METHOD AND SYSTEM FOR COMPOSITION AND DELIVERY OF ELECTRONIC MAIL

Abstract: A method for composition and transmission of an electronic mail message including: printing a document to facilitate composition and transmission of the electronic mail message; composing the electronic mail message on the document utilizing a sensing device adapted to read coded data in the document; transmitting interaction data from the sensing device to a computer system, the interaction data representing interaction of the sensing device with the coded data to allow the message to be electronically captured in the computer system; and transmitting the message to at least one recipient address.

Description: METHOD AND SYSTEM FOR COMPOSITION AND DELIVERY OF ELECTRONIC MAIL FIELD OF INVENTION The present invention relates generally to methods, systems and apparatus for interacting with computers More particularly, the invention relates to composition and delivery of electronic mail, utilizing such devices, systems and methods 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 printed matter on demand via high-speed networked color printers Although the invention will largely be described herein with reference to this use, it will be appreciated that the invention is not limited to use in this field CO-PENDING APPLICATIONS Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application PCT/AU00/00518, PCT/AU00/00519, PCT/AU00/00520. 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/AUOO/00531 , PCT/AU00/00532, PCT/AUOO/00533, PCT/AUOO/00534, PCT/AU00/00535, PCT/AUOO/00536, PCT/AUOO/00537, PCT/AU00/00538, PCT/AU00/00539, PCT/AUOO/00540, PCT/AU00/00541, PCT/AU00/00542, PCT/AU00/00543, PCT/AU00/00544, PCT/AU00/00545, PCT/AU00/00547, PC1/AU00/00546, PCT/AU00/00554, PCT/AU00/00556, PCT/AU00/00557. PCT/AU00/00558, PCT/AUOO/00559, PCT/AU00/00560, PCT/AU00/00561 , PCT/AU00/00562, PCT/AU00/00563, PCT/AUOO/00564, PCT/AU00/00566, PCT/AU00/00567, PCT/AU00/00568, PCT/AU00/00569, PCT/AU00/00570, PCT/AU00/00571 , PCT/AU00/00572, PCT/AU00/00573, PCT/AU00/00574, PCT/AU00/00575, PCT/AU00/00576, PCT/AU00/00577, PCT/AU00/00578, PCT/AU00/00579, PCT/AU00/00581, PCT/AU00/00580, PCT/AU00/00582, PCT/AU00/00587, PCT/AU00/00588, PCT/AU00/00589, PCT/AU00/00583, PCT/AU00/00593, PCT/AU00/00590, 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 Paper is widely used to display and record information Printed information is easier to read than information displayed on a computer screen Hand-drawing and handwriting afford greater richness of expression than input via a computer keyboard and mouse Moreover, paper doesn't run on batteries, can be read in bright light, more robustly accepts coffee spills, and is portable and disposable Online publication has many advantages over traditional paper-based publication From a consumer's point of view, information is available on demand, information can be navigated via hypertext links, searched and automatically personalized - 1a - From the publisher's point of view, the costs of printing and physical distribution are eliminated, and the publication becomes more attractive to the advertisers who pay for it because it can be targeted to specific demographics and linked to product sites Online publication also has disadvantages Computer screens are inferior to paper At the same quality as a magazine page, an SVGA computer screen displays only about a fifth as much information Both CRTs and LCDs have brightness and contrast problems, particularly when ambient light is strong, while ink on paper, being reflective rather than emissive, is both bright and sharp in ambient light - 2 - OBJECT It is an object of the mvention to combme advantages of conventional pπnted information and hand-wπtten messages with digital ink to facilitate composition and delivery of electromc mail SUMMARY OF INVENTION In accordance with the mvention, there is provided a method for composition and transmission of an electromc mail message mcludmg pπnting a document to facilitate composition and transmission of the electronic mail message, composing the electromc mail message on the document utilismg a sensmg device adapted to read coded data m the document, transmitting mteraction data from the sensmg device to a computer system, the mteraction data representing mteraction of the sensmg device with the coded data to allow the message to be electronically captured m the computer system, and transmitting the message to at least one recipient address Preferably, the address of the recipient is converted from hand-wπtten indicia on the document to an electromc form of the address to facilitate transmission Preferably, at least part of the message as applied to the document is converted from hand-wπtten indicia or alpha-numerals to electromc equivalents More preferably, at least part of the message as applied to the document is converted from hand-wπtten indicia or alpha-numerals to electromc equivalents The step of elecfromcally captunng the message preferably mcludes receiving, m the computer system, movement data regarding movement of the sensmg device relative to the document, with the sensmg device preferably sensmg its movement relative to the form usmg the coded data Followmg electromc capture, at least part of the electromc mail message is transmitted to the recipient address as digital ink and the second document preferably has at least one user mteractive element which enables a recipient to indicate a response to associated information in the second document by interacting with the user mteractive element usmg a sensmg device which is adapted to transmit response data to a computer Preferably also, only an electromc mail message from an approved sender is accepted at the recipient address, the approved sender bemg entered m a customizable electronic list or database Preferably, a user addresses the electromc mail message to the recipient address by selecting a name from a list on the document usmg the sensmg device Preferably, the method further mcludes receivmg, in the computer system, indicating data deπved from the coded data, regardmg the identity of the document and a position of the sensmg device relative to the document m order to identify the document and determine when the sensmg device is used to mteract with the document Preferably, the sensmg device mcludes an identification code specific to a particular user and the method mcludes monitoring use of the sensmg device m the computer system The method may further mclude printing the document on a surface of a surface-defining structure and, at the same time, pnnting the coded data on the surface with the coded data preferably bemg substantially invisible m the visible spectrum Preferably, the method includes retaining a retπevable record of the pπnted document, the document bemg retπevable using the identity data as contained m the coded data In another aspect, there is provided a system for composition and transmission of an electromc mail message mcludmg a pπnter for pnnting a document with coded data, to facilitate composition and transmission of the electromc mail message, - 3 - a sensmg device for reading the coded data and transmitting mteraction data, representing mteraction of the sensmg device with the coded data to allow for electromc capture of the message, generated by movmg the device relative to the document, and a computer system for receiving the mteraction data from the device and transmitting the message to a recipient address Preferably, the computer system is adopted to transmit the electromc mail message to an electromc mail server Preferably, the computer system is provided with means so that the address of the recipient is converted from hand-wπtten indicia on the document to an electromc form of the address Preferably, the computer system is provided with means so that at least part of the electromc mail message as applied to the document is converted from elecfromcally captured hand-wπtten indicia or alpha-numerals to electromc equivalents More preferably, the computer system is provided with means so that at least part of the electromc mail message as applied to the document is converted from elecfromcally captured hand-wπtten indicia, alpha-numerals- diagrams, figures, or the like, to an electromc form which substantially preserves the format and appearance of the relevant part of the electromc mail message In order to elecfromcally capture the message, the computer system is preferably, adapted to receive movement data regarding movement of the sensmg device relative to the coded data, m order to elecfromcally capture the message, and the sensmg device preferably, senses its own movement relative to the document usmg the coded data The system may further mclude a pπnter at the recipient address for producing a second document containmg the electromc mail message and the second document preferably has at least one user mteractive element which enables a recipient to indicate a response to associated information m the second document by interacting with the user mteractive element usmg a sensmg device which is adapted to transmit response data to a computer Preferably, the pπnter only accepts an electromc mail message from an approved sender, the approved sender bemg entered m a customisable electromc list or database Preferably, the coded data serves to identify the document and a position of the sensmg device relative to the document The sensing device preferably also mcludes a marking mb The pπnter is preferably arranged to pπnt the coded data on demand, at the same time as pnnting the document on the surface-defining structure, with the coded data preferably bemg substantially invisible m the visible spectrum The system preferably mcludes a database for keepmg a retπevable record of each document generated, each document bemg retπevable by usmg its identity, as mcluded m its coded data BRIEF DESCRIPTION OF DRAWINGS Prefeπed 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 pπnted netpage and its online page descnption, Figure 2 is a schematic view of a mteraction between a netpage pen, a netpage pπnter, a netpage page server, and a netpage application server, Figure 3 illustrates a collection of netpage servers and pπnters interconnected via a network, Figure 4 is a schematic view of a high-level structure of a printed netpage and its online page descnption, Figure 5 is a plan view showing a structure of a netpage tag, Figure 6 is a plan view showing a relationship between a set of the tags shown m Figure 5 and a field of view of a - 4 - netpage sensmg device m the form of a netpage pen, Figure 7 is a flowchart of a tag image processing and decoding algoπthm, Figure 8 is a perspective view 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 pπnter, Figure 12 is a section through the length of the netpage pπnter of Figure 11, Figure 12a is an enlarged portion of Figure 12 showing a section of the duplexed pπnt engmes and glue wheel assembly, Figure 13 is a detailed view of the ink cartndge, ink, air and glue paths, and pπnt engmes of the netpage pπnter of Figures 11 and 12, Figure 14 is a schematic block diagram of a pπnter controller for the netpage pπnter shown m Figures 11 and 12, Figure 15 is a schematic block diagram of duplexed pπnt engme controllers and Memjet™ pπntheads associated with the pπnter controller shown m Figure 14, Figure 16 is a schematic block diagram of the pπnt engme controller shown in Figures 14 and 15, Figure 17 is a perspective view of a smgle Memjet™ pπnting element, as used m, for example, the netpage pπnter of Figures 10 to 12, Figure 18 is a perspective view of a small part of an anay of Memjet™ pπnting elements, Figure 19 is a seπes of perspective views illustrating the operating cycle of the Memjet™ pπnting element shown m Figure 13, Figure 20 is a perspective view of a short segment of a pagewidth Memjet™ pnnthead, Figure 21 is a schematic view of a user class diagram, Figure 22 is a schematic view of a pπnter 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 termmal 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 hyperlinked 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 input processing algoπthm, 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 descπption class diagram, Figure 41 is a schematic view of a favoπtes 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 mdexed directory class diagram- Figure 51 is a schematic view of a genenc directory index page, Figure 52 is a schematic view of a directory navigation user mterface flow, Figure 53 is a schematic view of an e-mail user class diagram, Figure 54 is a schematic view of an e-mail class diagram, Figure 55 is a schematic view of a mailbox class diagram, Figure 56 is a schematic view of a contact list class diagram, Figure 57 is a schematic view of a baned user list class diagram, Figure 58 is a schematic view of a user mterface flow for e-mail, Figure 59 is a schematic view of a user mterface flow for an e-mail recipient exception, Figure 60 is a schematic view of an outgomg e-mail first page, Figure 61 is a schematic view of an outgomg e-mail second or subsequent page, Figure 62 is a schematic view of an add recipients page, Figure 63 is a schematic view of an incoming e-mail first page, Figure 64 is a schematic view of an incoming e-mail second or subsequent page, Figure 65 is a schematic view of a user mterface flow for editing a contact, Figure 66 is a schematic view of an edit contacts page, Figure 67 is a schematic view of a copy contact first page, Figure 68 is a schematic view of a set e-mail folder first page, Figure 69 is a schematic view of a user mterface flow for a mailbox listing, Figure 70 is a schematic view of a mailbox page, Figure 71 is a schematic view of an e-mail folder page, Figure 72 is a schematic view of a copy e-mail first page, Figure 73 is a schematic view of a user mterface flow for editing a barred user list, Figure 74 is a schematic view of an edit baned user list page, Figure 75 is a schematic view of a user mterface flow for a global user directory, Figure 76 is a schematic view of a global user directory page, Figure 77 is a schematic view of a user information page, Figure 78 is a schematic view of a user mterface flow for Internet contact registration, and Figure 79 is a schematic view of an Internet contact registration page DETAILED DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS Note Memjet™ is a trade mark of Silverbrook Research Pty Ltd, Australia In the prefened embodiment, the mvention 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 - 6 - embody all or even most of the specific details and extensions discussed below m relation to the basic system However, the system is descπbed m its most complete form to reduce the need for external reference when attempting to understand the context m which the prefened embodiments and aspects of the present mvention operate In bπef summary, the prefened 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 appropnate sensmg device Depending 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 contain 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 retπeved can take the form of actions which are initiated by the computer system on behalf of the operator in response to the operator's mteraction with the surface features In its prefened form, the netpage system relies on the production of, and human mteraction with, netpages These are pages of text, graphics and images pnnted on ordinary paper, but which work like mteractive web pages Information is encoded on each page usmg mk 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 prefened form, active buttons and hyperlinks on each page can be clicked with the pen to request information from the network or to signal preferences to a network server In one embodiment, text wntten by hand on a netpage is automatically recognized and converted to computer text m the netpage system, allowmg forms to be filled m In other embodiments, signatures recorded on a netpage are automatically venfied, allowmg e-commerce transactions to be securely authonzed As illustrated m Figure 1, a pπnted netpage 1 can represent a mteractive form which can be filled m by the user both physically, on the pπnted page, and "elecfromcally", via communication between the pen and the netpage system The example shows a "Request" form containmg name and address fields and a submit button The netpage consists of graphic data 2 pnnted usmg visible ink, and coded data 3 pπnted as a collection of tags 4 usmg invisible ink The conespondmg page descnption 5, stored on the netpage network, descnbes the mdividual elements of the netpage h particular it descnbes the type and spatial extent (zone) of each mteractive element (I e text field or button m the example), to allow the netpage system to conectlv interpret mput via the netpage The submit button 6, for example, has a zone 7 which conesponds to the spatial extent of the conespondmg graphic 8 As illustrated in Figure 2, the netpage pen 101, a prefened form of which is shown in Figures 8 and 9 and descnbed m more detail below, works m conjunction with a netpage pπnter 601, an Internet-connected pnnting 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 pπnter 601, a prefened form of which is shown m Figures 11 to 13 and descnbed m more detail below, is able to deliver, penodically or on demand, personalized newspapers, magazmes, catalogs, brochures and other publications, all pnnted at high quality as mteractive netpages Unlike a personal computer, the netpage pπnter 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 m tabletop, desktop, portable and miniature versions Netpages prmted at their pomt of consumption combme 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 communicates, via a short-range radio link 9, the mteraction to a netpage pnnter The pπnter 601 sends the mteraction to the relevant netpage page server 10 for mterpretation In appropnate circumstances, the page server sends a conespondmg message to application computer software running on a netpage application server 13 The application server may m turn send a response which is pπnted on the oπgmating pπnter 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™) pnnters In the prefened form of this technology, relatively high-speed and high-quality pπnting is made more affordable to consumers In its prefened form, a netpage publication has the physical charactenstics of a fraditional newsmagazme, such as a set of letter-size glossy pages pπnted m full color on both sides, bound together for easy navigation and comfortable handling The netpage pπnter exploits the growing availability of broadband Internet access Cable service is available to 95% of households in the Umted States, and cable modem service offeπng broadband Internet access is already available to 20% of these The netpage pπnter can also operate with slower connections, but with longer delivery times and lower image quality Indeed, the netpage system can be enabled usmg existing consumer inkjet and laser pπnters, 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 pnvate mfranet In still other embodiments, the netpage system is hosted on a smgle computer or computer-enabled device, such as a pnnter Netpage publication servers 14 on the netpage network are configured to deliver print-quality publications to netpage pnnters Penodical publications are delivered automatically to subscnbmg netpage pnnters via pointcasting and multicasting Internet protocols Personalized publications are filtered and formatted accordmg to mdividual user profiles A netpage pπnter can be configured to support any number of pens, and a pen can work with any number of netpage pπnters 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 authoπzed usu the netpage pen The netpage registration server compares the signature captured by the netpage pen with a previously registered signature, allowmg it to authenticate the user's identity to an e-commerce server Other biometπcs can also be used to venfy identity A version of the netpage pen mcludes fingerprint scanning, veπfied m a similar way by the netpage registration server Although a netpage pπnter may deliver penodicals such as the morning newspaper without user intervention, it can be configured never to deliver unsolicited junk mail In its prefened form, it only delivers penodicals from subscnbed or otherwise authoπzed sources In this respect, the netpage pπnter is unlike a fax machine 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 descπbed usmg 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 land of relationship between objects, I e between mstances of classes A generalization relates actual classes, and can be understood m the followmg 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 attπbutes of the class, separated from the name by a hoπzontal lme, and a list of the operations of the class, separated from the - 8 - attπbute list by a horizontal lme In the class diagrams which follow, however, operations are never modelled An association is drawn as a lme joining two classes, optionally labelled at either end with the multiplicity of the association The default multiplicity is one An asteπsk (*) 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 (m 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 attπbutes 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 mformation and mteractive services A netpage consists of a pnnted page (or other surface region) invisibly tagged with references to an online descπption of the page The online 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 markmgs 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 umque 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 pnnted tag The tag identifies the umque page on which it appears, and thereby indirectly identifies the page descπption The tag also identifies its own position on the page Charactenstics of the tags are descπbed m more detail below Tags are pπnted m 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 appropnate filter A tag is sensed by an area image sensor m the netpage pen, and the tag data is transmitted to the netpage system via the nearest netpage pπnter The pen is wireless and communicates with the netpage pnnter via a short-range radio link Tags are sufficiently small and densely ananged 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 Tags are enor-coπectably 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 in the page descnption for each pπnted netpage The relationship between the page descπption, the page mstance, and the pnnted netpage is shown m Figure 4 The page instance is associated with both the netpage pπnter 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 contain flags which relate to the region as a whole or to the tag One or more flag bits may, for - 9 - 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 having to refer to a descπption of the region A netpage pen may, for example, illuminate 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 m minimizing the effect of any warp duced by the surface or by the sensmg process The tags preferably tile the entire page, and are sufficiently small and densely ananged 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, m which case the region ID can directly identify the mteractive element Table 1 - Tag data Each tag contams 120 bits of information, 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 contmuously 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 tnlhon) different regions to be umquely 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 consisting 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 a spatially coherent way m the tag, and the symbols of the six codewords are mterleaved spatially withm the tag This ensures that a burst enor (an enor affecting multiple spatially adjacent bits) damages a minimum number of symbols overall and a minimum 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, mcludes 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 onentation relative to the sensor The data areas contain 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 pπnted at 1600 dots per mch 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 mcludes six target structures A detection nng 15 allows the sensmg device to initially detect the - 10 - tag The πng is easy to detect because it is rotationally mvanant and because a simple coπection of its aspect ratio removes most of the effects of perspective distortion An onentation axis 16 allows the sensmg device to determine the approximate planar onentation of the tag due to the yaw of the sensor The onentation 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 irregular tnangular gnd In combination with the circular detection nng, this makes a circular aπangement 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 minimum dimension of 8 dots at 1600 dpi and is designed so that its base (its inner arc), is at least equal to this minimum dimension The height of the wedge m the radial direction is always equal to the minimum dimension Each 4-bit data symbol is represented by an anay of 2x2 wedges The 15 4-bit data symbols of each of the six codewords are allocated to the four concentnc symbol rings 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 sensmg device must be able to see at least one entire tag m its field of view no matter where m the region or at what onentation it is positioned The required diameter of the field of view of the sensmg device is therefore a function of the size and spacing 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 processing and decoding performed by a sensmg device such as the netpage pen is shown m Figure 7 While a captured image is bemg acquired from the image sensor, the dynamic range of the image is determined (at 20) The center of the range is then chosen as the binary threshold for the image 21 The image is then thresholded and segmented 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 -ire by their nature mvanant of position, and can be easily made mvanant of scale, aspect ratio and rotation The πng target structure 15 is the first to be located (at 26) A πng has the advantage of bemg very well behaved when perspective-distorted Matching proceeds by aspect-normalizing and rotation-normalizing each shape's moments Once its second-order moments are normalized the nng is easy to recognize even if the perspective distortion was significant The nng's ongmal aspect and rotation 27 together provide a useful approximation of the perspective transform The axis target structure 16 is the next to be located (at 28) Matchmg proceeds by applymg the nng's normalizations to each shape's moments, and rotation-normalizing the resulting moments Once its second-order moments are normalized the axis target is easily recogmzed 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 - 11 - apphed, smce 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 πng and axis targets, the aspect and rotation of the πng, and the rotation of the axis Matchmg proceeds by applymg the nng'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 ongmal centroids of the four perspective targets are then taken to be the perspective-distorted corners 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 solving the well-understood equations relating the four tag-space and irnage- space pomt pairs The infened 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 bilinearly 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-interleaved 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 πng, 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 mdicates the identity of the region containmg the tag and the position of the tag within the region An accurate position 35 of the pen mb m the region, as well as the overall onentation 35 of the pen, is then infened (at 34) from the perspective transform 33 observed on the tag and the known spatial relationship between the pen's physical axis and the pen's optical axis 1.2.5 Tag Map Decoding a tag results in a region ID, a tag ID, and a tag-relative pen transform Before the tag ID and the tag-relative pen location can be translated mto an absolute location withm 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 m a tagged region to a conespondmg location The tag map class diagram is shown in Figure 22, as part of the netpage pnnter class diagram A tag map reflects the scheme used to tile the surface region with tags, and this can vary according to surface type When multiple tagged regions share the same tilmg scheme and the same tag numbering scheme, they can also share the same tag map The tag map for a region must be retπevable 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 withm the region 1.2.6 Tagging Schemes Two distinct surface codmg schemes are of interest, both of which use the tag structure descnbed earlier in this section The prefened coding scheme uses "location-indicating" tags as already discussed An alternative codmg scheme uses object-indicating tags A location-indicating tag contams a tag ID which, when translated through the tag map associated with the tagged region, yields a umque tag location withm the region The tag-relative location of the pen is added to this tag - 12 - location to yield the location of the pen withm the region This m turn is used to deteπnine 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 tnvially support the capture of an absolute pen path in the zone of a particular user mterface element An object-indicating tag contams a tag ID which directly identifies a user mterface element m 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 termmal elements 839 are associated with content objects 840 such as text objects, text style objects, image objects, etc Once the document is pnnted on a pπnter with a particular page size and according to a particular user's scale factor preference, the document is pagmated and otherwise formatted Formatted terminal elements 835 will m some cases be associated with content objects which are different from those associated with their conespondmg termmal elements, particularly where the content objects are style-related Each pπnted mstance of a document and page is also descπbed separately, to allow mput captured through a particular page mstance 830 to be recorded separately from mput captured through other mstances of the same page descnption The presence of the most abstract document descπption on the page server allows a user to request a copy of a document without bemg forced to accept the source document's specific format The user may be requesting a copy through a pnnter with a different page size, for example Conversely, the presence of the formatted document descnption on the page server allows the page server to efficiently interpret user actions on a particular pnnted page A formatted document 834 consists of a set of formatted page descnptions 5, each of which consists of a set of formatted termmal 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 mstances 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 ID 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 instance consists of a set of termmal element mstances 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 - 13 - 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 distnbuted set of netpage page servers 10, netpage registration servers 11, netpage ID servers 12, netpage application servers 13, netpage publication servers 14, and netpage pnnters 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, pnnters, applications and publications, and thereby authorizes vanous network activities It authenticates users and acts as a signmg proxy on behalf of authenticated users m application transactions It also provides handwnting recogmtion services As descπbed above, a netpage page server 10 maintains persistent mformation about page descnptions and page mstances The netpage network mcludes any number of page servers, each handling a subset of page mstances Smce a page server also maintains user mput values for each page mstance, clients such as netpage pnnters 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 ID server 12 allocates document IDs 51 on demand, and provides load-balancing of page servers via its ID allocation scheme A netpage pnnter uses the Internet 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 mteractive netpage applications A netpage publication server 14 is an application server which publishes netpage documents to netpage pnnters They are descnbed in detail m Section 2 Netpage servers can be hosted on a vanety of network server platforms from manufacturers such as IBM, Hewlett-Packard, and Sun Multiple netpage servers can run concunently on a smgle host, and a smgle server can be distnbuted over a number of hosts Some or all of the functionality provided by netpage servers, and m particular the functionality provided by the ID server and the page server, can also be provided directly m 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 m non-volatile memory, the netpage pnnter contains no persistent storage As far as a user is concerned, "the network is the computer" Netpages function interactively across space and time with the help of the distπbuted netpage page servers 10, mdependently of particular netpage pπnters The netpage pnnter receives subscnbed netpage documents from netpage publication servers 14 Each document is distnbuted m 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 pπnter 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' pnnters and the appropnate page servers - 14 - The netpage publication server optimizes the segmentation of document content mto pomtcasts and multicasts After receiving the pomtcast of a document's page layouts, the printer 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 pπnt the document The pπnter rastenzes and pnnts odd and even pages simultaneously on both sides of the sheet It contams duplexed pπnt engme controllers 760 and pπnt engmes utilizing Memjet™ pπntheads 350 for this purpose The pπnting process consists of two decoupled stages rasterization of page descπptions, and expansion and pπnting of page images The raster image processor (RIP) consists of one or more standard DSPs 757 running m parallel The duplexed pπnt engme controllers consist of custom processors which expand, dither and pπnt page images m real time, synchronized with the operation of the pπntheads m the pnnt engmes Pnnters not enabled for IR pnnting 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-pnnted pages, they are still classed as netpages A normal netpage pπnter pnnts netpages on sheets of paper More specialised netpage pnnters may pπnt onto more specialised surfaces, such as globes Each pπnter 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 pπnt a document becomes associated with that document so that the document's tags can be coπectly mterpreted 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 pπnters made with a wide range of digital pπnting technologies, mcludmg thermal inkjet, piezoelectnc inkjet, laser electrophotographic, and others However, for wide consumer acceptance, it is desirable that a netpage pnnter have the followmg charactenstics photographic quality color pnnting • high quality text pπnting • high reliability • low pπnter cost • low ink cost • low paper cost • simple operation • nearly silent pnnting • high pπnting speed • simultaneous double sided pnnting • compact form factor • low power consumption No commercially available prmtmg technology has all of these charactenstics To enable to production of pnnters 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 - 15 - pagewidth pnntheads fabπcated usmg microelectromechanical systems (MEMS) technology Figure 17 shows a smgle pπnting element 300 of a Memjet™ pnnthead The netpage wallpπnter mcorporates 168960 pnnting elements 300 to foπn a 1600 dpi pagewidth duplex pπnter This pnnter simultaneously pnnts cyan, magenta, yellow, black, and infrared inks as well as paper conditioner and ink fixative The pπnting element 300 is approximately 110 microns long by 32 microns wide Aπays of these pπnting elements are formed on a silicon substrate 301 that mcorporates CMOS logic, data transfer, timing, and dnve circuits (not shown) Major elements of the pnnting element 300 are the nozzle 302, the nozzle nm 303, the nozzle chamber 304, the fluidic seal 305, the ink channel nm 306, the lever arm 307, the active actuator beam pair 308, the passive actuator beam pair 309, the active actuator anchor 310, the passive actuator anchor 311, and the ink inlet 312 The active actuator beam pair 308 is mechanically jomed to the passive actuator beam pair 309 at the jo 319 Both beams pairs are anchored at their respective anchor pomts 310 and 311 The combination 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 pnnting elements 300, mcludmg a cross section 315 of a pnnting element 300 The cross section 315 is shown without ink, to clearly show the ink mlet 312 that passes through the silicon wafer 301 Figures 19(a), 19(b) and 19(c) show the operating cycle of a Memjet™ pnnting element 300 Figure 19(a) shows the quiescent position of the ink memscus 316 pnor to pnnting an ink 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 pnnting, the pnnthead CMOS circuitry distnbutes data from the pπnt engme controller to the conect pnnting element, latches the data, and buffers the data to dnve the electrodes 318 of the active actuator beam parr 308 This causes an electncal cunent to pass through the beam pair 308 for about one microsecond, resulting m Joule heating The temperature mcrease resulting from Joule heating causes the beam pair 308 to expand As the passive actuator beam parr 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 electrotheπ .dl bend actuator 320 bending 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 19(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 ongmal 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 pnnthead 350 In a netpage pnnter, the length of the pnnthead is the full width of the paper (typically 210 mm) m the direction 351 The segment shown is 04 mm long (about 0 2% of a complete pnnthead) When pπnting, the paper is moved past the fixed pnnthead m the direction 352 The pnnthead has 6 rows of interdigitated pπnting elements 300, pπnting 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 pnnthead 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 inlets 332 and out of the nozzle guard holes dunng pnnting To prevent ink 321 from drying, the nozzle guard is sealed while the pnnter is idle - 16 - 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 appropnate 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 m 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 pπnter (or base station), the pπnter or base station mterpretmg 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 b is m contact with a netpage, the pen determines its position and onentation relative to the page The mb is attached to a force sensor, and the force on the mb is mterpreted relative to a threshold to indicate whether the pen is "up" or "down" This allows a mteractive element on the page to be 'clicked' by pressmg with the pen mb, m order to request, say, information 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 determines the position and onentation of its b on the netpage by imaging, m the infrared spectrum, an area 193 of the page m the vicinity of the mb It decodes the nearest tag and computes the position of the mb relative to the tag from the observed perspective distortion on the imaged tag and the known geometry of the pen optics Although the position resolution of the tag may be low, because the tag density on the page is mversely proportional to the tag size, the adjusted position resolution is quite high, exceeding the minimum resolution required for accurate handwnting recogmtion Pen actions relative to a netpage are captured as a senes of strokes A stroke consists 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, allowmg the user to perform copy and paste operations etc The selection is timestamped to allow the system to discard it after a defined time peπod 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 mterpreted 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 markmg black ink nib or the non-markmg sfylus mb is cunent Each pen also has a cunent mb style 825 This is the mb style last associated with the pen by an application, e g m response to the user selecting a color from a palette The default mb style is the nib 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 m 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 "online" LED When the pen fails to decode a stroke relative to the page, it momentanly activates its "enor" LED When the pen succeeds m decoding a stroke relative to the page, it momentanly activates its "ok" LED - 17 - A sequence of captured strokes is refened to as digital ink Digital ink forms the basis for the digital exchange of drawings and handwπting, for online recogmtion of handwnting, and for online 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 pπvacy 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 internal memory, which has a capacity of over ten mmutes of continuous handwnting When the pen is once agam withm range of a pπnter, it transfers any buffered digital ink A pen can be registered with any number of pπnters, but because all state data resides m netpages both on paper and on the network, it is largely lmmateπal which pπnter a pen is communicating with at any particular time A prefened embodiment of the pen is descπbed m greater detail m Section 6 below, with reference to Figures 8 to 10 1.7 NETPAGE INTERACTION The netpage pπnter 601 receives data relating 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 identify of the particular page and associated mteractive element to be determined and an indication of the relative positioning of the pen relative to the page to be obtained The indicating data is transmitted to the pnnter, where it resolves, via the DNS, the page ID 50 of the stroke mto 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 m 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 descπption to which the stroke applies, and determines 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 time 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 descπption hyperlinks and form fields Input through a form field can also tngger the activation of an associated hyperlink 1.7.1 Hyperlinks A hyperlink is a means of sendmg a message to a remote application, and typically elicits a pnnted 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 favoπte or appears m the user's history The hyperlink element class diagram is shown in Figure 29 When a hyperlink is activated, the page server sends a request to an application somewhere on the network The application is identified 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 - 18 - 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 conespondmg form to the application A selection hyperlink submits the cunent selection to the application If the cunent selection contams a single-word piece of text, for example, the application may return a smgle-page document givmg the word's meaning withm the context in which it appears, or a translation mto a different language Each hyperlink type is characterized by what information is submitted to the application The conespondmg 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 "shoppmg 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 in 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 hyperlinked 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 hyperlinked group can be used to associate hyperlink behavior with a field such as a checkbox It can also be used, in conjunction with the "submit delta" attnbute of a form hyperlink, to provide continuous mput to an application It can therefore be used to support a "blackboard" mteraction model, I e where mput is captured and therefore shared as soon as it occurs 1.7.2 Forms A form defines a collection of related mput fields used to capture a related set of inputs through a pnnted netpage A form allows a user to submit one or more parameters to an application software program running on a server A form 867 is a group element 838 m the document hierarchy It ultimately contams a set of termmal field elements 839 A form mstance 868 represents a pnnted mstance of a form It consists of a set of field mstances 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 pπnted 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 mstance is associated (at 59) with any form mstances denved from it, thus providing 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 ink 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 nib force The digital ink class diagram is shown m 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 - 19 - the field A checkbox field has an associated boolean value 881, as shown m Figure 35 Any mark (a tick, a cross, a stroke, a fill zigzag, etc ) captured in 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 handwnting recogmtion, and the text is assigned to the field's value Onlme handwnting recogmtion is well-understood (see for example Tappert, C , C Y Suen and T Wakahara, "The State of the Art m On-Line Handwnting Recogmtion", IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol 12, No 8, August 1990) 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 veπfied 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 usmg 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) 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 containmg the field is submitted "Editing" commands, such as stπke-throughs indicating deletion, can also be recognized m form fields Because the handwnting 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 markmgs), 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 ink stream, ready for mterpretation 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 mterpreted as a selection gesture Circumscnption of one or more objects is generally mterpreted as a selection of the circumscnbed objects, although the actual mterpretation is application-specific Table 2 summanses these vanous pen interactions with a netpage Table 2 - Summary of pen interactions with a netpage - 20 - 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 intenogate the raw digital ink should it suspect the onginal conversion, such as the conversion of handwritten text This can, for example, mvolve human intervention at the application level for forms which fail certain application-specific consistency checks As an extension to this, the entire background area of a form can be designated as a drawing field The application can then decide, on the basis of the presence of digital ink outside the explicit fields of the form, to route the form to a human operator, on the assumption that the user may have indicated 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 receiving (at 884) a stroke from the pen, identifying (at 885) the page mstance 830 to which the page ID 50 m the stroke refers, retneving (at 886) the page descπption 5, identifying (at 887) a formatted element 839 whose zone 58 the stroke intersects, determimng (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, mterpretmg (at 893) the accumulated digital ink of the field, and determinmg (at 894) whether the field is part of a hyperlinked group 866 and if so activating (at 895) the associated hyperlink, alternatively determinmg (at 889) whether the formatted element conesponds to a hyperlink element and if so activating (at 895) the conespondmg hyperlink, alternatively, m the absence of an mput field or hyperlink, appendmg (at 890) the received sfroke to the digital ink of the background field 833, and copying (at 891) the received stroke to the current selection 826 of the cunent pen, as mamtamed by the regisfration 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 mterpreted according to the type of the field The process consists of determinmg (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 determinmg (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 determinmg (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 appropnate 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 relating 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 mstances 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 conespondmg form mstance and then produces an active pnnted copy of the cunent form mstance with field values preserved The copy contams the same hyperlink transaction IDs as the ongmal, and so is indistinguishable from the - 21 - 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 pnnted report on the status of the conespondmg form mstance, mcludmg who published it, when it was pπnted, for whom it was pπnted, 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 mterpreted as a duplicate form command A reset page command produces a prmted copy of the conespondmg page mstance with the background field value discarded If the page contams a foim or is part of a form, then the reset page command is mterpreted as a reset form command A get page status command produces a pπnted report on the status of the conespondmg page mstance, mcludmg who published it, when it was pnnted, for whom it was pπnted, and the status of any forms it contams 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 in their ongmal form, with a signature accompanied by a standard graphic indicating successful signature venfication A duplicate document command produces a pπnted copy of the conespondmg 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 m the same way a reset form command does A get document status command produces a pnnted report on the status of the conespondmg document mstance, mcludmg who published it, when it was pnnted, for whom it was pnnted, and the status of any forms it contams If the page server command's "on selected" attπbute 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 hyperlinked group The page server activates the hyperlink associated with the hyperlinked group rather than executing the page server command A page server command element is hidden 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 m 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 indicate that it is a netpage and therefore has mteractive properties The logo also acts as a copy button In most cases pressmg 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 - 22 - 1.9 USER HELP SYSTEM In a prefened embodiment, the netpage pnnter has a smgle button labelled "Help" When pressed it elicits a single page of information, mcludmg • status of pnnter connection • status of pπnter 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 followmg functions • pπnt a copy of a document • pπnt a clean copy of a form • pnnt the status of a document A document function is initiated by simply pressmg the button and then touchmg 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 pπnter 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 in the netpage system Although news is often used m the limited sense of newspaper and newsmagazme news, the intended scope m the present context is wider the netpage system, the editonal content and the advertismg content of a news publication are personalized usmg different mechamsms The editoπal content is personalized accordmg 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 vaπed a "raw" news feed from a news service, a cartoon stπp, 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 contnbutmg news publications, and creating a personalized version of each The resulting daily editions are pnnted and bound together mto a smgle newspaper The vanous members of a household typically express their different mterests and tastes by selecting - 23 - 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 Tunes onlme, for example, mclude "Page One Plus", "National", "International", "Opinion", "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 monitoring news feeds for specific topics ("Alerts" or "Clippings") For each section, the reader optionally specifies its size, either qualitatively (e g short, medium, or long), or numencally (I e as a limit on its number of pages), and the desired proportion of advertismg, either qualitatively (e g high, normal, low, none), or numeπcally (I e as a percentage) The reader also optionally expresses a preference for a large number of shorter articles or a small number of longer articles Each article is ideally wntten (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 appropnate 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 pπoπtized by the editors, and each is assigned a useful lifetime By default they are delivered to all relevant subscπbers, m pπoπty order, subject to space constraints m the subscπbers' editions In sections where it is appropnate, the reader may optionally enable collaborative filtenng This is then applied to articles which have a sufficiently long lifetime Each article which qualifies for collaborative filtenng is pnnted with rating buttons at the end of the article The buttons can provide an easy choice (e g "liked" and "disliked'), making it more likely that readers will bother to rate the article Articles with high pnonties and short lifetimes are therefore effectively considered essential readmg by the editors and are delivered to most relevant subscnbers The reader optionally specifies a serendipity factor, either qualitatively (e _, do or don't surpnse me), or numencally A high serendipity factor lowers the threshold used for matchmg dunng collaborative filtenng A high factor makes it more likely that the conespondmg 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 qualify 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 (I 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 impenal or metnc, a local timezone and time format, and a local cuπency, and whether the localization consist of in 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 information is accommodated on each page The language m which a news publication is published, and its conespondmg text encoding, is a property of - 24 - 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 editoπal content directly affects the advertismg content, because advertismg is typically placed to exploit the editoπal context Travel ads, for example, are more likely to appear m a travel section than elsewhere The value of the editoπal content to an advertiser (and therefore to the publisher) lies m its ability to attract large numbers of readers with the πght demographics Effective advertismg is placed on the basis of locality and demographics Locality determines proximity to particular services, retailers etc , and particular mterests and concerns associated with the local community and environment Demographics deteπnine general mterests and preoccupations as well as likely spending 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 compaπson with other media, the netpage system allows the advertismg space to be defined in greater detail, and allows smaller pieces of it to be sold separately It therefore allows it to be sold at closer to its true value For example, the same advertismg "slot" can be sold in varying proportions to several advertisers, with mdividual readers' pages randomly receiving the advertisement of one advertiser or another, overall preserving the proportion of space sold to each advertiser The netpage system allows advertismg 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 advertismg Even though the advertismg aggregator is taking a proportion of advertismg revenue, publishers may find the change profit-neutral because of the greater efficiency of aggregation The advertismg 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, advertismg 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 Coπespondingly, 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 Accordingly, a user may be provided with netpages, which may more generally be refened to as a pnnted - 25 - document with user mteractive elements, formatted m accordance with their own preferences, with additional content targeted specifically to demographics of the user The mteractive elements) relating to the targeted content allow the user to request further information relating to that content The targeted content may relate to advertismg matenal and the further information may be provided m the form of an advertismg brochure The manner m which the mteractive elements) are pπnted in the document and with which the sensmg device is used to interact with the elements), to indicate a request for further information, are as descnbed above 2.3 USER PROFILES 2.3.1 Information Filtering The personalization of news and other publications relies on an assortment of user-specific profile mformation, mcludmg • publication customizations • collaborative filteπng vectors • contact details • presentation preferences The customization of a publication is typically publication-specific, and so the customization information is maintained by the relevant netpage publication server A collaborative filtenng vector consists of the user's ratings of a number of news items It is used to conelate different users' mterests for the purposes of making recommendations Although there are benefits to mamtammg a smgle collaborative filtenng vector mdependently 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 subscπbers to the same publication than between those of subscnbers to different publications, and a publication is likely to want to present its users' collaborative filtenng vectors as part of the value of its brand, not to be found elsewhere Collaborative filtenng vectors are therefore also 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 mformation for advertismg purposes, the mformation is mamtamed by the relevant netpage registration server In the absence of such information, advertismg 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 umque identifier, and the netpage registration server maintains the relationships between them, as shown m Figures 21, 22, 23 and 24 For registration purposes, a publisher is a special land of application provider, and a publication is a special land of application Each user 800 may be authonzed 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 pπnter (at 66), to which peπodical publications are delivered by default, whilst pages pπnted on demand are delivered to the pnnter through which the user is mteracting The server keeps track of which publishers a user has authonzed to pnnt to the user's default pnnter A publisher does not record the ID of any particular pπnter, but mstead resolves the ID when it is required - 26 - When a user subscnbes 808 to a publication 807, the publisher 806 (I e application provider 803) is authoπzed to pnnt to a specified pπnter or the user's default pnnter This authorization can be revoked at any time by the user Each user may have several pens 801, but a pen is specific to a smgle user If a user is authonzed to use a particular pnnter, 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 m the usual way A Web termmal 809 can be authonzed to pnnt on a particular netpage pπnter, allowmg Web pages and netpage documents encountered dunng Web browsmg to be conveniently pnnted on the nearest netpage pπnter The netpage system can collect, on behalf of a pπnter provider, fees and commissions on mcome earned through publications pnnted on the provider's pnnters Such mcome can mclude advertismg fees, click-through fees, e- commerce commissions, and transaction fees If the pπnter 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 descnbed in the precedmg paragraph), contact details 815, mcludmg name, address and telephone numbers, global preferences 816, mcludmg pnvacy, delivery and localization settings, any number of biometnc records 817, containmg the user's encoded signature 818, fingerprint 819 etc, a handwnting 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 prefemed embodiment of which is shown in the class diagram m Figure 41 2.3.3 History List The system maintains a history list 929 on each user's behalf, containmg 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 in the class diagram in 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 m the form of pre-formatted rectangles, they are placed on the page before the editonal content The advertismg ratio for a section can be achieved with wildly varying advertising ratios on mdividual pages within the section, and the ad layout algoπthm exploits this The algoπthm is configured to attempt to co-locate closely tied editonal and advertismg content, such as placmg ads for roofing matenal specifically within the publication because of a special feature on do-it-yourself roofing repairs The editoπal 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 ol 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, allowmg 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 pπmary efficiency mechanism is the separation of mformation specific to a smgle user's edition and information shared between multiple users' editions The specific information consists of the page layout The shared - 27 - lnformation 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) using the Extensible Sfylesheet Language (XSL) XSL provides precise control over text formatting mdependently of the region mto which the text is bemg set, which m this case is bemg provided by the layout The text object contains embedded language codes to enable automatic translation, and embedded hyphenation hints to aid with paragraph formatting An image object encodes an image m the JPEG 2000 wavelet-based compressed image format A graphic 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 descπbed above, and watermark regions These layout objects are summarized m Table 3 The layout uses a compact format suitable for efficient distπbution and storage Table 3 - netpage layout objects 2.6 DOCUMENT DISTRIBUTION As descπbed 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 ready to be distnbuted, the netpage publication server allocates with the help of the netpage ID server 12, a umque 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 layout The server then pointcasts each user's layouts to that user's pnnter via the appropnate page server, and when the pointcasting is complete, multicasts the shared content on the specified channels After receivmg its pomtcast, each page server and pnnter subscnbes to the multicast channels specified m the page layouts Duπng the multicasts, each page server and pπnter 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 pπnter re-creates the fully- - 28 - populated layout and then rasteπzes and pnnts it Under normal circumstances, the pnnter pnnts 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 m excess of 100 such pages m its internal 64MB memory, allowmg for temporary buffers etc The pπnter pnnts at a rate of one page per second This is equivalent to 400KB or about 3Mbit of page data per second, which is similar to the highest expected rate of page data delivery over a broadband network Even under abnormal circumstances, such as when the pnnter runs out of paper, it is likely that the user will be able to replenish the paper supply before the pπnter' s 100-page mtemal storage capacity is exhausted However, if the pπnter' 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 pπnters 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 retnevmg 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 m much the same way as a peπodical However, smce there is no shared content, delivery is made directly to the requestmg pπnter without the use of multicast When a non-netpage document is requested on demand, it is not personalized, and it is delivered via a designated netpage formatting server which reformats it as a netpage document A netpage formatting server is a special mstance of a netpage publication server The netpage formatting server has knowledge of vanous Internet document formats, mcludmg Adobe's Portable Document Format (PDF), and Hypertext Markup Language (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 ongm 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 m widespread use secret-key cryptography and public-key cryptography The netpage network uses both classes of cryptography Secret-key cryptography, also refened to as symmetπc cryptography, uses the same key to encrypt and decrypt a message Two parties wishing to exchange messages must first anange 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 usmg 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 mtended 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 pnvate key is secure, it is normal for the holder of the pnvate key to generate the key pair - 29 - Pubhc-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 usmg the pnvate key Anyone can then venfy that the encrypted hash constitutes the "signature" of the holder of the pnvate key with respect to that particular message by decrypting the encrypted hash usmg the public key and venfymg 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 m 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 authonty is a trusted third party which authenticates the connection between a public key and someone's identity The certificate authonty venfies the person's identify by examinmg identify documents, and then creates and signs a digital certificate containing the person's identity details and public key Anyone who trusts the certificate authonty can use the public key m the certificate with a high degree of certamty that it is genume They just have to venfy that the certificate has mdeed been signed by the certificate authonty, 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 followmg discussion, when reference is made to the secure transmission of mformation between a netpage pnnter and a server, what actually happens is that the pπnter obtains the server's certificate, authenticates it with reference to the certificate authonty, 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 pair 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 umquely 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 pnnter connects to the netpage network for the first time after mstallation, it creates a signature public/pnvate key parr It transmits the secret ID and the public key securely to the netpage registration server The server compares the secret ID against the pnnter' s secret ID recorded m its database, and accepts the registration if the IDs match It then creates and signs a certificate containing the pπnter' s public ID and public signature key, and stores the certificate m the registration database The netpage registration server acts as a certificate authonty for netpage pnnters, smce it has access to secret information allowmg it to venfy pnnter identify 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 pπnter Every document sent to a pπnter 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 authonzed to deliver the publication to the specified user The page server veπfies 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 umque identifier at time of manufacture which is stored in read-only - 30 - memory m the pen and m the netpage registration server database The pen ED 61 umquely identifies the pen on the netpage network A netpage pen can "know" a number of netpage pπnters, and a pπnter can "know" a number of pens A pen communicates with a pπnter via a radio frequency signal whenever it is withm range of the pπnter Once a pen and pπnter are registered, they regularly exchange session keys Whenever the pen transmits digital ink to the pπnter, 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 ID, and a pπnter stores a session key for every pen it knows, mdexed by pen ID Both have a large but fimte storage capacify 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 determines whether it is supposed to know the pen This might be, for example, because the pen belongs to a user who is registered to use the pnnter If the pnnter is meant to know the pen but doesn't, then it initiates the automatic pen registration procedure If the pnnter isn't meant to know the pen, then it agrees with the pen to ignore it until the pen is placed m a charging cup, at which time it initiates the registration procedure In addition to its public ID, the pen contains a secret key-exchange key The key-exchange key is also recorded m the netpage registration server database at time of manufacture Dunng regisfration, the pen transmits its pen ID to the pnnter, and the pnnter fransmits 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 pπnter It also transmits a copy of the session key encrypted with the pen's key-exchange key The pπnter 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 pπnter 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 pπnter 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 pπnter mcludes a facility to pπnt watermarks, but will only do so on request from publishers who are suitably authonzed The publisher mdicates its authonty to pnnt watermarks in its certificate, which the pπnter is able to authenticate The "watermark" pnnting process uses an alternative dither matπx m specified "watermark" regions of the page Back-to-back pages contain nunor-image watermark regions which comcide when pπnted The dither matnces used m odd and even pages' watermark regions are designed to produce an interference effect when the regions are viewed together, achieved by looking through the pnnted 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 mechanism descnbed m Section 1 9 above This extends to copy g netpages on netpage-aware photocopiers - 31 - 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 information with the netpage registration server, as descπbed m 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 sigmficant obstacle to casual forgery Onlme document venfication, particularly usmg a venfication pen, provides an added level of secunty 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 in Section 4, are also impossible for the payee to repudiate 4 ELECTRONIC COMMERCE MODEL 4.1 SECURE ELECTRONIC TRANSACTION (SET) The netpage system uses the Secure Electromc 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 independent of the type of accounts bemg used SET, cardholders and merchants register with a certificate authonty and are issued with certificates containmg their public signature keys The certificate authonty venfies a cardholder's regisfration 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 Duπnt' the payment process, these certificates are used to mutually authenticate a merchant and cardholder, and to authenl icdte them both to the payment gateway SET has not vet 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 biometπcs 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 in a controlled environment, for example a bank, where the biometnc can be captured at the same time as the user's identity is venfied The biometnc is captured and stored in 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 resulting pnvate signature key and certificate are stored m the database The - 32 - user's payment card information is also stored, giving the netpage registration server enough information to act as the user's proxy in any SET payment transaction When the user eventually supplies the biometnc to complete a payment, for example by signmg a netpage order form, the pnnter securely transmits the order mformation, 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 mechanism for micro-payments, to allow the user to be conveniently charged for pnnting low-cost documents on demand and for copymg copynght documents, and possibly also to allow the user to be reimbursed for expenses mcuned m pnnting advertismg matenal 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 outstanding debit balance usmg the standard payment mechanism The network account can be extended to aggregate subscnption fees for peπodicals, 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-pπnted catalog page to the user's virtual "shoppmg 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 conelating mdependently 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 ED 64, together with the pen ID 61, mto an alias ID 65 The alias ID 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 identify 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 m Figure 40 Each document and content object may be descπbed by one or more resource descnptions 842 Resource - 33 - descπptions use the Dublm Core metadata element set, which is designed to facilitate discovery of elecfromc resources Dublin 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 copyπght fees from users to πghts holders when users prmt copynght content 5 COMMUNICATIONS PROTOCOLS A communications protocol defines an ordered exchange of messages between entities In the netpage system, entities such as pens, pnnters 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 entify is represented by a rectangle containmg the name of the entify and a vertical column representing the lifeline of the entify Duπng the time an entify exists, the lifeline is shown as a dashed lme Duπng the time an entity 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 entify 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 subscπbe 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 pnnters via pomtcast, but delivers shared content objects via multicast The application (l e publisher) first obtains a document ID 51 for each document from an ID server 12 It then sends each document structure, mcludmg its document ID and page 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 obtain 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 names for the pπnter to listen to It then returns the newly allocated page IDs to the application for future reference Once the application has distπbuted all of the document structures to the subscπbers' selected pπnters via the relevant page servers, it multicasts the vanous subsets of the shared objects on the previously selected multicast channels Both page servers and pπnters monitor the appropnate multicast channels and receive their required content objects They are then able to populate the previously pomtcast document structures This allows the page servers to add complete documents to their databases, and it allows the pπnters to pπnt 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 communicates the click to the nearest netpage pnnter 601 The click identifies the page and a location on the page The pnnter already knows the ID 61 of the pen from the pen connection protocol - 34 - The pnnter determines, 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 pπnter 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 determines which mput element's zone 58, if any, the click lies m Assummg the relevant mput element is a hyperlink element 844, the page server then obtains 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 obtain 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 requesting 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 obtains a document ID 51 from an ID server 12 It then sends the document to the page server 10b responsible for the document's newly allocated ID, together with the requesting 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 obtain 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 descπptions to the requesting pπnter 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, I 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 obtain 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, allowmg the application to establish a user-specific context for the hyperlink activation 5.3 HANDWRITING RECOGNITION PROTOCOL When a user draws a stroke on a netpage with a netpage pen, the pen communicates the stroke to the nearest netpage pnnter The stroke identifies the page and a path on the page The pnnter 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 determines which mput element's zone 58, if any, the stroke mtersects Assummg 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 m the zone of the text field, the page server sends the pen ID and the pending strokes to the registration server 11 for mterpretation The registration server identifies the user conespondmg to the pen, and uses the user's accumulated handwnting 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 requesting page server The page server appends the text to the text value of the text field - 35 - 5.4 SIGNATURE VERIFICATION PROTOCOL Assummg the mput element whose zone the sfroke intersects 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 pending 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 venfy the strokes as the user's signature Once it has venfied the signature, the registration server uses the application ID 64 and user ID 60 to identify the user's application-specific pnvate signature key It then uses the key to generate a digital signature of the form data, and returns the digital signature to the requesting page server The page server assigns the digital signature to the signature field and sets the associated form's status to frozen The digital signature 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 in Figure 46 Form submission occurs via a form hyperlink activation It thus follows the protocol defined m Section 5 2, 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 environment, fees and commissions may be payable from an application provider to a publisher on click-throughs, fransactions and sales Commissions on fees and commission 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 (1 e publisher), and from the source application provider 70b to the pπnter provider 72 The target application receives the hyperlink request ID from the page server 10 when the hyperlink is first activated, as descπbed m Section 5 2 When the target application needs to credit the source application provider, it sends the application provider credit to the ongmal 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 regisfration 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 pnnter provider credit to the onginal 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 pπnter provider account 814 The source application provider is optionally notified of the identify of the target application provider, and the pπnter provider of the identity of the source application provider - 36 - 6. NETPAGE PEN DESCRIPTION 6.1 PEN MECHANICS Refernng to Figures 8 and 9, the pen, generally designated by reference numeral 101, mcludes a housmg 102 m the form of a plastics moulding having walls 103 defining an mteπor 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 projecting 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 behmd the projecting portion 110, withm 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 withm the cover 107 is a tn-color status LED 116 on a flex PCB 117 The antenna 112 ιs 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 ink pen cartndge 118 with mb 119 and a stylus 120 with stylus mb 121 are mounted side by side within 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 baπel 125 is secured to the pen top 105 m operation and ananged to rotate therewith The cam baπel 125 mcludes a cam 126 m the form of a slot withm the walls 181 of the cam baπel Cam followers 127 and 128 projecting from slider blocks 123 and 124 fit withm the cam slot 126 On rotation of the cam baπel 125, the slider blocks 123 or 124 move relative to each other to project either the pen mb 119 or stylus mb 121 out through the hole 122 m the metal end piece 114 The pen 101 has three states of operation By turning the top 105 through 90° steps, the three states are • Stylus 120 mb 121 out, • Ink cartridge 118 nib 119 out, and • Neither ink cartndge 118 mb 119 out nor stylus 120 mb 121 out A second flex PCB 129, is mounted on an electronics chassis 130 which sits withm the housmg 102 The second flex PCB 129 mounts an infrared LED 131 for providing infrared radiation for projection onto the surface An image sensor 132 is provided mounted on the second flex PCB 129 for receivmg reflected radiation from the surface The second flex PCB 129 also mounts a radio frequency chip 133, which mcludes an RF transmitter and RF receiver, and a confroller 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 wires 136 connect the components on the second flex PCB 129 to battery contacts 137 which are mounted withm the cam baπel 125 A termmal 138 connects to the battery contacts 137 and the cam baπel 125 A three volt rechargeable battery 139 sits within the cam baπel 125 m contact with the battery contacts An induction charging coil 140 is mounted about the second flex PCB 129 to enable recharging of the battery 139 via induction The second flex PCB 129 also mounts an infrared LED 143 and infrared photodiode 144 for detectmg displacement m the cam baπel 125 when either the stylus 120 or the ink cartndge 118 is used for wnting, m 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 gnp pads 141 and 142 are provided towards the end 108 of the housmg 102 to assist gnpping the - 37 - pen 101, and top 105 also mcludes a clip 142 for clipping the pen 101 to a pocket 6.2 PEN CONTROLLER The pen 101 is aπanged 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 m the vicinity of the mb It records the location data from the nearest location tag, and is ananged to calculate the distance of the b 121 or 119 from the location tab utilismg 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 Utilismg the RF chip 133 and antenna 112 the pen 101 can transmit the digital ink data (which is encrypted for secunty and packaged for efficient transmission) to the computing system When the pen is m 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 within the pen 101 (the pen 101 circuitry mcludes a buffer aπanged to store digital ink data for approximately 12 mmutes of the pen motion on the surface) and can be transmitted later The controller chip 134 is mounted on the second flex PCB 129 m the pen 101 Figure 10 is a block diagram illustrating in more detail the architecture of the controller chip 134 Figure 10 also shows representations of the RF chip 133, the image sensor 132, the tπ-color status LED 116, the ER. 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 sensor mterface 152 interfaces with the image sensor 132 A fransceiver confroller 153 and base band circuit 154 are also mcluded to mterface with the RF chip 133 which mcludes an RF cncmt 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, momtors the force sensor photodiode 144, controls the LEDs 116, 131 and 143, and handles short-range radio communication via the radio fransceiver 153 It is a medium-performance (~40MHz) general-purpose RISC processor The processor 145, digital fransceiver components (transceiver controller 153 and baseband circuit 154), image sensor mterface 152, flash memory 147 and 512KB DRAM 148 are integrated m 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 Elecfromc Corporation, and is descnbed m a paper bv 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 Elecfromc Devices, Volt 47, number 1, January 2000, which is mcorporated herein 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 cucmt 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 communicates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively m the unlicensed 24GHz industnal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free communication In an alternative embodiment, the pen incorporates an Infrared Data Association (IrDA) mterface for short- range communication with a base station or netpage pπnter - 38 - In a further embodiment, the pen 101 mcludes a pair of orthogonal accelerometers mounted m 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, allowmg the location tags to be sampled at a lower rate Each location tag ID can then identify an object of mterest 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 within 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 integrated with respect to time to produce an instantaneous velocity and position Smce the starting position of the sfroke is not known, only relative positions withm a sfroke are calculated Although position mtegration accumulates enors m the sensed acceleration, accelerometers typically have high resolution, and the time duration of a stroke, over which enors accumulate, is short 7. NETPAGE PRINTER DESCRIPTION 7.1 PRINTER MECHANICS The vertically-mounted netpage wallpnnter 601 is shown fully assembled m Figure 11 It pnnts netpages on Letter/A4 sized media usmg duplexed 8'Λ" 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 pπnted sheet, allowmg it to adhere to the previous sheet when pressed agamst 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 engmes, 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 molding The micro air filter mterfaces 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™ pπntheads 350 which might otherwise clog the pnnthead 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 capacify for pπnting and gluing 3000 pages (1500 sheets) Refernng 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 mto 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 pnnting commences Fixative is pnnted simultaneously to aid drying m the shortest possible time The paper exits the first Memjet™ pπnt engine 602 through a set of powered exit spike wheels (aligned along the straight paper path), which act agamst a rubberized roller These spike wheels contact the 'wet' pnnted surface and contmue to feed the sheet 604 mto the second Memjet™ pπnt engme 603 Refernng to Figures 12 and 12a, the paper 604 passes from the duplexed pnnt engmes 602 and 603 mto the binder assembly 605 The pnnted page passes between a powered spike wheel axle 670 with a fibrous support roller and another movable axle with spike wheels and a momentary action glue wheel The movable axle/glue assembly 673 is mounted to a metal support bracket and it is transported forward to interface with the powered axle 670 via gears by action of a camshaft A separate motor powers this camshaft - 39 - The glue wheel assembly 673 consists of a partially hollow axle 679 with a rotating coupling for the glue supply hose 641 from the ink cartndge 627 This axle 679 connects to a glue wheel, which absorbs adhesive by capillary action through radial holes A molded housmg 682 sunounds the glue wheel, with an opemng at the front Pivoting side moldings and sprung outer doors are attached to the metal bracket and lunge 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 spnngs 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 bmdmg assembly 605 7.2 PRINTER CONTROLLER ARCHITECTURE The netpage pnnter confroller consists of a controlling processor 750, a factory-installed or field-installed network mterface module 625, a radio fransceiver (transceiver controller 753, baseband cucuit 754, RF circuit 755, and RF resonators and mductors 756), dual raster image processor (RIP) DSPs 757, duplexed pπnt 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 pπnt engme controllers 760 It consists of a medium-performance general-purpose microprocessor The controlling processor 750 communicates with the pπnt engme confrollers 760 via a high-speed senal bus 659 The REP DSPs rastenze and compress page descnptions to the netpage pnnter' s compressed page format Each pπnt engme controller expands, dithers and pnnts page images to its associated Memjet™ pnnthead 350 m real time (1 e at over 30 pages per mmute) The duplexed pπnt engme controllers pπnt both sides of a sheet simultaneously The master pπnt engme confroller 760a controls the paper transport and momtors ink usage m conjunction with the master QA chip 665 and the ink cartndge QA chip 761 The pnnter controller's flash memory 658 holds the software for both the processor 750 and the DSPs 757, as well as configuration data This is copied to mam memory 657 at boot time The processor 750, DSPs 757, and digital transceiver components (transceiver ontroller 753 and baseband circuit 754) are integrated m a smgle confroller ASIC 656 Analog RF components (RI uit-uit 755 and RF resonators and mductors 756) are provided m a separate RF chip 762 The network mterface module 625 is separate, smce netpage pnnters allow the network connection to be factory-selected or field-selected Flash memory 658 and the 2x256Mbit (64MB) DRAM 657 is also off-chip The pnnt engme controllers 760 are provided m separate ASICs A vanety of network mterface modules 625 are provided, each providing a netpage network 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 communicates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively m the unlicensed 2 4GHz industnal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free communication The pπnter controller optionally mcorporates an Infrared Data Association (IrDA) mterface for receiving data "squirted" from devices such as netpage cameras In an alternative embodiment, the pnnter uses the IrDA mterface for short-range communication with suitably configured netpage pens - 40 - 7.2.1 RASTERIZATION AND PRINTING Once the mam processor 750 has received and venfied the document's page layouts and page objects, it runs the appropnate REP 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 smce an arbifrary number of rastenzed pages can, m general, be stored m memory This sfrategy only leads to potentially poor DSP utilization when rasteπzmg short documents Watermark regions m the page descπption are rastenzed 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 pπnted 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 duπng rasterization and stored in the compressed page image The main processor 750 passes back-to-back page images to the duplexed pπnt engme controllers 760 Each pnnt engme confroller 760 stores the compressed page image m its local memory, and starts the page expansion and pπnting pipelme Page expansion and pπnting is pipelined because it is impractical to store an entire 114MB bi-level CMYK+IR page image m memory 7.2.2 PRINT ENGINE CONTROLLER The page expansion and pnnting 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 lme loader/formatter unit 767, and a custom mterface 768 to the Memjet™ pnnthead 350 The pnnt engme confroller 360 operates m a double buffered manner While one page is loaded mto DRAM 769 via the high speed senal mterface 659, the previously loaded page is read from DRAM 769 and passed through the pπnt engme controller pipelme Once the page has fimshed pπnting, the page just loaded is pπnted while another page is loaded The first stage of the pipelme 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 resulting bi-level CMYK layer The resultant bi-level CMYK+IR dot data is buffered and formatted (at 767) for pnnting on the Memjet™ pnnthead 350 via a set of lme 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 m unison, such as m a duplexed configuration, they are synchronized via a shared lme sync signal 770 Only one pnnt engme 760, selected via the external master/slave pin 771, generates the lme sync signal 770 onto the shared lme The pπnt engme confroller 760 contams a low-speed processor 772 for synchronizing the page expansion and rendering pipelme, configuring the pnnthead 350 via a low-speed senal bus 773, and controlling the stepper motors 675, 676 In the 8'/ 2 " versions of the netpage pnnter, the two pnnt engmes each pnnts 30 Letter pages per mmute 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 pπnter, the two pnnt engmes each pnnts 45 Letter pages per mmute along the short dimension of the page (8V2"), givmg - 41 - a lme rate of 102 kHz These lme rates are well withm the operating frequency of the Memjet™ pnnthead, which m the current design exceeds 30 kHz 8 DIRECTORY NAVIGATION A directory is an organized list of named objects It may be presented m many ways sorted alphabetically, ananged mto named groups or topics, etc The default presentation is specific to each kmd of directory A directory may also be searched For the purposes of navigation usmg a netpage, an n-ary mdex tree is built above the directory, with each node containmg enough mdex entπes to fill two pπnted pages (l e a double-sided sheet) If two pages hold k entnes, and the entire directory contams m entnes, then the number of levels m the mdex is log*rø For example, if two pages hold 200 entnes, and the entire directory represents a global telephone directory containmg six billion entπes, then the number of levels m the mdex is five, and a user can locate a desired entry m the directory by pπnting five sheets 8.1 APPLICATION DRAWING NOTATION An application user mterface flow is illustrated as a collection of documents linked by command anows A command anow mdicates that the target document is pπnted 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 (V's), indicating 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 pnnted information, as well as command buttons which can be pressed by the user to request further information or some other action Forms, in addition to behavmg like normal documents, also contam mput fields which can be filled m by the user They provide the system with a data mput mechanism It is also useful to distinguish between documents which contam geneπc information and documents which contam information specific to a particular mteraction between the user and an application Geneπc documents may be pre-pπnted publications such as magazmes sold at news stands or advertismg posters encountered in public places Forms may also be pre-pnnted, mcludmg, for example, subscnption forms encountered m pre-pπnted publications They may, of course, also be generated on-the-fly by a netpage pπnter m response to user requests User-specific documents and forms are normally generated on the fly by a netpage pπnter m response to user requests Figure 48 shows a geneπc document 990, a genenc form 991, a user- specific document 992, and a user-specific form 993 Netpages which participate m a user mterface flow are further descnbed by abstract page layouts A page layout may contam vanous kinds of elements, each of which has a umque style to differentiate it from the others As shown in Figure 49, these mclude fixed mformation 994, vanable information 995, mput 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 outlines m all but the mam diagram which defines it 8.2 DIRECTORY NAVIGATION An mdexed directory class diagram is shown m Figure 50, by way of example Each mdex entry 500 is either an mdex node entry 501 or a directory entry 502 representing a directory object 503, with the mdex entry 500 itself representing one of a possible number of entπes of a higher-level mdex node 504 The layout of the geneπc directory mdex page 520 is shown m Figure 51 Each mdex node 504 is descnbed by an entry 518 on the mdex page which specifies the starting and ending names on the double-sided page it is linked to, separated by "to", e g "Aardvark to Axolotl", "Ayatollah to Bernoulli", etc Each entry 518 acts as a hyperlink to the conespondmg lower-level mdex page 520 representing the lower-level mdex node 504 - 42 - If the entire directory fits on two pages, then it is presented directly without an intervening mdex tree The presentation of the mdex entπes of a terminal (bottom-level) mdex node in a termmal mdex page 521, l e a node which refers to actual named objects, is specific to each kmd of directory Each page contams a <top> button 511 which pnnts the root node of the mdex, an <up> button 512 which pnnts the page's parent node m the mdex and <first>, <prevιous>, <next> and <last> buttons 513 to 516 which pnnt the first, previous, next and last nodes, respectively, of the page's mdex level Particular navigation buttons don't appear if they have no meanmg for the cunent page, e g the page for the first mdex node m an mdex level doesnt have <first> and <prevιous> buttons Each page also contams a <search> button 517 which generates a search from which allows the directory to be searched The contents of the search form are specific to each kmd of directory The directory navigation user mterface flow is illustrated m Figure 52, where the navigation functions of buttons 511 to 516 are illustrated m relation to a directory mdex 520 and a termmal directory mdex 521 The navigation may result m a specific directory object 522 bemg pnnted A similar result may be achieved by conducting a search 523, usmg the search button 517 Of course, if the search results are ambiguous a list of matches 524 is provided for the user to select an appropnate result 9 ELECTRONIC MAIL Netpage electromc mail (e-mail) provides a messagmg service between netpage users It also supports message exchange with Internet e-mail users, and by extension, users of other e-mail systems interconnected with the Internet, such as corporate e-mail systems Each netpage user has a umque id withm the netpage system, and is also known to the system by their name, which may or may not be umque Netpage e-mail is usually addressed by selecting a name from a list, for example from the global list of netpage users or from a particular user's list of contacts The user's nickname or alias helps disambiguate similar names A netpage user usually doesn't have to know or specify another netpage user's umque id When a netpage user wants to send e-mail to an Internet user, they must specify an Internet e-mail address Similarly, when an Internet user wants to send e-mail to a netpage user, they must specify a netpage Internet e-mail address The netpage network is known by one or more doma names on the Internet Netpage mail gateway servers exchange e-mail with mail servers on the Internet, and in particular receive Internet e-mail addressed to a netpage domam name Each netpage user is given an e-mail alias id by which they are identified withm a netpage Internet domam A user's netpage Internet address therefore takes the form <e-maιl alias ιd>@<netpage domam name> E-mail is a core service of the netpage system 9.1 E-MAIL OBJECT MODEL 9.1.1 E-mail User The e-mail object model revolves around an e-mail user 1000, as shown m the class diagram of Figure 53 An e-mail user 1000 is either a netpage user 800 or an Internet user 1002 As illustrated m the e-mail class diagram of Figure 54, the e-mail 1003 itself consists of a number of pages 1004 Each page conesponds to a netpage The page structure is logical because the e-mail is delivered m the same form that it is composed, and it is composed by the sender page by page Each page contams digital ink 873 (Figure 33), together with any number of attachments 1005 An attachment is pnnted at its pomt of insertion, and may overflow onto the followmg page(s) The sender 1006 of the e-mail is an e-mail user 1000, as are any number of recipients 1007 and copy - 43 - recipients (CCs) 1008 Blmd copy recipients (BCCs) are not modelled here for clanfy, but can obviously be tπvially accommodated The e-mail has an explicit subject which is always converted from digital ink to text to support mteroperation with e-mail systems which dont directly support digital ink, such as e-mail systems on the Internet, and to streamline the presentation of mailbox contents withm the netpage system itself The e-mail has a high pnonty flag 1009 which allows both the sender and the recipients to control the timeliness of its delivery 9.1.3 Mailbox Incoming e-mails may be accumulated m the user's mailbox 1010, illustrated m the mailbox class diagram of Figure 55, pnnted on the user's default pnnter, mcorporated mto the user's daily newspaper, or any combmation of these The user can select, for example, to pnnt high-pπonfy e-mails immediately on receipt but to hold low-pnonty e- mails The user may create any number of named folders 1011 within the mailbox 1010, and either manually copy and move received e-mails 1003 between folders, or associate a folder with one or more e-mail contacts (mcludmg e- mail groups) to have e-mail received from those contacts automatically placed m the folder E-mail received from contacts not associated with a folder is placed m a predefined "inbox" folder All e-mail sent by the user is placed m a predefined "sent e-mail" folder for future reference Each folder has three delivery options "pπnt all e-mail", "pnnt high-pnonty e-mail", and "delete e-mail once pπnted" If a pπnt option is selected, e-mail messages with the conespondmg pnonty are pnnted on the user's default pnnter immediately on receipt If the delete option is selected, e-mail messages are deleted from the e-mail folder once pnnted Otherwise e-mail messages are held indefinitely m the e-mail folder, I e until manually deleted by the user 9.1.4 Contact List Each user has a list 1012 of contacts 1013 The contact list 1012, as illustrated m Figure 56, provides a more convenient basis for selecting e-mail recipients than the global list of users, particuldrly smce most user's contact lists will fit on a smgle double-sided pnnted page The contact list also provides a basι-> for ignoring unsolicited e-mail A pπvacy option allows a user to ignore e-mail not sent by a member of the contact list A user may create any number of contact groups 1014 withm the contact list, and treat a group as a smgle contact 1015 for the purposes of addressing outgomg e-mail and controlling the delivery of incoming e-mail Groups may themselves contam groups, and both mdividual contacts and groups may be members of multiple groups as well as of the top-level contact list itself 9.1.5 Barred User List Rather than accepting e-mail only from known contacts, a user 800 may choose to bar mdividual users 1016 The baned user list 1017, shown m Figure 57, records individuals from which the user refuses to accept e-mail 9.2 E-MAIL USER INTERFACE 9.2.1 Send E-mail E-mail is sent usmg the outgoing e-mail form 1020 (see Figures 60 and 61) The e-mail form is always pnnted with the sender's name already specified at 1021, smce the sender's identity is known from the pen used to request the e-mail form If the e-mail form is requested by pressmg a user-specific <e-maιl> button on some page, then the e-mail form is pnnted with the recipient's name 1007 already specified On the other hand, if the e-mail form is requested from the help page, then the recipient is unknown and is left blank on the form The user must specify at least one recipient before the e-mail can be sent - 44 - The user can also pre-address an e-mail form by pressmg the <e-maιl to contacts> button on the help page This elicits an add recipients form (Figure 62), which lists the user's contacts 1013 Each contact has a <To> and a <CC> checkbox 1022, 1023 as well as an <e-maιl> button 1024 The e-mail button elicits an e-mail form addressed to that user The <e-maιl selected> button 1025 at the bottom of the page elicits an e-mail addressed to all the users whose <To> or <CC> checkboxes have been checked The e-mail form initially consists of a double-sided page The front (Figure 60) contams fields 1026, 1027 for the names of recipients and copy recipients, for the subject 1028, and for the body of the e-mail 1029 The back (Figure 61) contams a field 1030 for continuing the body of the e-mail Any recipient names (or addresses) wntten by hand are converted from digital ink to text for lookup purposes The subject is also converted, for presentation purposes, as discussed earlier The body is retained as digital ink, to allow handwntten text and diagrams etc to be delivered m a uniform and expressive manner The <add page> button 1031 at the bottom of every page of the e-mail form adds another double-sided page to the e-mail form Only the additional page is pnnted, not the entire form, but the additional page is logically linked to the ongmal e-mail The <dιscard page> button 1032 at the bottom of every page discards the conespondmg page from the e-mail (but not both sides of the double-sided page) The entire e-mail is repnnted with the discarded page removed and subsequent pages, if any, moved to close the gap A blank page is added to make the page count even, if necessary Each pπnted e-mail form conesponds to a separate e-mail mstance, the uniqueness of which is indicated by the sender's name, date and time pπnted at the top of every page Once an e-mail has been sent, it can't be sent agam A copy, however, can be easily made, edited, and sent The standard <pnnt> button on every page of the e-mail form pnnts another copy of the e-mail form, conespondmg to a new e-mail mstance Both the ongmal and the copy can be edited further and sent mdependently Text m the <recιpιents>, <copy recιpιents> and <subject> fields can be struck out with the pen to remove recipients, subject text, etc The <pπnt button produces a copy of the e-mail form with the sfruck-out text removed The <attach> button 1033 at the bottom of every page attaches the cuπent selection at the cuπent end of the e-mail body The entire e-mail is repnnted with the attachment mcluded Additional pages are automatically added to the e-mail to accommodate the attachment The attachment can consist of anything which can be selected on any netpage The <add recιpιents> button 1034 adjacent to the <recιpιents> and <copy recιpιents> fields 1026, 1027 at the top of the first page of the e-mail form elicits an add recipients form 1036 (Figure 62), with the <subject> field 1028 reflecting the subject of the e-mail form The <e-maιl> and <e-maιl selected> buttons 1024, 1025 on the add recipients form elicits a copy of the e-mail foπn with the additional recipients and copy recipients added The <send> button 1035 at the bottom of every page sends the entire e-mail If the name of any recipient is unknown to the system, then the e-mail form is repnnted with the offending name pπnted m red, together with an enor message indicating the problem If the name of any recipient is ambiguous, then a list of matchmg users is pπnted, each with a checkbox allowmg it to be selected The <e-maιl> button at the bottom of the form reprints the e-mail form with the recipient names suitably updated The overall e-mail user mterface flow is illustrated m Figure 58 The e-mail recipient exception user mterface flow is illustrated m Figure 59 9.2.2 Receive E-mail E-mail is received m the form of an incoming e-mail document 1040 (Figures 63 and 64), which has the same page structure and content as the conespondmg outgomg e-mail form - 45 - The <reply> button 1041 at the bottom of every page of the e-mail document produces an outgomg e-mail form (Figures 60 and 61) addressed to the sender of the mcommg e-mail, and with the subject reflecting the subject of the mcommg e-mail, but with "In reply to " added as a prefix The <reply to all> button 1042 produces an outgomg e-mail form addressed to the sender of the mcommg e- mail, as well as to all of its recipients and copy recipients The <forward> button 1043 produces an outgomg e-mail form with no recipient, and with the subject reflecting the subject of the mcommg e-mail, but with "Forwarded " added as a prefix The body of the incoming e-mail is also copied to the body of the outgomg e-mail The <forward to contacts-* button 1044 creates, but doesn't pπnt, an outgomg e-mail m the same way as the <forward> button, and then implicitly mvokes the <add recipients command on it This elicits an add recipients form m the usual way (Figure 62), with the <subject> field reflecting the subject of the forwarded e-mail The <add to contacts> button 1045 adds the sender to the recipient's list of contacts and produces an edit contacts form reflecting the updated contact list Contact list editing is descπbed m more detail m Section 92 3 The <bar> button 1046 adds the sender to the recipient's list of baned users and produces an edit barred users form reflecting the updated baned user list Baned user list editing is descnbed m more detail m Section 9 2 5 9.2.3 Edit Contact List The contact list is edited usmg the edit contacts form 1050 (Figure 66) Because the structure of an mdividual contact group is the same as the structure of the top-level contact list, the same form is used to edit a contact group The form is obtained by pressmg the <edιt contact lιst> button on the help page It is also pπnted whenever a contact is added to the contact list, for example when the <add to contacts> button 1045 is pressed on an incoming e- mail 1040 to add the sender to the contact list Each entry 1051 on the contact list form shows the name on the contact 1052, and the cunent e-mail folder 1053 m which e-mail from the contact is placed Each entry has a checkbox 1054 which allows the contact to be selected, an <ιnfo> button 1055 which elicits a page of mformation about the user (Figure 77), and a <set e-mail folder> button 1056 which allows the e-mail folder associated with the contact to be changed via the set e-mail folder form (Figure 68) The <delete selected> button 1057 at the bottom of the form deletes the selected contacts from the contact list (or contact group) The form is repnnted with the deleted contacts removed The <copy to group> and <move to group> buttons 1058, 1059 at the bottom of the form allows the selected contacts to be copied and moved to a particular group via the copy contacts form 1060 (Figure 67) The contact list editing user mterface flow is illustrated m Figure 65 The copy (move) contacts form lists all of the groups m the user's contact list, each with a <copy to> (<move to>) button which copies (moves) the selected contacts to the specified group When a <copy to> (<move to>) button is pressed, an edit contacts form is pπnted which shows the updated membership of the destination group The copy (move) contacts form 1060 provides a <new group name> field 1061 with an associated <copy to new> (<move to new>) button 1062 This allows a new group to be simultaneously created and selected as the destination for the copy or move The set e-mail folder form 1070 (Figure 68) lists all of the folders m the user's mailbox, each with a <set button 1071 which sets the folder as the contact's e-mail folder When the <set> button is pressed, the edit contacts form is re-pnnted to reflect the new folder associated with the contact The set e-mail folder form 1070 provides a <new e-mail folder name> field 1072 with an associated <set new> button 1073 This allows a new folder to be simultaneously created and selected as the contact's e-mail folder The - 46 - new folder has an associated set of checkboxes 1074 which allow the folder's e-mail delivery options to be specified 9.2.4 List Mailbox The contents of the user's mailbox are listed usmg the mailbox form 1080 (Figure 70) and the e-mail folder form 1090 (Figure 71) The mailbox form lists all of the user's e-mail folders 1011, each with a set of checkboxes 1081 which reflect the folder's e-mail delivery options and allow the delivery options to be changed Each folder entry also has a checkbox 1082 which allows it to be selected The <count> button 1083 next to each folder name mdicates the number of un-pnnted (l e un-read) e-mails m the folder The <delete selected> button 1084 at the bottom of the form deletes all selected folders from the mailbox The mailbox form is re-pnnted with the deleted folders removed The <update options> button 1085 at the bottom of the form applies any changes made via the checkboxes to the folder's delivery options Each folder entry also has a <lιst> button 1086 which lists the contents of the folder via the e-mail folder form 1090 (Figure 71) The mailbox listing user mterface flow is illustrated in Figure 69 The e-mail folder form 1090 lists all of the e-mails m the folder Each single-line e-mail entry 1091 shows the sender of the e-mail 1092, the subject of the e-mail 1093, and the date and time 1094 the e-mail was received The list can be sorted by sender, subject, or date and time Each column which is not the cunent sort column has a <sort> button 1095 which allows the list to be sorted by that column When a <sort button is pressed the e-mail folder is sorted by the selected column and the form is re-pnnted Where an e-mail is a reply to another e-mail, the subject of the replying e-mails is mdented relative to the subject of the e-mail to which it is replymg Thus each thread of a discussion is clearly visible Entnes for e-mails which have never been pnnted are pπnted m bold to draw the user's attention Each e-mail entry has a checkbox 1096 which allows it to be selected, as well as a pπnt button 1097 which allows the entire e-mail to be pπnted m the form of an mcommg e-mail (Figure 63 and 64) The <delete selected> button 1098 at the bottom of the form deletes the cuπently selected e-mails The e- mail folder form is repnnted with the deleted e-mails removed The <copy selected> and <move selected> buttons 1099, 1100 at the bottom of the e-mail folder form allow the cuπently selected e-mails to be copied or moved to a different e-mail folder via the copy e-mail form 1110 (Figure 72) The copy (move) e-mail 1110 form lists all of the folders 1011 m the user's mailbox, each with a <copy to> (<move to>) button 1111 which copies (moves) the selected e-mails to the specified folder When a <copy to> (<move to>) button is pressed, an e-mail folder form is pnnted which shows the updated contents of the destination folder The copy (move) e-mail form 1110 provides a <new e-mail folder name> field 1112 with an associated <copy to new> (<move to new>) button 1113 This allows a new folder to be simultaneously created and selected as the destination for the copy or move The new folder has an associated set of checkboxes 1114 which allow the folder's e- mail delivery options to be specified 9.2.5 Edit Barred User List The baned user list is edited via the edit barred users form 1120 (Figure 74) The form 1120 is obtained by pressmg the <edιt baned user hst> button on the help page It is also pnnted whenever a user is baned, for example when the <bar> button 1046 is pressed on an mcommg e-mail 1040 to add the sender to the baned user list The form lists all of the users 1121 m the user's baned user list 1017 Each has a checkbox 1122 which allows it to be selected - 47 - The <unbar selected> button 1123 at the bottom of the form deletes the selected users from the baned user list The form is re-pnnted with the deleted users removed When a user is deleted from the list that user is no longer baned The baned user editing user mterface flow is illustrated m Figure 73 9.2.6 Global User Directory The global user directory, smce it is large, is navigated via a directory mdex (as descnbed previously in section 8) It is obtained by pressmg the <global user dιrectory> button on the help page The global user directory page 1130 (Figure 76) contams an alphabetical list, by family name, of users m the name range covered by the page Each entry has three associated buttons The <rnfo> button 1133 produces a user information page (Figure 77), the <e-maιl> button 1134 generates an outgomg e-mail form 1020 (Figures 60 and 61) addressed to the conespondmg user, and the <add to contacts> button 1135 adds the user to the user's contact list and pnnts the updated contact list 1050 (Figure 66) The globed user directory page 1130 also contams the standard mdex navigation buttons 1136 The global user directory user mterface flow is illustrated in Figure 75 The mdex user mterface flow and associated page layouts are as descnbed previously The user information page 1140 (Figure 77) contains the user's contact details as provided duπng user regisfration, subject to the user's pπvacy preferences It also contains <e-maιl> and <add to contacts> buttons 1141, 1142 which work m the usual way The <Internet e-mail address> field 1143 is only mcluded if the user mformation page is pnnted via the contact list for an Internet contact (as opposed to a netpage contact) 9.2.7 Add Internet Contact An Internet e-mail user can be added to a user's contact list usmg the Internet contact registration form 1170 (Figure 79) Smce an Internet user is not otherwise known to the netpage svstem, the form allows full name details 1171 to be specified, m addition to the Internet user's e-mail address 1172 The Internet contact registration user mterface flow is illustrated m Figure 78 CONCLUSION The present mvention has been descnbed with reference to a prefeπed embodiment and number of specific alternative embodiments However, it will be appreciated by those skilled m the relevant fields that a number of other embodiments, differing from those specifically descnbed, will also fall withm the spiπt and scope of the present mvention Accordingly, it will be understood that the mvention is not mtended to be limited to the specific embodiments descπbed 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: - 48 - C LAI MS I A method for composition and transmission of an electromc mail message mcludmg pnnting a document to facilitate composition and transmission of the elecfromc mail message, composmg the electromc mail message on the document utilizing a sensmg device adapted to read coded data m the document, transmitting mteraction data from the sensmg device to a computer system, the mteraction data representing mteraction of the sensmg device with the coded data to allow the message to be elecfromcally captured m the computer system, and transmitting the message to at least one recipient address 2 A method as claimed m claim 1, wherein the address of the recipient is converted from hand-wπtten indicia on the document to an elecfromc form of the address to facilitate transmission 3 A method as claimed m claim 1, wherem at least part of the message as applied to the document is converted from hand-wntten indicia or alpha-numerals to electromc equivalents 4 A method as claimed in claim 1, wherem at least part of the electromc mail message as applied to the document is converted from hand-wπtten indicia, alpha-numerals, diagrams, figures, or the like, to an elecfromc form which substantially preserves the format and appearance of the relevant part of the message 5 A method as claimed m claim 3 or 4, wherem elecfromcally captunng the message mcludes receiving, m the computer system, movement data regardmg movement of the sensmg device relative to the document 6 A method as claimed m claim 5, mcludmg the sensmg device sensmg its movement relative to the form usmg the coded data 7 A method as claimed m claim 1, wherem at least part of the electromc mail message is transmitted to the recipient address as digital ink 8 A method as claimed m claim 1 , wherein the message is delivered at the address m the form of a second document containmg the electromc mail message 9 A method as claimed m claim 8, wherem the second document has at least one user mteractive element which enables a recipient to mdicate a response to associated mformation m the second document by mteracting with the user mteractive element usmg a sensmg device which is adapted to transmit response data to a computer 10 A method as claimed m either claim 8 or 9, wherem the second document is automatically pnnted I I A method as claimed m claim 1, wherem only an electromc mail message from an approved sender is accepted at the recipient address, the approved sender being entered m a customizable electronic list or database 12 A method as claimed m claim 1, wherem a user addresses the electronic mail message to the recipient address by selecting a name from a list on the document usmg the sensmg device 13 A method as claimed m claim 1, mcludmg receiving, m the computer system, indicating data denved from the coded data, regardmg the identity of the document and a position of the sensmg device relative to the document m order to identify the document and determine when the sensmg device is used to interact with the document 14 A method as claimed m claim 13, mcludmg receivmg, m the computer system, movement data regardmg movement of the sensmg device relative to the document 15 A method as claimed m claim 15, mcludmg the sensmg device sensmg its movement relative to the document usmg the coded data 16 A method as claimed m claim 1 , wherem the sensmg device mcludes an identification code specific to a particular user and the method mcludes monitonng use of the sensmg device m the computer system 17 A method as claimed m claim 1, mcludmg pπnting the document on demand - 49 - 18 A method as claimed m claim 13, mcludmg pnnting the document on a surface of a surface-defining structure and, at the same time, pπnting the coded data on the surface 19 A method as claimed m claim 18 which mcludes pπnting the coded data to be substantially invisible m the visible spectrum 20 A method as claimed m claim 13, mcludmg retaining a retnevable record of the pnnted document, the document bemg retπevable usmg the identify data as contained m the coded data 21 A system for composition and transmission of an electromc mail message mcludmg a pπnter for pπnting a document with coded data, to facilitate composition and transmission of the electromc mail message, a sensmg device for reading the coded data and transmitting mteraction data, representing mteraction of the sensmg device with the coded data to allow for elecfromc capture of the message, generated by movmg the device relative to the document, and a computer system for receivmg the mteraction data from the device and transmitting the message to a recipient address 22 A system as claimed m claim 21, wherem the computer system is adopted to transmit the electromc mail message to an elecfromc mail server 23 A system as claimed m claim 21, wherem the computer system is provided with means so that the address of the recipient is converted from hand-wπtten indicia on the document to an electromc form of the address 24 A system as claimed m claim 21, wherem the computer system is provided with means so that at least part of the elecfromc mail message as applied to the document is converted from elecfromcally captured hand- wπtten indicia or alpha-numerals to elecfromc equivalents 25 A system as claimed m claim 21, wherem the computer system is provided with means so that at least part of the electromc mail message as applied to the document is converted from elecfromcally captured handwntten indicia, alpha-numerals, diagrams, figures, or the like, to an electromc form which substantially preserves the format and appearance of the relevant part of the electromc mail message 26 A system as claimed m claim 24 or 25, wherem the computer system is adapted to receive movement data regardmg movement of the sensmg device relative to the coded data, m order to electronically capture the message 27 A system as claimed m claim 26, wherem the sensmg device senses its own movement relative to the document usmg the coded data 28 A system as claimed m claim 21, further mcludmg a pπnter at the recipient address for producing a second document containmg the electromc mail message 29 A system as claimed m claim 28, wherem the second document has at least one user mteractive element which enables a recipient to mdicate a response to associated mformation m the second document by mteracting with the user mteractive element usmg a sensmg device which is adapted to transmit response data to a computer 30 A system as claimed m claim 28, wherem the pnnter only accepts an electromc mail message from an approved sender, the approved sender bemg entered m a customisable electromc list or database 31 A system as claimed m claim 21, wherem the coded data serves to identify the document and a position of the sensmg device relative to the document 32 A system as claimed m claim 22, wherem the computer system is adapted to receive movement data regardmg movement of the sensmg device relative to coded data, m order to capture the message 33 A system as claimed m claim 33, wherem the sensmg device sensing its movement relative to the document usmg the coded data - 50 - 34. A system as claimed in claim 21, wherein the sensing device includes a marking nib. 35. A system as claimed in claim 21, wherein the document is printed on a surface of a surface-defining structure and wherein the printer prints the document on demand. 36. A system as claimed in claim 21, wherein the printer is aπanged to print the coded data at the same time as printing the document on a surface-defining structure. 37. A system as claimed in claim 21, wherein the coded data is substantially invisible in the visible spectrum. 38. The system as claimed in claim 21, including a database for keeping a retrievable record of each document generated, each document being retrievable by using its identify, as included in its coded data.

Inventors: LAPSTUN PAUL, LAPSTUN, PAUL
Applicants: LAPSTUN PAUL, SILVERBROOK KIA, SILVERBROOK RES PTY LTD, LAPSTUN, PAUL, SILVERBROOK RESEARCH PTY LTD, SILVERBROOK, KIA
Application year: 2000
Main classification: G06K11
IPC codes: G06F3, H04L12