METHOD AND SYSTEM FOR ONLINE PAYMENTS

Abstract: Methods and systems are disclosed which relate to online payments via interface surfaces printed with information and coded data. The coded data, encoded visibly or invisibly, may be queried by an appropriate sensing device. The sensing device communicates with a computer system. Together, the interface surfaces, sensing device and computer system are capable of effecting payment transactions over a network.

Description: METHOD AND SYSTEM FOR ONLINE PAYMENTS FIELD OF INVENTION The present invention relates generally to methods, systems and apparatus for interacting with computers More particularly, the invention relates to making online payments utilizing such methods, systems and apparatus The invention 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 pπnted 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 field CO-PENDING APPLICATIONS Vaπous 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/AU00/00518, PCT/AU00/00519, PCT/AUOO/00520, PCT/AU00/00521 , PCT/AU00/00523, PCT/AU00/00524, PCT/AU00/00525, PCT/AU00/00526, PCT/AU00/00527, PCT/AU00/00528, PCT/AU00/00529, PCT/AU00/00530, PCT/AU00/00531 , PCT/AU00/00532, PCT/AUOO/00533, PCT/AU00/00534, PCT/AUOO/00535, PCT/AU00/00536, PCT/AUOO/00537, PCT/AU00/00538, PCT/AU00/00539, PCT/AU00/00540, PCT/AU00/00541 , PCT/AU00/00542, PCT/AUOO/00543. PCT/AU00/00544. PCT/AU00/00545. PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AUOO/00556. PCT/AU00/00557, PCT/AU00/00558, PCT/AU00/00559, PCT/AU00/00560, PCT/ALιOO/00561 , PCT/AU00/00562, PCT/AU00/00563, PCT/AU00/00564, PCT/AU00/00566. PCT/AU00/00567, PCT/AUOO/00568, PCT/AU00/00569, PCT/AU00/00570, PCT/AU00/00571, PCT/AU00/00572, PCT/AU00/00573, PCT/AU00/00574, PCT/AUOO/00575, PCT/AU00/00576, PCT/AU00/00577, PCT/AU00/00578, PCT/AU00/00579, PCT/AU00/00581, PCT/AU00/00580, PCT/AUOO/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/AU00/00516, and PCT/AU00/00517 The disclosures of these co-pending applications are incorporated herein by cross-reference BACKGROUND A bill, statement or invoice is commonly received in paper form through the mail system To make a payment, a payment section on the bill is typically filled in by hand and returned to the biller by mail Alternatively a bill may be paid using a telephone payment system allowing payment by credit card, or other pre-arranged payment method A bill may also be paid by giving the biller authority to directly debit a bank account for the full due amount on the due date Bill payment is also possible using an online bill payment system on the Internet, utilizing a conventional screen- and keyboard-based computer system and Internet browser software OBJECT It is an object of the present invention to combine advantages of paper-based forms and online payments SUMMARY OF INVENTION The present invention provides, in a first aspect, a method of enabling payment of bills, the method including the steps of providing a person with a bill containing information relating to a requested payment, the bill including coded data indicative of an identity of the bill and of at least one reference point of the bill, receiving, in a computer system, indicating data from a sensing device regarding the identity of the bill and a position of the sensing device relative to the bill, the sensing device, when placed in an operative position relative to the bill, sensmg the indicating data usmg at least some of the coded data, and identifymg, m the computer system and from the indicating data, at least one parameter relating to the requested payment Preferably, at least one parameter relatmg to the requested payment is associated with at least one zone of the bill and m which the method includes identifymg, in the computer system and from the zone relative to which the sensmg device is located, said at least one parameter Preferably the method further mcludes receivmg, m the computer system, data regardmg movement of the sensmg device relative to the bill, the sensmg device sensmg its movement relative to the bill usmg at least some of the coded data Preferably also the method mcludes identifymg, m the computer system and from the movement bemg at least partially withm at least one zone, at least one parameter of the requested payment In a second aspect, the mvention provides a method of enablmg payment of bills the method mcludmg the steps of providing a person with a bill containing mformation relatmg to a requested payment, the form mcludmg coded data mdicative of at least one parameter of the requested payment, receiving, in a computer system, data from a sensmg device regardmg said at least one parameter and regardmg movement of the sensmg device relative to the bill, the sensmg device, when moved relative to the bill, sensmg the data regardmg said at least one parameter usmg at least some of the coded data and generatmg the data regardmg its own movement relative to the bill, and interpreting, m the computer system, said movement of the sensmg device as it relates to said at least one parameter In a third aspect, the mvention provides a method of enablmg payment of bills, the method mcludmg the steps of providing a person with a bill mcludmg coded data mdicative of an identity of the bill, receiving, m a computer system, data from a sensmg device regarding an identity of the person and regardmg the identity of the bill, the sensing device containing the data regardmg the identity of the person and sensmg the data regarding the identity of the bill usmg at least some of the coded data, and identifying, m the computer system and from the data regardmg the identity of the person and the identity of the bill, a requested payment Preferably the coded data is also mdicative of at least one parameter of the requested payment, and the method mcludes receivmg, m the computer svstem, mdicatmg data from the sensmg device regardmg said at least one parameter of the requested payment, the sensmg device sensmg the mdicatmg data usmg at least some of the coded data Preferably also, the method mcludes receivmg, m the computer system, data from the sensmg device regardmg movement of the sensmg device relative to the bill, the sensmg device generatmg data regardmg its own movement relative to the bill Preferably, m any of these aspects, the parameter is an action parameter of the requested payment, the method mcludmg effecting, m the computer system, an operation respect of the action parameter Preferably the action parameter of the requested payment is selected from the group comprising requesting that payment be made, specifying a payment amount or resettmg the bill to an original state In a fourth aspect, the mvention provides a system for enabling payment of bills, the system mcludmg a bill containing mformation relatmg to a requested payment, the bill mcludmg coded data mdicative of an identity of the bill and of at least one reference pomt of the bill, and a computer system for receiving mdicatmg data from a sensmg device for identifymg at least one parameter relatmg to the requested payment, the mdicatmg data bemg mdicative of the identify of the bill and a position of the sensmg device relative to the bill, the sensmg device sensmg the mdicatmg data usmg at least some of the coded data In a fifth aspect, the invention provides a system for enablmg payment of bills, the system mcludmg a bill containing mformation relatmg to a requested payment, the bill mcludmg coded data mdicative of at least one parameter of the requested payment, and a computer system for receivmg data from a sensmg device regardmg said at least one parameter and regardmg movement of the sensmg device relative to the bill, and for interpreting said movement of the sensmg device as it relates to said at least one parameter, the sensmg device, when moved relative to the bill, sensmg the data regardmg said at least one parameter usmg at least some of the coded data and generatmg the data regardmg its own movement relative to the bill In a sixth aspect, the mvention provides a system for enablmg payment of bills, the system mcludmg a bill mcludmg coded data mdicative of an identity of the bill, and a computer svstem for receivmg from a sensmg device data regardmg an identity of the person and the identity of the bill, and for identifymg, from said received data, a requested payment, the sensing device containing the data regardmg the identity of the person and sensing the data regarding the identity of the bill usmg at least some of the coded data Accordingly, the present invention provides a system and a method which utilizes one or more forms capable of interacting with a computer system Whilst the novel method and system of the present mvention may be used in conjunction with a smgle computer system, m a particularly preferred form it is designed to operate over a computer network, such as the Internet Physically, the form is disposed on a surface medium of any suitable structure However, m a preferred arrangement, the form is disposed on sheet material such as paper or the like which has the coded data pπnted on it and which allows mteraction with the computer system The coded data is detectable preferably, but not exclusively, outside the visible spectrum, thereby enablmg it to be machine-readable but substantially invisible to the human eye The form may also mclude visible matenal which provides information to a user, such as the application or purpose of the form, and which visible information may be registered or correlate in position with the relevant hidden coded data The system also mcludes a sensmg device to convey data from the form to the computer system, and in some instances, to contribute additional data Again, the sensmg device may take a vaπety of forms but is preferably compact and easily portable In a particularly preferred arrangement, the sensmg device is configured as a pen which is designed to be able to physically mark the form as well as to selectively enable the coded data from the form to be read and transmitted to the computer system The coded data then provides control information, configured such that designation thereof by a user causes instructions to be applied to the software running on the computer system or network The nature of the mteraction between the form and the sensmg device and the data that each contributes to the computer system may vary In one arrangement, the coded data on the form is mdicative of the identify of the form and of at least one reference pomt on that form In another embodiment, the form mcludes coded data which is mdicative of a parameter of the form, whereas the sensmg device is operative to provide data regardmg its own movement relative to that form to the computer system together with coded data from the form In yet another arrangement, the form mcludes the coded data which at least identifies the form, and the sensing device is designed to provide, to the computer system, data based on the form coded data, and also on data which identifies the user of the device In a preferred arrangement, the system and method also employs specially designed prmters to pnnt the for Further these prmters constitute or form part of the computer system and are designed to receive data from the sensmg device As mdicated above, the system and method of the mvention is ideally suited to operate over a network In this arrangement, the prmters are fully mtegrated mto the network and allow for pπntmg of the forms on demand and also for distributing of the forms usmg a mixture of multicast and pomtcast communication protocols Accordingly, m a preferred form, the present mvention provides methods and systems which use a paper and pen based mterface for a computer system This provides many significant benefits over traditional computer systems The advantage of paper is that it is widely used to display and record mformation Further, pπnted mformation is easier to read than mformation displayed on a computer screen Moreover, paper does not run on batteπes, can be read m bπght light, or robustly accepts coffee spills or the like and is portable and disposable Furthermore, the system allows for hand-drawing and hand-wnting to be captured which affords greater nchness of expression than mput via a computer keyboard and mouse The present mvention therefore provides a novel system and method for enablmg the payment of a bill onlme making use of novel surface interfaces BRIEF DESCRIPTION OF DRAWINGS Preferred and other embodiments of the mvention will now be descπbed, by way of non-limiting example only, with reference to the accompanying drawings, m which Figure 1 is a schematic of a the relationship between a sample prmted netpage and its onlme page descnption, Figure 2 is a schematic view of a mteraction between a netpage pen, a netpage pnnter, a netpage page server, and a netpage application server, Figure 3 illustrates a collection of netpage servers and prmters interconnected via a network, Figure 4 is a schematic view of a high-level structure of a prmted netpage and its online page descnption, Figure 5 is a plan view showmg a structure of a netpage tag, Figure 6 is a plan view showmg a relationship between a set of the tags shown m Figure 5 and a field of view of a netpage sensmg device m the form of a netpage pen, Figure 7 is a flowchart of a tag image processing and decoding algonthm, Figure 8 is a perspective view of a netpage pen and its associated tag-sensing field-of-view cone, Figure 9 is a perspective exploded view of the netpage pen shown m Figure 8, Figure 10 is a schematic block diagram of a pen controller for the netpage pen shown m Figures 8 and 9, Figure 11 is a perspective view of a wall-mounted netpage printer, Figure 12 is a section through the length of the netpage pnnter of Figure 11 , Figure 12a is an enlarged portion of Figure 12 showmg a section of the duplexed pnnt engmes and glue wheel assembly, Figure 13 is a detailed view of the ink cartndge, ink, air and glue paths, and pnnt engmes of the netpage pnnter of Figures 11 and 12, Figure 14 is a schematic block diagram of a pnnter controller for the netpage pnnter shown m Figures 11 and 12, Figure 15 is a schematic block diagram of duplexed pnnt engme controllers and Memjet™ prmtheads associated with the pnnter 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 smgle Memjet™ printing element, as used m, for example, the netpage prmter of Figures 10 to 12, Figure 18 is a perspective view of a small part of an array of Memjet™ pnntmg elements, Figure 19 is a seπes of perspective views illustrating the operatmg cycle of the Memjet™ prmtmg element shown m Figure 13, Figure 20 is a perspective view of a short segment of a pagewidth Memjet™ prmthead, Figure 21 is a schematic view of a user class diagram, Figure 22 is a schematic view of a pnnter class diagram, Figure 23 is a schematic view of a pen class diagram, Figure 24 is a schematic view of an application class diagram, Figure 25 is a schematic view of 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 of a terminal element specialization class diagram, Figure 28 is a schematic view of 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 hyperlrnked 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 algonthm, Figure 38a is 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 descnption 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 of a subscnption delivery protocol, Figure 44 is a schematic view of a hyperlink request class diagram, Figure 45 is a schematic view of a hyperlink activation protocol, Figure 46 is a schematic view of a form submission protocol, Figure 47 is a schematic view of a commission payment protocol, Figure 48 is a schematic view of a set of user mterface flow document icons, Figure 49 is a schematic view of a set of user mterface page layout element icons, Figure 50 is a schematic view of a bill payments class diagram, Figure 51 is a schematic view of a user mterface flow for a bill payment, Figure 52 is a schematic view of a bill front page, Figure 53 is a schematic view of a bill payment method page being the back page of the document of figure 52, and Figure 54 is a schematic view of a bill payment receipt DETAILED DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS Note Memjet™ is a trade mark of Silverbrook Research Pty Ltd, Australia In the preferred embodiment, the invention is configured to work with the netpage networked computer system, a detailed overview of which follows It will be appreciated that not every implementation will necessanly embody all or even most of the specific details and extensions discussed below m relation to the basic system However, the system is descnbed m its most complete form to reduce the need for external reference when attemptmg to understand the context m which the preferred embodiments and aspects of the present mvention operate In bnef summary, the preferred form of the netpage system employs a computer mterface m the form of a mapped surface, that is, a physical surface which contams references to a map of the surface mamtamed m a computer system The map references can be quened by an appropπate sensmg device Dependmg upon the specific implementation, the map references may be encoded visibly or invisibly, and defined m such a way that a local query on the mapped surface yields an unambiguous map reference both withm the map and among different maps The computer system can contam information about features on the mapped surface, and such information can be retneved based on map references supplied by a sensmg device used with the mapped surface The information thus retneved can take the form of actions which are initiated by the computer system on behalf of the operator m response to the operator's mteraction with the surface features In its preferred form, the netpage system relies on the production of, and human mteraction with, netpages These are pages of text, graphics and images prmted on ordinary paper, but which work like mteractive web pages Information is encoded on each page usmg ink which is substantially invisible to the unaided human eye The ink, however, and thereby the coded data, can be sensed by an optically imaging 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 mformation from the network or to signal preferences to a network server In one embodiment, text wntten by hand on a netpage is automatically recognized and converted to computer text m the netpage system, allowing forms to be filled m In other embodiments, signatures recorded on a netpage are automatically venfied, allowing e-commerce transactions to be securely authorized As illustrated m Figure 1 , a pπnted netpage 1 can represent a mteractive form which can be filled in by the user both physically, on the pπnted 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 usmg visible ink, and coded data 3 pπnted as a collection of tags 4 usmg invisible mk The conespondmg 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 mteractive element (l e text field or button m the example), to allow the netpage system to conectly interpret mput via the netpage The submit button 6, for example, has a zone 7 which conesponds to the spatial extent of the corresponding graphic 8 As illustrated m Figure 2, the netpage pen 101, a prefened form of which is shown m Figures 8 and 9 and descnbed m more detail below, works m conjunction with a netpage pnnter 601, an Internet-connected prmtmg appliance for home, office or mobile use The pen is wireless and communicates securely with the netpage pnnter via a short-range radio link 9 The netpage pnnter 601 a prefened form of which is shown m Figures 11 to 13 and descπbed in more detail below, is able to deliver, penodically or on demand, personalized newspapers, magazmes, catalogs, brochures and other publications, all prmted at high quality as mteractive netpages Unlike a personal computer, the netpage pnnter is an appliance which can be, for example, wall-mounted adjacent to an area where the morning news is first consumed, such as m a user's kitchen, near a breakfast table, or near the household's pomt of departure for the day It also comes in tabletop, desktop, portable and miniature versions Netpages prmted at their point of consumption combine the ease-of-use of paper with the timeliness and interactivity of an mteractive medium As shown m Figure 2, the netpage pen 101 mteracts with the coded data on a pπnted netpage 1 and commumcates, via a short-range radio link 9, the mteraction to a netpage pnnter The pnnter 601 sends the mteraction to the relevant netpage page server 10 for interpretation In appropnate circumstances, the page server sends a coπespondmg message to application computer software runnmg on a netpage application server 13 The application server may m turn send a response which is prmted on the onginatmg pnnter The netpage system is made considerably more convenient m the prefened embodiment by bemg used m conjunction with high-speed microelectromechamcal system (MEMS) based inkjet (Memjet™) prmters In the preferred form of this technology, relatively high-speed and high-quality prmtmg is made more affordable to consumers In its prefened form, a netpage publication has the physical charactenstics of a traditional newsmagazme, such as a set of letter-size glossy pages prmted in full color on both sides, bound together for easy navigation and comfortable handling The netpage pnnter exploits the growing availability of broadband Internet access Cable service is available to 95% of households the U ted States, and cable modem service offering broadband Internet access is aheady available to 20% of these The netpage pnnter can also operate with slower connections, but with longer delivery tunes and lower image quality Indeed, the netpage system can be enabled usmg existing consumer Inkjet and laser prmters, although the system will operate more slowly and will therefore be less acceptable from a consumer's pomt of view In other embodiments, the netpage system is hosted on a pπvate intranet In still other embodiments, the netpage system is hosted on a single computer or computer-enabled device, such as a pnnter Netpage publication servers 14 on the netpage network are configured to deliver print-qualify publications to netpage prmters Peπodical publications are delivered automatically to subscnbmg netpage prmters via pomtcastmg and multicasting Internet protocols Personalized publications are filtered and formatted accordmg to mdividual user profiles A netpage pnnter can be configured to support any number of pens, and a pen can work with any number of netpage prmters In the prefened implementation, each netpage pen has a umque 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 11 and linked to one or more payment card accounts This allows e-commerce payments to be securely authorized 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 biometncs can also be used to veπfy identity A version of the netpage pen mcludes fingerprint scanning, veπfied m a similar way by the netpage registration server Although a netpage pnnter may deliver penodicals such as the morning newspaper without user mtervention, it can be configured never to deliver unsolicited junk mail In its prefened form, it onlv delivers penodicals from subscnbed or otherwise authorized sources In this respect, the netpage pnnter is unlike a fax machme or e-mail account which is visible to any junk mailer who knows the telephone number or email address 1 NETPAGE SYSTEM ARCHITECTURE Each object model m the system is descnbed using a Umfied Modelmg Language (UML) class diagram A class diagram consists of a set of object classes connected by relationships, and two lands of relationships are of mterest here associations and generalizations An association represents some kmd of relationship between objects, l e between instances of classes A generalization relates actual classes, and can be understood m the following way if a class is thought of as the set of all objects of that class, and class A is a generalization of class B, then B is simply a subset of A The UML does not directly support second-order modelling - I e classes of classes Each class is drawn as a rectangle labelled with the name of the class It contams a list of the attnbutes of the class, separated from the name by a horizontal lme, and a list of the operations of the class, separated from the attnbute list by a horizontal lme In the class diagrams which follow however, operations are never modelled An association is drawn as a line joining two classes, optionally labelled at either end with the multiplicity of the association The default multiplicity is one An astensk (*) mdicates a multiplicity of "many", 1 e zero or more Each association is optionally labelled with its name, and is also optionally labelled at either end with the role of the conespondmg class An open diamond mdicates an aggregation association ("is-part-of '), and is drawn at the aggregator end of the association lme A generalization relationship ("ls-a") is drawn as a solid lme joining two classes, with an anow (in the form of 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 mam diagram which defines it It is shown with attnbutes only where it is defined 1.1 NETPAGES Netpages are the foundation on which a netpage network is built They provide a paper-based user mterface to published information and mteractive services A netpage consists of a prmted page (or other surface region) mvisibly tagged with references to an onlme descnption of the page The onlme page descnption is mamtamed persistently by a netpage page server The page descnption descnbes the visible layout and content of the page, mcludmg text, graphics and images It also descnbes the mput elements on the page, mcludmg buttons, hyperlinks, and mput fields A netpage allows markings made with a netpage pen on its surface to be simultaneously captured and processed by the netpage system Multiple netpages can share the same page descnption However, to allow mput 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 descnption is encoded m a printed tag The tag identifies the umque page on which it appears, and thereby indirectly identifies the page descnption The tag also identifies its own position on the page Charactenstics of the tags are descnbed m 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 eye but are easily sensed by a solid-state image sensor with an appropπate filter A tag is sensed by an area image sensor m the netpage pen, and the tag dat -, is transmitted to the netpage system via the nearest netpage pnnter The pen is wireless and commumcates with the netpage pnnter via a short-range radio link Tags are sufficiently small and densely ananged 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 mteraction with the page, since the interaction is stateless Tags are enor-conectably encoded to make them partially tolerant to surface damage The netpage page server maintains a umque page mstance for each pnnted netpage, allowing it to maintain a distinct set of user-supplied values for mput fields m the page descnption for each pπnted netpage The relationship between the page descnption, the page mstance, and the pπnted netpage is shown m Figure 4 The page instance is associated with both the netpage pnnter which pnnted it and, if known, the netpage user who requested it 1.2 NETPAGE TAGS 1.2.1 Tag Data Content In a prefened form, each tag identifies the region m which it appears, and the location of that tag withm the region A tag may also contam flags which relate to the region as a whole or to the tag One or more flag bits may, for example, signal a tag sensmg device to provide feedback mdicative of a function associated with the immediate area of the tag, without the sensmg device havmg to refer to a descnption of the region A netpage pen may, for example, llluminate an "active area" LED when m the zone of a hyperlink As will be more clearly explained below, m a prefened embodiment, each tag contams an easily recognized mvanant structure which aids initial detection, and which assists minimizing the effect of any warp mduced by the surface or by the sensmg process The tags preferably tile the entire page, and are sufficiently small and densely arranged that the pen can reliably 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 mteraction with the page, smce the mteraction is stateless In a prefened embodiment, the region to which a tag refers comcides 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 comcide with the zone of an mteractive element, which case the region ID can directly identify the mteractive element Table 1 - Tag data Each tag contains 120 bits of mformation, typically allocated as shown m Table 1 Assuming a maximum tag density of 64 per square mch, a 16-bit tag ID supports a region size of up to 1024 square mches Larger regions can be mapped continuously without increasing the tag ID precision simply by usmg abutting regions and maps The 100-bit region ID allows 2 100 (~10 30 or a million tnllion trillion) different regions to be uniquely identified 1.2.2 Tag Data Encoding The 120 bits of tag data are redundantly encoded usmg a (15, 5) Reed-Solomon code This yields 360 encoded bits consistmg of 6 codewords of 15 4-bit symbols each The (15, 5) code allows up to 5 symbol enors to be conected per codeword, l e it is tolerant of a symbol enor rate of up to 33% per codeword Each 4-bit symbol is represented in a spatially coherent way m the tag, and the symbols of the six codewords are interleaved spatially withm the tag This ensures that a burst enor (an enor affecting multiple spatially adjacent bits) damages a mmimum number of symbols overall and a mmimum number of symbols m any one codeword, thus maximising the likelihood that the burst enor can be fully conected 1.2.3 Physical Tag Structure The physical representation of the tag, shown m Figure 5, includes fixed target structures 15, 16, 17 and vanable data areas 18 The fixed target structures allow a sensmg device such as the netpage pen to detect the tag and infer its three-dimensional oπentation relative to the sensor The data areas contam representations of the mdividual bits of the encoded tag data To achieve proper tag reproduction, the tag is rendered at a resolution of 256x256 dots When prmted at 1600 dots per inch this yields a tag with a diameter of about 4 mm At this resolution the tag is designed to be sunounded by a 'quiet area" of radius 16 dots Smce the quiet area is also contnbuted by adjacent tags, it only adds 16 dots to the effective diameter of the tag The tag includes six target structures A detection nng 15 allows the sensmg device to initially detect the tag The nng is easy to detect because it is rotationally mvanant and because a simple conection of its aspect ratio removes most of the effects of perspective distortion An oπentation axis 16 allows the sensing device to determine the approximate planar oπentation of the tag due to the yaw of the sensor The oπentation axis is skewed to yield a umque onentation Four perspective targets 17 allow the sensmg device to infer an accurate two-dimensional perspective transform of the tag and hence an accurate three-dimensional position and onentation 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 uregular tnangular gnd In combmation with the circular detection nng, this makes a circular anangement of data bits withm the tag optimal To maximise its size, each data bit is represented by a radial wedge m the form of an area bounded by two radial lmes and two concentnc circular arcs Each wedge has a mmimum 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 m the radial direction is always equal to the mmimum 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 symbol nngs 18a to 18d m mterleaved fashion Symbols are allocated alternately m circular progression around the tag The interleaving is designed to maximise the average spatial distance between any two symbols of the same codeword In order to support "single-click" mteraction with a tagged region via a sensmg device, the sensing 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 onentation 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 tnangular gnd, as shown m Figure 6 1.2.4 Tag Image Processing and Decoding The tag image processmg and decodmg performed by a sensmg device such as the netpage pen is shown in 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 mto connected pixel regions (I e shapes 23) (at 22) Shapes which are too small to represent tag target structures are discarded The size and centroid of 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 by their nature mvanant of position, and can be easily made mvanant of scale, aspect ratio and rotation The nng 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 by aspect-normalizmg and rotation-normalizmg 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 onginal aspect and rotation 27 together provide a usefiil approximation of the perspective transform The axis target structure 16 is the next to be located (at 28) Matchmg proceeds by applymg the πng's normalizations to each shape's moments, and rotation-normalizmg the resultmg moments Once its second-order moments are normalized the axis target is easily recognized Note that one third order moment is required to disambiguate the two possible onentations of 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 onginal rotation provides a useful approximation of the tag's rotation due to pen yaw 29 The four perspective target structures 17 are the last to be located (at 30) Good estimates of their positions are computed based on their known spatial relationships to the nng and axis targets, the aspect and rotation of the nng, and the rotation of the axis Matchmg proceeds by applymg the πng's normalizations to each shape's moments Once their second-order moments are normalized the circular perspective targets are easy to recognize, and the target closest to each estimated position is taken as a match The onginal cenfroids of the four perspective targets are then taken to be the perspective-distorted comers 31 of a square of known size m tag space, and an eight-degree-of-freedom perspective transform 33 is infened (at 32) based on solvmg the well-understood equations relatmg the four tag-space and image- space pomt pans (see Heckbert, P , Fundamentals of Texture Mappmg and Image Warpmg, Masters Thesis, Dept of EECS, U of California at Berkeley, Technical Report No UCB/CSD 89/516, June 1989, the contents of which are herein incorporated by cross-reference) The mfened tag-space to image-space perspective transform is used to project (at 36) each known data bit position m tag space mto image space where the real-valued position is used to bilmearly interpolate (at 36) the four relevant adjacent pixels m the mput 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 m 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 m total Note that the codeword symbols are sampled m codeword order, so that codewords are implicitly de-mterleaved dunng the sampling process The nng target 15 is only sought m a subarea of the image whose relationship to the image guarantees that the nng, 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 cunent frame Given adequate processmg power and ideally a non-minimal field of view 193, an alternative strategy mvolves seeking another tag m the cunent image The obtained tag data indicates the identify of the region containing the tag and the position of the tag withm 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 mfened (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 m 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 withm the region must be known This is given by a tag map, a function which maps each tag ID in a tagged region to a conespondmg location The tag map class diagram is shown m Figure 22, as part of the netpage prmter class diagram A tag map reflects the scheme used to tile the surface region with tags, and this can vary according to surface type When multiple tagged regions share the same tiling scheme and the same tag numbering scheme, they can also share the same tag map The tag map for a region must be retnevable via the region ID Thus, given a region ID, a tag ID and a pen transform, the tag map can be retneved, the tag ID can be translated mto an absolute tag location withm 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 distinct surface coding schemes are of mterest, both of which use the tag structure descπbed earlier m this section The prefened codmg scheme uses "location-mdicatmg" tags as already discussed An alternative codmg scheme uses object-indicating tags A location-mdicatmg tag contams a tag ID which, when translated through the tag map associated with the tagged region, yields a unique tag location withm the region The tag-relative location of the pen is added to this tag location to yield the location of the pen withm the region This m tum is used to determme the location of the pen relative to a user mterface element m 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-mdicatmg tags therefore tπvially support the capture of an absolute pen path m the zone of a particular user mterface element An object-mdicatmg tag contams a tag ID which directly identifies a user mterface element the page descnption associated with the region All the tags m the zone of the user mterface 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 withm a stroke can be unambiguously determined With either tagging scheme, the tags function m cooperation with associated visual elements on the netpage as user mteractive elements m that a user can mteract with the pnnted page usmg an appropnate sensmg device m order for tag data to be read by the sensmg device and for an appropnate response to be generated m the netpage system 1.3 DOCUMENT AND PAGE DESCRIPTIONS A prefened 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 sfyle objects, image objects, etc Once the document is pnnted on a pnnter with a particular page size and accordmg 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 conespondmg terminal elements, particularly where the content objects are style-related Each pnnted mstance of a document and page is also descnbed separately, to allow input captured through a particular page mstance 830 to be recorded separately from mput captured through other instances of the same page descnption The presence of the most abstract document descnption 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 mav be requesting a copy through a pnnter with a different page size, for example Conversely, the presence υl 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 mput elements such as hyperlinks and mput fields A document mstance 831 conesponds to a formatted document 834 It consists of a set of page instances 830, each of which conesponds to a page descnption 5 of the formatted document Each page mstance 830 descnbes a smgle umque pnnted netpage 1 , and records the page 3D 50 of the netpage A page mstance is not part of a document mstance if it represents a copy of a page requested m isolation A page mstance consists of a set of terminal element instances 832 An element mstance only exists if it records mstance-specific mformation Thus, a hyperlink mstance exists for a hyperlink element because it records a transaction ID 55 which is specific to the page mstance, and a field mstance exists for a field element because it records mput specific to the page mstance An element mstance does not exist, however, for static elements such as textflows A terminal element can be a static element 843, a hyperlink 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 style element 847 with an associated style object 854, a textflow element 848 with an associated styled 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 scnpt element 853 with an associated scnpt object 860, as shown m Figure 28 A page mstance has a background field 833 which is used to record any digital ink captured on the page which does not apply to a specific mput element In the prefened form of the mvention, a tag map 811 is associated with each page mstance to allow tags on the page to be translated mto locations on the page 1.4 THE NETPAGE NETWORK In a prefened embodiment, a netpage network consists of a distπbuted set of netpage page servers 10, netpage registration servers 11, netpage ID servers 12, netpage application servers 13, netpage publication servers 14, and netpage prmters 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, prmters, applications and publications, and thereby authorizes vaπous network activities It authenticates users and acts as a sigmng proxy on behalf of authenticated users in application transactions It also provides handwπtmg recogmtion services As descπbed above, a netpage page server 10 maintains persistent information about page descnptions and page instances The netpage network mcludes any number of page servers, each handling a subset of page instances Smce a page server also maintains user mput values for each page mstance, clients such as netpage prmters send netpage mput directly to the appropnate page server The page server interprets any such mput relative to the descnption of the conespondmg page A netpage D 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 Distnbuted Name System (DNS), or similar, to resolve a netpage page ID 50 mto the network address of the netpage page server handling the conespondmg page mstance A netpage application server 13 is a server which hosts interactive netpage applications A netpage publication server 14 is an application server which publishes netpage documents to netpage prmters They are descπbed m detail m Section 2 Netpage servers can be hosted on a vaπety of network server platforms from manufacturers such as IBM, Hewlett-Packard, and Sun Multiple netpage servers can run concunently on a smgle host, and a smgle server can be distπbuted over a number of hosts Some or all of the functionality provided bv netpage servers, and m particular the functionality provided by 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 system and pnnts netpage documents on demand and via subscnption Each pnnter has a umque pnnter ID 62, and is connected to the netpage network via a network such as the Internet, ideally via a broadband connection Apart from identity and secunty settings in non- volatile memory, the netpage prmter 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 distnbuted netpage page servers 10, mdependentiy of particular netpage prmters The netpage pnnter receives subscnbed netpage documents from netpage publication servers 14 Each document is distπbuted in two parts the page layouts, and the actual text and image objects which populate the pages Because of personalization, page layouts are typically specific to a particular subscnber and so are pomtcast to the subscnber's pnnter via the appropnate page server Text and image objects, on the other hand, are typically shared with other subscnbers, and so are multicast to all subscnbers' prmters and the appropπate page servers The netpage publication server optimizes the segmentation of document content mto pomtcasts and multicasts After receivmg the pomtcast of a document's page layouts, the pnnter knows which multicasts, if any, to listen to Once the pnnter has received the complete page layouts and objects that define the document to be pnnted, it can pnnt the document The pnnter rasteπzes and prints odd and even pages simultaneously on both sides of the sheet It contams duplexed prmt engme controllers 760 and pnnt engmes utilizing Memjet™ prmtheads 350 for this purpose The pπntmg process consists of two decoupled stages rasterization of page descnptions, and expansion and prmtmg of page images The raster image processor (RIP) consists of one or more standard DSPs 757 runnmg m parallel The duplexed pnnt engme controllers consist of custom processors which expand, dither and pnnt page images m real time, synchronized with the operation of the prmtheads m the pnnt engmes Printers not enabled for IR pπntmg have the option to pnnt tags usmg IR-absorptive black ink, although this restncts 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 prints netpages on sheets of paper More specialised netpage prmters may pnnt onto more specialised surfaces, such as globes Each pnnter supports at least one surface type, and supports at least one tag tilmg scheme, and hence tag map, for each surface type The tag map 811 which descnbes the tag tilmg scheme actually used to pnnt a document becomes associated with that document so that the document's tags can be conectly interpreted Figure 2 shows the netpage pnnter class diagram, reflecting printer-related information mamtamed by a registration server 11 on the netpage network A prefened embodiment of the netpage pnnter is descnbed in greater detail m Section 6 below, with reference to Figures 11 to 16 1.5.1 Memjet™ Printheads The netpage system can operate usmg printers made with a wide range of digital prmtmg technologies, mcludmg thermal inkjet, piezoelectnc inkjet, laser electrophotographic, and others However, for wide consumer acceptance, it is desirable that a netpage pnnter have the following charactenstics • photographic qualify color prmtmg • high quality text pπntmg • high reliability • low pnnter cost • low ink cost • low paper cost • simple operation • nearly silent pnntmg • high pπntmg speed • simultaneous double sided pπntmg • compact form factor • low power consumption No commercially available pπnting technology has all of these charactenstics To enable to production of prmters with these charactenstics, the present applicant has mvented a new pnnt technology, refened to as Memjet™ technology Memjet™ is a drop-on-demand inkjet technology that mcorporates pagewidth prmtheads fabncated usmg microelectromecha cal systems (MEMS) technology Figure 17 shows a smgle prmtmg element 300 of a Memjet™ prmthead The netpage wallprmter mcorporates 168960 pπntmg elements 300 to form a 1600 dpi pagewidth duplex pnnter This pnnter simultaneously prints cyan, magenta, yellow, black, and infrared inks as well as paper conditioner and ink fixative The pπntmg element 300 is approximately 110 microns long by 32 microns wide Anays of these prmtmg elements are formed on a silicon substrate 301 that mcorporates CMOS logic, data transfer, timing, and dnve circuits (not shown) Major elements of the prmtmg element 300 are the nozzle 302, the nozzle run 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 mlet 312 The active actuator beam pair 308 is mechanically joined to the passive actuator beam pair 309 at the jom 319 Both beams pairs are anchored at their respective anchor po ts 310 and 311 The combmation of elements 308, 309, 310, 311, and 319 form a cantilevered electrothermal bend actuator 320 Figure 18 shows a small part of an anay of prmtmg elements 300, mcludmg a cross section 315 of a pπntmg element 300 The cross section 315 is shown without ink, to clearly show the mk inlet 312 that passes through the silicon wafer 301 Figures 19(a), 19(b) and 19(c) show the operating cycle of a Memjet™ prmtmg element 300 Figure 19(a) shows the quiescent position of the ink memscus 316 pnor to pπntmg an mk droplet Ink is retained m the nozzle chamber by 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 pπntmg, the prmthead CMOS circuitry distnbutes data from the pnnt engme controller to the conect pπntmg element, latches the data, and buffers the data to dnve the electrodes 318 of the active actuator beam pair 308 This causes an electncal cunent to pass through the beam pair 308 for about one microsecond, resultmg m Joule heating The temperature mcrease resultmg from Joule heatmg causes the beam pan 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 m Figure 1 (b) This increases the ink pressure, forcmg ink 321 out of the nozzle 302, and causmg the ink memscus 316 to bulge The nozzle nm 303 prevents the ink memscus 316 from spreading across the surface of the nozzle chamber 304 As the temperature of the beam pairs 308 and 309 equalizes, the actuator 320 returns to its oπgmal position This aids m the break-off of the ink droplet 317 from the ink 321 m the nozzle chamber, as shown m Figure 19(c) The nozzle chamber is refilled by the action of the surface tension at the memscus 316 Figure 20 shows a segment of a prmthead 350 In a netpage prmter, the length of the prmthead is the full width of the paper (typically 210 mm) m the direction 351 The segment shown is 0 4 mm long (about 0 2% of a complete prmthead) When prmtmg, the paper is moved past the fixed pnnthead m the direction 352 The prmthead has 6 rows of mterdigitated pπntmg elements 300, pπntmg the six colors or types of ink supplied by the ink mlets 312 To protect the fragile surface of the pnnthead dunng operation, a nozzle guard wafer 330 is attached to the prmthead substrate 301 For each nozzle 302 there is a conespondmg nozzle guard hole 331 through which the ink droplets are fired To prevent the nozzle guard holes 331 from becommg blocked by paper fibers or other debns, filtered air is pumped through the air mlets 332 and out of the nozzle guard holes dunng pπntmg To prevent ink 321 from drying, the nozzle guard is sealed while the prmter is idle 1.6 The Netpage Pen The active sensmg device of the netpage system is typically a pen 101, which, usmg 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 only near-infrared wavelengths As descnbed m more detail below, the system is able to sense when the mb is in contact with the surface, and the pen is able to sense tags at a sufficient rate to capture human handwnting (l e at 200 dpi or greater and 100 Hz or faster) Information captured by the pen is encrypted and wirelessly transmitted to the pnnter (or base station), the pnnter or base station interpreting the data with respect to the (known) page structure The prefened embodiment of the netpage pen operates both as a normal markmg ink pen and as a non- markmg sfylus The markmg aspect, however, is not necessary for usmg the netpage system as a browsmg system, such as when it is used as an Internet mterface 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 mamtamed by a registration server 11 on the netpage network When either nib is m contact with a netpage, the pen determmes its position and onentation relative to the page The mb is attached to a force sensor, and the force on the mb is interpreted relative to a threshold to mdicate whether the pen is "up" or "down" This allows a mteractive element on the page to be 'clicked' by pressmg with the pen nib, m 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 venfied The pen determmes the position and onentation of its nib 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 b 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 may 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 handwπtmg recogmtion Pen actions relative to a netpage are captured as a seπes of strokes A stroke <. onsists of a sequence of time- stamped pen positions on the page, initiated by a pen-down event and completed by the subsequent pen-up event A stroke is also tagged with the page ID 50 of the netpage whenever the page ID changes, which, under normal circumstances, is at the commencement of the stroke Each netpage pen has a cunent selection 826 associated with it, allowing the user to perform copy and paste operations etc The selection is timestamped to allow the system to discard it after a defined time penod The cunent selection descnbes a region of a page mstance It consists of the most recent digital ink stroke captured through the pen relative to the background area of the page It is interpreted m an application-specific manner once it is submitted to an application via a selection hyperlink activation Each pen has a cunent mb 824 This is the mb last notified by the pen to the system In the case of the default netpage pen descnbed above, either the marking black ink nib or the non-markmg stylus mb is cunent Each pen also has a cunent mb style 825 This is the nib style last associated with the pen by an application, e g m response to the user selectmg a color from a palette The default b style is the mb style associated with the cunent mb Strokes captured through a pen are tagged with the cunent mb style When the strokes are subsequently reproduced, they are reproduced in the mb style with which they are tagged Whenever the pen is withm range of a pnnter with which it can communicate the pen slowly flashes its "onlme" LED When the pen fails to decode a stroke relative to the page, it momentanly activates its "enor" LED When the pen succeeds in decodmg a stroke relative to the page, it momentanly activates its "ok" LED A sequence of captured strokes is refened to as digital ink Digital ink forms the basis for the digital exchange of drawings and handwπtmg, for onlme recogmtion 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 secunfy and packetized for efficient transmission, but is always flushed on a pen-up event to ensure timely handling m the pnnter When the pen is out-of-range of a pnnter it buffers digital ink m mtemal memory, which has a capacify of over ten minutes of contmuous handwnting When the pen is once agam within range of a pnnter, it transfers any buffered digital ink A pen can be registered with any number of prmters, but because all state data resides m netpages both on paper and on the network, it is largely lmmatenal which prmter a pen is communicating with at any particular time A prefened embodiment of the pen is descnbed m greater detail in Section 6 below, with reference to Figures 8 to 10 1.7 NETPAGE INTERACTION The netpage pnnter 601 receives data relatmg to a stroke from the pen 101 when the pen is used to mteract 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 mdicatmg data is transmitted to the pnnter, where it resolves, via the DNS, the page ID 50 of the stroke into the network address of the netpage page server 10 which maintains the conespondmg page mstance 830 It then transmits the stroke to the page server If the page was recently identified in an earlier stroke, then the pnnter may already have the address of the relevant page server m its cache Each netpage consists of a compact page layout mamtamed persistently by a netpage page server (see below) The page layout 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 retneves the page descnption to which the stroke applies, and determmes which element of the page descnption the stroke mtersects 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 tune between the pen down position and the subsequent pen up position are both less than some small maximum An object which is activated by a click typically requires a click to be activated, and accordmgly, a longer stroke is ignored The failure of a pen action, such as a "sloppy" click, to register is indicated by the lack of response from the pen's "ok" LED There are two lands of mput elements m a netpage page descnption hyperlinks and form fields Input through a form field can also tagger the activation of an associated hyperlink 1.7.1 Hyperlinks A hyperlink is a means of sending a message to a remote application, and typically elicits a pπnted response m the netpage system A hyperlink element 844 identifies 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 mclude the user's application alias ID 65 m the hyperlink activation, and a descnption which is used when the hyperlink is recorded as a favonte or appears m the user's history The hyperlink element class diagram is shown m Figure 29 When a hyperlink is activated, the page server sends a request to an application somewhere on the network The application is identified by an application ID 64, and the application ID is resolved m the normal way via the DNS There are three types of hyperlinks general hyperlinks 863, form hyperlinks 865, and selection hyperlinks 864, as shown m Figure 30 A general hyperlink can implement a request for a linked document, or may simply signal a preference to a server A form hyperlink submits the conesponding form to the application A selection hyperlink submits the cunent selection to the application If the cunent selection contams a smgle-word piece of text, for example, the application may return a smgle-page document givmg the word's meanmg withm the context m which it appears, or a translation mto a different language Each hyperlink type is characterized by what information is submitted to the application The conesponding hyperlink mstance 862 records a transaction ID 55 which can be specific to the page mstance on which the hyperlink mstance appears The transaction ID can identify user-specific data to the application, for example a "shopping cart" of pending purchases mamtamed by a purchasing application on behalf of the user The system mcludes the pen's cunent selection 826 m a selection hyperlink activation The system mcludes the content of the associated form mstance 868 m a form hyperlink activation, although if the hyperlink has its "submit delta" attnbute set, only mput smce the last form submission is mcluded The system mcludes an effective return path m all hyperlink activations A hyperhnked group 866 is a group element 838 which has an associated hyperlink, as shown m Figure 31 When mput occurs through any field element m the group, the hyperlink 844 associated with the group is activated A hyperlrnked group can be used to associate hyperlink behavior with a field such as a checkbox It can also be used, m conjunction with the "submit delta" attribute of a form hyperlink, to provide contmuous mput to an application It can therefore be used to support a "blackboard" mteraction 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 mputs through a pπnted netpage A foπn allows a user to submit one or more parameters to an application software program runnmg on a server A form 867 is a group element 838 m the document hierarchy It ultimately contains a set of terminal field elements 839 A form instance 868 represents a pπnted mstance of a form It consists of a set of field instances 870 which conespond to the field elements 845 of the form Each field mstance has an associated value 871, whose type depends on the type of the conespondmg field element Each field value records mput through a particular pnnted form mstance, l e through one or more prmted netpages The form class diagram is shown m Figure 32 Each form mstance has a status 872 which mdicates whether the form is active, frozen, submitted, void or expired A form is active when first pnnted 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 form has been active exceeds the form's specified lifetime While the form is active, form mput is allowed Input through a form which is not active is mstead captured m the background field 833 of the relevant page mstance When the form is active or frozen, form submission is allowed Any attempt to submit a form when the form is not active or frozen is rejected, and mstead elicits an form status report Each form instance is associated (at 59) with any form instances denved from it, thus providmg a version history This allows all but the latest version of a form m a particular time penod to be excluded from a search All mput is captured as digital ink Digital mk 873 consists of a set of timestamped stroke groups 874, each of which consists of a set of styled strokes 875 Each stroke consists of a set of timestamped pen positions 876, each of which also mcludes 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, a text field 878, a drawing field 879, or a signature field 880 The field element class diagram is shown m Figure 34 Any digital ink captured m a field's zone 58 is assigned to 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 m 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 handwπtmg recogmtion is well-understood (see, for example, Tappert, C , C Y Suen and T Wakahara, "The State of the Art m On-Line Handwπtmg Recogmtion", IEEE Transactions on Pattern Analysis and Machme 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 m Figure 37 Any digital ink captured m a signature field's zone is automatically venfied with respect to the identify of the owner of the pen, and a digital signature of 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 key specific to the application which owns the form Onlme signature venfication is well-understood (see, for example, Plamondon, R and G Lorette, "Automatic Signature Venfication and Wnter Identification - The State of the Art", Pattern Recogmtion, Vol 22, No 2, 1989, the contents of which are here incorporated by cross-reference) 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 mput It can have an associated field value which is mcluded m the form data when the form containing the field is submitted "Editing" commands, such as stnke-throughs mdicatmg deletion, can also be recognized in form fields Because the handwntmg recogmtion algonthm works "onlme" (I e with access to the dynamics of the pen movement), rather than "offline" (l e with access only to a bitmap of pen markings), it can recognize run-on discretely- wπtten characters with relatively high accuracy, without a wnter-dependent training phase A wnter-dependent model of handwnting is automatically generated over time, however, and can be generated up-front if necessary, Digital ink, as already stated, consists of a sequence of strokes Any stroke which starts m a particular element's zone is appended to that element's digital mk stream, ready for interpretation Any stroke not appended to an object's digital ink stream is appended to the background field's digital ink stream Digital ink captured m the background field is interpreted as a selection gesture Circumscnption of one or more objects is generally interpreted as a selection of the circumscπbed objects, although the actual interpretation is application-specific Table 2 summaπses these vanous pen interactions with a netpage Table 2 - Summary of pen interactions with a netpage The system maintains a cunent selection for each pen The selection consists simply of the most recent stroke captured m 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 mtenogate the raw digital ink should it suspect the onginal conversion, such as the conversion of handwritten text This can, for example, mvolve human mtervention 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 form to a human operator, on the assumption that the user may have mdicated amendments to the filled-m fields outside of those fields Figure 38 shows a flowchart of the process of handling pen mput relative to a netpage The process consists of receivmg (at 884) a stroke from the pen, identifymg (at 885) the page mstance 830 to which the page ID 50 m the stroke refers, retπevmg (at 886) the page descnption 5, identifymg (at 887) a formatted element 839 whose zone 58 the stroke mtersects, determining (at 888) whether the formatted element conesponds to a field element, and if so appending (at 892) the received stroke to the digital ink of the field value 871, interpreting (at 893) the accumulated digital ink of the field, and determining (at 894) whether the field is part of a hyperlrnked group 866 and if so activating (at 895) the associated hyperlink, alternatively determining (at 889) whether the formatted element conesponds to a hyperlink element and if so activating (at 895) the conespond g hyperlink, alternatively, m the absence of an mput field or hyperlink, appending (at 890) the received stroke to the digital ink of the background field 833, and copymg (at 891) the received stroke to the cunent selection 826 of the cunent pen, as mamtamed by the registration server Figure 38a shows a detailed flowchart of step 893 in the process shown m Figure 38, where the accumulated digital ink of a field is interpreted according to the type of the field The process consists of 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 appropnate 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 venfymg (at 903) the digital ink as the signature of the pen's owner, with the help of the appropπate registration server, creating (at 904) a digital signature of the contents of the conespondmg form, also with the help of the registration server and usmg the pen owner's pnvate signature key relatmg to the conespondmg application, and assigning (at 905) the digital signature to the field value 1.7.3 Page Server Commands A page server command is a command which is handled locally by the page server It operates directly on form, page and document instances A page server command 907 can be a void form command 908, a duplicate form command 909, a reset form command 910, a get form 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 m Figure 39 A void form command voids the conespondmg form mstance A duplicate form command voids the conesponding form mstance and then produces an active pnnted copy of the cunent foπn mstance with field values preserved The copy contams the same hyperlink transaction IDs as the onginal, and so is indistinguishable from the onginal to an application A reset form command voids the conespondmg form mstance and then produces an active pπnted copy of the form mstance with field values discarded A get form status command produces a pπnted report on the status of the conesponding form mstance, mcludmg who published it, when it was pnnted, for whom it was pnnted, and the form status of the form mstance Smce a form hyperlink mstance contams a transaction ID, the application has to be mvolved m producmg a new form mstance A button requesting a new form mstance is therefore typically implemented as a hyperlink A duplicate page command produces a pnnted copy of the conespondmg page mstance with the background field value preserved If the page contams a form or is part of a form, then the duplicate page command is interpreted as a duplicate form command A reset page command produces a pπnted copy of the conespondmg page mstance with the background field value discarded If the page contams a foπn or is part of a form, then the reset page command is interpreted as a reset foπn command A get page status command produces a pnnted report on the status of the conespondmg page mstance, mcludmg who published it, when it was pnnted, for whom it was pnnted, and the status of any forms it contains or is part of 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 pπnted m their native form, l e a checkmark appears as a standard checkmark graphic, and text appears as typeset text Only drawings and signatures appear m their ongmal foπn, with a signature accompanied by a standard graphic mdicatmg successful signature venfication A duplicate document command produces a pnnted copy of the conesponding document mstance with background field values preserved If the document contams any forms, then the duplicate document command duplicates the forms m the same way a duplicate form command does A reset document command produces a pnnted copy of the conespondmg document mstance with background field values discarded If the document contams any forms, then the reset document command resets the forms in the same way a reset form command does A get document status command produces a pπnted report on the status of the conespondmg document mstance, mcludmg who published it, when it was pnnted, for whom it was pπnted, and the status of any forms it contams If the page server command's "on selected" attnbute is set, then the command operates on the page identified by the pen's cunent selection rather than on the page containing the command This allows a menu of page server commands to be pπnted 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 by embedding the relevant page server command element m a hyperlrnked group The page server activates the hyperlink associated with the hyperlrnked group rather than executing the page server command A page server command element is hidden if its "hidden" attnbute is set A hidden command element does not have an mput 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, if that page server command has its "on selected" attnbute set 1.8 STANDARD FEATURES OF NETPAGES In the prefened form, each netpage is pnnted with the netpage logo at the bottom to mdicate that it is a netpage and therefore has mteractive properties The logo also acts as a copy button In most cases pressing the logo produces a copy of the page In the case of a form, the button produces a copy of the entire form And m the case of a secure document such as a ticket or coupon, the button elicits an explanatory note or advertismg page The default smgle-page copy function is handled directly by the relevant netpage page server Special copy functions are handled by linking the logo button to an application 1.9 USER HELP SYSTEM In a prefened embodiment, the netpage pnnter has a smgle button labelled "Help" When pressed it elicits a smgle page of information, mcludmg • status of pnnter 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 mcludes the following functions • pnnt a copy of a document • pnnt a clean copy of a form • pnnt the status of a document A document function is initiated by simply pressing the button and then touching any 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 Depending on the document type, the publisher or the user pays the small "yellow pages" service fee The help page is obviously unavailable if the pnnter is unable to pnnt In this case the "enor" light is lit and the user can request remote diagnosis over the network 2 PERSONALIZED PUBLICATION MODEL In the following descnption, news is used as a canonical publication example to illustrate personalization mechamsms m the netpage system Although news is often used m the limited sense of newspaper and newsmagazine news, the mtended scope m the present context is wider In the netpage system, the editonal content and the advertismg content of a news publication are personalized using different mechamsms The editonal content is personalized according to the reader's explicitly stated and implicitly captured mterest profile The advertismg content is personalized accordmg to the reader's locality and demographic 2.1 EDITORIAL PERSONALIZATION A subscnber 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 by the publisher, news streams are aggregated either by a news publisher or by a specialized news aggregator News publications typically conespond to traditional newspapers and newsmagazines, while news streams can be many and vaned a "raw" news feed from a news service, a cartoon stnp, a freelance wnter' s column, a friend's bulletin board, or the reader's own e-mail The netpage publication server supports the publication of edited news publications as well as the aggregation of multiple news streams By handling the aggregation and hence the formatting of news streams selected directly by the reader, the server is able to place advertismg on pages over which it otherwise has no editonal control The subscnber builds a daily newspaper by selecting one or more contπbutmg news publications, and creating a personalized version of each The resultmg dailv editions are pπnted and bound together mto a smgle newspaper The vanous members of a household typically express their different mterests 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", "Opimon", "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 by 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 momtonng 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 numencally (l e as a limit on its number of pages), and the desired proportion of advertismg, either qualitatively (e g high, normal, low, none), or numencally (l 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 forms to support this preference An article may also be wntten (or edited) m different versions to match the expected sophistication of the reader, for example to provide children's and adults' versions The appropπate version is selected accordmg 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 pnontized by the editors, and each is assigned a useful lifetime By default they are delivered to all relevant subscnbers, m pnonfy order, subject to space constraints m the subscnbers' editions In sections where it is appropnate, the reader may optionally enable collaborative filtering This is then applied to articles which have a sufficiently long lifetime Each article which qualifies for collaborative filtering is pπnted with ratmg 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 therefore effectively considered essential reading by the editors and are delivered to most relevant subscnbers The reader optionally specifies a serendipity factor, either qualitatively (e g do or don't surpnse me), or numencally A high serendipity factor lowers the threshold used for matchmg dunng collaborative filtering A high factor makes it more likely that the conesponding section will be filled to the reader's specified capacity A different serendipity factor can be specified for different days of the week The reader also optionally specifies topics of particular mterest withm a section, and this modifies the pnonties assigned by 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 for fewer images or smaller images or both If the number or size of images is not reduced, then images may be delivered at lower qualify (l e at lower resolution or with greater compression) At a global level, the reader specifies how quantities, dates, times and monetary values are localized This mvolves specifying whether units are lmpenal or metπc, a local timezone and time format, and a local cunency, and whether the localization consist of tn situ translation or annotation These preferences are denved from the reader's locality by default To reduce readmg difficulties caused by poor eyesight, the reader optionally specifies a global preference for a larger presentation Both text and images are scaled accordingly, and less mformation is accommodated on each page The language m which a news publication is published, and its conespondmg text encoding, is a property of the publication and not a preference expressed by 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 of the editonal content directly affects the advertismg content, because advertismg is typically placed to exploit the editonal context Travel ads, for example, are more likely to appear m a travel section than elsewhere The value of the editonal content to an advertiser (and therefore to the publisher) lies m its ability to attract large numbers of readers with the nght demographics Effective advertismg is placed on the basis of locality and demographics Locality determmes proximity to particular services, retailers etc , and particular mterests and concerns associated with the local community and environment Demographics determme general mterests and preoccupations as well as likely spendmg patterns A news publisher's most profitable product is advertismg "space", a multi-dimensional entity determined by the publication's geographic coverage, the size of its readership, its readership demographics, and the page area available for advertismg In the netpage system, the netpage publication server computes the approximate multi-dimensional size of a publication's saleable advertismg 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 advertismg proportion, and each reader's demographic In companson with other media, the netpage system allows the advertismg space to be defined m 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 advertismg "slot" can be sold m varying proportions to several advertisers, with mdividual readers' pages randomly receivmg the advertisement of one advertiser or another, overall preservmg the proportion of space sold to each advertiser The netpage system allows advertising to be linked directly to detailed product information and onlme purchasing It therefore raises the intrinsic value of the advertismg space Because personalization and localization are handled automatically by netpage publication servers, an advertismg aggregator can provide arbitranly broad coverage of both geography and demographics The subsequent disaggregation is efficient because it is automatic This makes it more cost-effective for publishers to deal with advertismg aggregators than to directly capture advertising Even though the advertising aggregator is taking a proportion of advertising revenue, publishers may 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 m the publication's traditional counterpart, because the publication's advertismg space is more complex While ignoring the full complexities of negotiations between advertisers, advertising aggregators and publishers, the prefened form of the netpage system provides some automated support for these negotiations, mcludmg support for automated auctions of advertismg space Automation is particularly desirable for the placement of advertisements which generate small amounts of mcome, such as small or highly localized advertisements Once placement has been negotiated, the aggregator captures and edits the advertisement and records it on a netpage ad server Conespondmgly, the publisher records the ad placement on the relevant netpage publication server When the netpage publication server lays out each user's personalized publication, it picks the relevant advertisements from the netpage ad server 2.3 USER PROFILES 2.3.1 Information Filtering The personalization of news and other publications relies on an assortment of user-specific profile information, mcludmg • publication customizations • collaborative filtermg vectors • contact details • presentation preferences The customization of a publication is typically publication-specific, and so the customization information is mamtamed by the relevant netpage publication server A collaborative filtermg vector consists of the user's ratmgs of a number of news items It is used to conelate different users' mterests for the purposes of making recommendations Although there are benefits to mamtammg a smgle collaborative filtermg vector mdependentiy of any particular publication, there are two reasons why it is more practical to maintain a separate vector for each publication there is likely to be more overlap between the vectors of subscnbers to the same publication than between those of subscnbers to different publications, and a publication is likely to want to present its users' collaborative filtermg vectors as part of the value of its brand, not to be found elsewhere Collaborative filtenng vectors are therefore also mamtamed by the relevant netpage publication server Contact details, mcludmg name, street address, ZIP Code, state, country, telephone numbers, are global by nature, and are mamtamed by a netpage registration server Presentation preferences, mcludmg those for quantities, dates and times, are likewise global and mamtamed m the same way The localization of advertismg relies on the locality mdicated m the user's contact details, while the targeting of advertismg relies on personal information such as date of birth, gender, mantal status, mcome, profession, education, or qualitative denvatives such as age range and mcome range For those users who choose to reveal personal information for advertismg 'imposes, the information is mamtamed by the relevant netpage registration server In the absence of such mformation, --ivertisrng can be targeted on the basis of 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 kmd of application provider, and a publication is a special kmd of application Each user 800 may be authorized to use any number of pnnters 802, and each pnnter may allow any number of users to use it Each user has a smgle default pnnter (at 66), to which peπodical publications are delivered by default, whilst pages pnnted on demand are delivered to the pnnter through which the user is mteracting The server keeps track of which publishers a user has authorized to pnnt to the user's default pnnter A publisher does not record the ID of any particular pnnter, but mstead resolves the ID when it is required When a user subscnbes 808 to a publication 807, the publisher 806 (l e application provider 803) is authorized to pnnt to a specified pnnter or the user's default pnnter This authorization can be revoked at any tune by the user Each user may have several pens 801, but a pen is specific to a single user If a user is authorized to use a particular prmter, then that pnnter recognizes any of the user' s pens The pen ID is used to locate the conespondmg user profile mamtamed by a particular netpage registration server, via the DNS in the usual way A Web terminal 809 can be authorized to pnnt on a particular netpage pnnter, allowing Web pages and netpage documents encountered dunng Web browsmg to be conveniently pnnted on the nearest netpage pnnter The netpage system can collect, on behalf of a pnnter provider, fees and commissions on mcome earned through publications pnnted on the provider's prmters Such mcome can mclude advertismg fees, click-through fees, e- commerce commissions, and transaction fees If the prmter is owned by 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 descπbed m the precedmg paragraph), contact details 815, mcludmg name, address and telephone numbers, global preferences 816, mcludmg pnvacy, delivery and localization settmgs, any number of biometnc records 817, contammg the user's encoded signature 818, fingerprint 819 etc, a handwntmg model 819 automatically mamtamed 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 "favontes" - links to useful documents etc on the netpage network The list is mamtamed by the system on the user's behalf It is organized as a hierarchy of folders 924, a prefeπred embodiment of which is shown m the class diagram m Figure 41 2.3.3 History List The system maintains a history list 929 on each user's behalf, contammg links to documents etc accessed by the user through the netpage system It is organized as a date-ordered list, a prefened embodiment of which is shown m the class diagram m Figure 42 2.4 INTELLIGENT PAGE LAYOUT The netpage publication server automatically lays out the pages of each user's personalized publication on a section-by-section basis Smce most advertisements are the form of pre-foimatted rectangles, they are placed on the page before the editonal content The advertismg ratio for a section can be achieved with wildly varying advertismg ratios on mdividual pages withm the section, and the ad layout algonthm exploits this The algorithm is configured to attempt to co-locate closely tied editonal and advertising content, such as placmg ads for roofing matenal specifically within the publication because of a special feature on do-it-yourself roofing repairs The editonal content selected for the user, mcludmg text and associated images and graphics, is then laid out according to vanous aesthetic rules The entire process, mcludmg the selection of ads and the selection of editonal content, must be iterated once the layout has converged, to attempt to more closely achieve the user's stated section size preference The section size preference can, however, be matched on average over time, allowing significant day-to-day vanations 2.5 DOCUMENT FORMAT Once the document is laid out, it is encoded for efficient distnbution and persistent storage on the netpage network The primary efficiency mechamsm 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 layout The shared mformation consists of the objects to which the page layout refers, mcludmg images, graphics, and pieces of text A text object contams fully-formatted text represented m the Extensible Markup Language (XML) usmg the Extensible Stylesheet Language (XSL) XSL provides precise control over text formatting mdependentiy of the region mto which the text is bemg set, which m this case is bemg provided by the layout The text object contams embedded language codes to enable automatic translation, and embedded hyphenation hmts to aid with paragraph formatting An image object encodes an image in the JPEG 2000 wavelet-based compressed image format A graphic object encodes a 2D graphic m Scalable Vector Graphics (SVG) format The layout itself consists of a seπes of placed image and graphic objects, linked textflow objects through which text objects flow, hyperlinks and mput fields as descnbed above, and watermark regions These layout ob j ects are summarized m Table 3 The layout uses a compact format suitable for efficient distnbution 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 layout is separated from the shared objects to which it refers When a subscnbed publication is readv to be distnbuted, the netpage publication server allocates, with the help of the netpage ID server 12, a unique ID for each page, page mstance document, and document mstance 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 layout with the names of the multicast channels which will carry the shared content used by that lavout The server then pomtcasts each user's layouts to that user's pnnter via the appropnate page server, and when the pomtcasting is complete, multicasts the shared content on the specified channels After receivmg its pomtcast, each page server and pnnter subscπbes to the multicast channels specified m the page layouts Dunng the multicasts, each page server and printer extracts from the multicast streams those objects refened to by its page layouts The page servers persistently archive the received page layouts and shared content Once a pnnter has received all the objects to which its page layouts refer, the pnnter re-creates the fully- populated layout and then rastenzes and prints it Under normal circumstances, the prmter pπnts pages faster than they 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 of 100 such pages m its internal 64MB memorv, allowing for temporary buffers etc The pnnter prints 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 Even under abnormal circumstances, such as when the pnnter runs out of paper, it is likely that the user will be able to replemsh the paper supply before the pnnter' s 100-page mtemal storage capacity is exhausted However, if the pnnter' s mtemal 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 prmters to submit requests for re- multicasts When a cntical number of requests is received or a timeout occurs, the server re-multicasts the conespondmg shared objects Once a document is pnnted, a pnnter can produce an exact duplicate at any time by retπevmg its page layouts 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 penodical However, since there is no shared content, delivery is made directly to the requestmg pnnter 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 vaπous Internet document formats, mcludmg Adobe's Portable Document Format (PDF), and Hypertext Markup Language (HTML) In the case of HTML, it can make use of the higher resolution of the pnnted page to present Web pages m a multi-column format, with a table of contents It can automatically mclude 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 pnnter 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 m transit, and to authenticate parties to a transaction There are two classes of cryptography in widespread use secret-key cryptography and public-key cryptography The netpage network uses both classes of cryptography Secret-key cryptography, also refened to as symmetnc cryptography, uses the same kev to encrypt and decrypt a message Two parties wishing to exchange messages must first aπange to securely exchange the secret key Public-key cryptography, also refened to as asymmetnc cryptography, uses two encryption keys The two keys are mathematically related m such a way that any message encrypted usmg one key can only be decrypted using the other key One of these keys is then published, while the other is kept pnvate The public key is used to encrypt any message intended for the holder of the pnvate key Once encrypted usmg the public key, a message can only be decrypted usmg the pnvate key Thus two parties can securely exchange messages without first havmg to exchange a secret key To ensure that the pπvate key is secure, it is normal for the holder of the pnvate key to generate the key pair Public-key cryptography can be used to create a digital signature The holder of the pnvate key can create a known hash of a message and then encrypt the hash using the pπvate key Anyone can then veπfy that the encrypted hash constitutes the "signature" of the holder of the private key with respect to that particular message by decrypting the encrypted hash usmg the public key and veπfymg the hash against the message If the signature is appended to the message, then the recipient of the message can venfy both that the message is genume and that it has not been altered in transit To make public-key cryptography work, there has to be a way to distnbute public keys which prevents impersonation This is normally done usmg certificates and certificate authoπties A certificate authoπty is a trusted third party which authenticates the connection between a public key and someone's identity The certificate authoπty venfies the person's identity by examining identity documents, and then creates and signs a digital certificate contammg the person's identity details and public key Anyone who trusts the certificate authoπty can use the public key m the certificate with a high degree of certainty that it is genume They just have to venfy that the certificate has mdeed been signed by the certificate authonfy, whose public key is well-known In most transaction environments, public-key cryptography is only used to create digital signatures and to securely exchange secret session keys Secret-key cryptography is used for all other purposes In the following discussion, when reference is made to the secure transmission of information between a netpage pnnter and a server, what actually happens is that the pnnter obtams the server's certificate, authenticates it with reference to the certificate authoπty, uses the public key-exchange key m the certificate to exchange a secret session key with the server and then uses the secret session key to encrypt the message data A session key, by definition, can have an arbitraπly short lifetime 3.2 NETPAGE PRINTER SECURITY Each netpage pnnter is assigned a pan of umque identifiers at time of manufacture which are stored m read-only memory m the pnnter and m the netpage registration server database The first ID 62 is public and uniquely identifies the pnnter on the netpage network The second ID is secret and is used when the pnnter is first registered on the network When the prmter connects to the netpage network for the first tune after installation, it creates a signature pubhc/pπvate key pair It transmits the secret ID and the public key securely to the netpage registration server The server compares the secret ID agamst the pnnter' s secret ID recorded m its database, and accepts the registration if the IDs match It then creates and signs a certificate contammg the pnnter' s public ID and public signature key, and stores the certificate m the registration database The netpage registration server acts as a certificate authonfy for netpage pπηlers, smce it has access to secret information allowing it to venfy pnnter identity When a user subscnbes to a publication, a record is created m the netpage registration server database authorizing the publisher to pnnt the publication to the user's default pnnter or a specified pnnter Every document sent to a prmter via a page server is addressed to a particular user and is signed by the publisher usmg the publisher's pnvate signature key 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 usmg the publisher's public key, obtained from the publisher's certificate stored m the registration database The netpage registration server accepts requests to add prmtmg authorizations 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 is assigned a unique identifier at time of manufacture which is stored m read-only memory m the pen and m the netpage registration server database The pen ID 61 uniquely identifies the pen on the netpage network A netpage pen can "know" a number of netpage prmters, and a pnnter can 'know" a number of pens A pen commumcates with a pnnter via a radio frequency signal whenever it is withm range of the prmter Once a pen and pnnter are registered, they regularly exchange session keys Whenever the pen transmits digital ink to the pnnter, the digital ink is always encrypted usmg the appropnate session key Digital ink is never transmitted m the clear A pen stores a session key for every pnnter it knows, mdexed by pnnter TD, and a pnnter stores a session key for every pen it knows, mdexed by pen ID Both have a large but fimte storage capacity for session keys, and will forget a session key on a least-recently-used basis if necessary When a pen comes withm range of a pnnter, the pen and pnnter discover whether they know each other If they don't know each other, then the pnnter determmes 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 pnnter If the pnnter is meant to know the pen but doesn't, then it mitiates 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 m a chargmg cup, at which time it mitiates the registration procedure In addition to its public ID, the pen contams a secret key-exchange key The key-exchange key is also recorded m the netpage registration server database at time of manufacture Dunng registration, the pen transmits its pen ID to the pnnter, and the prmter 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 key-exchange key The pnnter stores the session key internally, mdexed by the pen ID, and transmits the encrypted session key to the pen The pen stores the session key internally, mdexed 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 public-key encryption because of hardware performance constraints m the pen 3.4 SECURE DOCUMENTS The netpage system supports the delivery of secure documents such as tickets and coupons The netpage pnnter mcludes a facility to pnnt watermarks, but will only do so on request from publishers who are suitably authorized The publisher mdicates its authoπty to pnnt watermarks m its certificate, which the pnnter is able to authenticate The "watermark" prmtmg process uses an alternative dither matnx m specified "watermark" regions of the page Back-to-back pages contam minor-image watermark regions which comcide when pπnted The dither matπces used m odd and even pages' watermark regions are designed to produce an interference effect when the regions are viewed together, achieved by looking through the pπnted sheet The effect is similar to a watermark m that it is not visible when looking at only one side of the page, and is lost when the page is copied by normal means Pages of secure documents cannot be copied usmg the built-in netpage copy mechamsm descnbed m Section 1 9 above This extends to copymg netpages on netpage-aware photocopiers Secure documents are typically generated as part of e-commerce transactions They can therefore mclude the user's photograph which was captured when the user registered biometnc mformation with the netpage registration server, as descnbed in Section 2 When presented with a secure netpage document, the recipient can venfy its authenticity by requesting its status m the usual way The umque ID of a secure document is only valid for the lifetime of the document, and secure document IDs are allocated non-contiguously to prevent their prediction by opportunistic forgers A secure document venfication pen can be developed with built-in feedback on venfication failure, to support easy point-of-presentation document venfication Clearly neither the watermark nor the user's photograph are secure m a cryptographic sense They simply provide a significant obstacle to casual forgery Onlme document venfication, particularly usmg a venfication pen, provides an added level of secunfy where it is needed, but is still not entirely immune to forgenes 3.5 NON-REPUDIATION In the netpage system, forms submitted by users are delivered reliably to forms handlers and are persistently archived on netpage page servers It is therefore impossible for recipients to repudiate delivery E-commerce payments made through the system, as descnbed m 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) system as one of its payment systems SET, having been developed by MasterCard and Visa, is organized around payment cards, and this is reflected m the terminology However, much of the system is mdependent of the type of accounts bemg used In SET, cardholders and merchants register with a certificate authonfy and are issued with certificates contammg their public signature keys The certificate authonty venfies a cardholder's registration details with the card issuer as appropnate, and venfies a merchant's registration details with the acquirer as appropnate Cardholders and merchants store their respective pnvate signature keys securely on their computers Dunng the payment process, these certificates are used to mutually authenticate a merchant and cardholder, and to authenticate them both to the payment gateway SET has not yet been adopted widely, partly because cardholder maintenance of keys and certificates is considered burdensome Interim solutions which maintain cardholder keys 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 system the netpage registration server acts as a proxy for the netpage user (l e the cardholder) m SET payment transactions The netpage system uses biometncs to authenticate the user and authorize SET payments Because the system is pen-based, the biometnc used is the user's on-lme signature, consisting of time- varying pen position and pressure A fingerprint biometnc can also be used by designing a fingerprint sensor mto the pen, although at a higher cost The type of biometnc used only affects the capture of the biometnc, not the authorization aspects of the system The first step to bemg able to make SET payments is to register the user's biometnc with the netpage registration server This is done m a controlled environment, for example a bank, where the biometnc can be captured at the same time as the user's identity is veπfied The biometnc is captured and stored m the registration database, linked to the user's record The user's photograph is also optionally captured and linked to the record The SET cardholder registration process is completed, and the resultmg pnvate signature key and certificate are stored m the database The user's payment card information is also stored, givmg the netpage registration server enough mformation to act as the user's proxy m any SET payment transaction When the user eventually supplies the biometnc to complete a payment, for example by sigmng a netpage order form, the pnnter securely transmits the order information, the pen ID and the biometnc data to the netpage registration server The server venfies the biometnc with respect to the user identified by the pen ID, and from then on acts as the user's proxy m completing the SET payment transaction 4.3 MICRO-PAYMENTS The netpage system mcludes a mechamsm for micro-payments, to allow the user to be conveniently charged for pπntmg low-cost documents on demand and for copymg copynght documents, and possibly also to allow the user to be reimbursed for expenses mcuned m pπntmg 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 any outstandmg debit balance usmg the standard payment mechamsm The network account can be extended to aggregate subscnption fees for penodicals, which would also otherwise be presented to the user m the form of mdividual statements 4.4 TRANSACTIONS When a user requests a netpage m a particular application context, the application is able to embed a user- specific transaction ID 55 m 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 mput 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 mvolves addmg items from a pre-pnnted catalog page to the user's virtual "shopping cart" To protect the user's pnvacy, 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 mdependentiy accumulated behavioral data The netpage registration server mstead maintains 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" attnbute, the netpage page server asks the netpage registration server to translate the associated application ID 64, together with the pen ID 61 , into an alias ID 65 The alias ED is then submitted to the hyperlink's application The application maintains state information mdexed by alias ID, and is able to retneve user-specific state information without knowledge of the global identity of the user The system also maintains an mdependent certificate and pnvate signature key for each of a user's applications, to allow it to sign application transactions on behalf of the user usmg only application-specific mformation To assist the system m routing product bar code (UPC) "hyperlink" activations, the system records a favoπte application on behalf of the user for any number of product types Each application is associated with an application provider, and the system maintains 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 of penodical subscnbed content The system 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 prefened embodiment of a resource descnption class diagram is shown in Figure 40 Each document and content object may be descπbed by one or more resource descnptions 842 Resource descnptions use the Dublm Core metadata element set, which is designed to facilitate discovery of electronic resources Dublm Core metadata conforms to the World Wide Web Consortium (W3C) Resource Descnption Framework (RDF) A resource descnption may identify nghts holders 920 The netpage system automatically transfers copynght fees from users to nghts holders when users pnnt copynght content 5 COMMUNICATIONS PROTOCOLS A communications protocol defines an ordered exchange of messages between entities In the netpage system, entities such as pens, prmters and servers utilise a set of defined protocols to cooperatively handle user mteraction with the netpage system Each protocol is illustrated by way of a sequence diagram m 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 contammg the name of the entity and a vertical column representing the lifeline of the entity Dunng the time an entity exists, the lifeline is shown as a dashed lme Dunng the tune an entify is active, the lifeline is shown as a double lme Because the protocols considered here do not create or destroy entities, lifelmes are generally cut short as soon as an entity ceases to participate m a protocol 5.1 SUBSCRIPTION DELIVERY PROTOCOL A prefened embodiment of a subscnption delivery protocol is shown m Figure 43 A large number of users may subscnbe to a penodical 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 subscnption delivery protocol therefore delivers document structures to mdividual printers via pomtcast, but delivers shared content objects via multicast The application (I e publisher) first obtams a document ID 51 for each document from an ID server 12 It then sends each document structure, mcludmg its document ID and page descnptions, to the page server 10 responsible for the document's newly allocated ID It mcludes its own application ID 64, the subscπber'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 obtam from the registration server the conespondmg 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 pnnter), and the application's certificate The application's certificate allows the page server to venfy 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 IDs and forwards the page descnptions, mcludmg page IDs 50, to the pnnter It mcludes the relevant set of multicast channel name * - for the pnnter to listen to It then returns the newly allocated page IDs to the application for future refer ...ice Once the application has distnbuted all of the document structures to the subscnbers' selected printers via the relevant page servers, it multicasts the vanous subsets of the shared objects on the previously selected multicast channels Both page servers and prmters momtor the appropπate multicast channels and receive then 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 prmters to pnnt the documents 5.2 HYPERLINK ACTIVATION PROTOCOL A prefened embodiment of a hyperlink activation protocol is shown m Figure 45 When a user clicks on a netpage with a netpage pen, the pen commumcates the click to the nearest netpage pnnter 601 The click identifies the page and a location on the page The pnnter aheady knows the ID 61 of the pen from the pen connection protocol The pnnter determmes, via the DNS, the network address of the page server 10a handling the particular page ID 50 The address may already be m its cache if the user has recently mteracted with the same page The pnnter then forwards the pen ID, its own pnnter ID 62, the page ID and click location to the page server The page server loads the page descnption 5 identified by the page ID and determmes which mput element's zone 58, if any, the click lies m Assuming the relevant mput element is a hyperlink element 844, the page server then obtams the associated application ID 64 and link ID 54, and determines, via the DNS, the network address of the application server hosting the application 71 The page server uses the pen ID 61 to obtam the conespondmg user ID 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 pnnter, and identifies the clicked hyperlink mstance 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 accordmg to application-specific logic, and obtams a document ID 51 from an ID server 12 It then sends the document to the page server 10b responsible for the document's newly allocated ID, together with the requestmg page server's ID and the hyperlink request ID The second page server sends the hyperlink request ID and application ID to the first page server to obtam the conespondmg 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 mstance and page IDs 50, returns the newly allocated page IDs to the application, adds the complete document to its own database, and finally sends the page descnptions to the requestmg pnnter The hyperlink mstance may mclude a meaningful transaction ID 55, m 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 hyperlink requires a user alias, l e its "alias required" attnbute 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 obtam not just the user ID conespondmg to the pen ID but also the alias ID 65 conespondmg to the application ID and the user ID It mcludes the alias ID m 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 commumcates the stroke to the nearest netpage pnnter The stroke identifies the page and a path on the page The pnnter forwards the pen ID 61 , its own pnnter ID 62, the page ID 50 and stroke path to the page server 10 m the usual way The page server loads the page descnption 5 identified by the page ID and determmes which mput element's zone 58, if any, the stroke mtersects Assuming the relevant mput element is a text field 878, the page server appends the stroke to the text field's digital ink After a penod of inactivity in the zone of the text field, the page server sends the pen ID and the pending strokes to the registration server 11 for interpretation The registration server identifies the user conespondmg to the pen, and uses the user's accumulated handwntmg model 822 to interpret the strokes as handwntten text Once it has converted the strokes to text, the registration server returns the text to the requestmg 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 mtersects is a signature field 880, the page server 10 appends the stroke to the signature field's digital ink After a penod of inactivity m the zone of the signature field, the page server sends the pen ID 61 and the pendmg strokes to the registration server 11 for venfication It also sends the application ID 64 associated with the form of which the signature field is part, as well as the form ID 56 and the cunent data content of the form The registration server identifies the user conespondmg 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 pπvate signature key It then uses the key to generate a digital signature of the form data, and returns the digital signature to the requestmg 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 mcludes the alias ID 65 of the conespondmg user This allows a smgle form to capture multiple users' signatures 5.5 FORM SUBMISSION PROTOCOL A prefened 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 m Section 52, with some form-specific additions In the case of a form hyperlink, the hyperlink activation message sent by the page server 10 to the application 71 also contams the form ID 56 and the cunent data content of the form If the form contams any signature fields, then the application venfies each one by extracting the alias ID 65 associated with the conespondmg digital signature and obtaining the conespondmg certificate from the registration server 11 5.6 COMMISSION PAYMENT PROTOCOL A prefened embodiment of a commission payment protocol is shown m Figure 47 In an e-commerce envnonment, fees and commissions may 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 ID 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 ID from the page server 10 when the hyperlink is first activated, as descnbed m 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 ID to identify the source application, and sends the credit on to the relevant registration server 11 together with the source application ID 64, its own server ID 53, and the hyperlink request ID The registration server credits the conespondmg application provider's account 827 It also notifies the application provider If the application provider needs to credit the pnnter provider, it sends the prmter provider credit to the ongmal page server together with the hyperlink request ID The page server uses the hyperlink request ID to identify the pnnter, and sends the credit on to the relevant registration server together with the pnnter ID The registration server credits the conespondmg pnnter provider account 814 The source application provider is optionally notified of the identity of the target application provider, and the pnnter provider of the identity of the source application provider 6. NETPAGE PEN DESCRIPTION 6.1 PEN MECHANICS Referring to Figures 8 and 9, the pen, generally designated by reference numeral 101, mcludes a housmg 102 m the form of a plastics moulding havmg walls 103 defining an tenor space 104 for mounting the pen components The pen top 105 is m operation rotatably mounted at one end 106 of the housmg 102 A semi-transparent cover 107 is secured to the opposite end 108 of the housmg 102 The cover 107 is also of moulded plastics, and is formed from semi-transparent matenal m order to enable the user to view the status of the LED mounted withm the housmg 102 The cover 107 mcludes a mam part 109 which substantially sunounds the end 108 of the housmg 102 and a projectmg portion 110 which projects back from the mam part 109 and fits withm a conespondmg slot 111 formed m the walls 103 of the housmg 102 A radio antenna 112 is mounted behind the projectmg portion 110, within the housmg 102 Screw threads 113 suπounding an aperture 113A on the cover 107 are ananged to receive a metal end piece 114, mcludmg conespondmg screw threads 115 The metal end piece 114 is removable to enable mk cartndge replacement Also mounted within the cover 107 is a tπ-color status LED 116 on a flex PCB 117 The antenna 112 is also mounted on the flex PCB 117 The status LED 116 is mounted at the top of 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 mk pen cartndge 118 with mb 119 and a stylus 1 0 with stylus mb 121 are mounted side by side withm the housmg 102 Either the ink cartndge mb 119 or the stylus 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 mk cartndge 118 and stylus 120, respectively A rotatable cam banel 125 is secured to the pen top 105 in operation and ananged to rotate therewith The cam banel 125 mcludes a cam 126 m the form of a slot within the walls 181 of the cam banel Cam followers 127 and 128 projectmg from slider blocks 123 and 124 fit within the cam slot 126 On rotation of the cam banel 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 nib 121 out, • Ink cartridge 118 mb 119 out, and • Neither ink cartndge 118 mb 119 out nor stylus 120 nib 121 out A second flex PCB 129, is mounted on an electronics chassis 130 which sits within the housing 102 The second flex PCB 129 mounts an infrared LED 131 for providmg infrared radiation for projection onto the surface An image sensor 132 is provided mounted on the second flex PCB 129 for receiving reflected radiation from the surface The second flex PCB 129 also mounts a radio frequency chip 133, which mcludes 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 withm the cover 107 and projects an infrared beam onto the surface and receives images onto the image sensor 132 Power supply wues 136 connect the components on the second flex PCB 129 to battery contacts 137 which are mounted withm the cam banel 125 A terminal 138 connects to the battery contacts 137 and the cam banel 125 A three volt rechargeable battery 139 sits within the cam banel 125 m contact with the battery contacts An induction chargmg 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 detectmg displacement m the cam banel 125 when either the stylus 120 or the ink cartndge 118 is used for wntmg, in order to enable a determination of the force bemg applied to the surface by the pen mb 119 or stylus mb 121 The IR photodiode 144 detects light from the IR 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 gnpprng 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 ananged to determine the position of its mb (stylus mb 121 or ink cartndge mb 119) by imaging, m the infrared spectrum, an area of the surface the vicinity of the mb It records the location data from the nearest location tag, and is ananged to calculate the distance of the nib 121 or 119 from the location tab utilising optics 135 and controller chip 134 The controller chip 134 calculates the onentation of the pen and the nib-to-tag distance from the perspective distortion observed on the imaged tag 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 of 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 withm the pen 101 (the pen 101 circuitry mcludes a buffer ananged to store digital ink data for 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 illusfratmg 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 tn-color status LED 116, the IR illumination LED 131, the IR force sensor LED 143, and the force sensor photodiode 144 The pen controller chip 134 mcludes 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 ananged to convert the analog signal from the force sensor photodiode 144 to a digital signal An image senso mterface 152 mterfaces with the image sensor 132 A transceiver controller 153 and base band circuit 154 are also mcluded to mterface with the RF chip 133 which mcludes an RF circuit 155 and RF resonators and mductors 156 connected to the antenna 112 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-performance (~40MHz) general-purpose RISC processor The processor 145, digital transceiver components (transceiver controller 153 and baseband circuit 154), uiiage sensor mterface 152, flash memory 147 and 512KB DRAM 148 are mtegrated in a smgle controller ASIC Analog RF components (RF circuit 155 and RF resonators and mductors 156) are provided m the separate RF chip The image sensor is a 215x215 pixel CCD (such a sensor is produced by Matsushita Electronic Corporation, and is descnbed m a paper by Itakura, K T Nobusada, N Okusenya, R Nagayoshi, and M Ozaki, "A 1mm 50k-Pιxel IT CCD Image Sensor for Miniature Camera System", IEEE Transactions on Electu di Devices, Volt 47, number 1, January 2000, which is incorporated herem by 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 surface It mcorporates a dedicated circuit 150 which momtors the force sensor photodiode 144 and wakes up the controller 134 via the power manager 151 on a pen-down event The radio transceiver commumcates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively the unlicensed 2 4GHz lndustnal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free communication In an alternative embodiment, the pen mcorporates an Infrared Data Association (IrDA) mterface for short- range communication with a base station or netpage prmter In a further embodiment, the pen 101 mcludes a pair of orthogonal accelerometers mounted in the normal plane of the pen 101 axis The accelerometers 190 are shown m Figures 9 and 10 m ghost outline The provision of the accelerometers enables this embodiment of the pen 101 to sense motion without reference to surface location tags, allowing the location tags to be sampled at a lower rate Each location tag ID can then identify an object of interest rather than a position on the surface For example, if the object is a user mterface mput element (e g a command button), then the tag ID of each location tag withm the area of the mput element can directly identify the mput element The acceleration measured by the accelerometers m each of the x and y directions is mtegrated with respect to time to produce an instantaneous velocity and position Smce the starting position of the stroke is not known, only relative positions within a stroke are calculated Although position mtegration accumulates enors m the sensed acceleration, accelerometers typically have high resolution, and the tune duration of a stroke, over which enors accumulate, is short 7. NETPAGE PRINTER DESCRIPTION 7.1 PRINTER MECHANICS The vertically-mounted netpage wallprmter 601 is shown fully assembled m Figure 11 It prints netpages on Letter/A4 sized media usmg 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 passmg through the duplexed pnnt engmes 602 and 603 which pnnt both sides of a sheet simultaneously, m full color and with full bleed An integral binding assembly 605 applies a stnp 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 from one sheet to several hundred sheets The replaceable ink cartndge 627, shown m Figure 13 coupled with the duplexed pnnt engines, has bladders or chambers for storing fixative, adhesive, and cyan, magenta, yellow, black and infrared inks The cartndge also contams a micro air filter m a base moldmg The micro air filter interfaces with an air pump 638 mside the pnnter via a hose 639 This provides filtered air to the pπntheads to prevent ingress of micro particles mto the Memjet™ prmtheads 350 which might otherwise clog the prmthead nozzles By incorporating the air filter withm 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 prmtmg 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 tray past a paper sensor on the first pnnt engme 602 mto the duplexed Memjet™ pnnthead assembly The two Memjet™ pnnt engmes 602 and 603 are mounted m an opposmg in-line sequential configuration along the straight paper path The paper 604 is drawn into the first pnnt engme 602 by integral, powered pick-up rollers 626 The position and size of the paper 604 is sensed and full bleed prmtmg commences Fixative is pπnted simultaneously to aid drying the shortest possible time The paper exits the first Memjet™ pnnt engine 602 through a set of powered exit spike wheels (aligned along the straight paper path), which act against a rubberized roller These spike wheels contact the 'wet' pπnted surface and continue to feed the sheet 604 mto the second Memjet™ pnnt engme 603 Referring to Figures 12 and 12a, the paper 604 passes from the duplexed pnnt engmes 602 and 603 mto the bmder assembly 605 The pπnted 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 forward 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 of a partially hollow axle 679 with a rotating couplmg for the glue supply hose 641 from the ink cartndge 627 This axle 679 connects to a glue wheel, which absorbs adhesive by capillary action through radial holes A molded housmg 682 sunounds the glue wheel, with an opemng at the front Pivotmg side moldmgs and sprung outer doors are attached to the metal bracket and hinge out sideways when the rest of the assembly 673 is thrust forward This action exposes the glue wheel through the front of the molded housmg 682 Tension springs close the assembly and effectively cap the glue wheel dunng penods of inactivity As the sheet 604 passes mto the glue wheel assembly 673, adhesive is applied to one vertical edge on the front side (apart from the first sheet of a document) as it is transported down mto the binding assembly 605 7.2 PRINTER CONTROLLER ARCHITECTURE The netpage prmter controller consists of a controlling processor 750, a factory-installed or field-installed network mterface module 625, a radio transceiver (transceiver controller 753, baseband circuit 754, RF circuit 755, and RF resonators and mductors 756), dual raster image processor (RIP) DSPs 757, duplexed pnnt engme controllers 760a and 760b, flash memory 658, and 64MB of DRAM 657, as illustrated m 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 mterface LEDs 613-616, and feeds and synchronizes the RIP DSPs 757 and pnnt engme controllers 760 It consists of a medium-performance general-purpose microprocessor The controlling processor 750 commumcates with the pnnt engme controllers 760 via a high-speed senal bus 659 The RIP DSPs rastenze and compress page descnptions to the netpage pnnter' s compressed page format Each pnnt engme controller expands, dithers and pnnts page images to its associated Memjet™ pnnthead 350 m real tune (I e at over 30 pages per minute) The duplexed pnnt engme controllers pnnt both sides of a sheet simultaneously The master pnnt engine controller 760a controls the paper transport and monitors ink usage m conjunction with the master QA chip 665 and the mk 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 mam memory 657 at boot tune The processor 750, DSPs 757, and digital transceiver components (transceiver controller 753 and baseband circuit 754) are mtegrated m a smgle controller ASIC 656 Analog RF components (RF circuit 755 and RF resonators and mductors 756) are provided in a separate RF chip 762 The network interface module 625 is separate, since netpage prmters 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 pnnt engme controllers 760 are provided m separate ASICs A vanety of network mterface modules 625 are provided, each providing a netpage netwo k mterface 751 and optionally a local computer or network mterface 752 Netpage network Internet interfaces mclude POTS modems, Hybπd Fiber-Coax (HFC) cable modems, ISDN modems, DSL modems, satellite transceivers, cunent and next- generation cellular telephone transceivers, and wireless local loop (WLL) transceivers Local interfaces mclude IEEE 1284 (parallel port), lOBase-T and 100Base-T Ethernet, USB and USB 2 0, IEEE 1394 (Firewire), and vanous emergmg home networking interfaces If an Internet connection is available on the local network, then the local network mterface can be used as the netpage network mterface The radio transceiver 753 commumcates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively m the unlicensed 2 4GHz mdustnal, 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 (IrDA) mterface for receivmg 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 mam processor 750 has received and venfied the document's page layouts and page ob j ects, it runs the appropnate RIP software on the DSPs 757 The DSPs 757 rastenze each page descnption and compress the rastenzed page image The mam processor stores each compressed page image m memory The simplest way to load-balance multiple DSPs is to let each DSP rastenze a separate page The DSPs can always be kept busy since an arbitrary number of rastenzed pages can, m general, be stored m memory This strategy only leads to potentially poor DSP utilization when rastenzmg short documents Watermark regions m the page descnption are rasteπzed to a contone-resolution bi-level bitmap which is losslessly compressed to negligible size and which forms part of the compressed page image The infrared (IR.) layer of the prmted page contams coded netpage tags at a density of about six per mch Each tag encodes the page ID, tag ID, and control bits, and the data content of each tag is generated dunng rasterization and stored m the compressed page image The mam processor 750 passes back-to-back page images to the duplexed pnnt engme controllers 760 Each pnnt engme controller 760 stores the compressed page image m its local memory, and starts the page expansion and pπntmg pipelme Page expansion and prmtmg is pipelmed because it is unpractical to store an entire 114MB bi-level CMYK+IR page image m memory 7.2.2 PRINT ENGINE CONTROLLER The page expansion and pπntmg pipelme of the pnnt engme controller 760 consists of a high speed IEEE 1394 senal mterface 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 line loader/formatter unit 767, and a custom mterface 768 to the Memjet™ pnnthead 350 The pnnt engme controller 360 operates in a double buffered manner While one page is loaded mto DRAM 769 via the high speed senal interface 659, the previously loaded page is read from DRAM 769 and passed through the pnnt engme controller pipelme Once the page has finished printing, the page just loaded is pnnted 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 accordmg to the tag format defined m section 1 2, all m parallel The second stage dithers (at 765) the contone CMYK layer and composites (at 765) the bi-level black layer over the resultmg bi-level CMYK layer The resultant bi-level CMYK+IR dot data is buffered and formatted (at 767) for pπntmg on the Memjet™ pnnthead 350 via a set of line buffers Most of these lme 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™ pnnthead 350 via the pnnthead mterface 768 When several pnnt engme controllers 760 are used in unison, such as m a duplexed configuration, they are synchronized via a shared lme sync signal 770 Only one pnnt engine 760, selected via the external master/slave pin 771, generates the line sync signal 770 onto the shared lme The pnnt engine controller 760 contams a low-speed processor 772 for synchronizing the page expansion and rendering pipelme, configunng the pnnthead 350 via a low-speed senal bus 773, and controlling the stepper motors 675, 676 In the 8! " versions of the netpage pnnter, the two pnnt engmes each pnnts 30 Letter pages per minute along the long dimension of the page (11"), giving a lme rate of 8 8 kHz at 1600 dpi In the 12" versions of the netpage pnnter, the two pnnt engmes each pnnts 45 Letter pages per mmute along the short dimension of the page (8V2"), givmg a lme rate of 10 2 kHz These lme rates are well withm the operatmg frequency of the Memjet™ pnnthead, which in the cunent design exceeds 30 kHz 8 PAYMENTS The netpage system provides efficient mechanisms for the secure and auditable delivery of mvoices, statements, and bills directly to the user's netpage pnnter Such documents may mclude regular bills from utility companies for services such as electncity, gas, and telephone The bill can mclude a mechamsm for the user to make a payment The user can select from previously established payment methods or enter a new payment card, sign the bill, and submit the payment 8.1 APPLICATION DIAGRAM NOTATION Each application user mterface flow is illustrated as a collection of documents linked by command anows A command anow mdicates that the target document is pnnted as a result of the user pressmg the conespondmg command button on the source page Some command anows are labelled with multiple commands separated by slashes (7's), mdicatmg that any one of the specified commands causes the target document to be pπnted Although multiple commands may label the same command anow, they typically have different side-effects In application terms, it is important to distinguish between netpage documents and netpage forms Documents contam pπnted mformation, as well as command buttons which can be pressed by the user to request further mformation or some other action Forms, m addition to behaving like normal documents, also contam mput fields which can be filled m by the user They provide the system with a data mput mechamsm It is also useful to distinguish between documents which contam genenc mformation and documents which contam information specific to a particular mteraction between the user and an application Genenc documents may be pre-pπnted publications such as magazmes sold at news stands or advertismg posters encountered m public places Forms may also be pre-pπnted, mcludmg, for example, subscnption forms encountered m pre-pπnted publications They may, of course, also be generated on-the-fly by a netpage pnnter m response to user requests User-specific documents and forms are normally generated on the fly by a netpage pnnter m response to user requests Figure 48 shows a genenc document 990, a genenc form 991 , a user- specific document 992, and a user-specific form 993 Netpages which participate m a user interface flow are further descnbed by abstract page layouts A page layout may contam vaπous kmds of elements, each of which has a unique style to differentiate it from the others As shown m Figure 49, these mclude fixed information 994, vanable information 995, input fields 996, command buttons 997, and draggable commands 998 When a user mterface flow is broken up mto multiple diagrams, any document which is duplicated is shown with dashed outlmes m all but the mam diagram which defines it 8.2 PAYMENTS OBJECT MODEL The payments object model revolves around a biller, customers, bills and bn payments Each biller 500 has a umque identifier and a name Each customer 501 is related to a particular biller 500, and has an identifier 65 which is umque withm the scope of the particular biller The customer id 65 is the alias id for the application user 805, as allocated by a registration server Each customer 501 represents a particular netpage user 800 to the biller A netpage user 800, on the other hand, can be the customer of any number of billers Each customer 501 has a history of payment methods 504 with the biller The name and descnption of a customer denves from the details of the conespondmg netpage user 800 Each bill 502 is associated with one customer and one biller, and has a umque bill number, a due date, and a due amount Each bill payment 503 has a umque payment number, the date and time of the payment, the amount paid, and a receipt number Each bill payment 503 has associated with it a payment method 504 When the SET payment method 506 is used, the conespondmg SET payment card 821 linked to the use is used to make payment accordmg to the normal SET protocol When the payment card payment method 505 is used, the specified payment card is used to make payment accordmg to the normal protocol between the biller and their acquiring bank or institution which handles the particular payment card type The Bill Payments class diagram is shown m Figure 50 8.2 PAYMENTS USER INTERFACE A bill may be delivered to a user directly to their netpage pnnter, or may be delivered through the normal postal service A typical bill 507 507a mcludes a section explaining the detailed charges 509 making up the bill, the total amount due and the payment due date The bill also mcludes a list of the customer's previously used payment methods A typical bill 507 507a is shown m Figures 52 and 53 The user selects a payment card, or enters a new payment card to be used for payment, signs the form with their netpage pen, and presses the <Pay Now> button The user is identified by the netpage pen 801 they are usmg and the signature is veπfied from netpage records 818 If the user clicks <Reset Form> the bill is re-pπnted When the payment is complete a Payment Receipt 508 is pnnted, as shown m Figure 54 The Bill Payment user mterface flow is shown m Figure 51 CONCLUSION The present mvention has been descnbed with reference to a prefened 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, differing from those specifically descnbed, will also fall withm the spint and scope of the present mvention Accordingly, it will be understood that the mvention is not mtended to be limited to the specific embodiments descnbed m the present specification, mcludmg documents mcorporated by cross-reference as appropnate The scope of the mvention is only limited by the attached claims

Claims: CLAIMS 1 A method of enablmg payment of bills, the method mcludmg the steps of providing a person with a bill contammg information relatmg to a requested payment, the bill mcludmg coded data mdicative of an identity of the bill and of at least one reference pomt of the bill, receivmg, m a computer system, mdicatmg data from a sensmg device regardmg the identity of the bill and a position of the sensmg device relative to the bill, the sensmg device, when placed m an operative position relative to the bill, sensmg the mdicatmg data usmg at least some of the coded data, and identifymg, m the computer system and from the mdicatmg data, at least one parameter relatmg to the requested payment 2 The method of claim 1 m which said at least one parameter relating to the requested payment is associated with at least one zone of the bill and m which the method mcludes identifymg, in the computer system and from the zone relative to which the sensmg device is located, said at least one parameter 3 The method of claim 2 which mcludes receivmg, m the computer system, data regarding movement of the sensing device relative to the bill, the sensmg device sensmg its movement relative to the bill usmg at least some of the coded data, and identifymg, m the computer system and from said movement bemg at least partially withm said at least one zone, said at least one parameter of the requested payment 4 A method of enablmg payment of bills, the method mcludmg the steps of providing a person with a bill contammg information relatmg to a requested payment, the form mcludmg coded data mdicative of at least one parameter of the requested payment, receivmg, m a computer system, data from a sensmg device regarding said at least one parameter and regardmg movement of the sensmg device relative to the bill, the sensmg device, when moved relative to the bill, sensmg the data regardmg said at least one parameter using at least some of the coded data and generatmg the data regardmg its own movement relative to the bill, and interpreting, m the computer system, said movement of the sensmg device as it relates to said at least one parameter 5 A method of enablmg payment of bills, the method including the steps of providmg a person with a bill mcludmg coded data mdicative of an identity of the bill, receivmg, m a computer system, data from a sensmg device regarding an identity of the person and regarding the identity of the bill, the sensing device contammg the data regardmg the identity of the person and sensmg the data regardmg the identity of the bill usmg at least some of the coded data, and identifymg, m the computer system and from the data regarding the identity of the person and the identity of the bill, a requested payment 6 The method of claim 5 m which the coded data is also indicative of at least one parameter of the requested payment, and the method mcludes receivmg, m the computer system, mdicatmg data from the sensmg device regardmg said at least one parameter of the requested payment, the sensmg device sensmg the mdicatmg data usmg at least some of the coded data 7 The method of claim 6 which mcludes receivmg, in the computer system, data from the sensmg device regardmg movement of the sensmg device relative to the bill, the sensmg device generatmg data regarding its own movement relative to the bill 8 The method of any one of claims 2, 4 or 6 m which the parameter is an action parameter of the requested payment, the method mcludmg effecting, m the computer system an operation m respect of the action parameter 9 The method of claim 8 m which the action parameter of the requested payment is selected from the group compπsmg requestmg that payment be made, specifying a payment amount or resetting the bill to an ongmal state 10 The method of any one of claims 3, 4 or 7 m which the parameter is an option parameter of the requested payment, the method mcludmg identifymg, m the computer system, that the person has entered a hand-drawn mark by means of the sensmg device and effectmg, m the computer system, an operation associated with the option parameter 11 The method of claim 10 m which the option parameter is associated with at least one of cardholder name, payment method or credit card type 12 The method of any one of claims 3, 4 or 7 m which the parameter is a text parameter of the requested payment, the method mcludmg identifymg, m the computer system, that the person has entered handwritten text data by means of the sensmg device and effectmg, m the computer system, an operation associated with the text parameter 13 The method of claim 12 which mcludes converting, m the computer system, the handwritten text data to computer text 14 The method of claim 13 in which the text parameter is associated with at least one of a cardholder name, an amount paid or a card expiry date 15 The method of any one of claims 3, 4 or 7 m which the parameter is an authorization parameter of the requested payment, the method mclud g identifymg, m the computer system, that the person has entered a handwritten signature by means of the sensmg device and effectmg, m the computer system, an operation associated with the authoπzation parameter 16 The method of claim 15 which mcludes venfymg, m the computer system, that the signature is that of the person 17 The method of claim 16 in which the authorization parameter is associated with payment authorization 18 The method of any one of claims 1 , 4 or 5 which mcludes enablmg the person to pnnt the bill on demand 19 The method of anyone of claims 1 , 4 or 5 which mcludes pπntmg the bill on a surface of a surface- defining means and, at the same time that the bill is pπnted, pπntmg the coded data on the surface 20 The method of claim 19 which includes pπntmg the coded data to be substantially invisible 21 The method of claim 1 or 5 which mcludes retaining a retnevable record of each bill generated, the bill bemg retnevable usmg its identity as contained m its coded data 22 The method of any one of claims 1 , 4 or 5 which mcludes distnbuting a plurality of the bills usmg a mixture of multicast and pomtcast communications protocols 23 The method of claim 1 or 4 m which the sensmg device contams an identification means which imparts a umque identity to the sensmg device and identifies it as belonging to a particular person and m which the method mcludes momtonng, m the computer system, said identity 24 The method of any one of claims 1 , 4 or 5 which mcludes providing all required information relatmg to the requested payment m the bill to eliminate the need for a separate display device 25 The method of any one of claims 1, 4 or 5 m which the bill is pnnted on multiple pages and m which the method mcludes binding the pages 26 The method of any of claims 1 , 4 or 5 wherem providmg the person with a bill is done by sending the bill by mail 27 The method of any one of claims 1 , 4 or 5 wherem a pnnter associated with the person is caused to pnnt a payment receipt after a payment has been completed 28 The method of claim 27, wherem the payment receipt compπses coded data mdicative of the identity of the receipt 29 A system for enablmg payment of bills, the system mcludmg a bill contammg information relating to a requested payment, the bill mcludmg coded data mdicative of an identity of the bill and of at least one reference pomt of the bill, and a computer system for receivmg mdicatmg data from a sensmg device for identifymg at least one parameter relatmg to the requested payment, the indicating data being mdicative of the identity of the bill and a position of the sensmg device relative to the bill, the sensmg device sensmg the mdicatmg data usmg at least some of the coded data 30 The system of claim 29 m which said at least one parameter relating to the requested payment is associated with at least one zone of the bill 31 The system of claim 29 which mcludes the sensmg device, the sensmg device sensmg its movement relative to the bill usmg at least some of the coded data 32 A system for enablmg payment of bills, the system mcludmg a bill contammg mformation relatmg to a requested payment, the bill mcludmg coded data indicative of at least one parameter of the requested payment, and a computer system for receivmg data from a sensmg device regardmg said at least one parameter and regardmg movement of the sensmg device relative to the bill, and for mterpretmg said movement of the sensmg device as it relates to said at least one parameter, the sensmg device, when moved relative to the bill, sensmg the data regarding said at least one parameter usmg at least some of the coded data and generatmg the data regardmg its own movement relative to the bill 33 A system for enabling payment of bills, the system mcludmg a bill mcludmg coded data indicative of an identity of the bill, and a computer system for receivmg from a sensmg device data regardmg an identity of the person and the identity of the bill, and for identifying, from said received data, a requested payment, the sensmg device contammg the data regarding the identity of the person and sensmg the data regardmg the identity of the bill usmg at least some of the coded data 34 The system of claim 33 m which the coded data is also indicative of at least one parameter of the requested payment, the computer system receivmg mdicatmg data from the sensmg device regardmg said at least one parameter of the requested payment, and the sensmg device sensmg the mdicatmg data usmg at least some of the coded data 35 The system of claim 33 which mcludes the sensmg device, the sensmg device sensmg its movement relative to the bill 36 The system of any one of claims 29, 32 or 34 m which said at least one parameter of the requested payment is selected from the group compnsing an action parameter of the requested payment, an option parameter of the requested payment, a text parameter of the requested payment, or an authorization parameter of the requested payment 37 The system of claim 36 m which the action parameter of the requested payment is selected from the group compπsmg requestmg that payment be made, specifying a payment amount, or resetting the bill to an ongmal state 38 The system of claim 36 m which the option parameter is associated with at least one of cardholder name, payment method, or credit card type 39 The system of claim 36 m which the text parameter is associated with at least one of a cardholder name, an amount paid, or a card expiry date 40 The system of claim 36 m which the authorization parameter is associated with payment authorization 41 The system of any one of claims 31, 32 or 35 m which the sensmg device mcludes a markmg mb 42 The system of claim 31 or 32 m which the sensmg device contams an identification means which imparts a umque identity to the sensmg device and identifies it as belongmg to a particular person 43 The system of any one of claims 29, 32 or 33 m which the bill is pnnted on a surface of a surface- defining means and m which the system mcludes a pnnter for prmtmg the bill on demand 44 The system of claim 43 m which the pnnter pnnts the coded data at the same tune as pπntmg the bill or payment receipt 45 The system of any one of claims 29, 32 or 33 m which the coded data is substantially invisible 46 The system of claim 29 or 33 which mcludes a database for keepmg a retnevable record of each bill generated, each bill bemg retnevable by usmg its identity as mcluded m its coded data 47 The system of claim 43 m which, to cater for a bill pπnted on multiple pages, the pnnter mcludes a bmdmg means for bmdmg the pages

Inventors: LAPSTUN JACQUELINE ANNE, LAPSTUN PAUL, WALMSLEY SIMON ROBERT, LAPSTUN, JACQUELINE, ANNE, LAPSTUN, PAUL, WALMSLEY, SIMON, ROBERT
Applicants: LAPSTUN JACQUELINE ANNE, LAPSTUN PAUL, SILVERBROOK KIA, SILVERBROOK RES PTY LTD, WALMSLEY SIMON ROBERT, LAPSTUN, JACQUELINE, ANNE, LAPSTUN, PAUL, SILVERBROOK RESEARCH PTY. LTD., SILVERBROOK, KIA, WALMSLEY, SIMON, ROBERT
Application year: 2000
Main classification: G06K11
IPC codes: B41J2, B41J29, G06F3, G06F15, G06F17, G06F19, G06F21, G06K9, G06K11, G06K17, G06Q10, G06Q20, G06Q30, G06Q40, G06Q50, G06T1