speak to a human operator The operator can locate the desired document and route it to the user's pnnter Dependmg on the document type, the publisher or the user pays the small "vellow pages ' service fee The help page is obviously unavailable if the pnnter is unable to pnnt In this case the "eπor" light is lit and the user can request remote diagnosis over the network 2 PERSONALIZED PUBLICATION MODEL In the following descπption, news is used as a canonical publication example to illustrate personalization mechanisms m the netpage svstem Although news is often used in the limited sense ot newspaper and newsmagazme news, the intended scope m the present context is wider In the netpage system, the editoπal content and the advertising content ot a news publication are personalized usmg different mechanisms The editonal content is personalized according to the reader's explicitly stated and implicitly captured interest profile The advertising content is personalized according to the reader's locality and demographic 2.1 EDITORIAL PERSONALIZATION A subscπber can draw on two kinds of news sources those that deliver news publications, and those that deliver news streams While news publications are aggregated and edited bv the publisher, news streams are aggregated either bv a news publisher or bv a specialized news aggregator News publications tvpicallv coπespond to traditional newspapers and newsmagazines, while news streams can be manv and vaπed a "raw" news feed from a news service, a cartoon strip, a freelance wπter's column, a friend ' s bulletin board, or the reader's own e-mail The netpage publication server supports the publication ot edited news publications as well as the aggregation ot multiple news streams Bv handling the aggregation and hence the formatting of news streams selected directly bv the reader, the server is able to place advertising on pages over which it otherwise has no editoπal control The subscπber builds a daily newspaper bv selectmg one or more contnbut g news publications, and creating a personalized version of each The resulting daily editions are pπnted and bound together into a single - 23 - newspaper The vaπous members ol a household typically express their different interests and tastes by selectmg different daily publications and then customizing them For each publication, the reader optionally selects specific sections Some sections appear daily, while others appear weekly The daily sections available from The New York Times onlme, for example, mclude "Page One Plus", 'National ', "International", "Opmion ', "Busmess", "Arts/Living", "Technology ', and 'Sports" The set of available sections is specific to a publication, as is the default subset The reader can extend the daily newspaper bv creating custom sections, each one drawing on any number of news streams Custom sections might be created for e-mail and friends' announcements ("Personal"), or for monitoring news feeds for specific topics ("Alerts" or "Clippings") For each section, the reader optionally specifies its size, either qualitatively (e g short, medium, or long), or numeπcally (I e as a limit on its number of pages), and the desired proportion of advertising, either qualitatively (e g high, normal, low, none), or numeπcally (I e as a percentage) The reader also optionally expresses a preference for a large number of shorter articles or a small number of longer articles Each article is ideally written (or edited) m both short and long torms to support this prelerence An article may also be written (or edited) in different versions to match the expected sophistication of the reader, for example to provide children's and adults' versions The appropnate version is selected according to the reader s age The reader can specify a 'reading age" which takes precedence over their biological age The articles which make up each section are selected and pπoπtized by the editors, and each is assigned a useful lifetime By default they are delivered to all relevant subscnbers, m pπoπty order, subject to space constraints in the subscnbers' editions In sections where it is appropnate, the reader mav optionally enable collaborative filtering This is then applied to articles which have a sufficiently long lifetime Each article which qualifies tor collaborative filtering is pnnted with rating buttons at the end of the article The buttons can provide an easy choice (e g "liked" and "disliked'), making it more likely that readers will bother to rate the article Articles with high pnonties and short lifetimes are theretore effectively considered essential reading by the editors and are delivered to most relevant subscnbers The reader optionally specifies a serendipity tactor, either qualitatively (e g do or don t surpnse me), or numeπcallv A high serendipity tactor lowers the threshold used tor matching dunng collaborative filtering A high factor makes it more hkelv that the coπesponding section will be filled to the reader s specified capacity A different serendipity tactor can be specified for different days ot the week The reader also optionally specifies topics ot particular mterest within α section, and this modifies the pnonties assigned bv the editors The speed of the reader s Internet connection affects the quality at which images can be delivered The reader optionally specifies a preference lor tevver images or smaller images or both If the number or size of images is not reduced, then images mav be delivered at lower quality (l e at lower resolution or with greater compression) At a global lev el the reader specifies how quantities dates, times and monetary values are localized This involves specifying whether units are impenal or metnc a local timezone and time lormat, and a local cuπency, and whether the localization consist ot m situ translation or annotation These preterences are denved from the reader's locality bv detault To reduce reading difficulties caused bv poor eyesight, the reader optionally specifies a global prelerence tor a larger presentation Both text and images are scaled accordmglv, and less mlormation is accommodated on each page - 24 - The language m which a news publication is published, and its coπespondmg text encodmg, is a property of the publication and not a preference expressed bv the user However, the netpage system can be configured to provide automatic translation services m vanous guises 2.2 ADVERTISING LOCALIZATION AND TARGETING The personalization ot the editonal content directly affects the advertising content, because advertising is typically placed to exploit the editoπal context Travel ads, for example, are more hkelv to appear m a travel section than elsewhere The value of the editoπal content to an advertiser (and therefore to the publisher) lies m its ability to attract large numbers of readers with the nght demographics Effective advertising is placed on the basis of locality and demographics Locality determines proximity to particular services, retailers etc , and particular interests and concerns associated with the local community and environment Demographics determine general interests and preoccupations as well as likely spending patterns A news publisher's most profitable product is advertising "space", a multi-dimensional entitv determined by the publication s geographic coverage, the size of its readership, its readership demographics, and the page area available for advertising In the netpage system, the netpage publication server computes the approximate multi-dimensional size of a publication's saleable advertising space on a per-section basis, taking mto account the publication's geographic coverage, the section s readership, the size of each reader's section edition, each reader's advertising proportion, and each reader's demographic In compaπson with other media, the netpage system allows the advertising space to be defined in greater detail, and allows smaller pieces of it to be sold separately It therefore allows it to be sold at closer to its true value For example, the same advertising 'slot" can be sold m varying proportions to several advertisers, with individual readers' pages randomly receiving the advertisement of one advertiser or another, overall preserving the proportion of space sold to each advertiser The netpage svstem allows advertising to be linked directlv to detailed product information and onlme purchasing It theret ore raises the intrinsic value of the advertising space Because personalization and localization are handled automatically bv netpage publication servers, an advertising aggregator can provide arbitraπly broad coverage of both geography and demographics The subsequent disaggregation is efficient because it is automatic This makes it more cost-effective tor publishers to deal with advertising aggregators than to directlv capture advertising Even though the advertising aggregator is taking a proportion of advertising revenue, publishers mav find the change profit-neutral because of the greater efficiency of aggregation The advertising aggregator acts as an intermediary between advertisers and publishers, and may place the same advertisement m multiple publications It is worth noting that ad placement m a netpage publication can be more complex than ad placement in the publication s traditional counterpart, because the publication s advertising space is more complex While ignoring the lull complexities ot negotiations between advertisers, advertising aggregators and publishers, the preteπed form of the netpage svstem provides some automated support for these negotiations, mcludmg support tor automated auctions of advertising space Automation is particularly desirable for the placement ot advertisements which generate small amounts of mcome, such as small or highlv localized advertisements Once placement has been negotiated the aggregator captures and edits the advertisement and records it on a netpage ad server Coπespondmglv, the publisher records the ad placement on the relevant netpage publication server When the netpage publication server lavs out each user s personalized publication, it picks the relevant advertisements trom the netpage ad server - 25 - 2.3 USER PROFILES 2.3.1 Information Filtering The personalization ot news and other publications relies on an assortment of user-specific profile information, mcludmg • publication customizations • collaborative filtenng vectors • contact details presentation preferences The customization of a publication is typically publication-specific, and so the customization information is maintamed bv the relevant netpage publication server A collaborative filtenng vector consists of the user's ratings of a number of news items. It is used to coπelate different users' interests for the purposes of makmg recommendations Although there are benefits to maintaining a single collaborative tilteπng vector independently of any particular publication, there are two reasons why it is more practical to maintain a separate vector for each publication there is hkelv to be more overlap between the vectors ot subscnbers to the same publication than between those of subscnbers to different publications: and a publication is hkelv to want to present its users' collaborative filtenng vectors as part of the value of its brand, not to be found elsewhere Collaborative filtenng vectors are therefore also maintamed bv the relevant netpage publication server Contact details, including name, street address, ZEP Code, state, country, telephone numbers, are global by nature, and are mamtained bv a netpage registration server Presentation preferences, including those tor quantities, dates and times, are likewise global and maintained m the same wav The localization of advertising relies on the locality indicated in the user's contact details, while the targeting of advertising relies on personal information such as date of birth, gender, maπtal status, income, profession, education, or qualitative denvatives such as age range and income range For those users who choose to reveal personal mformation for advertising purposes, the mlormation is maintained bv the relevant netpage registration server In the absence of such information, advertising can be targeted on the basis ot the demographic associated with the user s ZIP or ZIP+4 Code Each user, pen, pnnter. application provider and application is assigned its own unique identifier, and the netpage registration server maintains the relationships between them, as shown in Figures 21 , 22, 23 and 24 For registration purposes, a publisher is a special kind of application provider, and a publication is a special kind of application Each user 800 mav be authoπzed to use anv number of pnnters 802. and each pπnter mav allow anv number of users to use it Each user has a single default pnnter (at 66), to which penodical publications are delivered bv default, whilst pages pnnted on demand are delivered to the pnnter through which the user is interacting The server keeps track of which publishers a user has authonzed to pnnt to the user s default pnnter A publisher does not record the ED of anv particular pnnter. but instead resolves the ID when it is required When a user subscπbes 808 to a publication 807. the publisher 806 (l e application provider 803) is authoπzed to pπnt to a specified pnnter or the user ' s default pπnter This authorization can be revoked at anv time bv the user Each user mav have several pens 801. but a pen is specific to a smgle user If a user is authoπzed to use a particular pnnter. then that pnnter recognizes anv of the user s pens The pen ID is used to locate the coπesponding user profile maintained bv a particular netpage registration server, via the DNS m the usual vvav - 26 - A Web terminal 809 can be authoπzed to pπnt on a particular netpage pnnter. allowing Web pages and netpage documents encountered duπng Web browsing to be conveniently pπnted on the nearest netpage pπnter. The netpage svstem can collect, on behalf of a pπnter provider, fees and commissions on mcome earned through publications pπnted on the provider ' s pnnters Such income can include advertising fees, click-through fees, e- commerce commissions, and transaction fees If the pnnter is owned bv the user, then the user is the pnnter provider. Each user also has a netpage account 820 which is used to accumulate micro-debits and credits (such as those descnbed m the precedmg paragraph), contact details 815, mcludmg name, address and telephone numbers; global preferences 816, mcluding pnvacv, delivery and localization settings, any number of biometπc records 817, containing the user's encoded signature 818. fingerpπnt 819 etc. a handwntmg model 819 automatically maintained by the system; and SET payment card accounts 821 with which e-commerce payments can be made 2.3.2 Favorites List A netpage user can maintain a list 922 of "favoπtes" - links to useful documents etc. on the netpage network. The list is mamtained bv the svstem on the user s behalf It is organized as a hierarchy of folders 924, a preferπed embodiment of which is shown in the class diagram in Figure 41 2.3.3 History List The svstem mamtams a history list 929 on each user's behalf, containing links to documents etc accessed bv the user through the netpage svstem It is organized as a date-ordered list, a prefeπed embodiment of which is shown m the class diagram m Figure 42. 2.4 INTELLIGENT PAGE LAYOUT The netpage publication server automatically lavs out the pages of each user's personalized publication on a section-by-section basis Smce most advertisements are m the form of pre-formatted rectangles, thev are placed on the page before the editonal content The advertising ratio for a section can be achieved with wildly varying advertising ratios on individual pages within the section, and the ad lavout algoπthm exploits this The algoπthm is configured to attempt to co-locate ^ loselv tied editonal and advertising content, such as placing ads for rooting matenal specifically within the publication because of a special feature on do-it-vourseif roofing repairs The editoπal content selected tor the user, mcludmg text and associated images and graphics, is then laid out according to vanous aesthetic rules The entire process, including the selection of ads and the selection of editonal content, must be iterated once the layout has converged, to attempt to more closelv achieve the user's stated section size preference The section size preference can. however, be matched on average over time, allowing significant dav-to-dav vanations 2.5 DOCUMENT FORMAT Once the document is laid out. it is encoded tor efficient distπbution and persistent storage on the netpage network The primary efficiency mechanism is the separation of information specific to a smgle user ' s edition and information shared between multiple users editions The specific information consists of the page lavout The shared information consists of the objects to which the page lavout refers, mcludmg images, graphics, and pieces of text. A text obiect contams fullv-tormatted text represented in the Extensible Markup Language (XML) using the Extensible Stylesheet Language fXSL) XSL provides precise control over text formatting independently of " the region into which the text is being set. which in this case is being provided bv the lavout The text obiect contams embedded language codes to enable automatic translation, and embedded hyphenation hints to aid with paragraph formatting An image object encodes an image m the JPEG 2000 wavelet-based compressed image format A graphic - 27 - object encodes a 2D graphic in Scalable Vector Graphics (SVG) format. The layout itself consists of a seπes of placed image and graphic objects, linked textfiow objects through which text objects flow, hyperlinks and input fields as descnbed above, and watermark regions These layout objects are summarized in Table 3. The lavout uses a compact format sui table for efficient distπbution and storage. Table 3 - netpage layout objects 2.6 DOCUMENT DISTRIBUTION As descnbed above, for purposes of efficient distnbution and persistent storage on the netpage network, a user-specific page lavout is separated from the shared objects to which it refers When a subscπbed publication is ready to be distnbuted, the netpage publication server allocates, with the help of the netpage ID server 12, a unique ID for each page, page instance, document, and document instance The server computes a set of optimized subsets of the shared content and creates a multicast channel for each subset, and then tags each user-specific lavout with the names of the multicast channels which will carry the shared content used by that lavout The server then pointcasts each user ' s layouts to that user ' s pπnter via the appropπate page server, and when the pointcasting is complete, multicasts the shared content on the specified channels After receivmg its pomtcast. each page server and pπnter subscπbes to the multicast channels specified in the page lavouts. Duπng the multicasts. each page server and pnnter extracts from the multicast streams those objects refeπed to bv its page lavouts The page servers persistently archive the received page layouts and shared content Once a pnnter has received all the objects to which its page lavouts refer, the pnnter re-creates the fully- populated lavout and then rasteπzes and pnnts it Under normal circumstances, the pπnter pnnts pages faster than thev can be delivered Assuming a quarter of each page is covered with images, the average page has a size of less than 400KB The pnnter can therefore hold in excess ot 100 such pages in its internal 64MB memory, allowing tor temporary buffers etc The pπnter pnnts at a rate of one page per second This is equivalent to 400KB or about 3Mbit of page data per second, which is similar to the highest expected rate of page data delivery over a broadband network - 28 - Even under abnormal circumstances, such as when the pnnter runs out of paper, it is likely that the user will be able to replenish the paper supply before the pnnter' s 100-page mtemal storage capacity is exhausted. However, if the pπnter' s internal memory does fill up, then the pnnter will be unable to make use of a multicast when it first occurs. The netpage publication server therefore allows pπnters to submit requests for re- multicasts When a cntical number of requests is received or a timeout occurs, the server re-multicasts the coπesponding shared objects Once a document is pnnted, a pnnter can produce an exact duplicate at anv time bv retπevmg its page lavouts and contents from the relevant page server 2.7 ON-DEMAND DOCUMENTS When a netpage document is requested on demand, it can be personalized and delivered in much the same way as a peπodical However, since there is no shared content, delivery is made directlv to the requesting printer without the use of multicast. When a non-netpage document is requested on demand, it is not personalized, and it is delivered via a designated netpage formatting server which reformats it as a netpage document A netpage formatting server is a special mstance of a netpage publication server The netpage formatting server has knowledge of vanous Internet document formats, mcludmg Adobe's Portable Document Format (PDF), and Hypertext Markup Language (EETML) In the case of HTML, it can make use of the higher resolution of the pπnted page to present Web pages m a multi-column format, with a table ol " contents It can automatically include all Web pages directly linked to the requested page The user can tune this behavior via a preference The netpage formatting server makes standard netpage behavior, mcludmg interactivity and persistence, available on any Internet document, no matter what its oπgm and format It hides knowledge of different document formats from both the netpage pπnter and the netpage page server, and hides knowledge of the netpage system from Web servers 3 SECURITY 3.1 CRYPTOGRAPHY Cryptography is used to protect sensitive information, both m storage and in transit, and to authenticate parties to α transaction There are two classes of cryptography in widespread use secret-kev cryptography and public-key cryptography The netpage network uses both classes of cryptography Secret-kev cryptography, also refeπed to as svmmetπc cryptography, uses the same key to encrypt and decrypt a message Two parties wishing to exchange messages must first aπange to securely exchange the secret key Public-kev cryptography, also refeπed to as asymmetnc cryptography, uses two encryption keys The two keys are mathematically related m such a vvav that anv message encrypted using one key can onlv be decrypted using the other key One of these kevs is then published, while the other is kept pnvate The public kev is used to encrypt any message intended for the holder of the pnvate kev Once encrypted using the public key. a message can only be decrypted using the pnvate kev Thus two parties can securely exchange messages without first havmg to exchange a secret key To ensure that the pnvate kev is secure, it is normal for the holder of the pnvate kev to generate the key pair Public-key cryptography can be used to create a digital signature The holder of the pnvate kev can create a known hash of a message and then encrypt the hash using the pnvate kev Anyone can then veπfv that the encrypted hash constitutes the ' signature ' ot the holder ol ' the pnvate key with respect to that particular message bv decrypting the encrypted hash using the public kev and ventving the hash against the message If the signature is appended to the message, then the recipient ot the message con veπfv both that the message is genuine and that it has not been altered in transit - 29 - To make pub c-kev cryptography work, there has to be a vvav to distπbute public keys which prevents impersonation This is normally done using certificates and certificate authoπties A certificate authonty is a trusted third party which authenticates the connection between a public key and someone ' s identity The certificate authonty veπfies the person ' s identity bv examimng identitv documents, and then creates and signs a digital certificate containing the person ' s identity details and public kev Anyone who trusts the certiticate authonty can use the public kev m the certificate with a high degree of certamtv that it is genuine They just have to veπfy that the certificate has mdeed been signed bv the certificate authonty, whose public kev is well-known. In most transaction environments, pubhc-kev cryptography is only used to create digital signatures and to securely exchange secret session keys Secret-kev cryptography is used for all other purposes. In the following discussion, when reference is made to the secure transmission of information between a netpage pπnter and a server, what actually happens is that the pnnter obtains the server's certificate, authenticates it with reference to the certificate authonty, uses the public key-exchange key in the certificate to exchange a secret session kev with the server, and then uses the secret session key to encrypt the message data A session key, by definition, can have an arbitranlv short lifetime 3.2 NETPAGE PRINTER SECURITY Each netpage pπnter is assigned a pair of umque identifiers at time ot manufacture which are stored m read-onlv memory in the pπnter and m the netpage registration server database The first ID 62 is public and uniquely identifies the pπnter on the netpage network The second ID is secret and is used when the pnnter is first registered on the network When the pnnter connects to the netpage network for the first time after installation, it creates a signature pubhc/pnvate key pair It transmits the secret ID and the public key securely to the netpage registration server. The server compares the secret ID against the pnnter' s secret ID recorded in its database, and accepts the registration if the IDs match It then creates and signs a certificate containing the printer's public ID and public signature key, and stores the certificate in the registration database The netpage registration server acts as a certificate authonty for netpage pπnters. since it has access to secret information allowing it to veπtv pnnter identity When a user subscnbes to α publication, a record is created in the netpage registration server database authorizing the publisher to pπnt the publication to the user s default pπnter or a specified pπnter Every document sent to a pπnter via a page server is addressed to a particular user and is signed bv the publisher using the publisher's pnvate signature kev The page server venfies. via the registration database, that the publisher is authorized to deliver the publication to the specified user The page server venfies the signature using the publisher ' s public kev, obtamed from the publisher's certificate stored in the registration database The netpage registration server accepts requests to add pnnting authoπzations to the database, so long as those requests are initiated via a pen registered to the pnnter 3.3 NETPAGE PEN SECURITY Each netpage pen ι_> assigned a unique identifier at time of manufacture which is stored in read-onlv memory m the pen and in the netpage registration server database The pen ID 61 uniquely identifies the pen on the netpage network A netpage pen can know α number ol netpage pnnters. and a pnnter can know " a number of pens A pen communicates with a pπnter via a radio frequency signal whenever it is within range of the pnnter Once a pen and pnnter are registered, thev regularly exchange session kevs Whenever the pen transmits digital ink to the pnnter, the digital ink is always encrypted using the appropnate session kev Digital ink is never transmitted in the clear - 30 - A pen stores a session key for every pnnter it knows, mdexed by pnnter ID, and a pnnter stores a session key for every pen it knows, indexed bv pen ID Both have a large but fimte storage capacity for session keys, and will forget a session kev on a least-recentlv-used basis if necessary When a pen comes within range of " a pπnter. the pen and pnnter discover whether thev know each other. If they don ' t know each other, then the pnnter determines whether it is supposed to know the pen. This might be, for example, because the pen belongs to a user who is registered to use the pπnter If the pπnter is meant to know the pen but doesn ' t, then it initiates the automatic pen registration procedure. If the pnnter isn't meant to know the pen, then it agrees with the pen to ignore it until the pen is placed in a charging cup, at which time it initiates the registration procedure. In addition to its public ID, the pen contams a secret key-exchange key The key-exchange key is also recorded in the netpage registration server database at time of manufacture. Duπng registration, the pen transmits its pen ID to the pnnter, and the pnnter transmits the pen ID to the netpage registration server The server generates a session key for the pnnter and pen to use, and securely transmits the session key to the pnnter. It also transmits a copy of the session key encrypted with the pen ' s kev-exchange kev The pπnter stores the session kev internally, indexed by the pen ID, and transmits the encrypted session kev to the pen The pen stores the session kev internally, indexed by the pnnter ID Although a fake pen can impersonate a pen m the pen registration protocol, only a real pen can decrypt the session key transmitted by the pnnter. When a previously unregistered pen is first registered, it is of limited use until it is linked to a user. A registered but "un-owned" pen is only allowed to be used to request and fill m netpage user and pen registration forms, to register a new user to which the new pen is automatically linked, or to add a new pen to an existing user. The pen uses secret-key rather than pubhc-kev encryption because of hardware performance constraints in the pen. 3.4 SECURE DOCUMENTS The netpage svstem supports the deliver.' of secure documents such as tickets and coupons The netpage pnnter includes a facility to pnnt watermarks, but will only do so on request from publishers who are suitably authorized The publisher indicates its authontv to pnnt watermarks in its certificate, which the pπnter is able to authenticate. The "watermark" pnntmg process uses an alternative dither matπx in specified '"watermark" regions of the page. Back-to-back pages contain mirror-image watermark regions which coincide when pπnted The dither matnces used m odd and even pages ' watermark regions are designed to produce an interference effect when the regions are viewed together, achieved bv looking through the pπnted sheet The effect is similar to a watermark in that it is not visible when looking at only one side of the page, and is lost when the page is copied bv normal means Pages of secure documents cannot be copied usmg the built-in netpage copy mechanism descnbed in Section 1 9 above This extends to copying netpages on netpage-aware photocopiers Secure documents are tvpicallv generated as part of e-commerce transactions Thev can therefore mclude the user s photograph hich was captured when the user registered biometnc information with the netpage registration server, as descnbed m Section 2 When presented with a secure netpage document, the recipient can veπfv its authenticity by requestmg its status in the usual av The umque ID of α secure document is only valid for the lifetime of the document, and secure document IDs are allocated non-contiguouslv to prevent their prediction bv opportunistic forgers A secure document - 31 - venfication pen can be developed with built-in feedback on venfication failure, to support easv point-of-presentation document venfication. Clearly neither the watermark nor the user ' s photograph are secure m a cryptographic sense. They simply provide a sigmticant obstacle to casual forgery Onlme document venfication, particularly usmg a venfication pen, provides an added level of security where it is needed, but is still not entirely immune to forgeπes 3.5 NON-REPUDIATION In the netpage system, forms submitted by users are delivered rehablv to forms handlers and are persistently archived on netpage page servers It is theretore impossible for recipients to repudiate delivery E-commerce payments made through the system, as descnbed in Section 4, are also impossible for the payee to repudiate 4 ELECTRONIC COMMERCE MODEL 4.1 SECURE ELECTRONIC TRANSACTION (SET) The netpage system uses the Secure Electronic Transaction (SET) svstem as one of its payment systems SET. having been developed bv MasterCard and Visa, is organized around pavment cards, and this is reflected m the terminology However, much ol the system is mdependent of the type ol accounts being used In SET, cardholders and merchants register with a certificate authonty and are issued with certificates containing their public signature kevs The certificate authontv venfies a cardholder's registration details with the card issuer as appropnate, and venfies a merchant's registration details with the acquirer as appropπate. Cardholders and merchants store their respective pnvate signature kevs securely on their computers Dunng the pavment process, these certificates are used to mutually authenticate a merchant and cardholder, and to authenticate them both to the payment gateway SET has not vet been adopted widely, partlv because cardholder maintenance of keys and certificates is considered burdensome Intenm solutions which maintain cardholder kevs and certificates on a server and give the cardholder access via a password have met with some success 4.2 SET PAYMENTS In the netpage svstem the netpage registration server acts as a proxy for the netpage user (l e the cardholder) m SET pavment transactions The netpage svstem uses biometrics to authenticate the user and authorize SET payments Because the system is pen-based, the biometnc used is the user's online signature, consisting of time- varying pen position and pressure A fingerpπnt biometπc can also be used bv designing a fingerpnnt sensor mto the pen, although at a higher cost The type of biometnc used onlv affects the capture of the biometnc, not the authorization aspects of the system The first step to being able to make SET payments is to register the user s biometπc with the netpage registration server This is done m a controlled environment, tor example a bank, where the biometnc can be captured at the same time as the user s identity is veπtied The biometπc is captured and stored m the registration database, linked to the user s record The user s photograph is also optionallv captured and linked to the record The SET cardholder registration process is completed, and the resulting pnvate signature kev and certificate are stored in the database The user s pavment card information is also stored, giving the netpage registration server enough information to act as the user s proxy m anv SET pavment transaction When the user eventually supplies the biometnc to complete α payment, lor example bv signing a netpage order form, the pπnter securely transmits the order information, the pen ID and the biometπc data to the netpage registration server The server venfies the biometnc with respect to the user identified bv the pen ID. and from then on acts as the user s proxy in completing the SET pavment transaction - 32 - 4.3 MICRO-PAYMENTS The netpage system includes a mechanism for micro-pavments, to allow the user to be conveniently charged for pnntmg low-cost documents on demand and for copying copynght documents, and possibly also to allow the user to be reimbursed for expenses mcurred in pnnting advertismg mateπal The latter depends on the level of subsidy already provided to the user When the user registers for e-commerce, a network account is established which aggregates micro- payments The user receives a statement on a regular basis, and can settle anv outstanding debit balance usmg the standard pavment mechanism The network account can be extended to aggregate subscπption fees for penodicals, which would also otherwise be presented to the user m the form of individual statements 4.4 TRANSACTIONS When a user requests a netpage in a particular application context, the application is able to embed a user- specific transaction ID 55 in the page Subsequent mput through the page is tagged with the transaction ID, and the application is thereby able to establish an appropnate context for the user ' s mput When input occurs through a page which is not user-specific, however, the application must use the user's umque identity to establish a context. A typical example involves adding items from a pre-pnnted catalog page to the user's virtual "shopping cart" To protect the user's pπvacv, however, the umque user ID 60 known to the netpage system is not divulged to applications This is to prevent different application providers from easily coπelating independently accumulated behavioral data The netpage registration server mstead mamtams an anonymous relationship between a user and an application via a umque alias ID 65, as shown m Figure 24 Whenever the user activates a hyperlink tagged with the "registered " attπbute, the netpage page server asks the netpage registration server to translate the associated application ID 64, together with the pen ID 61, mto an alias ID 65 The alias ED is then submitted to the hyperlink's application. The application mamtams state mformation mdexed by alias ID, and is able to retneve user-specific state information without knowledge of the global identity of the user The svstem also mamtams an independent certificate and pnvate signature kev for each of a user's applications, to allow it to sign application transactions on behalf of the user using onlv application-specific information. To assist the system in routing product bar code (UPC) '"hyperlink" activations, the system records a favonte application on behalf of the user tor anv number of product types Each application is associated with an application provider, and the svstem mamtams an account on behalf of each application provider, to allow it to credit and debit the provider for click-through fees etc An application provider can be a publisher ol penodical subscπbed content The svstem records the user's willingness to receive the subscnbed publication, as well as the expected frequency of publication 4.5 RESOURCE DESCRIPTIONS AND COPYRIGHT A preteπed embodiment of a resource descnption class diagram is shown in Figure 40 Each document and content object mav be descnbed bv one or more resource descnptions 842 Resource descπptions use the Dublin Core metadata element set, which is designed to facilitate discovery ot electronic resources Dublin Core metadata conforms to the World Wide Web Consortium (W3C) Resource Descπption Framework (RDF) A resource descnption may identify nghts holders 920 The netpage svstem automatically transfers copynght tees trom users to nghts holders when users pnnt copynght content 5 COMMUNICATIONS PROTOCOLS A communications protocol defines an ordered exchange ot messages between entities In the netpage - 33 - system, entities such as pens, pnnters and servers utilise a set of defined protocols to cooperatively handle user interaction with the netpage svstem Each protocol is illustrated by wav ol " a sequence diagram in which the horizontal dimension is used to represent message flow and the vertical dimension is used to represent time. Each entity is represented by a rectangle containing the name of the entity and a vertical column representing the lifelme of the entitv. Duπng the time an entity exists, the lifeline is shown as a dashed line. Dunng the time an entity is active, the lifelme is shown as a double line. Because the protocols considered here do not create or destroy entities, lifelines are generally cut short as soon as an entity ceases to participate in a protocol 5.1 SUBSCRIPTION DELIVERY PROTOCOL A prefeπed embodiment of a subscπptton delivery protocol is shown m Figure 43 A large number of users mav subscribe to a peπodical publication. Each user ' s edition may be laid out differently, but many users' editions will share common content such as text objects and image objects The subscription delivery protocol therefore delivers document structures to individual pπnters via pointcast, but delivers shared content objects via multicast The application (l e publisher) first obtains a document ID 51 for each document from an ID server 12. It then sends each document structure, mcludmg its document ID and page descπptions, to the page server 10 responsible for the document's nevvlv allocated ID It includes its own application ED 64, the subscnber s alias ID 65, and the relevant set of multicast channel names. It signs the message usmg its pnvate signature key. The page server uses the application ID and alias ID to obtain from the registration server the coπesponding user ID 60, the user s selected pnnter ID 62 (which may be explicitly selected for the application, or may be the user's default pπnter), and the application ' s certificate. The application ' s certificate allows the page server to veπfy the message signature. The page server's request to the registration server fails if the application ID and alias ID don't together identify a subscnption 808. The page server then allocates document and page mstance EDs and forwards the page descnptions, including page IDs 50. to the pnnter It includes the relevant set ol " multicast channel names for the pnnter to listen to It then returns the newly allocated page IDs to the application for future reference Once the application has distnbuted all of the document structures to the subscnbers ' selected pnnters via the relevant page servers, it multicasts the vanous subsets of the shared objects on the previously selected multicast channels Both page servers and pnnters monitor the appropnate multicast channels and receive their required content objects. They are then able to populate the previously pomtcast document structures This allows the page servers to add complete documents to their databases, and it allows the pπnters to pnnt the documents 5.2 HYPERLINK ACTIVATION PROTOCOL A prefeπed embodiment of a hvperlmk activation protocol is shown in Figure 45 When a user clicks on a netpage with a netpage pen. the pen communicates the click to the nearest netpage pπnter 601 The click identifies the page and a location on the page. The pπnter already knows the ID 61 of the pen from the pen connection protocol The pπnter determines, via the DNS, the network address of the page server 10a handling the particular page ID 50 The address mav already be in its cache if the user has recently interacted with the same page The pnnter then forwards the pen ID. its own pnnter ID 62, the page ED and click location to the page server The page server loads the page descπption 5 identified bv the page ID and determines which mput element s zone 58. if any. the click lies in Assuming the relevant input element is a hvperlmk element 844. the page server then obtains the associated application ID 64 and link ID 54. and determines, via the DNS, the network address - 34 - of the application server hosting the application 71 The page server uses the pen ED 61 to obtain the coπespondmg user ED 60 from the registration server 11 , and then allocates a globally umque hyperlink request ID 52 and builds a hyperlink request 934 The hyperlink request class diagram is shown m Figure 44 The hyperlink request records the IDs of the requestmg user and pπnter, and identifies the clicked hvperlmk instance 862 The page server then sends its own server ID 53, the hyperlink request ID, and the link ID to the application The application produces a response document according to application-specific logic, and obtains a document ID 51 from an ID server 12 It then sends the document to the page server 10b responsible for the document's newlv allocated ID, together with the requesting page server's ID and the hyperlink request ID. The second page server sends the hvperlmk request ID and application ID to the first page server to obtain the coπespondmg user ID and pnnter ID 62 The first page server rejects the request if the hyperlink request has expired or is for a different application The second page server allocates document instance and page IDs 50, returns the newlv allocated page IDs to the application, adds the complete document to its own database, and finally sends the page descπptions to the requesting pnnter The hyperlink instance mav include a meaningfiil transaction ID 55, in which case the first page server mcludes the transaction ID m the message sent to the application This allows the application to establish a transaction- specific context for the hyperlink activation If the hvperlmk requires a user alias, I e its "alias required" attπbute is set, then the first page server sends both the pen ID 61 and the hyperlink's application ID 64 to the registration server 11 to obtain not just the user ID coπespondmg to the pen ID but also the alias ID 65 coπesponding to the application ID and the user ED It mcludes the alias ID in the message sent to the application, allowing the application to establish a user-specific context for the hyperlink activation 5.3 HANDWRITING RECOGNITION PROTOCOL When a user draws a stroke on a netpage with a netpage pen. the pen communicates the stroke to the nearest netpage pnnter The stroke identifies the page and a path on the page The pnnter torwards the pen ID 61. its own pnnter ID 62, the page ED 50 and stroke path to the page server 10 in the usual way The page server loads the page descnption 5 identified bv the page ID and determines which mput element's zone 58. if anv, the stroke intersects Assuming the relevant mput element is a text field 878, the page server appends the stroke to the text field's digital ink Alter a peπod of inactivity in the zone of the text field, the page server sends the pen ID and the pending strokes to the registration server 1 1 for interpretation The registration server identifies the user coπespondmg to the pen, and uses the user s accumulated handwntmg model 822 to interpret the strokes as handwritten text Once it has converted the strokes to text, the registration server returns the text to the requesting page server The page server appends the text to the text value of the text field 5.4 SIGNATURE VERIFICATION PROTOCOL Assuming the mput element whose zone the stroke intersects is a signature field 880. the page server 10 appends the stroke to the signature field's digital ink Alter a peπod ot mactivitv in the zone of the signature field, the page server sends the pen ID 61 and the pendmg strokes to the registration server 1 1 for venfication It also sends the application ED 64 associated with the form of which the signature field is pan. as well as the torm ED 56 and the current data content ol the torm The registration - 35 - server identifies the user coπespondmg to the pen, and uses the user s dynamic signature biometnc 818 to veπfy the strokes as the user s signature Once it has venfied the signature, the registration server uses the application ID 64 and user ID 60 to identify the user s application-specific pnvate signature kev It then uses the kev to generate a digital signature of the form data, and retums the digital signature to the requesting page server The page server assigns the digital signature to the signature field and sets the associated form's status to frozen The digital signature includes the alias ED 65 of the coπespondmg user. This allows a smgle form to capture multiple users' signatures 5.5 FORM SUBMISSION PROTOCOL A prefeπed embodiment of a form submission protocol is shown m Figure 46 Form submission occurs via a form hyperlink activation It thus follows the protocol defined in Section 5.2, with some form-specific additions In the case of a form hyperlink, the hvperlmk activation message sent by the page server 10 to the application 71 also contains the form ED 56 and the current data content of the form. If the form contams any signature fields, then the application venfies each one bv extracting the alias ID 65 associated with the coπespondmg digital signature and obtaining the coπespondmg certiticate trom the registration server 11 5.6 COMMISSION PAYMENT PROTOCOL A prefeπed embodiment of a commission payment protocol is shown in Figure 47 In an e-commerce environment, fees and commissions mav be payable from an application provider to a publisher on chck-throughs, transactions and sales Commissions on fees and commissions on commissions may also be payable from the publisher to the provider of the pnnter The hyperlink request E_D 52 is used to route a fee or commission credit from the target application provider 70a (e g merchant) to the source application provider 70b (l e publisher), and from the source application provider 70b to the pnnter provider 72 The target application receives the hyperlink request ED from the page server 10 when the hyperlink is first activated, as descnbed in Section 5 2 When the target application needs to credit the source application provider, it sends the application provider credit to the onginal page server together with the hyperlink request ID The page server uses the hyperlink request ED to identify the source application, and sends the credit on to the relevant registration server 1 1 together with the source application ID 64. its own server ID 53, and the hyperlink request ID The registration server credits the coπespondmg application provider ' s account 827 It also notifies the application provider If the application provider needs to credit the pπnter provider, it sends the pπnter provider credit to the onginal page server together with the hvperlmk request ID The page server uses the hyperlink request ID to identify the pπnter, and sends the credit on to the relevant registration server together with the prmter ID The registration server credits the coπespondmg pπnter provider account 814 The source application provider is optionallv notified ot the identity of the target application provider, and the pπnter provider of the identity of the source application provider 6. NETPAGE PEN DESCRIPTION 6.1 PEN MECHANICS Referπng to Figures 8 and 9, the pen. generally designated bv relerence numeral 101. includes a housing 102 in the form of a plastics moulding having walls 103 defining on inteπor space 104 for mounting the pen components The pen top 105 is in operation rotatablv mounted at one end 106 of the housing 102 A semi-transparent cover 107 is secured to the opposite end 108 ol the housing 102 The cover 107 is also of moulded plastics, and is tormed from semi-transparent mateπal in order to enable the user to view the status of the LED mounted within the - 36 - housmg 102 The cover 107 includes a mam part 109 which substantially suπounds the end 108 of the housmg 102 and a projecting portion 1 10 which projects back from the mam part 109 and tits vvithm a coπesponding slot 1 11 formed in the walls 103 of the housmg 102 A radio antenna 1 12 is mounted behind the projectmg portion 110, within the housmg 102 Screw threads 113 surrounding an aperture 1 13A on the cover 107 are arranged to receive a metal end piece 114, including coπespondmg screw threads 1 15 The metal end piece 114 is removable to enable ink cartndge replacement. Also mounted vvithm the cover 107 is a tn-color status LED 1 16 on a flex PCB 1 17 The antenna 112 is also mounted on the flex PCB 1 17 The status LED 116 is mounted at the top ot the pen 101 for good all-around visibility. The pen can operate both as a normal markmg ink pen and as a non-markmg stylus An ink pen cartndge 1 18 with nib 1 19 and a stylus 120 with stylus mb 121 are mounted side by side within the housmg 102 Either the ink cartndge b 1 19 or the stvlus mb 121 can be brought forward through open end 122 of the metal end piece 114, by rotation of the pen top 105 Respective slider blocks 123 and 124 are mounted to the ink cartndge 118 and stylus 120, respectively A rotatable cam baπel 125 is secured to the pen top 105 in operation and arranged to rotate therewith. The cam baπel 125 mcludes a cam 126 m the form of a slot within the walls 181 of the cam barrel Cam followers 127 and 128 projecting from slider blocks 123 and 124 fit within the cam slot 126 On rotation ot the cam barrel 125, the slider blocks 123 or 124 move relative to each other to project either the pen mb 119 or stylus mb 121 out through the hole 122 m the metal end piece 114 The pen 101 has three states of operation By turning the top 105 through 90° steps, the three states are Stylus 120 mb 121 out, • Ink cartndge 118 nib 119 out, and • Neither ink cartndge 1 18 mb 1 19 out nor stylus 120 mb 121 out A second flex PCB 129, is mounted on an electronics chassis 130 which sits within the housmg 102. The second flex PCB 129 mounts an infrared LED 131 for providmg infrared radiation for projection onto the surface. An unage sensor 132 is provided mounted on the second flex PCB 129 for receivmg reflected radiation from the surface. The second flex PCB 129 also mounts a radio frequency chip 133, which includes an RF transmitter and RF receiver, and a controller chip 134 for controlling operation of the pen 101 An optics block 135 (formed from moulded clear plastics) sits within the cover 107 and projects an infrared beam onto the surface and receives images onto the image sensor 132 Power supply wires 136 connect the components on the second flex PCB 129 to battery contacts 137 which are mounted within the cam barrel 125 A terminal 138 connects to the battery contacts 137 and the cam baπel 125 A three volt rechargeable battery 139 sits within the cam baπel 125 in contact with the battery contacts An induction charging coil 140 is mounted about the second flex PCB 129 to enable recharging of the battery 139 via induction. The second flex PCB 129 also mounts an infrared LED 143 and infrared photodiode 144 for detecting displacement m the cam baπel 125 when either the stvlus 120 or the ink cartndge 118 is used for wnting, in order to enable a determination ot the force being applied to the surface bv the pen nib 119 or stylus nib 121 The IR photodiode 144 detects light from the ER LED 143 via reflectors (not shown) mounted on the slider blocks 123 and 124 Rubber gπp pads 141 and 142 are provided towards the end 108 of the housing 102 to assist gnpping the pen 101 , and top 105 also includes a clip 142 for clipping the pen 101 to a pocket 6.2 PEN CONTROLLER The pen 101 is aπanged to determine the position ot its nib (stylus mb 121 or ink cartndge mb 1 19) by imagmg, in the infrared spectrum, an area of the surface in the vicmitv ol the mb It records the location data from the nearest location tag, and is aπanged to calculate the distance ot the nib 121 or 1 19 from the location tab utilising optics 135 and controller chip 134 The controller chip 134 calculates the oπentation ot the pen and the nib-to-tag distance from the perspective distortion observed on the imaged tag - 37 - Utihsmg the RF chip 133 and antenna 112 the pen 101 can transmit the digital ink data (which is encrypted for secuπty and packaged for efficient transmission) to the computing system. When the pen is in range ot a receiver, the digital ink data is transmitted as it is formed When the pen 101 moves out of range, digital ink data is buffered within the pen 101 (the pen 101 circuitry includes a buffer aπanged to store digital ink data tor approximately 12 minutes of the pen motion on the surface) and can be transmitted later. The controller chip 134 is mounted on the second flex PCB 129 in the pen 101 Figure 10 is a block diagram illustrating m more detail the architecture of the controller chip 134 Figure 10 also shows representations of the RF chip 133, the image sensor 132, the tπ-color status LED 1 16, the IR illumination LED 131 , the ER force sensor LED 143, and the torce sensor photodiode 144 The pen controller chip 134 includes a controlling processor 145 Bus 146 enables the exchange of data between components of the controller chip 134 Flash memory 147 and a 512 KB DRAM 148 are also mcluded. An analog-to-digital converter 149 is aπanged to convert the analog signal from the force sensor photodiode 144 to a digital signal An image sensor interlace 152 interfaces with the image sensor 132 A transceiver controller 153 and base band circuit 154 are also included to interface with the RF chip 133 which mcludes an RF circuit 155 and RF resonators and mductors 156 connected to the antenna 1 12 The controlling processor 145 captures and decodes location data from tags from the surface via the image sensor 132, monitors the force sensor photodiode 144, controls the LEDs 116, 131 and 143. and handles short-range radio communication via the radio transceiver 153 It is a medium-periormance (~40MHz) general-purpose RISC processor The processor 145, digital transceiver components (transceiver controller 153 and baseband circuit 154), image sensor mterface 152, flash memory 147 and 512KB DRAM 148 are integrated in a single controller ASIC Analog RF components (RF circuit 155 and RF resonators and mductors 156) are provided in the separate RF chip The image sensor is a 215x215 pixel CCD (such a sensor is produced bv Matsushita Electronic Corporation, and is descnbed in a paper by Itakura. K T Nobusada. N Okusenva. R Nagayoshi. and M Ozaki. ""A 1mm 50k-Pιxel IT CCD Image Sensor for Miniature Camera System ", EEE Transactions on Electronic Devices. Volt 47, number 1, January 2000 which is incorporated herein bv reference) with an IR filter The controller ASIC 134 enters a quiescent state after a penod of inactivity when the pen 101 is not m contact with a surtace It mcorporates α dedicated circuit 150 which monitors the force sensor photodiode 144 and wakes up the controller 134 via the power manager 151 on a pen-down event The radio transceiver communicates in the unlicensed 900MHz band normally used bv cordless telephones, or alternatively in the unlicensed 2 4GHz lndustnal. scientific and medical (ISM) band, and uses trequency hoppmg and collision detection to provide mterlerence-tree communication In an alternative embodiment, the pen incorporates an Infrared Data Association ( IrDA) interface for short- range communication with a base station or netpage pnnter In a turther embodiment, the pen 101 includes a pair ol orthogonal accelerometers mounted in the normal plane ot the pen 101 axis The accelerometers 190 are shown in Figures 9 and 10 in ghost outline The provision ol the accelerometers enables this embodiment of the pen 101 to sense motion without reterence to surface location tags, allowing the location tags to be sampled at a lower rate Each location tag ED can then identify an object ot interest rather than α position on the surtace For example, if the object is a user interlace mput element (e g . command button), then the tag ED of each location tag vvithm the area of the mput element can directly identify the input element - 38 - The acceleration measured bv the accelerometers m each of the x and v directions is integrated with respect to time to produce an instantaneous velocity and position Since the starting position ot the stroke is not known, onlv relative positions within a stroke are calculated. .•Mthough position mtegration accumulates eπors in the sensed acceleration, accelerometers typically have high resolution, and the time duration ot a stroke, over which eπors accumulate, is short 7. NETPAGE PRINTER DESCRIPTION 7.1 PRINTER MECHANICS The verticallv-mounted netpage wallpnnter 601 is shown fully assembled m Figure 1 1 It pnnts netpages on Letter/A4 sized media using duplexed 8' " Memjet™ pnnt engmes 602 and 603, as shown in Figures 12 and 12a It uses a straight paper path with the paper 604 passing through the duplexed pnnt engmes 602 and 603 which pπnt both sides of a sheet simultaneously, m full color and with full bleed An integral binding assembly 605 applies a strip of glue along one edge of each pnnted sheet, allowing it to adhere to the previous sheet when pressed against it This creates a final bound document 618 which can range m thickness trom one sheet to several hundred sheets The replaceable ink cartridge 627, shown in Figure 13 coupled with the duplexed pπnt engmes, has bladders or chambers for stoπng fixative, adhesive, and cyan, magenta, yellow, black and infrared inks The cartridge also contams a micro air filter in a base molding The micro air filter interfaces with an air pump 638 inside the pnnter via a hose 639 This provides filtered air to the pnnfheads to prevent ingress of micro particles mto the Memjet™ pπntheads 350 which might otherwise clog the pπnthead nozzles By incorporating the air filter within the cartndge, the operational life of the filter is effectively linked to the life of the cartndge The ink cartndge is a fully recyclable product with a capacity for pnntmg and gluing 3000 pages (1500 sheets) Referring to Figure 12, the motorized media pick-up roller assembly 626 pushes the top sheet directly from the media frav past a paper sensor on the first pnnt engine 602 into the duplexed Memjet™ pnnthead assembly The two Memjet™ pnnt engmes 602 and 603 are mounted in an opposing in-line sequential configuration along the straight paper path The paper 604 is drawn into the first pnnt engme 602 bv integral, powered pick-up rollers 626 The position and size ot the paper 604 is sensed and full bleed pnntmg commences Fixative is pπnted simultaneouslv to aid drying m the shortest possible time The paper exits the first Memjet™ pπnt engine 602 through a set of powered exit spike wheels (aligned along the straight paper path), which act against a rubbeπzed roller These spike wheels contact the wet' pπnted surface and continue to feed the sheet 604 into the second Memjet™ pnnt engine 603 Referring to Figures 12 and 12a, the paper 604 passes trom the duplexed pnnt engmes 602 and 603 mto the bmder assembly 605 The pnnted page passes between a powered spike wheel axle 670 with a fibrous support roller and another movable axle with spike wheels and a momentary action glue wheel The movable axle/glue assembly 673 is mounted to a metal support bracket and it is transported for ard to interface with the powered axle 670 via gears by action of a camshaft A separate motor powers this camshaft The glue wheel assembly 673 consists ot a partially hollow axle 679 with a rotating coupling for the glue supply hose 641 from the ink cartndge 627 This axle 679 connects to a glue wheel, which absorbs adhesive bv capillary action through radial holes A molded housmg 682 surrounds the glue wheel with an opening at the front Pivoting side moldings and sprung outer doors are attached to the metal bracket and hmge out sidewavs when the rest ol the assemblv 73 is thrust forward This action exposes the glue wheel through the front ot the molded housing 682 Tension springs dose the assemblv and effectively cap the glue wheel dunng penods ot inactivity As the sheet 604 passes into the glue wheel assembly 673 adhesive is applied to one vertical edge on the - 39 - front side (apart from the first sheet of a document) as it is transported down mto the binding assemblv 605 7.2 PRINTER CONTROLLER ARCHITECTURE The netpage pnnter confroller consists of a controlling processor 750, a factory-installed or field-mstalled network mterface module 625, a radio transceiver (transceiver controller 753. baseband circuit 754, RF circmt 755, and RF resonators and mductors 756), dual raster image processor (RIP) DSPs 757, duplexed pnnt engine confrollers 760a and 760b, flash memory 658, and 64MB of DRAM 657, as illustrated in Figure 14 The controlling processor handles communication with the network 19 and with local wireless netpage pens 101, senses the help button 617, controls the user interface LEDs 613-616, and feeds and synchronizes the RIP DSPs 757 and pπnt engine controllers 760 It consists of a medium-performance general-purpose microprocessor. The controlling processor 750 communicates with the pnnt engme controllers 760 via a high-speed seπal bus 659 The REP DSPs rasteπze and compress page descπptions to the netpage pnnter' s compressed page format. Each pπnt engme controller expands, dithers and pnnts page images to its associated Memjet™ prmthead 350 in real time (l e at over 30 pages per minute) The duplexed pnnt engme controllers pnnt both sides of a sheet simultaneously The master pπnt engme controller 760a controls the paper transport and monitors ink usage m conjunction with the master QA chip 665 and the ink cartndge QA chip 761 The pnnter controller's flash memory 658 holds the software for both the processor 750 and the DSPs 757, as well as configuration data. This is copied to ma memory 657 at boot time. The processor 750, DSPs 757, and digital transceiver components (transceiver confroller 753 and baseband circmt 754) are integrated m a single controller ASIC 656 Analog RF components (RF circmt 755 and RF resonators and mductors 756) are provided in a separate RF chip 762 The network interface module 625 is separate, smce netpage pnnters allow the network connection to be factory-selected or field-selected. Flash memory 658 and the 2x256Mbit (64MB) DRAM 657 is also off-chip The pπnt engme controllers 760 are provided m separate ASICs A vanety of network mterface modules 625 are provided, each providmg a netpage network mterface 751 and optionally a local computer or network interface 752 Netpage network Internet interfaces include POTS modems, Hybnd Fiber-Coax (FEFC) cable modems, ISDN modems. DSL modems, satellite transceivers, cuπent and next- generation cellular telephone transceivers, and wireless local loop (WLL) transceivers Local interlaces mclude IEEE 1284 (parallel port), lOBase-T and l OOBase- E Ethernet, USB and USB 2 0. IEEE 1394 (Firewirej, and vaπous emerging home networking interfaces It ' an Internet connection is available on the local network, then the local network mterface can be used as the netpage network interlace The radio transceiver 753 communicates in the unlicensed 900MHz band normally used by cordless telephones, or alternatively in the unlicensed 2 4GHz mdustπal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free communication The pnnter controller optionally incorporates an Infrared Data Association (ErDA) interlace for receiving data "squirted " from devices such as netpage cameras In an alternative embodiment, the pnnter uses the IrDA mterface for short-range communication with suitably configured netpage pens 7.2.1 RASTERIZATION AND PRINTING Once the main processor 750 has received and venfied the document s page lavouts and page objects, it runs the appropnate REP software on the DSPs 757 The DSPs 757 rastenze each page descnption and compress the rasteπzed page image The mam processor stores each compressed page image in memory The simplest way to load-balance multiple DSPs is to let each DSP rasteπze a separate page The DSPs can always be kept busy since an arbitrary number ot rasteπzed pages can. in general, be stored in memory This strategy onlv leads to potentially poor DSP utilization when rastenzing short - 40 - documents Watermark regions in the page descπption are rastenzed to a contone-resolution bi-level bitmap which is losslesslv compressed to negligible size and which forms part of the compressed page image The infrared (IR) layer of the pnnted page contains coded netpage tags at a density of about six per mch Each tag encodes the page ED, tag ED, and control bits, and the data content ot each tag is generated duπng rasterization and stored in the compressed page image The mam processor 750 passes back-to-back page images to the duplexed pnnt engme controllers 760. Each pnnt engine controller 760 stores the compressed page image in its local memory, and starts the page expansion and pnnting pipeline Page expansion and pnnting is pipelmed because it is impractical to store an entire 1 14MB bi-level CMYK+IR page image in memory 7.2.2 PRINT ENGINE CONTROLLER The page expansion and pnntmg pipeline of the pnnt engine controller 760 consists of a high speed IEEE 1394 seπal interlace 659. a standard JPEG decoder 763, a standard Group 4 Fax decoder 764, a custom halftoner/compositor unit 765. a custom tag encoder 766. a lme loader/formatter unit 767, and a custom mterface 768 to the Memjet™ pπnthead 350 The pnnt engme controller 360 operates m a double buffered manner While one page is loaded mto DRAM 769 via the high speed senal interlace 659, the previously loaded page is read from DRAM 769 and passed through the pπnt engme controller pipeline Once the page has finished pnntmg, the page just loaded is pπnted while another page is loaded The first stage of the pipeline expands (at 763) the JPEG-compressed contone CMYK layer, expands (at 764) the Group 4 Fax-compressed bi-level black layer, and renders (at 766) the bi-level netpage tag layer according to the tag format defined in section 1 2. all in parallel The second stage dithers (at 765) the contone CMYK layer and composites (at 765) the bi-level black laver over the resulting bi-level CMYK layer The resultant bi-level CMYK+IR dot data is buffered and formatted (at 767) for pnntmg on the Memjet™ pnnthead 350 via a set of line buffers Most of these line buffers are stored m the off-chip DRAM The final stage pnnts the six channels of bi-level dot data (mcludmg fixative) to the Memjet™ pπnthead 350 via the pnnthead interface 768 When several pnnt engine controllers 760 are used in unison such as in a duplexed configuration, they are synchronized via a shared lme svnc signal 770 Onlv one pnnt engine 760. selected via the external master/slave pm 771 , generates the line svnc signal 770 onto the shared line The pnnt engine controller 760 contams a low-speed processor 772 for synchronizing the page expansion and rendenng pipeline, conligunng the pnnthead 350 via a low-speed senal bus 773, and controlling the stepper motors 675. 676 In the 8.4" versions of the netpage pnnter. the two pnnt engmes each pnnts 30 Letter pages per minute along the long dimension ot the page ( 1 1 " ), givmg a lme rate ot 8 8 kHz at 1600 dpi In the 12" versions ol " the netpage pnnter. the two pnnt engines each pnnts 45 Letter pages per minute along the short dimension of the page (8.4"), giving a line rate of 10 2 kHz These lme rates are well vvithm the operating frequency of the Memiet™ pπnthead. which in the current design exceeds 30 kHz 8 BUSINESS IMPLEMENTATION PROCEDURES The netpage svstem accommodates a large vanety of business implementation procedures tor allowing users and providers ot the technologv to leverage oft " and to profit from their participation in the netpage svstem To best understand the svstem the following descnption ot the busmess implementation procedures and equipment should be read m conjunction with the descπption m the specification of the available hardware and software options, mcludmg - 41 - pnnters. communication protocols, protocols tor pavment. determining account balances and the like The usual parties to the netpage system are: An onlme publisher 41 who provides an onlme publication that is accessible via the netpage network. One or more online advertisers 42 who wish to place advertismg in the online publication. A number of users 40. each of which is accesses the onlme publication with a pπnter module 45. Preferably, the modules are provided bv a pnnter module provider 72 to the users at no cost, or at a cost that is subsidised by the advertisers or the publisher. However, m some cases the user purchases the module at its market value. A storage provider who mamtams one or more data bases which store the information required to allow the system to operate These parties interact to provide a structure that facilitates onlme dissemination of mformation and commerce While the following embodiments illustrate specific ones of the many possible interactions it will be appreciated by those skilled in the art that other mteractions are possible and are intended to fall within the scope of the claims It will also be appreciated bv those skilled m the art that all the above named roles need not necessanly be performed bv different entities For example, in some cases the storage provider and the publisher are the same entity, while in other cases the pnnter provider and the publisher are the same entity. Reference is also made in the descπption to "interactive paper". This is reference to paper that contams tags or other markings, visible or otherwise, that interact with the netpage system to allow identification of the page and, preferablv, identification of the position on the page. Examples of these tags are descnbed elsewhere in this specification and it will be understood that many other tags or identifiers can be used m a vanety of configurations to achieve the same result. Other terms used include "a pnnter using mteractive paper" and "an on-demand pπnter". This is reference to a pπnter for interacting with the netpage system to apply the tags and or interacting with the user to determine which tag the user has designated. A vanety of alternative pπnter configurations are available, some of which have been descnbed m more detail elsewhere in the specification It will be understood that the term " pnnted medium" is used for convenience and can be substituted with the term pnnted media" That is the former term is intended to broadlv encompass a pnnted product, whether this product includes one or more pnnted sheets, documents or the like. 8.1 NOTATION To assist understanding of the prefeπed embodiments of the business implementation procedures and equipment use is made of diagrams, which follow, to illustrate the interactions between the vanous participant roles in a busmess procedure Each participant is shown as a pair of overlappmg rectangles The front rectangle is labelled with the name of the participant and the back rectangle is used as the source and/or target of actions Each action is shown as an aπovv joining a subiect participant with an object participant Each action aπow is labelled with a descπption of the action Actions are spatiallv aπanged so that time proceeds from top to bottom and left to πght " Later" actions may coincide with, but never be earlier than, earlier ' actions Anv action is understood to be "'caused ' bv the immediately pnor action which the subject of the action was an object of In the absence ot a pnor action, the action is understood to be spontaneous Respective reference numerals ore used to label certain actions and participants to assist the reader ' s understanding of the embodiment being descnbed 8.2 COMBINATIONS OF DIFFERENT EMBODIMENTS WITHIN THE SCOPE OF THE INVENTION The following prefeπed embodiments are separately' descnbed to facilitate understanding of the invention - 42 - However, it will appreciated that more complex embodiments are obtained through the combmation of these different embodiments to achieve advantageous results for specific circumstances Accordingly, the combination of different embodiments to form a hybnd system is intended to fall within the scope of the present mvention and the following claims which define that invention 8.2.1 Netpage Publisher In broad terms, this embodiment mcludes a svstem for providing a user with a pnnted publication from a first party who is an online publisher The svstem includes a publication source m the form of a computer based storage server for storing publication data representative of the publication The publication data includes first information about a second partv who is an advertiser in the online publication A user pnnter module, m the form of an on-demand interactive pnnter, interfaces the user with the publication server and is responsive to the user requestmg the pnnted publication for reproducing the pnnted publication on a pnnted medium for viewing by the user Identifier means, in the form of a pπnter head and associated hardware and software contained within the pπnter, applies an identifier to the pnnted medium Upon designation of the identifier bv the user the pnnter generates a second pnnted medium that displays to the user second mformation This second information is usually further mformation about the goods and/or services being offered for sale bv the advertiser, or an order form for the specific goods and or services contained m the advertisement, or a hyperlink to the advertiser's site Calculation means, m the form of the publication server, is responsive to the pπnter for determining a payment that is made by the advertiser to the publisher In other embodiments the calculation means is the storage server In other embodiments, the calculation means is an account server separate from but linked to the other servers The payment is calculated in one of a number ol " alternative methods which are agreed on in advance. For example, payment may be based upon The number of copies of the online publication that are requested The number of requests that are made for the third information The sales of the goods and or services that are achieved by hits on the advertisement The pavment mav be in addition to an agreed flat fee for a given penod of time For example, m one embodiment, the advertiser pavs a flat fee for each month that their advertisement is included, plus a pavment based upon the number ot copies of the publication that are requested bv users of the svstem That is, the svstem allows the advertiser to pav for the circulation that the publication achieves when including the desired advertising matenal, unlike the pnor art systems which are based upon past circulation figures The svstem includes a plurality of modules associated with coπesponding users and the calculation means, in whatever form it takes, is responsive to the number of pnnted media generated that display one of the first information, the second information, and the third information That is, the first mtormation is usually the editonal or other content of the publication, the second mformation is usually the advertisement, and the third mformation is either further information about the goods and/or services being offered tor sale and or an order torm for those goods and/or services Preferablv. the calculation means is responsive to the number of pπnted media generated that displav two or more of the first information, the second information, and the third mformation That is, the svstem allows a combmation tee structure to be utilised, as required In the preteπed embodiments, use is made ot account means, usually in the torm ot an account server that is linked to the information server and one or more electronic bank accounts, for receiving the pavment trom the second partv and tor providing the pavment to the first partv Where the second partv is α supplier of goods and or services and the second information or the third information allows the user to purchase those goods and or services at respective predetermined purchase pπces, it is - 43 - prefeπed that the calculation means is responsive to the monetary value of the purchases completed by the users for determining the payment That is, the svstem provides a vanetv of options for calculating the payment mcludmg a combmation of a flat fee for each purchase, a fixed proportion of the purchase pπce for the goods and/or services that are purchased: and a proportion of the purchased pnce of the goods and or services that are purchased, where that proportion is different for particular goods and/or services It will be appreciated that the system accommodates a plurality ol second parties and a plurality of respective second mformation and third information that is deπved from those parties. Preferably, the quantum of the payments made by the respective second parties is contingent upon one or more of the following characteπstics of the second party: geographic location, quantity of purchases completed in a given time penod; and relative geographic location with respect to the user As bnefly foreshadowed above, it is prefeπed that the identifier is a tag although, m practice, it is usually embodied as a plurality of tags spaced apart on the respective pnnted medium. In other embodiments, however, the identifier is a character stnng that the user provides to the module to obtain the third information In this case, the string preferablv mcludes a sequence of numbers that are manually keyed into the module However, in alternative embodiments the stnng is scanned bv sensor means that are manuallv operated by the user In some embodiments, the account server automates the payments and provides the parties to the transactions with all the necessary reporting and summaπes to substantiate the quantum of the payments Preferably, the account server generates a disable signal if the payment calculated as payable bv the second party is not made available or paid within a predetermined time, where the generation of the disable signal prevents the module from obtaining the first or the second information which is deπved from that second party That is, an automated debtor system is applied Preferably, all parties to the transaction have electronic bank accounts that are accessible to the account server for effecting the necessary transactions The system also allows the parties, and importantly the second partv or the advertiser, to obtain an indication of the success of the advertising by morutonng one or more of " the following. the number ol " times that the users designate the second information, the number and/or value ot sales that are achieved through the users designating the second information, and the cost savings gained through the use of online selling over that of shop front retailing. Where the second information is a link to a third partv, the identifier is related to that second information such that designation by the user ol " the second information results in designation of the identifier which, m turn, ensures that the third information includes either or both of further mformation about the goods and/or services being offered for use and or sale bv the third partv or instructions as to ho the user should proceed to effect that use and/or a purchase of those goods and or services of the third party Preferably, the second party obtains an indication of the success of the link by monitoring one or more of the number or proportion of users selecting the click-through, and the number or proportion of users purchasing or making use of the goods and or services of the third party It will be appreciated that the momtoπng allows the parties to accurately estimate the cost/benefit achieved bv the advertising and. hence to plan tor future promotions or advertising campaigns In other embodiments the first information includes advertising denved from a third party and the calculation means determines the quantum of α payment that is made bv the third party to the first party In some cases the advertismg is solicited bv the user, while in others the advertising is unsolicited The svstem also allows the first partv to preferentially display of the advertising to the user While in the above embodiments the pπnted media are generated by the user s pnnter module, as an - 44 - alternative. or m addition to this, the pnnted media are selectively generated at a remote pπnter and subsequently provided to the user for viewing. Some more specific examples follow and are descnbed with reference to Figures 1 to 3. 8.2.1.1 Advertising Fees This embodiment allows the publisher, who publishes to the on-demand pnnters, to receive advertismg fees on advertismg placed within the publication This provides a profitable role for the publisher, and allows the publisher to attract readers bv being able to provide them with subsidised or free publications. In some embodiments the publisher automatically delivers the publication to a subscπbing user ' s pπnter on a penodic basis For example, in the case of the publisher bemg an online newspaper, an updated publication is provided to the user ' s pnnter each weekday morning at a predetermined time. This time will default to a non-peak processmg time for the publisher However, the user can specify the time, and may be coordmated with the normal nsmg time of the user. In other embodiments, the publication is delivered to a user ' s pnnter ad hoc at the user ' s request. Preferably, the publication is pπnted as interactive paper As illustrated m Figure 48. this embodiment operates as follows The advertiser, which is indicated generally by reference numeral 42, places an advertisement 501 with the publisher 41 The publisher 41 eventually pnnts the advertisement, as represented bv arrow 502, on the user ' s on-demand pnnter 44 This pnntmg occurs tvpicallv as part of one of the publisher ' s publications and results m one or more pπnted pages 1 that contain the publication, mcludmg the advertismg The publisher 41 charges the advertiser 42 an agreed advertismg fee, as represented by arrow 503. The advertiser pays the publisher the advertismg fee, as represented by aπow 504 For practical purposes, advertising fees are negotiated, invoiced and settled in bulk. In some embodiments the fees are part of a wider advertising agreement. 8.2.1.2 Click-Through Fees This embodiment allows a publisher who publishes on interactive paper to receive click-through fees on advertismg placed vvithm its publications This provides a profitable role for a publisher who publishes on interactive paper, and allows the publisher to attract readers by bemg able to provide them with subsidised or free publications As illustrated in Figure 49. the embodiment operates as follows. An advertiser 42 places a hyperlink 505 with a publisher 41 The publisher 41 eventually pnnts the hvperlmk, as represented by aπow 506, and typically as part of one of the publisher ' s publications The result is one or more pπnted pages 1 being created that contain the publication, mcludmg the hyperlink. When a user 40 selects the hvperlmk. as represented bv aπow 507. for example to request a linked document trom the advertiser, the advertiser 42 is notified, as represented by aπow 508 The advertiser 42 pays the publisher 41 on agreed click-through fee 509 For practical purposes, click-through tees are negotiated, invoiced and settled in bulk In some embodiments the fees are part of a wider advertising agreement 8.2.1.3 Sales Commissions This embodiment allows a publisher who publishes on interactive paper to receive commissions on sales initiated through advertising placed within its publications This provides a profitable role for a publisher who publishes on interactive paper, and allows the publisher to attract readers bv being able to provide them with subsidised or free - 45 - pub cations. As illustrated in Figure 50, this embodiment operates as follows A merchant 43 places a hyperlink, as represented by arrow 510. with a publisher 41 The publisher 41 eventuallv pnnts the hyperlink, as represented bv aπow 51 1. typically as part of one of the publisher s publications The result is one or more pnnted pages 1 bemg created that contam the publication, mcludmg the hyperlink When a user 40 clicks on the hyperlink to request a linked document from the merchant 43, the merchant is notified When the user 40 eventuallv makes an onlme purchase via the linked document (or via a document obtained via the linked document), the merchant 43 is notified The merchant 43 pays the publisher 41 an agreed commission on the sale Preferablv, the sales commission is a fixed fee. However, other embodiments make use of a commission that is based on the value of the sale For practical purposes, sales commissions are negotiated, mvoiced and settled m bulk, and are often part of wider advertismg agreements 8.2.2 Netpage Printer Provider In broad terms, this embodiment mcludes a system for providing to a user prmted information obtained from a remote source m the form of the online publication The system mcludes a user module in the form of an interactive pπnter for interfacing the user with the online publication The module is responsive to the user requestmg first information from the publication, which mav be the publication itself, for generating a first prmted medium that displays to the user the first information together with second information. The second information is the advertismg information that is denved from the advertiser Identifier means, m the form ol " the pπnter module, applies an identifier to the first pπnted medium such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user third information Calculation means, m the form of the onlme publisher's server, is responsive to the module for determining a payment to be made by the advertiser to the pnnter provider In practice, the advertiser would pay the onlme publisher and, m the case where the pnnter provider was different to the publisher, the publisher w ould provide a pavment to the pnnter provider As a default, the pavment is a predetermined function ot the number of reproductions of the pπnted publication that are generated That is, where the second partv is on advertiser in the publication the payment is a predetermined function of the circulation achieved bv the publication This allows the advertiser to pay for the actual circulation achieved, and the publisher to be rewarded for increasing that circulation The pavment includes, in some embodiments, another component in addition to or as a substitute for the above For example, where the second mformation is associated with the second partv the payment is a predetermined function of the number ot second pnnted media generated So. where the second party is an advertiser the payment is mcreased for successful hits on their specific advertismg The pavment is. in other embodiments, a predetermined function of both the number of pπnted publications generated that display the first information and the number ot " second pnnted media generated that display the second mtormation Where the second partv is a supplier of goods and or services, the first information or the second mformation is usually aπanged to allow the user to purchase those goods and or services at a predetermined purchase pnce In turn, the pavment is calculated as a predetermined function of the purchase pnce ot the goods and or services actually purchased bv the user For some items the user will desire to obtain turther information about the goods and/or services - 46 - pπor to proceedmg further Accordingly, in some embodiments the module is responsive to the designation of the identifier by the user for accessmg advertismg, techmcal or other information about particular goods and/or services of the second party In these embodiments the calculation means is responsive to the designation of the identifier for determining the pavment. If required, however, the calculation means is responsive only to the designation of the identifier for determining the pavment such that the advertiser pays the publisher only for successful links to the advertismg mformation Some more specific examples follow and are descnbed with reference to Figures 4 to 6. 8.2.2.1 Commissions on Advertising Fees In this embodiment the provider of an interactive prmter receives a percentage of advertising fees earned directly through the pπnter. This provides a profitable role for a provider of mteractive pπnters, and allows the provider to attract users bv partially or fully subsidising the capital and running costs of each user's pnnter. As illustrated in Figure 51 , the system is operates as follows: A pnnter provider 72 provides a user with a pnnter 45 While m this embodiment the provider 72 retains ownership of the pnnter, in other embodiments that ownership resides with the respective users An advertiser 42 places an advertisement, as represented by arrow 520, with a publisher 41 The publisher 41 eventually pnnts the advertisement on the pπnter 45, typically as part of one of the publisher's publications The result is one or more pnnted pages 1 being created that contam the publication, mcluding the advertisement The publisher 41 charges the advertiser 42 an agreed advertismg fee, as represented by arrow 523. The advertiser 42 pays the publisher 41 the advertismg fee, as represented by arrow 524. The publisher 41 pays the pnnter provider 72 an agreed commission on the advertismg fee, as represented by arrow 525 8.2.2.2 Commissions on Click-Through Fees In another embodiment, the provider of an mteractive pnnter receives a percentage of click-through fees earned directlv through the pnnter This provides a profitable role for the provider of interactive pnnters, and allows the provider to attract users bv partially or fullv subsidising the capital and running costs of each user ' s pπnter As illustrated in Figure 52. the svstem operates as follows The pnnter provider 72 provides the user 40 with a pnnter 45 An advertiser 42 places a hyperlink with a publisher 41 The publisher eventuallv pnnts the hyperlink, typically as part of " one of the publisher ' s publications. The result is one or more pπnted pages 1 being created that contam the publication, mcludmg the hyperlink. When the user 40 clicks on the hyperlink, as it is represented on the interactive paper, for example to request a linked document from the advertiser 42, the advertiser is notified. The advertiser 42 pays the publisher 41 an agreed click-through fee. The publisher 41 pays the pnnter provider 72 an agreed commission on the click-through fee 8.2.2.3 Commissions on Sales Commissions This embodiment allows the provider ol " an mteractive pnnter to receive a percentage of sales commissions earned directlv through the pnnter This provides a profitable role for the provider of interactive pnnters. and allows the provider to attract users bv partially or tullv subsidising the capital and running costs of each user ' s pπnter As illustrated m Figure 53. this embodiment operates as follows The pnnter provider 72 provides the user 40 with a pnnter 45 An advertiser in the form ot a merchant 43 places a hyperlink with a publisher 41 - 47 - The publisher 41 eventuallv pnnts the hyperlink, typically as part of one of the publisher ' s publications The result is one or more pnnted pages 1 being created that contain the publication, mcludmg the hyperlink When the user 40 clicks on the hvperlmk to request a linked document trom the merchant 43, the merchant is notified The "click" occurs through use ofthe interactive paper. When the user 40 eventuallv makes an onlme purchase via the linked document (or via a document obtained via the linked document), the merchant 43 is notified The merchant 43 pays the publisher 41 an agreed commission on the sale The publisher 41 pavs the pπnter provider 72 an agreed commission on the sales commission CONCLUSION The present invention has been descnbed with reference to a prefeπed embodiment and number of specific alternative embodiments However, it will be appreciated by those skilled m the relevant fields that a number of other embodiments, diffenng trom those specifically descnbed, will also fall withm the spiπt and scope of the present mvention Accordmgly, it will be understood that the mvention is not mtended to be limited to the specific embodiments descnbed in the present specification, mcludmg documents incorporated bv cross-relerence as appropnate The scope of the mvention is onlv limited bv the attached claims

Claims: - 48 - CLAIMS 1 A system for providing to a user printed information obtained from a remote source, the system including a user module that is provided by a first party to the user for interfacing the user with the source, the module being responsive to the user requesting first information from the source for generating a first printed medium that displays to the user the first information together with second information derived from a second party, identifier means for applying an identifier to the first printed medium such that designation of the identifier by the user results in the module generating a second pπnted medium that displays to the user third information, and calculation means being responsive to the module for determining a payment to be made by the second party to the first party 2 A system according to claim 1 including a plurality of modules associated with corresponding users wherein the calculation means is responsive to the number of pπnted media generated that display one of the first information, the second information and the third information 3 A system according to claim 2 wherein the calculation means is responsive to the number of printed media generated that display two or more of the first information, the second information, and the third information 4 A system according to claim 2 including account means for receiving the payment from the second party and for providing the payment to the first party 5 A system according to claim 4 wherein the payment from the second party is a fixed amount for a predetermined period 6 A system according to claim 1 wherein the second party is a supplier of goods and/or services and the second information or the third information allows the user to purchase those goods and/or services at respective predetermined purchase prices 7 A system according to claim 6 wherein the calculation means is responsive to the monetary value of the purchases completed by the users for determining the payment 8 A system according to claim 7 wherein the payment is one or a combination of a flat fee for each purchase, a fixed proportion of the purchase pπce for the goods and/or services that are purchased, and a proportion of the purchased price of the goods and/or services that are purchased, where that proportion is different for particular goods and/or services 9 A system according to claim 1 wherein there are a plurality of second parties and the quantum of their respective payments is contingent upon one or more of the following characteristics of the second party geographic location, quantity of purchases completed in a given time period, and relative geographic location with respect to the user 10 A system according to claim 1 wherein the identifier is a tag 11 A system according to claim 10 wherein the identifier is a plurality of tags spaced apart on the respective pπnted medium 12 A system according to claim 1 wherein the identifier is a character string that the user provides to the module to obtain the third information 13 A system according to claim 12 wherein the string includes a sequence of numbers that are manually keyed into the module 14 A system according to claim 12 wherein the string is scanned by sensor means that are - 49 - manually operated by the user 15 A system according to claim 4 wherein the account means generates a disable signal if the payment calculated as payable by the second party is not paid within a predetermined time, the generation of the disable signal preventing the module obtaining the first or the second information 16 A system according to claim 6 wherein the second information is advertising for the goods and/or services and the identifier is related to that information such that designation by the user of the second information results in designation of the identifier which, in turn, ensures that the third information includes either or both of further information about the goods and/or services or instructions as to how the user should proceed to effect a purchase of those goods and/or services 17 A system according to claim 16 wherein the second party obtains an indication of the success of the advertising by monitoring one or more of the following the number of times that the user designates the second information, the number and/or value of sales that are achieved through the user designating the second information; and the cost savings gained through the use of on-line selling over that of shop front retailing 18 A system according to claim 1 wherein the second information is a link to a third party and the identifier is related to that information such that designation by the user of the second information results in designation of the identifier which, in turn, ensures that the third information includes either or both of further information about the goods and/or services being offered for use and/or sale by the third party or instructions as to how the user should proceed to effect that use and/or a purchase of those goods and/or services of the third party 19 A system according to claim 18 wherein the second party obtains an indication of the success of the link by monitoring one or more of the number or proportion of users selecting the click- through, and the number or proportion of users purchasing or making use of the goods and/or services of the third party 20 A system according to claim 17 or claim 19 wherein the monitoring allows the second party to accurately estimate the cost/benefit achieved by the advertising 21 A system according to claim 1 wherein the first information includes advertising deπved from a third party wherein the calculation means determines the quantum of a payment that is made by the third party to the first party 22 A system according to claim 21 wherein the advertising is either solicited or unsolicited by the user 23 A system according to claim 23 wherein the first party, as the printer provider, gains an income stream through the preferential display of the advertising to the user 24 A system according to claim 1 wherein the user module includes a pπnter unit for generating the printed medium 25 A system according to claim 1 or claim 24 wherein the pπnted medium are selectively generated at a remote printer and subsequently provided to the user for viewing 26 A system for providing to a user printed information obtained from a remote computer source, the system including a user printer module that is provided by a first party to the user for interfacing the user with the source, the module being responsive to the user requesting first information from the source for generating a first pπnted medium that displays to the user the first information together with second information derived from a second party, - 50 - an identifier device for applying an identifier to the first pπnted medium such that designation of the identifier by the user results in the module generating a second printed medium that displays to the user third information, and an account computer being responsive to the module and/or the remote computer source for determining a payment to be made by the second party to the first party 27 A system according to claim 26 wherein the user pπnter module and the identifier device are contained within a single housing 28 A system according to claim 27 wherein the identifier device applies the identifier to the surface of a medium as it is being produced by the printer module 29 A system according to claim 28 wherein the identifier is printed on the medium 30 A system according to claim 29 wherein the identifier is printed with ink that does not substantially reflect light in the visible spectrum 31 A method for providing to a user pπnted information obtained from a remote source, the method including the steps of interfacing the user with the source via a user module that is provided by a first party to the user, the module being responsive to the user requesting first information from the source for generating a first printed medium that displays to the user the first information together with second information derived from a second party, applying an identifier to the first printed medium with identifier means such that designation of the ' identifier by the user results in the module generating a second pπnted medium that displays to the user third information, and being responsive to the module with calculation means for determining a payment to be made by the second party to the first party 32 A method according to claim 31 including a plurality of modules associated with corresponding users including the further step of the calculation means being responsive to the number of pπnted medium generated that display one of the first information, the second information, and the third information 33 A method according to claim 32 including the further step of the calculation means being responsive to the number of printed medium generated that display two or more of the first information, the second information, and the third information 34 A method according to claim 32 including account means, the method including the step of the account means receiving the payment from the second party and for providing the payment to the first party 35 A method according to claim 34 wherein the payment from the second party is a fixed amount for a predetermined period 36 A method according to claim 31 wherein the second party is a supplier of goods and/or services and the second information or the third information allows the user to purchase those goods and/or services at respective predetermined purchase prices 37 A method according to claim 36 including the step of the calculation means being responsive to the monetary value of the purchases completed by the users for determining the payment 38 A method according to claim 37 wherein the payment is one or a combination of a flat fee for each purchase a fixed proportion of the purchase pπce for the goods and/or services that are purchased, and a proportion of the purchased pπce of the goods and/or services that are purchased where that - 51 - proportion is different for particular goods and/or services 39 A method according to claim 31 wherein there are a plurality of second parties and the quantum of their respective payments is contingent upon one or more of the following characteristics of the second party geographic location, quantity of purchases completed in a given time peπod, and relative geographic location with respect to the user 40 A method according to claim 31 wherein the identifier is a tag 41 A method according to claim 40 wherein the identifier is a plurality of tags spaced apart on the respective pπnted medium 42 A method according to claim 31 wherein the identifier is a character string and the method includes the step of the user providing that character string to the module to obtain the third information 43 A method according to claim 42 wherein the string includes a sequence of numbers that are manually keyed into the module 44 A method according to claim 42 wherein the string is scanned by sensor means that are manually operated by the user 45 A method according to claim 44 wherein the account means generates a disable signal if the payment from the party is not settled within a predetermined time, the generation of the disable signal preventing the module obtaining the first or the second information 46 A method according to claim 46 wherein the second information is advertising for the goods and/or services and the identifier is related to that information such that designation by the user of the second information results in designation of the identifier which, in turn, ensures that the third information includes either or both of further information about the goods and/or services or instructions as to how the user should proceed to effect a purchase of those goods and/or services 47 A method according to claim 46 wherein the second party obtains an indication of the success of the advertising by monitoring one or more of the following the number of times that the user designates the second information, the number and/or value of sales that are achieved through the user designating the second information, and the cost savings gained through the use of on-line selling over that of shop front retailing 48 A method according to claim 31 wherein the second information is a click-through to a third party and the identifier is related to that information such that designation by the user of the second information results in designation of the identifier which, in turn, ensures that the third information includes either or both of further information about the goods and/or services being offered for use and/or sale by the third party or instructions as to how the user should proceed to effect that use and/or a purchase of those goods and/or services of the third party 49 A method according to claim 18 wherein the second party obtains an indication of the success of the click-through by monitoring one or more of the number or proportion of users selecting the click-through, and the number or proportion of users purchasing or making use of the goods and/or services of the third party 50 A method according to claim 47 or claim 49 wherein the monitoring allows the second party to accurately estimate the cost benefit achieved by the advertising 51 A method according to claim 31 wherein the first information includes advertising derived from a third party wherein the calculation means determines the quantum of a payment that is to be made by the third party to the first party - 52 - 52 A method according to claim 51 wherein the advertising is either solicited or unsolicited by the user 53 A method according to claim 53 wherein the first party, as the printer provider, gains an income stream through the preferential display of the advertising to the user 54 A method according to claim 31 wherein the user module includes a printer unit for generating the pπnted medium 55 A method according to claim 31 or claim 54 wherein the printed medium are selectively generated at a remote printer and subsequently provided to the user for viewing 56 A method for providing to a user printed information obtained from a remote computer source, the method including the steps of interfacing the user with the source via a user printer module that is provided to the user by a first party, the module being responsive to the user requesting first information from the source for generating a first pπnted medium that displays to the user the first information together with second information derived from a second party, applying an identifier to the first pπnted medium with an identifier device such that designation of the identifier by the user results in the module generating a second pπnted medium that displays to the user third information, and being responsive to the module and/or the remote computer source with an account computer for determining a payment to be made by the second party to the first party 57 A method according to clam 56 wherein the user printer module and the identifier device are contained within a single housing 58 A method according to claim 57 wherein the identifier device applies the identifier to the surface of a medium as it is being produced by the pπnter module 59 A method according to claim 58 wherein the identifier is printed on the medium 60 A method according to claim 59 wherein the identifier is pπnted with ink that does not substantially reflect light in the visible spectrum

Inventors: LAPSTUN PAUL, LAPSTUN, PAUL
Applicants: LAPSTUN PAUL, SILVERBROOK KIA, SILVERBROOK RES PTY LTD, LAPSTUN, PAUL, SILVERBROOK RESEARCH PTY LTD, SILVERBROOK, KIA
Application year: 2000
Main classification: G06F17
IPC codes: B41J29, G06F3, G06Q30, G06Q50, H04N1