INTERACTIVE PAPER PUBLISHER

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

Description: INTERACTIVE PAPER PUBLISHER FIELD OF INVENTION The present invention relates to generally to systems, apparatus, devices and methods for interacting with computers and in particular to a system and method for providing to a user printed information The 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/AUOO/00530. PCT/AU00/00531. PCT/AU00/00532. PCT/AU00/00533. PCT/AU00/00534. PCT/AU00/00535, PCT/AUOO/00536. PCT/AU00/00537, PCT/AU00/00538, PCT/AU00/00539. PCT/AU00/00540, PCT/AU00/00541 , PCT/AU00/00542, PCT/AU00/00543, PCT/AU00/00544, PCT/AU00/00545, PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AUOO/00556. PCT/AU00/00557. PCT/AUOO/00558, PCT/AU00/00559, PCT/AU00/00560, PCT/AU00/00561. PCT/AU00/00562, PCT/AU00/00563. PCT/AU00/00564, PCT/AU00/00566, PCT/AU00/00567. PCT/AUOO/00568, PCT/AU00/00569, PCT/AUOO/00570. PCT/AU00/00571 , PCT/AU00/00572. PCT/AUOO/00573. PCT/AU00/00574. PCT/AUOO/00575, PCT/AU00/00576, PCT/AU00/00577. PCT/AU00/00578. PCT/AU00/00579, PCT/AU00/00581 , PCT/AU00/00580, PCT/AUOO/00582, PCT/AU00/00587. PCT/AUOO/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 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 - 1 a - Online publication also has disadvantages Computer screens are interior to paper At the same quality as a magazine page, an SVGA computer screen displays onl> 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 SUMMARY OF INVENTION It is an ob]ect of the present invention at least in the preferred embodiments, to overcome or substantially ameliorate one or more of these disadvantages of the prior art. or at least to provide a useful alternative According to a first aspect of the invention there is provided a system for providing a user with a printed - 2 - pubhcation from a first party, the system including a publication source for storing publication data representative of the publication, the publication data including first information about a second party, a user printer module for interfacing the user with the publication source, the module bemg responsive to the user requestmg the prmted publication for reproducmg the prmted publication on a prmted medium for viewing by the user, identifier means for applying an identifier to the print medium such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user second information, and calculation means bemg responsive to the module for determining a payment that is made by the second party to the first party Preferably, the payment is a predetermined function of the number of reproductions of the pπnted publication that are generated More preferably, the second party is an advertiser m the publication and the payment is a predetermined function of the circulation achieved by the publication Preferably also, the second information is associated with the second party and the payment is a predetermined function of the number of second pπnted media generated In a preferred form, the second party is an advertiser and the payment is increased for successful hits on their specific advertising Preferably, the payment is a predetermined function of both the number of pπnted publications generated that display the first information and the number of second prmted media generated that display the second information Preferably also, the second party is a supplier of goods and or services and the first information or the second information allows the user to purchase those goods and/or services at a predetermined purchase pπce More preferably, the payment is a predetermined function of the purchase pnce of the goods and/or services actually purchased by the user In a prefeπed form, the module is responsive to the designation of the identifier by the user for accessing advertising information about particular goods and/or services of the second party More preferably, the calculation means is responsive to the designation of the identifier for determining the payment Even more preferably, the calculation means is responsive only to the designation of the identifier for detemumng the payment such that the advertiser pays the publisher only for successful links to the advertising information Accordmg to a second aspect of the invention there is provided a system for providing a user with a pπnted publication from a first party, the system including a publication source computer for storing electronic publication data representative of the publication, the publication data including first ---formation about a second party, a user printer module for interfacing the user with the publication source, the module bemg responsive to the user requesting the pπnted publication for reproducing the pπnted publication on a prmted medium for viewmg by the user, an identifier device for applymg an identifier to the pπnted medium such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user second information, and an account computer bemg responsive to the module for detemumng a payment that is made by the second party to the first party Preferably, the user printer module and the identifier device are contained within a single housing More preferably, the identifier device applies the identifier to the surface of a medium as it is bemg produced by the printer module - 3 - In a preferred lorm, the identifier is pπnted on the medium More preferably, the identifier is prmted with ink that does not substantially reflect light m the visible spectrum Accordmg to a third aspect of the invention there is provided a method for providing a user with a pπnted publication from a first party, the method including the steps of storing publication data representative of the publication on a publication source, the publication data including first information about a second party, interfacing the user with the publication source via a user printer module, the module bemg responsive to the user requesting the pπnted publication for reproducmg the pπnted publication on a printed medium for viewmg by the user, applying an identifier to the print medium with identifier means such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user second information, and bemg responsive to the module with calculation means for determining a payment that is made by the second party to the first party Accordmg to a fourth aspect of the invention there is provided a method for providing a user with a pπnted publication from a first party, the method including the steps of storing electronic publication data representative of the publication on a publication source computer, the publication data including first information about a second party, interfacing the user with the publication source computer with a user printer module, the module bemg responsive to the user requesting the pπnted publication for reproducmg the pπnted publication on a printed medium for viewmg by the user, applying an identifier to the print medium with an identifier device such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user second information, and bemg responsive to the module with an account computer for determining a payment that is made by the second party to the first party - 4 - BRIEF DESCRIPTION OF DRAWINGS Preferred and other embodiments of the invention will now be descπbed, by way of non-limiting example only, with reference to the accompanying drawings, in which Figure 1 is a schematic of a the relationship between a sample pπnted netpage and its online page descπption, Figure 2 is a schematic view of a mteraction between a netpage pen, a netpage prmter, a netpage page server, and a netpage application server, Figure 3 illustrates a collection of netpage servers and printers interconnected via a network, Figure 4 is a schematic view of a high-level structure of a prmted netpage and its online page descπption, Figure 5 is a plan view showmg a structure of a netpage tag, Figure 6 is a plan view showmg a relationship between a set of the tags shown m Figure 5 and a field of view of a netpage sensing device m the form of a netpage pen, Figure 7 is a flowchart of a tag image processing and decodmg algonthm, Figure 8 is a perspective view of a netpage pen and its associated tag-sensing field-of-view cone, Figure 9 is a perspective exploded view of the netpage pen shown m Figure 8, Figure 10 is a schematic block diagram of a pen controller for the netpage pen shown m Figures 8 and 9, Figure 11 is a perspective view of a wall-mounted netpage prmter, Figure 12 is a section through the length of the netpage prmter of Figure 11, Figure 12a is an enlarged portion of Figure 12 showmg a section of the duplexed print engmes and glue wheel assembly, Figure 13 is a detailed view of the ink cartπdge, ink, air and glue paths, and print engmes of the netpage prmter of Figures 11 and 12, Figure 14 is a schematic block diagram of a prmter controller for the netpage prmter shown m Figures 11 and 12, Figure 15 is a schematic block diagram of duplexed print engme controllers and Memjet™ pπntheads associated with the prmter controller shown m Figure 14, Figure 16 is a schematic block diagram of the print engme controller shown m Figures 14 and 15, Figure 17 is a perspective view of a single Memjet™ printing element, as used m, for example, the netpage prmter of Figures 10 to 12, Figure 18 is a perspective view of a small part of an array of Memjet™ printing elements, Figure 19 is a seπes of perspective views illustrating the operating cycle of the Memjet™ printing element shown in Figure 13, Figure 20 is a perspective view of a short segment of a pagewidth Memjet™ pπnthead, Figure 21 is a schematic view of a user class diagram, Figure 22 is a schematic view of a prmter 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 descπption class diagram, Figure 26 is a schematic view of a document and page ownership class diagram, Figure 27 is a schematic view of a terminal element specialization class diagram, Figure 28 is a schematic view of a static element specialization class diagram, Figure 29 is a schematic view of a hyperlink element class diagram, Figure 30 is a schematic view of a hyperlink element specialization class diagram, Figure 31 is a schematic view of a 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 mput processmg algonthm, Figure 38a is a detailed flowchart of one step of the flowchart of Figure 38, Figure 39 is a schematic view of a page server command element class diagram, Figure 40 is a schematic view of a resource descπption class diagram, Figure 41 is a schematic view of a favontes list class diagram, Figure 42 is a schematic view of a history list class diagram, Figure 43 is a schematic view of a subscπption 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 an advertismg fee payment protocol, Figure 49 is a schematic view of a click-through fee payment protocol, Figure 50 is a schematic view of a sales commission payment protocol, Figure 51 is a schematic view of an advertismg fee commission payment protocol, Figure 52 is a schematic view of a click-through fee commission payment protocol, and Figure 53 is a schematic view of a sales commission commission payment protocol - 6 - DETAILED DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS Note Memjet™ is a trade mark of Silverbrook Research Pty Ltd, Australia In the preferred 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 necessaπly embody all or even most of the specific details and extensions discussed below in relation to the basic system However, the system is descnbed in its most complete form to reduce the need for external reference when attempting to understand the context in which the preferred embodiments and aspects of the present mvention operate In bnef summary, the preferred form of the netpage system employs a computer interface m the form of a mapped surface, that is, a physical surface which contains references to a map of the surface maintained in a computer system The map references can be queπed by an appropnate sensing 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 within the map and among different maps The computer system can contain information about features on the mapped surface, and such information can be retπeved 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 m response to the operator's mteraction with the surface features In its preferred form, the netpage system relies on the production of, and human mteraction with, netpages These are pages of text, graphics and images pπnted on ordinary paper, but which work like mteractive web pages Information is encoded on each page using ink which is substantially invisible to the unaided human eye The ink, however, and thereby the coded data, can be sensed by an optically imaging pen and transmitted to the netpage system In the preferred form, active buttons and hyperlinks on each page can be clicked with the pen to request information from the network or to signal preferences to a network server In one embodiment, text wπtten by hand on a netpage is automatically recognized and converted to computer text m the netpage system, allowing forms to be filled in In other embodiments, signatures recorded on a netpage are automatically veπfied, allowing e-commerce transactions to be securely authorized As illustrated m Figure 1, a pπnted netpage 1 can represent a mteractive form which can be filled m by the user both physically, on the pπnted page, and "electronically", via commumcation between the pen and the netpage system The example shows a "Request" form containing name and address fields and a submit button The netpage consists of graphic data 2 pπnted using visible ink, and coded data 3 pπnted as a collection of tags 4 using invisible ink The corresponding page description 5, stored on the netpage network, descnbes the individual elements of the netpage In particular it descnbes the type and spatial extent (zone) of each mteractive element (l e text field or button m the example), to allow the netpage system to correctly interpret mput via the netpage The submit button 6, for example, has a zone 7 which coπesponds to the spatial extent of the corresponding graphic 8 As illustrated m Figure 2, the netpage pen 101 , a preferred form of which is shown m Figures 8 and 9 and descπbed m more detail below, works m conjunction with a netpage prmter 601, an Internet-connected printing appliance for home, office or mobile use The pen is wireless and communicates securely with the netpage prmter via a short-range radio link 9 The netpage prmter 601, a preferred form of which is shown m Figures 11 to 13 and descπbed m more detail below, is able to deliver, peπodically or on demand, personalized newspapers, magazmes, catalogs, brochures and other publications, all prmted at high quality as mteractive netpages Unlike a personal computer, the netpage prmter is an appliance which can be, for example, wall-mounted adjacent to an area where the morning news is first consumed, such as in a user's kitchen, near a breakfast table, or near the household's point of departure for the day It also comes m - 7 - tabletop, desktop, portable and mmiature versions Netpages pπnted at their pomt of consumption combine the ease-of-use of paper with the timeliness and interactivity of an mteractive medium As shown m Figure 2, the netpage pen 101 interacts with the coded data on a pπnted netpage 1 and commumcates, via a short-range radio link 9, the mteraction to a netpage prmter The prmter 601 sends the mteraction to the relevant netpage page server 10 for interpretation In appropπate circumstances, the page server sends a corresponding 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 onginating prmter The netpage system is made considerably more convement m the preferred embodiment by bemg used m conjunction with high-speed microelectromechanical system (MEMS) based Inkjet (Memjet™) prmters In the preferred form of this technology, relatively high-speed and high-quality printing is made more affordable to consumers In its prefeπed form, a netpage publication has the physical charactenstics of a traditional 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 prmter exploits the growing availability of broadband Internet access Cable service is available to 95% of households in the Umted States, and cable modem service offering broadband Internet access is already available to 20% of these The netpage prmter 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 mkjet and laser prmters, although the system will operate more slowly and will therefore be less acceptable from a consumer's pomt of view In other embodiments, the netpage system is hosted on a pnvate intranet In still other embodiments, the netpage system is hosted on a smgle computer or computer-enabled device, such as a printer Netpage publication servers 14 on the netpage network are configured to deliver pnnt-quality publications to netpage prmters Penodical publications are delivered automatically to subscnbmg netpage printers via pointcasting and multicasting Internet protocols Personalized publications are filtered and formatted accordmg to individual user profiles A netpage prmter can be configured to support any number of pens, and a pen can work with any number of netpage prmters In the preferred implementation, each netpage pen has a unique identifier A household may have a collection of colored netpage pens, one assigned to each member of the family This allows each user to maintain a distinct profile with respect to a netpage publication server or application server A netpage pen can also be registered with a netpage registration server 11 and linked to one or more payment card accounts This allows e-commerce payments to be securely authorized usmg the netpage pen The netpage registration server compares the signature captured by the netpage pen with a previously registered signature, allowing it to authenticate the user's identity to an e-commerce server Other 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 printer may deliver peπodicals such as the morning newspaper without user intervention, it can be configured never to deliver unsolicited junk mail In its preferred form, it only delivers peπodicals from subscnbed or otherwise authorized 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 descnbed using a Unified 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 instances of classes A generalization relates actual classes, and can be understood m the following way if a class is - 8 - 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 - 1 e classes of classes Each class is drawn as a rectangle labelled with the name of the class It contains a list of the attπbutes of the class, separated from the name by a horizontal lme, and a list of the operations of the class, separated from the attnbute list by a horizontal lme In the class diagrams which follow, however, operations are never modelled An association is drawn as a lme joining two classes, optionally labelled at either end with the multiplicity of the association The default multiplicity is one An astensk (*) mdicates a multiplicity of "many", l 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 correspondmg 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 arrow (m the form of an open tπangle) at the generalization end When a class diagram is broken up mto multiple diagrams, any class which is duplicated is shown with a dashed outline m all but the main diagram which defines it It is shown with attπbutes 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 interface to published information and mteractive services A netpage consists of a prmted page (or other surface region) invisibly tagged with references to an online descnption of the page The online page descπption is maintained persistently by a netpage page server The page descnption descnbes the visible layout and content of the page, including text, graphics and images It also descnbes the mput elements on the page, including buttons, hyperlinks, and mput fields A netpage allows markings made with a netpage pen on its surface to be simultaneously captured and processed by the netpage system Multiple netpages can share the same page descπption However, to allow mput through otherwise identical pages to be distinguished, each netpage is assigned a unique page identifier This page ID has sufficient precision to distinguish between a very large number of netpages Each reference to the page descnption is encoded m a pπnted tag The tag identifies the unique page on which it appears, and thereby indirectly identifies the page descnption The tag also identifies its own position on the page Characteπstics of the tags are descπbed m more detail below Tags are prmted 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 prmter The pen is wireless and commumcates with the netpage prmter via a short-range radio link Tags are sufficiently small and densely arranged that the pen can reliably image at least one tag even on a smgle click on the page It is important that the pen recognize the page ID and position on every mteraction with the page, smce the mteraction is stateless Tags are error-coπectably encoded to make them partially tolerant to surface damage The netpage page server maintains a unique page instance for each prmted netpage, allowing it to maintain a distinct set of user-supplied values for mput fields m the page descπption for each pπnted netpage The relationship between the page descπption, the page instance, and the pπnted netpage is shown in Figure 4 The page instance is associated with both the netpage prmter which prmted it and, if known, the netpage user who requested it 1.2 NETPAGE TAGS 1.2.1 Tag Data Content In a prefeπed form, each tag identifies the region m which it appears, and the location of that tag within the region A tag may also contam flags which relate to the region as a whole or to the tag One or more flag bits may, for example, signal a tag sensmg device to provide feedback indicative 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, in a prefeπed embodiment, each tag contains an easily recognized lnvanant structure which aids initial detection, and which assists m ininimizing the effect of any warp mduced by the surface or by the sensmg process The tags preferably tile the entire page, and are sufficiently small and densely arranged that the pen can reliably image at least one tag even on a smgle click on the page It is important that the pen recognize the page ID and position on every mteraction with the page, smce the mteraction is stateless In a preferred 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 coincide 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 contains 120 bits of information, typically allocated as shown in Table 1 Assuming a maximum tag density of 64 per square inch, a 16-bit tag ID supports a region size of up to 1024 square mches Larger regions can be mapped continuously without increasing the tag ID precision simply by usmg abutting regions and maps The 100-bit region ID allows 2 100 (~10 30 or a million tnlhon tnllion) different regions to be uniquely identified 1.2.2 Tag Data Encoding The 120 bits of tag data are redundantly encoded usmg a (15, 5) Reed-Solomon code This yields 360 encoded bits consisting of 6 codewords of 15 4-bit symbols each The (15, 5) code allows up to 5 symbol eπors to be corrected per codeword, I e it is tolerant of a symbol eπor rate of up to 33% per codeword Each 4-bit symbol is represented in a spatially coherent way in the tag, and the symbols of the six codewords are mterleaved spatially within the tag This ensures that a burst eπor (an error 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 eπor can be fully coπected 1.2.3 Physical Tag Structure The physical representation of the tag, shown m Figure 5, mcludes fixed target structures 15, 16, 17 and vaπable 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 contam representations of the mdividual bits of the encoded tag data To achieve proper tag reproduction, the tag is rendered at a resolution of 256x256 dots When prmted at 1600 dots per mch this yields a tag with a diameter of about 4 mm At this resolution the tag is designed to be suπounded by a "quiet area" of radius 16 dots Smce the quiet area is also contnbuted by ad j acent tags, it only adds 16 dots to the effective diameter of the tag - 10 - The tag mcludes six target structures A detection nng 15 allows the sensmg device to initially detect the tag The nng is easy to detect because it is rotationally mvanant and because a simple coπection of its aspect ratio removes most of the effects of perspective distortion An onentation axis 16 allows the sensmg device to determme 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 nregular tnangular gnd In combination with the circular detection nng, this makes a circular aπangement of data bits within 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 concentπc 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 array of 2x2 wedges The 15 4-bit data symbols of each of the six codewords are allocated to the four concentπc symbol rings 18a to 18d in interleaved fashion Symbols -ire 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 spacmg of the tags Assuming a circular tag shape, the minimum diameter of the sensor field of view is obtained when the tags are tiled on a equilateral tnangular gnd, as shown in Figure 6 1.2.4 Tag image Processing and Decoding The tag image processmg and decodmg performed by a sensmg device such as the netpage pen is shown 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 (l e shapes 23) (at 22) Shapes which are too small to represent tag target structures are discarded The size and centroid of each shape is also computed Binary shape moments 25 are then computed (at 24) for each shape, and these provide the basis for subsequently locating target structures Central shape moments are by their nature mvaπant of position, and can be easily made mvanant ot scale, aspect ratio and rotation The nng target structure 15 is the first to be located (at 26) A nng has the advantage of bemg very well behaved when perspective-distorted Matching proceeds by aspect-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 ring's oπginal aspect and rotation 27 together provide a useful approximation of the perspective transform The axis target structure 16 is the next to be located (at 28) Matching proceeds by applying the rmg'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 recognized Note that one third order moment is required to disambiguate the two possible oπentations ot the axis The shape is deliberately skewed to one side to make this - 1 1 - possible Note also that it is only possible to rotation-normalize the axis target after it has had the ring's normalizations applied, 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 nng and axis targets, the aspect and rotation of the nng, and the rotation of the axis Matching proceeds by applymg the ring's normalizations to each shape's moments Once their second-order moments are normalized the circular perspective targets are easy to recognize, and the target closest to each estimated position is taken as a match The onginal centroids of the four perspective targets are then taken to be the perspective-distorted corners 31 of a square of known size in tag space, and an eight-degree-of-freedom perspective transform 33 is inferred (at 32) based on solving the well-understood equations relating the four tag-space and image- space pomt pairs (see Heckbert, P , Fundamentals of Texture Mappmg and Image Warpmg, Masters Thesis, Dept of EECS, U of California at Berkeley, Technical Report No UCB/CSD 89/516, June 1989, the contents of which are herein incorporated by cross-reference) The infeπed 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 in 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 nng, if found, is part of a complete tag If a complete tag is not found and successfully decoded, then no pen position is recorded for the ctuτent frame Given adequate processmg power and ideally a non-minimal field of view 193, an alternative strategy mvolves seeking another tag m the cturent image The obtained tag data mdicates the identity of the region contaimng 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 infeπed (at 34) from the perspective transform 33 observed on the tag and the known spatial relationship between the pen's physical axis and the pen's optical axis 1.2.5 Tag Map Decoding a tag results m a region ID, a tag ID, and a tag-relative pen transform Before the tag ID and the tag-relative pen location can be translated mto an absolute location within the tagged region, the location of the tag within 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 correspondmg location The tag map class diagram is shown in Figure 22, as part of the netpage prmter class diagram A tag map reflects the scheme used to tile the surface region with tags, and this can vary accordmg to surface type When multiple tagged regions share the same tiling scheme and the same tag numbering scheme, they can also share the same tag map The tag map for a region must be retnevable via the region ID Thus, given a region ID, a tag ID and a pen transform, the tag map can be retneved, the tag ID can be translated mto an absolute tag location within the region, and the tag-relative pen location can be added to the tag location to yield an absolute pen location within the region 1.2.6 Tagging Schemes Two distinct surface coding schemes are of interest, both of which use the tag structure descnbed earlier m this section The prefeπed coding scheme uses "location-indicating" tags as already discussed An alternative coding scheme uses object-indicating tags - 12 - A location-mdicatmg tag contains a tag ID which, when translated through the tag map associated with the tagged region, yields a umque tag location within the region The tag-relative location of the pen is added to this tag location to yield the location of the pen withm the region This m turn is used to determme the location of the pen relative to a user mterface element m the page descπption 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 m the zone of a particular user mterface element An object-indicating tag contains 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 prmted page usmg an appropπate sensmg device m order for tag data to be read by the sensmg device and for an appropπate response to be generated m the netpage system 1.3 DOCUMENT AND PAGE DESCRIPTIONS A prefeπed embodiment of a document and page descπption class diagram is shown m Figures 25 and 26 In the netpage system a document is descπbed at three levels At the most abstract level the document 836 has a hierarchical structure whose terminal elements 839 are associated with content objects 840 such as text objects, text style objects, image objects, etc Once the document is pπnted on a prmter with a particular page size and accordmg to a particular user's scale factor preference, the document is paginated and otherwise formatted Formatted terminal elements 835 will m some cases be associated with content objects which are different from those associated with their correspondmg terminal elements, particularly where the content objects are style-related Each pπnted instance of a document and page is also descnbed separately, to allow mput captured through a particular page instance 830 to be recorded separately from mput captured through other instances of the same page descπption The presence of the most abstract document descπption on the page server allows a user to request a copy of a document without bemg forced to accept the source document's specific format The user may be requesting a copy through a prmter 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 prmted page A formatted document 834 consists of a set of formatted page descπptions 5, each of which consists of a set of formatted terminal elements 835 Each formatted element has a spatial extent or zone 58 on the page This defines the active area of input elements such as hyperlinks and mput fields A document instance 831 coπesponds to a formatted document 834 It consists of a set of page instances 830, each of which coπesponds to a page descnption 5 of the formatted document Each page instance 830 descnbes a smgle unique prmted netpage 1 , and records the page ID 50 of the netpage A page instance is not part of a document instance if it represents a copy of a page requested m isolation A page instance consists of a set of terminal element instances 832 An element instance only exists if it records instance-specific information Thus, a hyperlink instance exists for a hyperlink element because it records a transaction ID 55 which is specific to the page instance, and a field instance exists for a field element because it records mput specific to the page instance An element instance does not exist, however, for static elements such as textflows A terminal element can be a static element 843, a hyperlink element 844, a field element 845 or a page server command element 846, as shown in Figure 27 A static element 843 can be a style element 847 with an - 13 - associated style object 854, a textflow element 848 with an associated styled text object 855, an image element 849 with an associated image element 856, a graphic element 850 with an associated graphic object 857, a video clip element 851 with an associated video clip object 858, an audio clip element 852 with an associated audio clip object 859, or a scπpt element 853 with an associated scπpt object 860, as shown in Figure 28 A page instance 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 prefeπed form of the mvention, a tag map 811 is associated with each page instance to allow tags on the page to be translated mto locations on the page 1.4 THE NETPAGE NETWORK In a prefeπed embodiment, a netpage network consists of a distπbuted set of netpage page servers 10, netpage registration servers 11, netpage ID servers 12, netpage application servers 13, netpage publication servers 14, and netpage prmters 601 connected via a network 19 such as the Internet, as shown m Figure 3 The netpage registration server 11 is a server which records relationships between users, pens, prmters, applications and publications, and thereby authorizes vanous network activities It authenticates users and acts as a signing proxy on behalf of authenticated users m application transactions It also provides handwπting recognition services As descnbed above, a netpage page server 10 maintains persistent information about page descnptions and page instances The netpage network mcludes any number of page servers, each handling a subset of page instances Smce a page server also maintains user mput values for each page instance, clients such as netpage prmters send netpage mput directly to the appropπate page server The page server interprets any such mput relative to the descπption of the coπesponding page A netpage ED server 12 εdlocates document IDs 51 on demand, and provides load-balancing of page servers via its ID allocation scheme A netpage prmter 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 coπesponding page instance A netpage application server 13 is a server which hosts mteractive netpage applications A netpage publication server 14 is an application server which publishes netpage documents to netpage prmters They are descnbed m detail m Section 2 Netpage servers can be hosted on a vanety of network server platforms from manufacturers such as IBM, Hewlett-Packard, and Sun Multiple netpage servers can run concuπently 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 prints 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 distnbuted netpage page servers 10, independently of particular netpage prmters 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 pnnter via the appropnate page server Text and image objects, on the other hand, are typically shared with - 14 - other subscnbers, and so are multicast to all subscπbers' prmters and the appropπate page servers The netpage publication server optimizes the segmentation of document content mto pointcasts and multicasts After receiving the pointcast of a document's page layouts, the pnnter knows which multicasts, if any, to listen to Once the pnnter has received the complete page layouts and objects that define the document to be pπnted, it can print the document The pnnter rasteπzes and prints odd and even pages simultaneously on both sides of the sheet It contains duplexed prmt engme controllers 760 and prmt engmes utilizing Memjet™ pπntheads 350 for this purpose The pnntmg process consists of two decoupled stages rasterization of page descnptions, and expansion and printing of page images The raster image processor (RTF) consists of one or more standard DSPs 757 runmng parallel The duplexed prmt engme controllers consist of custom processors which expand, dither and pπnt page images m real time, synchronized with the operation of the pπntheads in the prmt engmes Printers not enabled for DR. pnntmg have the option to prmt tags usmg IR-absorptive black ink, although this restncts tags to otherwise empty areas of the page Although such pages have more limited functionality than IR-pπnted pages, they are still classed as netpages A normal netpage pnnter pnnts netpages on sheets of paper More specialised netpage prmters may prmt onto more specialised surfaces, such as globes Each pnnter supports at least one surface type, and supports at least one tag tilmg scheme, and hence tag map, for each surface type The tag map 811 which descnbes the tag tilmg scheme actually used to prmt a document becomes associated with that document so that the document's tags can be coπectly interpreted Figure 2 shows the netpage pnnter class diagram, reflecting pπnter-related information maintained by a registration server 11 on the netpage network A prefeπed embodiment of the netpage printer is descπbed m greater detail m Section 6 below, with reference to Figures 11 to 16 1.5.1 Memjet™ Printheads The netpage system can operate usmg prmters made with a wide range of digital pnntmg technologies, mcludmg thermal mkjet, piezoelectπc mkjet, laser electrophotographic, and others However, for wide consumer acceptance, it is desirable that a netpage pnnter have the following charactenstics photographic quality color pnntmg • high quality text pnntmg high reliability low pnnter cost low paper cost • simple operation nearly silent pnntmg high pnnt g speed simultaneous double sided pnntmg compact form factor • low power consumption No commercially available pnntmg technology has all of these charactenstics To enable to production of prmters with these charactenstics, the present applicant has mvented a new print - 15 - technology, refeπed to as Memjet™ technology Memjet™ is a drop-on-demand Inkjet technology that mcorporates pagewidth prmtheads fabπcated usmg microelectromechanical systems (MEMS) technology Figure 17 shows a smgle printing element 300 of a Memjet™ pnnthead The netpage wallpnnter mcorporates 168960 pnntmg elements 300 to form a 1600 dpi pagewidth duplex pnnter This pnnter simultaneously prints cyan, magenta, yellow, black, and infrared inks as well as paper conditioner and ink fixative The pnntmg element 300 is approximately 110 microns long by 32 microns wide Aπays of these pnntmg elements are formed on a silicon substrate 301 that mcorporates CMOS logic, data transfer, timing, and dnve circuits (not shown) Major elements of the pnntmg element 300 are the nozzle 302, the nozzle nm 303, the nozzle chamber 304, the fluidic seal 305, the ink channel nm 306, the lever arm 307, the active actuator beam pair 308, the passive actuator beam pair 309, the active actuator anchor 310, the passive actuator anchor 311, and the ink inlet 312 The active actuator beam pair 308 is mechanically joined to the passive actuator beam parr 309 at the join 319 Both beams pairs are anchored at their respective anchor points 310 and 311 The combination of elements 308, 309, 310, 311, and 319 form a cantilevered electrothermal bend actuator 320 Figure 18 shows a small part of an array of pnntmg elements 300, including a cross section 315 of a pnntmg element 300 The cross section 315 is shown without ink, to clearly show the ink inlet 312 that passes through the silicon wafer 301 Figures 19(a), 19(b) and 19(c) show the operating cycle of a Memjet™ printing element 300 Figure 19(a) shows the quiescent position of the ink meniscus 316 pnor to pnntmg an ink droplet Ink is retained m the nozzle chamber by surface tension at the ink meniscus 316 and at the fluidic seal 305 formed between the nozzle chamber 304 and the ink channel nm 306 While pnntmg, the pnnthead CMOS circuitry distnbutes data from the prmt engme controller to the correct pnnt g element, latches the data, and buffers the data to dnve the electrodes 318 of the active actuator beam pair 308 This causes an electncal current to pass through the beam parr 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 pair 309 is not heated, it does not expand, resulting m a stress difference between the two beam pairs This stress difference is partially resolved by the cantilevered end of the electrothermal bend actuator 320 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 mcreases the ink pressure, forcing ink 321 out of the nozzle 302, and causing the ink meniscus 316 to bulge The nozzle nm 303 prevents the ink meniscus 316 from spreading across the surface of the nozzle chamber 304 As the temperature of the beam pairs 308 and 309 equalizes, the actuator 320 returns to its onginal 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 meniscus 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 0 4 mm long (about 0 2% of a complete pnnthead) When pnntmg, the paper is moved past the fixed pnnthead m the direction 352 The pnnthead has 6 rows of interdigitated pnntmg elements 300, pnntmg the six colors or types of ink supplied by the ink inlets 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 coπesponding nozzle guard hole 331 through which the ink droplets are fired To prevent the nozzle guard holes 331 from becoming blocked by paper fibers or other debns, filtered air is pumped through the air inlets 332 and out of the nozzle guard holes duπng pnntmg To prevent ink 321 from - 16 - drymg, the nozzle guard is sealed while the pnnter is idle 1.6 The Netpage Pen The active sensmg device of the netpage system is typically a pen 101, which, using its embedded controller 134, is able to capture and decode IR position tags from a page via an image sensor The image sensor is a solid-state device provided with an appropnate filter to permit sensmg at only near-infrared wavelengths. As descπbed m more detail below, the system is able to sense when the mb is in contact with the surface, and the pen is able to sense tags at a sufficient rate to capture human handwnting (I e at 200 dpi or greater and 100 Hz or faster) Information captured by the pen is encrypted and wirelessly transmitted to the pnnter (or base station), the pnnter or base station interpreting the data with respect to the (known) page structure The prefeπed embodiment of the netpage pen operates both as a normal markmg ink pen and as a non- marking stylus 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, reflecting pen-related information mamtamed by a registration server 11 on the netpage network When either mb 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 interpreted 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 veπfied The pen determines the position and onentation of its mb on the netpage by imaging, m the infrared spectrum, an area 193 of the page m the vicinity of the mb It decodes the nearest tag and computes the position of the mb relative to the tag from the observed perspective distortion on the imaged tag and the known geometry of the pen optics Although the position resolution of the tag may be low, because the tag density on the page is inversely proportional to the tag size, the adjusted position resolution is quite high, exceeding the minimum resolution required for accurate handwnting recognition 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 cuπent selection 826 associated with it, allowing the user to perform copy and paste operations etc The selection is timestamped to allow the system to discard it after a defined time peπod The current selection descnbes a region of a page instance It consists of the most recent digital ink stroke captured through the pen relative to the background area of the page It is interpreted in an application-specific manner once it is submitted to an application via a selection hyperlink activation Each pen has a cuπent mb 824 This is the nib last notified by the pen to the system In the case of the default netpage pen descnbed above, either the markmg black ink mb or the non-marking stylus mb is current Each pen also has a cturent 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 mb style associated with the cturent mb Strokes captured through a pen are tagged with the current 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 commumcate, the pen slowly flashes its "online" LED When the pen fails to decode a stroke relative to the page, it momentaπly activates its "eπor" LED - 17 - When the pen succeeds decodmg a stroke relative to the page, it momentanly activates its "ok" LED A sequence of captured strokes is refeπed to as digital ink Digital ink forms the basis for the digital exchange of drawings and handwnting, for online recognition of handwnting, and for online veπfication of signatures The pen is wireless and transmits digital ink to the netpage pnnter via a short-range radio link The transmitted digital ink is encrypted for pnvacy and secunty 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 prmter 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 pnnter, it transfers any buffered digital ink A pen can be registered with any number of prmters, but because all state data resides m netpages both on paper and on the network, it is largely lmmatenal which pnnter a pen is communicating with at any particular time A prefeπed embodiment of the pen is descnbed m greater detail m Section 6 below, with reference to Figures 8 to 10 1.7 NETPAGE INTERACTION The netpage pnnter 601 receives data relating to a stroke from the pen 101 when the pen is used to mteract with a netpage 1 The coded data 3 of the tags 4 is read by the pen when it is used to execute a movement, such as a stroke The data allows the identity of the particular page and associated mteractive element to be determined and an indication of the relative positioning of the pen relative to the page to be obtained The 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 coπesponding page instance 830 It then transmits the stroke to the page server If the page was recently identified in an earlier stroke, then the pnnter may already have the address of the relevant page server m its cache Each netpage consists of a compact page layout mamtamed persistently by a netpage page server (see below) The page layout refers to objects such as images, fonts and pieces of text, typically stored elsewhere on the netpage network When the page server receives the stroke from the pen, it retneves the page descnption to which the stroke applies, and determines which element of the page descnption the stroke intersects It is then able to interpret the stroke m the context of the type of the relevant element A "click" is a stroke where the distance and time between the pen down position and the subsequent pen up position are both less than some small maximum An object which is activated by a click typically requires a click to be activated, and accordingly, a longer stroke is ignored The failure of a pen action, such as a "sloppy" click, to register is indicated by the lack of response from the pen's "ok" LED There are two kinds of mput elements m a netpage page descnption 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 pπnted response m the netpage system A hyperlink element 844 identifies the application 71 which handles activation of the hyperlink, a link ED 54 which identifies the hyperlink to the application, an "alias required" flag which asks the system to mclude the user's application alias ID 65 m the hyperlink activation, and a descnption which is used when the hyperlink is recorded as a favonte or appears m the user's history The hyperlink element class diagram is shown m Figure 29 When a hyperlink is activated, the page server sends a request to an application somewhere on the network The application is identified by an application ID 64, and the application ID is resolved m the normal way via the DNS There are three types of hyperlinks general hyperlinks 863, form hyperlinks 865, and selection hyperlinks 864, as - 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 coπespondmg form to the application A selection hyperlink submits the cuπent selection to the application If the cuπent selection contains a smgle-word piece of text, for example, the application may return a single-page document giving the word's meamng 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 coπesponding hyperlink instance 862 records a transaction ID 55 which can be specific to the page instance on which the hyperlink instance appears The transaction ID can identify user-specific data to the application, for example a "shopping cart" of pendmg purchases mamtamed by a purchasing application on behalf of the user The system includes the pen's cuπent selection 826 m a selection hyperlink activation The system mcludes the content of the associated form instance 868 m a form hyperlink activation, although if the hyperlink has its "submit delta" attπbute set, only mput 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 in 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, m 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" interaction model, l e where mput is captured and therefore shared as soon as it occurs 1.7.2 Forms A form defines a collection of related mput fields used to capture a related set of inputs through a prmted netpage A form allows a user to submit one or more parameters to an application software program runmng on a server A form 867 is a group element 838 m the document hierarchy It ultimately contains a set of terminal field elements 839 A form instance 868 represents a pπnted instance of a form It consists of a set of field instances 870 which coπespond to the field elements 845 of the form Each field instance has an associated value 871, whose type depends on the type of the coπesponding field element Each field value records mput through a particular pπnted form instance, I e through one or more prmted netpages The form class diagram is shown m Figure 32 Each form instance has a status 872 which mdicates whether the form is active, frozen, submitted, void or expired A form is active when first prmted 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 input is allowed Input through a form which is not active is mstead captured m the background field 833 of the relevant page instance When the form is active or frozen, form submission is allowed Any attempt to submit a form when the form is not active or frozen is rejected, and mstead elicits an form status report Each form instance is associated (at 59) with any form instances denved from it, thus providing a version history This allows all but the latest version of a form m a particular time peπod to be excluded from a search All mput is captured as digital ink Digital ink 873 consists of a set of timestamped stroke groups 874, each of which consists of a set of styled strokes 875 Each stroke consists of a set of timestamped pen positions 876, each of which also includes 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 in a field's zone 58 is assigned to - 19 - the field A checkbox field has an associated boolean value 881, as shown m Figure 35 Any mark (a tick, a cross, a stroke, a fill zigzag, etc ) captured m a checkbox field's zone causes a true value to be assigned to the field's value A text field has an associated text value 882, as shown 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, Tapper-, C , C Y Suen and T Wakahara, "The State of the Art m On-Line Handwnting Recogmtion", EEE Transactions on Pattern Analysis and Machine Intelligence, Vol 12, No 8, August 1990, the contents of which are herem incorporated by cross-reference) A signature field has an associated digital signature value 883, as shown m Figure 37 Any digital ink captured m a signature field's zone is automatically venfied with respect to the identity 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, the contents of which are herem incorporated by cross-reference) A field element is hidden if its "hidden" attnbute is set A hidden field element does not have an mput zone on a page and does not accept mput It can have an associated field value which is mcluded the form data when the form containing the field is submitted "Editing" commands, such as stnke-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" (I e with access only to a bitmap of pen markings), it can recognize run-on discretely- wπtten characters with relatively high accuracy, without a wπter-dependent training phase A wπter-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 interpretation Any stroke not appended to an object's digital ink stream is appended to the background field's digital ink stream Digital ink captured m the background field is interpreted as a selection gesture Circumscnption of one or more objects is generally interpreted as a selection of the circumscπbed objects, although the actual interpretation is application-specific Table 2 summanses these vanous pen interactions with a netpage The system maintains a current 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 - 20 - 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 mteπogate the raw digital ink should it suspect the ongmal conversion, such as the conversion of handwntten 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 input relative to a netpage The process consists of receiving (at 884) a stroke from the pen, identifying (at 885) the page instance 830 to which the page ID 50 in the stroke refers, retneving (at 886) the page descnption 5, identifying (at 887) a formatted element 839 whose zone 58 the stroke intersects, determining (at 888) whether the formatted element coπesponds to a field element, and if so appending (at 892) the received stroke to the digital ink of the field value 871, interpreting (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 deterrmr-mg (at 889) whether the formatted element coπesponds to a hyperlink element and if so activating (at 895) the coπespondmg hyperlink, alternatively, m the absence of an mput field or hyperlink, appending (at 890) the received stroke to the digital ink of the background field 833, and copying (at 891) the received stroke to the current selection 826 of the current pen, as maintained by the registration server Figure 38a shows a detailed flowchart of step 893 m the process shown m Figure 38, where the accumulated digital ink of a field is interpreted 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 determining (at 899) whether the field is a text field and if so converting (at 900) the digital ink to computer text, with the help of the appropnate registration server, and assigning (at 901) the converted computer text to the field value, alternatively deterπumng (at 902) whether the field is a signature field and if so venfying (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 coπespondmg form, also with the help of the registration server and usmg the pen owner's pnvate signature key relating to the coπesponding application, and assigning (at 905) the digital signature to the field value 1.7.3 Page Server Commands A page server command is a command which is handled locally by the page server It operates directly on form, page and document instances A page server command 907 can be a void form command 908, a duplicate form command 909, a reset form command 910, a get form status command 911, a duplicate page command 912, a reset page command 913, a get page status command 914, a duplicate document command 915, a reset document command 916, or a get document status command 917, as shown m Figure 39 A void form command voids the coπespondmg form instance A duplicate form command voids the coπespondmg form instance and then produces an active prmted copy of the current form instance with field values preserved The copy contains the same hyperlink transaction IDs as the ongmal, and so is indistinguishable from the ongmal to an application A reset form command voids the coπespondmg form instance and then produces an active prmted copy of the form instance with field values discarded A get form status command produces a prmted report on the status of the coπespondmg form instance, mcludmg who published it, when it was pπnted, for whom it was prmted, - 21 - and the form status of the form instance Smce a form hyperlink instance contams a transaction ID, the application has to be mvolved m producing a new form mstance A button requesting a new form mstance is therefore typically implemented as a hyperlink A duplicate page command produces a prmted copy of the coπespondmg 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 coπespondmg page mstance with the background field value discarded If the page contams a form or is part of a form, then the reset page command is mterpreted as a reset form command A get page status command produces a pπnted report on the status of the correspondmg page mstance, mcludmg who published it, when it was prmted, 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 in their native form, l e a checkmark appears as a standard checkmark graphic, and text appears as typeset text Only drawings and signatures appear m 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 coπespondmg 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 prmted copy of the coπesponding document mstance with background field values discarded If the document contains any forms, then the reset document command resets the forms in the same way a reset foim command does A get document status command produces a prmted report on the status of the coπespondmg document mstance, mcludmg who published it, when it was prmted, for whom it was prmted, and the status of any forms it contains If the page server command's "on selected" attnbute is set, then the command operates on the page identified by the pen's cturent selection rather than on the page containing the command This allows a menu of page server commands to be prmted If the target page doesn t contam 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 prefeπed 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 1.9 USER HELP SYSTEM In a prefeπed embodiment, the netpage prmter has a single button labelled "Help" When pressed it elicits a smgle page of information, mcludmg • status of pnnter connection - 22 - • status of pnnter consumables • top-level help menu • document function menu • top-level netpage network directory The help menu provides a hierarchical manual on how to use the netpage system The document function menu mcludes the following functions • prmt a copy of a document • prmt a clean copy of a form • prmt the status of a document A document function is initiated by simply pressmg the button and then touching any page of the document The status of a document mdicates who published it and when, to whom it was delivered, and to whom and when it was subsequently submitted as a form The netpage network directory allows the user to navigate the hierarchy of publications and services on the network As an alternative, the user can call the netpage network "900" number "yellow pages" and speak to a human operator The operator can locate the desired document and route it to the user's pnnter Dependmg on the document type, the publisher or the user pays the small "yellow pages" service fee The help page is obviously unavailable if the pnnter is unable to prmt In this case the "eπor" light is lit and the user can request remote diagnosis over the network 2 PERSONALIZED PUBLICATION MODEL In the following descnption, news is used as a canonical publication example to illustrate personalization mechanisms m the netpage system Although news is often used m the limited sense of newspaper and newsmagazine news, the mtended scope m the present context is wider In the netpage system, the editoπal content and the advertismg content of a news publication are personalized using different mechanisms The editonal content is personalized according to the reader's explicitly stated and implicitly captured mterest profile The advertising content is personalized accordmg to the reader's locality and demographic 2.1 EDITORIAL PERSONALIZATION A subscnber can draw on two lands 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 coπespond to traditional newspapers and newsmagazmes, while news streams can be many and vaned 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 editoπal control The subscnber builds a daily newspaper by selecting one or more contnbuting news publications, and creating a personalized version of each The resulting daily editions are pπnted and bound together mto a single newspaper The vanous members of a household typically express their different mterests and tastes by selecting different daily publications and then customizing them For each publication, the reader optionally selects specific sections Some sections appear daily, while others appear weekly The daily sections available from The New York Times online, for example, mclude "Page One Plus", ''National", "International", "Opinion", "Business", "Arts/Living", "Technology", and "Sports" The set of available sections is specific to a publication, as is the default subset - 23 - The reader can extend the daily newspaper by creatmg 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 numencally (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 according to the reader's age The reader can specify a "reading age" which takes precedence over their biological age The articles which make up each section are selected and pπontized by the editors, and each is assigned a useful lifetime By default they are delivered to all relevant subscnbers, m pnoπty order, subject to space constraints m the subscnbers' editions In sections where it is appropπate, the reader may optionally enable collaborative filtering This is then applied to articles which have a sufficiently long lifetime Each article which qualifies for collaborative filtering is pπnted with 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 pnoπties and short lifetimes are therefore effectively considered essential reading by the editors and are delivered to most relevant subscnbers The reader optionally specifies a serendipity factor, either qualitatively (e g do or don't surpnse me), or numencally A high serendipity factor lowers the threshold used for matching dunng collaborative filtering A high factor makes it more likely that the coπespondmg 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 within a section, and this modifies the pπonties assigned by the editors The speed of the reader's Internet connection affects the quality at which images can be delivered The reader optionally specifies a preference for fewer images or smaller images or both If the number or size of images is not reduced, then images may be delivered at lower quality (l e at lower resolution or with greater compression) At a global level, the reader specifies how quantities, dates, times and monetary values are localized This involves specifying whether units are impenal or metnc, a local timezone and time format, and a local currency, and whether the localization consist of in situ translation or annotation These preferences are deπved from the reader's locality by default To reduce reading 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 coπespondmg text encoding, is a property of the publication and not a preference expressed by the user However, the netpage system can be configured to provide automatic translation services m vanous guises 2.2 ADVERTISING LOCALIZATION AND TARGETING The personalization of the editonal content directly affects the advertismg content, because advertising is typically placed to exploit the editoπal context Travel ads, for example, are more likely to appear m a travel section - 24 - than elsewhere The value of the editonal content to an advertiser (and therefore to the publisher) lies m its ability to attract large numbers of readers with the nght demographics Effective advertismg is placed on the basis of locality and demographics Locality determines proximity to particular services, retailers etc , and particular mterests and concerns associated with the local community and environment Demographics determme general mterests and preoccupations as well as likely spendmg patterns A news publisher's most profitable product is advertismg "space", a multi-dimensional entity determined by the publication's geographic coverage, the size of its readership, its readership demographics, and the page area available for advertismg In the netpage system, the netpage publication server computes the approximate multi-dimensional size of a publication's saleable advertismg space on a per-section basis, taking mto account the publication's geographic coverage, the section's readership, the size of each reader's section edition, each reader's advertismg proportion, and each reader's demographic In compaπson with other media, the netpage system allows the advertismg space to be defined m greater detail, and allows smaller pieces of it to be sold separately It therefore allows it to be sold at closer to its true value For example, the same advertismg "slot" can be sold m varying proportions to several advertisers, with mdividual readers' pages randomly 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 prefeπed 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 Coπespondmgly, the publisher records the ad placement on the relevant netpage publication server When the netpage publication server lays out each user's personalized publication, it picks the relevant advertisements from the netpage ad server 2.3 USER PROFILES 2.3.1 Information Filtering The personalization of news and other publications relies on an assortment of user-specific profile information, mcludmg • publication customizations • collaborative filtering vectors • contact details - 25 - • presentation preferences The customization of a publication is typically publication-specific, and so the customization information is mamtamed by the relevant netpage publication server A collaborative filtermg vector consists of the user's ratings of a number of news items It is used to coπelate different users' mterests for the purposes of makmg recommendations Although there are benefits to maintaining a smgle collaborative filtermg vector mdependently of any particular publication, there are two reasons why it is more practical to mamtam a separate vector for each publication there is likely to be more overlap between the vectors of subscnbers to the same publication than between those of subscnbers to different publications, and a publication is likely to want to present its users' collaborative filtermg vectors as part of the vεdue of its brand, not to be found elsewhere Collaborative filtermg 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 the same way The localization of advertismg relies on the locality indicated in the user's contact details, while the targeting of advertismg relies on personal information such as date of birth, gender, mantal status, mcome, profession, education, or qualitative denvatives such as age range and mcome range For those users who choose to reveal personal information for advertismg purposes, the information is mamtamed by the relevant netpage registration server In the absence of such information, advertising can be targeted on the basis of the demographic associated with the user's ZIP or Z-P+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 authorized to use any number of prmters 802, and each prmter may allow any number of users to use it Each user has a smgle default pnnter (at 66), to which penodical publications are delivered by default, whilst pages pπnted on demand are delivered to the pnnter through which the user is interacting The server keeps track of which publishers a user has authorized to prmt to the user's default pnnter A publisher does not record the ID of any particular pnnter, but instead resolves the ID when it is required When a user subscπbes 808 to a publication 807, the publisher 806 (l e application provider 803) is authorized to prmt to a specified pnnter 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 authorized to use a particular pnnter, then that pnnter recognizes any of the user's pens The pen ID is used to locate the coπespondmg user profile mamtamed by a particular netpage registration server, via the DNS m the usual way A Web terminal 809 can be authorized to print on a particular netpage prmter, allowing Web pages and netpage documents encountered dunng Web browsmg to be conveniently prmted on the nearest netpage pnnter The netpage system can collect, on behalf of a pnnter provider, fees and commissions on mcome earned through publications prmted on the provider s prmters Such mcome can mclude advertismg fees, click-through fees, e- commerce commissions, and transaction fees If the pnnter 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 - 26 - preferences 816, mcludmg pnvacy, delivery and localization settings, any number of biometnc records 817, contammg the user's encoded signature 818, fingerprint 819 etc, a handwntmg model 819 automatically mamtamed by the system, and SET payment card accounts 821 with which e-commerce payments can be made 2.3.2 Favorites List A netpage user can maintain a list 922 of "favontes" - links to useful documents etc on the netpage network The list is maintained by the system on the user's behalf It is organized as a hierarchy of folders 924, a prefeπred embodiment of which is shown m the class diagram m Figure 41 2.3.3 History List The system maintains a history list 929 on each user's behalf, containing links to documents etc accessed by the user through the netpage system It is organized as a date-ordered list, a prefeπed embodiment of which is shown m the class diagram m Figure 42 2.4 INTELLIGENT PAGE LAYOUT The netpage publication server automatically lays out the pages of each user's personalized publication on a section-by-section basis Since most advertisements are m the form of pre-foimatted rectangles, they are placed on the page before the editonal content The advertismg ratio for a section can be achieved with wildly varying advertismg ratios on mdividual pages withm the section, and the ad layout algonthm exploits this The algonthm is configured to attempt to co-locate closely tied editonal and advertismg content, such as placmg ads tor roofing matenal specifically withm the publication because of a special feature on do-it-yourself roofing repairs The editonal content selected for the user, mcludmg text and associated images and graphics, is then laid out accordmg to vanous aesthetic rules The entire process, mcludmg the selection of ads and the selection of editonal content, must be iterated once the layout has converged, to attempt to more closely achieve the user's stated section size preference The section size preference can, however, be matched on average over time, allowing significant day-to-day vanations 2.5 DOCUMENT FORMAT Once the document is laid out, it is encoded for efficient distnbution and persistent storage on the netpage network The primary efficiency mechanism is the separation of information specific to a smgle user's edition and information shared between multiple users' editions The specific information consists of the page layout The shared information consists of the objects to which the page layout refers, mcludmg images, graphics, and pieces of text A text object contams fully-formatted text represented m the Extensible Markup Language (XML) usmg the Extensible Stylesheet Language (XSL) XSL provides precise control over text formatting mdependently of the region mto which the text is bemg set, which m this case is being provided by the layout The text object contams embedded language codes to enable automatic translation, and embedded hyphenation hints to aid with paragraph formatting An image object encodes an image m the JPEG 2000 wavelet-based compressed image format A graphic object encodes a 2D graphic m Scalable Vector Graphics (SVG) format The layout itself consists of a senes of placed image and graphic objects, linked textflow objects through which text objects flow, hyperlinks and mput fields as descnbed above, and watermark regions These layout objects are summarized m Table 3 The layout uses a compact format suitable for efficient distnbution and storage ■ 27 - 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 unique ID for each page, page mstance, document, and document mstance The server computes a set of optimized subsets of the shared content and creates a multicast channel for each subset, and then tags each user-specific layout with the names of the multicast channels which will carry the shared content used by that layout The server then pomtcasts 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 receiving its pomtcast, each page server and pnnter subscnbes to the multicast channels specified m the page layouts Duπng the multicasts, each page server and pnnter extracts from the multicast streams those objects refeπed to by its page layouts The page servers persistently archive the received page layouts and shared content Once a pnnter has received all the objects to which its page layouts refer, the pnnter re-creates the fully- populated layout and then rastenzes and prints it Under normal circumstances, the pnnter prints 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, allowing for temporary buffers etc The pnnter prints at a rate of one page per second This is equivalent to 400KB or about 3Mbit of page data per second, which is similar to the highest expected rate of page data delivery over a broadband network Even under abnormal circumstances, such as when the pnnter runs out of paper, it is likely that the user will be able to replemsh the paper supply before the printer's 100-page internal storage capacity is exhausted However, if the pnnter' s internal memory does fill up, then the pnnter will be unable to make use of a multicast when it first occurs The netpage publication server therefore allows prmters to submit requests for re- multicasts When a cntical number of requests is received or a timeout occurs, the server re-multicasts the coπesponding shared objects Once a document is prmted, a pnnter can produce an exact duplicate at any time by retπevmg its page layouts and contents from the relevant page server 2.7 ON-DEMAND DOCUMENTS When a netpage document is requested on demand, it can be personalized and delivered in much the same way as a penodical However, smce there is no shared content, delivery is made directly to the requesting pnnter without the use of multicast When a non-netpage document is requested on demand, it is not personalized, and it is delivered via a designated netpage formatting server which reformats it as a netpage document A netpage formatting server is a special - 28 - 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 pπnted page to present Web pages m a multi-column format, with a table of contents It can automatically include all Web pages directly linked to the requested page The user can tune this behavior via a preference The netpage formatting server makes standard netpage behavior, mcludmg interactivity and persistence, available on any Internet document, no matter what its 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 refeπed to as symmetnc cryptography, uses the same key to encrypt and decrypt a message Two parties wishing to exchange messages must first aπange to securely exchange the secret key Public-key cryptography, also refeπed to as asymmetπc 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 Public-key cryptography can be used to create a digital signature The holder of the pnvate key can create a known hash of a message and then encrypt the hash 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 veπfying the hash against the message If the signature is appended to the message, then the recipient of the message can veπfv both that the message is genuine 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 authonties A certificate authonty is a trusted third party which authenticates the connection between a public key and someone's identity The certificate authoπty venfies the person's identity by examining identity documents, and then creates and signs a digital certificate contammg the person's identity details and public key Anyone who trusts the certificate authonty can use the public key m the certificate with a high degree of certainty that it is genuine 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 following discussion, when reference is made to the secure transmission of information between a netpage pnnter and a server, what actually happens is that the pnnter obtains the server's certificate, authenticates it with reference to the certificate authonty, uses the public key-exchange key in the certificate to exchange a secret session key with the server, and then uses the secret session key to encrypt the message data A session key, by definition, can have an arbitranly short lifetime - 29 - 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 installation, it creates a signature public/pnvate key pair It transmits the secret ID and the public key securely to the netpage registration server The server compares the secret ID against the printer's secret ID recorded m its database, and accepts the registration if the IDs match It then creates and signs a certificate contammg the printer's public ID and public signature key, and stores the certificate m the registration database The netpage registration server acts as a certificate authoπty for netpage prmters, smce it has access to secret information allowing it to venfy pnnter identity When a user subscπbes to a publication, a record is created m the netpage registration server database authorizing the publisher to prmt the publication to the user's default pnnter or a specified prmter Every document sent to a pnnter via a page server is addressed to a particular user and is signed by the publisher usmg the publisher's pnvate signature key The page server venfies, via the registration database, that the publisher is authorized to deliver the publication to the specified user The page server venfies the signature usmg the publisher's public key, obtained from the publisher's certificate stored m the registration database The netpage registration server accepts requests to add pnntmg 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 m read-only memory m the pen and m the netpage registration server database The pen ID 61 umquely identifies the pen on the netpage network A netpage pen can "know" a number of netpage prmters, and a pnnter can "know" a number of pens A pen commumcates with a pnnter via a radio frequency signal whenever it is withm range of the pnnter Once a pen and prmter are registered, they regularly exchange session keys Whenever the pen transmits digital ink to the pnnter, the digital ink is always encrypted usmg the appropnate session key Digital ink is never transmitted m the clear A pen stores a session key for every pnnter it knows, mdexed by pnnter ID, and a prmter stores a session key for every pen it knows, mdexed by pen ID Both have a large but finite storage capacity for session keys, and will forget a session key on a least-recently-used basis if necessary When a pen comes withm range of a pnnter, the pen and pnnter discover whether they know each other If they don't know each other, then the pnnter 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 contams a secret key-exchange key The key-exchange key is also recorded m the netpage registration server database at time of manufacture Duπng registration, the pen transmits its pen ID to the pnnter, and the pnnter transmits the pen ID to the netpage registration server The server generates a session key for the pnnter and pen to use, and securely transmits the session key to the pnnter It also transmits a copy of the session key encrypted with the pen's key-exchange key The pnnter stores the session key internally, mdexed by the pen ID, and transmits the encrypted session key to the pen The pen stores the session key internally, mdexed by the - 30 - pnnter ID Although a fake pen can impersonate a pen m the pen registration protocol, only a real pen can decrypt the session key transmitted by the pnnter When a previously unregistered pen is first registered, it is of limited use until it is linked to a user A registered but "un-owned" pen is only allowed to be used to request and fill m netpage user and pen registration forms, to register a new user to which the new pen is automatically linked, or to add a new pen to an existing user The pen uses secret-key rather than public-key encryption because of hardware performance constraints m the pen 3.4 SECURE DOCUMENTS The netpage system supports the delivery of secure documents such as tickets and coupons The netpage pnnter mcludes a facility to pπnt watermarks, but will only do so on request from publishers who are suitably authorized The publisher mdicates its authonty to pπnt watermarks m its certificate, which the pnnter is able to authenticate The "watermark" pnntmg process uses an alternative dither matπx m specified "watermark" regions of the page Back-to-back pages contam mirror-image watermark regions which comcide when prmted 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 prmted 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 descπbed m Section 1 9 above This extends to copying netpages on netpage-aware photocopiers Secure documents are typically generated as part of e-commerce transactions They can therefore mclude the user's photograph which was captured when the user registered biometnc information with the netpage registration server, as descnbed 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 unique ID of a secure document is only valid for the lifetime of the document, and secure document IDs are allocated non-contiguously to prevent their prediction by opportunistic forgers A secure document venfication pen can be developed with built-in feedback on venfication failure, to support easy point-of-presentation document venfication Clearly neither the watermark nor the user's photograph are secure m a cryptographic sense They simply provide a significant obstacle to casual forgery Onlme document venfication, particularly usmg a venfication pen, provides an added level of 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 -ire 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 descπbed m Section 4, are also impossible for the payee to repudiate 4 ELECTRONIC COMMERCE MODEL 4.1 SECURE ELECTRONIC TRANSACTION (SET) The netpage system uses the Secure Electronic Transaction (SET) system as one of its payment systems SET, havmg been developed by MasterCard and Visa, is organized around payment cards, and this is reflected m the terminology However, much of the system is mdependent of the type of accounts bemg used In SET, cardholders and merchants register with a certificate authoπty and are issued with certificates - 31 - containing their public signature keys The certificate authonty venfies a cardholder's registration details with the card issuer as appropnate, and venfies a merchant's registration details with the acquirer as appropnate Cardholders and merchants store their respective pnvate signature keys securely on their computers Dunng the payment process, these certificates are used to mutually authenticate a merchant and cardholder, and to authenticate them both to the payment gateway SET has not yet been adopted widely, partly because cardholder maintenance of keys and certificates is considered burdensome Interim solutions which mamtam 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 regisfration server acts as a proxy for the netpage user (I e the cardholder) m SET payment transactions The netpage system uses biometncs to authenticate the user and authorize SET payments Because the system is pen-based, the biometnc used is the user's onlme signature, consisting of time- varying pen position and pressure A fingerprint biometnc can also be used by designing a fingerprint sensor mto the pen, although at a higher cost The type of biometnc used only affects the capture of the biometnc, not the authorization aspects of the system The first step to bemg able to make SET payments is to register the user's biometnc with the netpage registration server This is done m a controlled environment, for example a bank, where the biometnc can be captured at the same time as the user's identity is venfied The biometnc is captured and stored m the registration database, linked to the user's record The user's photograph is also optionally captured and linked to the record The SET cardholder regisfration process is completed, and the resulting pnvate signature key and certificate are stored m the database The user's payment card information is also stored, givmg the netpage regisfration server enough information to act as the user's proxy m any SET payment transaction When the user eventually supplies the biometnc to complete a payment, for example by signing a netpage order form, the pnnter securely transmits the order information, the pen ID and the biometnc data to the netpage registration server The server venfies the biometnc with respect to the user identified by the pen ID, and from then on acts as the user's proxy in 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 pnntmg low-cost documents on demand and for copying copynght documents, and possibly also to allow the user to be reimbursed for expenses incurred m pnntmg 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 penodicals, which would also otherwise be presented to the user m the form of mdividual statements 4.4 TRANSACTIONS When a user requests a netpage m a particular application context, the application is able to embed a user- specific transaction ID 55 m the page Subsequent mput through the page is tagged with the transaction ID, and the application is thereby able to establish an appropnate context for the user's mput When mput occurs through a page which is not user-specific, however, the application must use the user's umque identity to establish a context A typical example mvolves addmg items from a pre-pnnted catalog page to the user's virtual "shopping cart" To protect the user's pnvacy, however, the umque user ID 60 known to the netpage - 32 - system is not divulged to applications This is to prevent different application providers from easily coπelating 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 ID 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 identity of the user The system also maintains an mdependent certificate and pnvate signature key for each of a user's applications, to allow it to sign application transactions on behalf of the user usmg only application-specific information To assist the system m routing product bar code (UPC) "hyperlink" activations, the system records a favonte 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 prefeπed embodiment of a resource descπption class diagram is shown m Figure 40 Each document and content object may be descnbed by one or more resource descnptions 842 Resource descnptions use the Dublm Core metadata element set, which is designed to facilitate discovery of electronic resources Dublm Core metadata conforms to the World Wide Web Consortium (W3C) Resource Descπption Framework (RDF) A resource descπption may identify πghts holders 920 The netpage system automatically transfers copynght fees from users to nghts holders when users prmt copynght content 5 COMMUNICATIONS PROTOCOLS A commumcations protocol defines an ordered exchange of messages between entities In the netpage system, entities such as pens, prmters and servers utilise a set of defined protocols to cooperatively handle user mteraction with the netpage system Each protocol is illustrated by way of a sequence diagram m which the horizontal dimension is used to represent message flow and the vertical dimension is used to represent time Each entity is represented by a rectangle contammg the name of the entity and a vertical column representing the lifeline of the entity Dunng the time an entity exists, the lifeline is shown as a dashed lme Dunng the time an entity is active, the lifeline is shown as a double lme Because the protocols considered here do not create or destroy entities, lifelines are generally cut short as soon as an entity ceases to participate m a protocol 5.1 SUBSCRIPTION DELIVERY PROTOCOL A prefeπed 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 prmters 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 subscnber's alias ID 65, and the relevant set of multicast channel names It signs the message usmg its pnvate signature key - 33 - The page server uses the application ID and alias ID to obtain from the registration server the coπespondmg 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 ED 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 pnnter to listen to It then returns the newly allocated page IDs to the application for future reference Once the application has distnbuted all of the document structures to the subscnbers' selected prmters via the relevant page servers, it multicasts the vanous subsets of the she-red objects on the previously selected multicast channels Both page servers and prmters monitor the appropπate 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 prmters to print the documents 5.2 HYPERLINK ACTIVATION PROTOCOL A prefeπed embodiment of a hyperlink activation protocol is shown m Figure 45 When a user clicks on a netpage with a netpage pen, the pen commumcates the click to the nearest netpage pnnter 601 The click identifies the page and a location on the page The pnnter already knows the ID 61 of the pen from the pen connection protocol 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 in its cache if the user has recently interacted with the same page The pnnter then forwards the pen ID, its own pnnter ID 62, the page ED and click location to the page server The page server loads the page descnption 5 identified by the page ID and determines which mput element's zone 58, if any, the click lies in Assuming the relevant mput element is a hyperlmk 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 coπespondmg user ID 60 from the regisfration 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 in 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 coπesponding user ID and pnnter ED 62 The first page server rejects the request if the hyperlink request has expired or is for a different application The second page server allocates document instance and page IDs 50, returns the newly allocated page IDs to the application, adds the complete document to its own database, and finally sends the page descnptions to the requesting pnnter The hyperlink mstance may mclude a meaningful transaction ID 55, m which case the first page server mcludes the transaction ID m the message sent to the application This allows the application to establish a transaction- specific context for the hyperlink activation - 34 - If the hyperlink requires a user alias, 1 e its "alias required" attnbute is set, then the first page server sends both the pen ID 61 and the hyperlink's application ID 64 to the registration server 11 to obtam not just the user ID coπespondmg to the pen ID but also the alias ID 65 coπespondmg to the application ID and the user ID It mcludes the alias ID m the message sent to the application, allowing the application to establish a user-specific context for the hyperlink activation 5.3 HANDWRITING RECOGNITION PROTOCOL When a user draws a stroke on a netpage with a netpage pen, the pen commumcates the stroke to the nearest netpage pnnter The stroke identifies the page and a path on the page The pnnter forwards the pen ID 61 , its own pnnter ID 62, the page ID 50 and stroke path to the page server 10 m the usual way The page server loads the page descnption 5 identified by the page ID and determines which mput element's zone 58, if any, the stroke intersects Assuming the relevant mput element is a text field 878, the page server appends the stroke to the text field's digital ink After a peπod 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 interpretation The registration server identifies the user coπespondmg to the pen, and uses the user's accumulated handwnting model 822 to interpret the strokes as handwπtten text Once it has converted the strokes to text, the registration server returns the text to the requesting page server The page server appends the text to the text value of the text field 5.4 SIGNATURE VERIFICATION PROTOCOL Assuming the mput element whose zone the stroke intersects is a signature field 880, the page server 10 appends the stroke to the signature field's digital ink After a penod of inactivity in 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 foim ID 56 and the cuπent data content of the form The registration server identifies the user coπespondmg 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 coπespondmg user This allows a smgle form to capture multiple users' signatures 5.5 FORM SUBMISSION PROTOCOL A prefeπed embodiment of a form submission protocol is shown m Figure 46 Form submission occurs via a form hyperlink activation It thus follows the protocol defined 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 cuπent 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 coπespondmg digital signature and obtaining the coπespondmg certificate from the registration server 11 5.6 COMMISSION PAYMENT PROTOCOL A prefeπed 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 chck-throughs, transactions and sales Commissions on fees and commissions on commissions may also be - 35 - 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 (I e publisher), and from the source application provider 70b to the prmter provider 72 The target application receives the hyperlink request ID from the page server 10 when the hyperlink is first activated, as descnbed m Section 5 2 When the target application needs to credit the source application provider, it sends the application provider credit to the onginal page server together with the hyperlink request ID The page server uses the hyperlink request ID to identify the source application, and sends the credit on to the relevant registration server 11 together with the source application ID 64, its own server ID 53, and the hyperlink request ED The registration server credits the coπespondmg application provider's account 827 It also notifies the application provider If the application provider needs to credit the 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 coπesponding pnnter provider account 814 The source application provider is optionally notified of the identity of the target application provider, and the pnnter provider of the identity of the source application provider 6. NETPAGE PEN DESCRIPTION 6.1 PEN MECHANICS Referring to Figures 8 and 9, the pen, generally designated by reference numeral 101, mcludes a housing 102 m the form of a plastics moulding having walls 103 defining an lntenor space 104 for mounting the pen components The pen top 105 is m operation rotatably mounted at one end 106 of the housing 102 A semi-transparent cover 107 is secured to the opposite end 108 of the housing 102 The cover 107 is also of moulded plastics, and is formed from semi-transparent matenal in order to enable the user to view the status of the LED mounted withm the housing 102 The cover 107 mcludes a mam part 109 which substantially suπounds the end 108 of the housing 102 and a projecting portion 110 which projects back from the mam part 109 and fits withm a coπespondmg slot 111 formed m the walls 103 of the housing 102 A radio antenna 112 is mounted behind the projecting portion 110, withm the housing 102 Screw threads 113 surrounding an aperture 113A on the cover 107 are aπanged to receive a metal end piece 114, mcludmg coπespondrng screw threads 115 The metal end piece 114 is removable to enable ink cartndge replacement Also mounted within the cover 107 is a tn-color status LED 116 on a flex PCB 117 The antenna 112 is also mounted on the flex PCB 117 The status LED 116 is mounted at the top of the pen 101 for good all-around visibility The pen can operate both as a normal markmg ink pen and as a non-marking stylus An ink pen cartπdge 118 with mb 119 and a stylus 120 with stylus mb 121 are mounted side by side withm the housing 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 ink cartndge 118 and stylus 120, respectively A rotatable cam baπel 125 is secured to the pen top 105 m operation and aπanged to rotate therewith The cam baπel 125 mcludes a cam 126 m the form of a slot within the walls 181 of the cam baπel Cam followers 127 and 128 projecting from slider blocks 123 and 124 fit within 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 cartπdge 118 mb 119 out, and • Neither ink cartndge 118 mb 119 out nor stylus 120 mb 121 out - 36 - A second flex PCB 129, is mounted on an electronics chassis 130 which sits within the housing 102 The second flex PCB 129 mounts an infrared LED 131 for providmg infrared radiation for projection onto the surface An image sensor 132 is provided mounted on the second flex PCB 129 for 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 controller chip 134 for confrollmg 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 terminal 138 connects to the battery contacts 137 and the cam baπel 125 A three volt rechargeable battery 139 sits withm 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 detecting displacement m the cam baπel 125 when either the stylus 120 or the ink cartndge 118 is used for wπting, 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 gπp pads 141 and 142 are provided towards the end 108 of the housing 102 to assist gnpping the pen 101, and top 105 also mcludes a clip 142 for clipping the pen 101 to a pocket 6.2 PEN CONTROLLER The pen 101 is aπanged to determme the position of its mb (stylus mb 121 or ink cartπdge 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 arranged to calculate the distance of the mb 121 or 119 from the location tab utilising optics 135 and controller chip 134 The controller chip 134 calculates the onentation of the pen and the nib-to-tag distance from the perspective distortion observed on the imaged tag Utilising 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 withm 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 m more detail the architecture of the controller chip 134 Figure 10 also shows representations of the RF chip 133, the image sensor 132, the tn-color status LED 116, the IR illumination LED 131, the IR force sensor LED 143, and the force sensor photodiode 144 The pen controller chip 134 mcludes a confrollmg processor 145 Bus 146 enables the exchange of data between components of the confroller chip 134 Flash memory 147 and a 512 KB DRAM 148 are also included An analog-to-digital converter 149 is -uranged 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 transceiver controller 153 and base band circuit 154 are also mcluded to mterface with the RF chip 133 which mcludes an RF circuit 155 and RF resonators and mductors 156 connected to the antenna 112 The controlling processor 145 captures and decodes location data from tags from the surface via the image sensor 132, monitors the force sensor photodiode 144, controls the LEDs 116, 131 and 143, and handles short-range radio commumcation via the radio transceiver 153 It is a medium-performance (~40MHz) general-purpose RISC processor - 37 - The processor 145, digital transceiver components (transceiver controller 153 and baseband circuit 154), image sensor mterface 152, flash memory 147 and 512KB DRAM 148 are mtegrated m a smgle controller ASIC Analog RF components (RF circmt 155 and RF resonators and mductors 156) are provided m the separate RF chip The image sensor is a 215x215 pixel CCD (such a sensor is produced by Matsushita Electronic Corporation, and is descnbed m a paper by Itakura, K T Nobusada, N Okusenya, R Nagayoshi, and M Ozaki, "A 1mm 50k-Pιxel IT CCD Image Sensor for Miniature Camera System", IEEE Transactions on Electronic Devices, Volt 47, number 1, January 2000, which is incorporated herem by reference) with an IR filter The controller ASIC 134 enters a quiescent state after a penod of inactivity when the pen 101 is not m contact with a surface It mcorporates a dedicated circmt 150 which momtors the force sensor photodiode 144 and wakes up the controller 134 via the power manager 151 on a pen-down event The radio transceiver commumcates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively m the unlicensed 2 4GHz lndustnal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free commumcation In an alternative embodiment, the pen mcorporates an Infrared Data Association (IrDA) mterface for short- range commumcation with a base station or netpage pnnter 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 in Figures 9 and 10 m ghost outline The provision of the accelerometers enables this embodiment of the pen 101 to sense motion without reference to surface location tags, allowing the location tags to be sampled at a lower rate Each location tag ID can then identify an object of 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 withm the area of the mput element can directly identify the mput element The acceleration measured by the accelerometers m each of the x and y directions is mtegrated with respect to time to produce an instantaneous velocity and position Smce the starting position of the stroke is not known, only relative positions within a stroke are calculated Although position integration accumulates errors m the sensed acceleration, accelerometers typically have high resolution, and the time duration of a stroke, over which eπors accumulate, is short 7. NETPAGE PRINTER DESCRIPTION 7.1 PRINTER MECHANICS The vertically-mounted netpage wallpπnter 601 is shown fully assembled in Figure 11 It prints netpages on Letter/A4 sized media usmg duplexed 8 1 -" Memjet™ prmt engmes 602 and 603, as shown m Figures 12 and 12a It uses a straight paper path with the paper 604 passmg through the duplexed pπnt engmes 602 and 603 which pπnt both sides of a sheet simultaneously, in full color and with full bleed An integral binding assembly 605 applies a stnp of glue along one edge of each prmted sheet, allowing it to adhere to the previous sheet when pressed against it This creates a final bound document 618 which can range m thickness from one sheet to several hundred sheets The replaceable ink cartndge 627, shown m Figure 13 coupled with the duplexed prmt 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 in a base molding The micro air filter interfaces with an air pump 638 mside the pnnter via a hose 639 This provides filtered air to the pnntheads to prevent ingress of micro particles mto the Memjet™ prmtheads 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 capacity for pnntmg and gluing 3000 pages (1500 sheets) - 38 - 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 prmt engme 602 mto the duplexed Memjet™ pnnthead assembly The two Memjet™ pπnt engmes 602 and 603 are mounted m an opposmg m-lme sequential configuration along the straight paper path The paper 604 is drawn mto the first prmt engme 602 by integral, powered pick-up rollers 626 The position and size of the paper 604 is sensed and full bleed pnntmg commences Fixative is prmted simultaneously to aid drymg m the shortest possible time The paper exits the first Memjet™ prmt engme 602 through a set of powered exit spike wheels (aligned along the straight paper path), which act against a rubberized roller These spike wheels contact the 'wet' pπnted surface and continue to feed the sheet 604 mto the second Memjet™ prmt engme 603 Referring to Figures 12 and 12a, the paper 604 passes from the duplexed pπnt engmes 602 and 603 mto the binder assembly 605 The prmted 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 mterface with the powered axle 670 via gears by action of a camshaft A separate motor powers this camshaft The glue wheel assembly 673 consists of a partially hollow axle 679 with a rotating couplmg for the glue supply hose 641 from the ink cartndge 627 This axle 679 connects to a glue wheel, which absorbs adhesive by capillary action through radial holes A molded housing 682 surrounds the glue wheel, with an opening at the front Pivoting side moldings and sprung outer doors are attached to the metal bracket and 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 housing 682 Tension springs close the assembly and effectively cap the glue wheel dunng peπods of inactivity As the sheet 604 passes mto the glue wheel assembly 673, adhesive is applied to one vertical edge on the front side (apart from the first sheet of a document) as it is transported down mto the binding assembly 605 7.2 PRINTER CONTROLLER ARCHITECTURE The netpage pnnter confroller consists of a confrollmg processor 750, a factory-installed or field-installed network mterface module 625, a radio transceiver (transceiver controller 753, baseband circmt 754, RF circmt 755, and RF resonators and mductors 756), dual raster image processor (RIP) DSPs 757, duplexed prmt engme controllers 760a and 760b, flash memory 658, and 64MB of DRAM 657, as illustrated in Figure 14 The confrollmg processor handles commumcation 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 prmt engme controllers 760 It consists of a medium-performance general-purpose microprocessor The confrollmg processor 750 commumcates with the pπnt engme controllers 760 via a high-speed seπal bus 659 The RIP DSPs rastenze and compress page descnptions to the netpage pnnter' s compressed page format Each prmt engme controller expands, dithers and prints page images to its associated Memjet™ pnnthead 350 m real time (l e at over 30 pages per minute) The duplexed pπnt engme controllers print both sides of a sheet simultaneously The master prmt engme controller 760a controls the paper transport and momtors ink usage m conjunction with the master QA chip 665 and the ink cartπdge 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 main memory 657 at boot time The processor 750, DSPs 757, and digital transceiver components (transceiver controller 753 and baseband circmt 754) are mtegrated m a smgle controller ASIC 656 Analog RF components (RF circmt 755 and RF resonators and mductors 756) are provided m a separate RF chip 762 The network mterface module 625 is separate, smce netpage prmters allow the network connection to be factory-selected or field-selected Flash memory 658 and the 2x256Mbit - 39 - (64MB) DRAM 657 is also off-chip The prmt engme controllers 760 are provided m separate ASICs A vanety of network mterface modules 625 are provided, each providmg a netpage network mterface 751 and optionally a local computer or network mterface 752 Netpage network Internet mterfaces mclude POTS modems, Hybnd Fiber-Coax (HFC) cable modems, ISDN modems, DSL modems, satellite transceivers, current and next- generation cellular telephone fransceivers, and wireless local loop (WLL) transceivers Local mterfaces mclude IEEE 1284 (parallel port), lOBase-T and 100Base-T Ethernet, USB and USB 2 0, IEEE 1394 (Firewire), and vanous emergmg home networkmg mterfaces If an Internet connection is available on the local network, then the local network mterface can be used as the netpage network mterface The radio transceiver 753 commumcates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively m the unlicensed 2 4GHz mdustnal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free commumcation The pnnter controller optionally incorporates 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 commumcation with suitably configured netpage pens 7.2.1 RASTERIZATION AND PRINTING Once the mam processor 750 lias received and venfied the document's page layouts and page objects, it runs the appropnate RIP software on the DSPs 757 The DSPs 757 rastenze each page descπption and compress the rastenzed page image The main 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 arbitrary number of rastenzed pages can, m general, be stored m memory This strategy only leads to potentially poor DSP utilization when rasteπzing short documents Watermark regions in 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 inch Each tag encodes the page ID, tag ID, and control bits, and the data content of each tag is generated dunng rasterization and stored m the compressed page image The mam processor 750 passes back-to-back page images to the duplexed pπnt engme controllers 760 Each print engme controller 760 stores the compressed page image m its local memory, and starts the page expansion and pnntmg pipeline Page expansion and pnntmg 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 pnntmg pipeline of the prmt 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 prmt engme controller 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 print engme controller pipeline Once the page has finished pnntmg, the page just loaded is pπnted while another page is loaded The first stage of the pipeline expands (at 763) the JPEG-compressed contone CMYK layer, expands (at 764) the Group 4 Fax-compressed bi-level black layer, and renders (at 766) the bi-level netpage tag layer accordmg to the tag format defined in section 1 2, all m parallel The second stage dithers (at 765) the contone CMYK layer and - 40 - 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 pnntmg on the Memjet™ pnnthead 350 via a set of lme buffers Most of these lme buffers are stored in the off-chip DRAM The final stage prints the six channels of bi-level dot data (mcludmg fixative) to the Memjet™ pnnthead 350 via the pnnthead mterface 768 When several prmt 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 pπnt engme 760, selected via the external master/slave pm 771, generates the lme sync signal 770 onto the shared lme The prmt engme controller 760 contams a low-speed processor 772 for synchronizing the page expansion and rendering pipeline, configuring the pnnthead 350 via a low-speed senal bus 773, and confrollmg the stepper motors 675, 676 In the 854" versions of the netpage pnnter, the two pπnt engmes each prints 30 Letter pages per minute along the long dimension of the page (11"), giving a lme rate of 8 8 kHz at 1600 dpi In the 12" versions of the netpage pnnter, the two prmt engmes each pπnts 45 Letter pages per minute εdong the short dimension of the page (854"), giving a lme rate of 10 2 kHz These lme rates are well withm the operating frequency of the Memjet™ pnnthead, which m the current design exceeds 30 kHz 8 BUSINESS IMPLEMENTATION PROCEDURES The netpage system accommodates a large vanety of business implementation procedures for allowing users and providers of the technology to leverage off and to profit from their participation m the netpage system To best understand the system the following descnption of the business implementation procedures and equipment should be read m conjunction with the descπption m the specification of the available hardware and software options, mcludmg prmters, commumcation protocols, protocols for payment, determinmg account balances and the like The usual parties to the netpage system are An onlme publisher 41 who provides an onlme publication that is accessible via the netpage network One or more onlme advertisers 42 who wish to place advertismg m the onlme publication A number of users 40, each of which is accesses the onlme publication with a pnnter module 45 Preferably, the modules are provided by a pnnter module provider 72 to the users at no cost, or at a cost that is subsidised by the advertisers or the publisher However, m some cases the user purchases the module at its market value A storage provider who maintains one or more data bases which store the information required to allow the system to operate These parties mteract to provide a structure that facilitates onlme dissemination of ---formation and commerce While the following embodiments illustrate specific ones of the many possible interactions it will be appreciated by those skilled m the art that other interactions are possible and are mtended to fall withm the scope of the claims It will also be appreciated by those skilled m the art that all the above named roles need not necessanly be performed by different entities For example, m some cases the storage provider and the publisher are the same entity, while m other cases the pnnter provider and the publisher are the same entity Reference is also made m the descnption to "mteractive paper" This is reference to paper that contams tags or other markings, visible or otherwise, that mteract with the netpage system to allow identification of the page and, preferably, identification of the position on the page Examples of these tags are descnbed elsewhere m this specification and it will be understood that many other tags or identifiers can be used m a vanety of configurations to achieve the same result Other terms used mclude "a pnnter usmg mteractive paper" and "an on-demand pnnter" This is reference - 41 - to a pnnter for mteracting with the netpage system to apply the tags and/or mteracting with the user to determme which tag the user has designated A vanety of alternative pnnter configurations are available, some of which have been descnbed m more detail elsewhere m the specification It will be understood that the term "pπnted medium" is used for convenience and can be substituted with the term "pπnted media" That is the former term is mtended to broadly encompass a pπnted product, whether this product mcludes one or more pπnted sheets, documents or the like 8.1 NOTATION To assist understanding of the prefeπed embodiments of the business implementation procedures and equipment use is made of diagrams, which follow, to illustrate the interactions between the vanous participant roles m a business procedure Each participant is shown as a pair of overlappmg rectangles The front rectangle is labelled with the name of the participant and the back rectangle is used as the source and/or target of actions Each action is shown as an arrow joining a subject participant with an object participant Each action aπow is labelled with a descnption of the action Actions are spatially arranged so that time proceeds from top to bottom and left to πght "Later" actions may comcide with, but never be earlier than, "earlier" actions Any action is understood to be "caused" by the immediately pπor action which the subject of the action was an object of In the absence of a pπor action, the action is understood to be spontaneous Respective reference numerals are used to label certain actions and participants to assist the reader's understanding of the embodiment bemg descnbed 8.2 COMBINATIONS OF DIFFERENT EMBODIMENTS WITHIN THE SCOPE OF THE INVENTION The following prefeπed embodiments are separately descnbed to facilitate understanding of the mvention However, it will appreciated that more complex embodiments are obtained through the combination of these different embodiments to achieve advantageous results for specific circumstances Accordingly, the combination of different embodiments to form a hybnd system is mtended to fall withm the scope of the present mvention and the following claims which define that mvention 8.2.1 Netpage Publisher In broad terms, this embodiment mcludes a system for providing a user with a pπnted publication from a first party who is an onlme publisher The system mcludes a publication source m the form of a computer based storage server for storing publication data representative of the publication The publication data mcludes first information about a second party who is an advertiser m the onlme publication A user pnnter module, m the form of an on-demand mteractive pnnter, mterfaces the user with the publication server and is responsive to the user requesting the prmted publication for reproducmg the prmted publication on a pπnted medium for viewmg by the user Identifier means, m the form of a pnnter head and associated hardware and software contained withm the pnnter, applies an identifier to the pπnted medium Upon designation of the identifier by the user the pnnter generates a second pπnted medium that displays to the user second information This second information is usually further information about the goods and/or services bemg offered for sale by the advertiser, or an order form for the specific goods and/or services contained m the advertisement, or a hyperlink to the advertiser's site Calculation means, m the form of the publication server, is responsive to the pnnter for determinmg a payment that is made by the advertiser to the publisher In other embodiments the calculation means is the storage server In other embodiments, the calculation means is an account server separate from but linked to the other servers The payment is calculated m one of a number of alternative methods which are agreed on m advance For example, payment may be based upon The number of copies of the onlme publication that are requested The number of requests that are made for the third information - 42 - The sales of the goods and/or services that are achieved by hits on the advertisement The payment may be m addition to an agreed flat fee for a given penod of time For example, m one embodiment, the advertiser pays a flat fee for each month that their advertisement is mcluded, plus a payment based upon the number of copies of the publication that are requested by users of the system That is, the system allows the advertiser to pay for the circulation that the publication achieves when mcludmg the desired advertismg matenal, unlike the pnor art systems which are based upon past circulation figures The system mcludes a plurality of modules associated with coπespondmg users and the calculation means, m whatever form it takes, is responsive to the number of prmted media generated that display one of the first information, the second information, and the third information That is, the first ---formation is usually the editonal or other content of the publication, the second information is usually the advertisement, and the third information is either further information about the goods and/or services bemg offered for sale and/or an order form for those goods and/or services Preferably, the calculation means is responsive to the number of pπnted media generated that display two or more of the first information, the second information, and the third information That is, the system allows a combmation fee structure to be utilised, as required In the prefeπed embodiments, use is made of account means, usually in the form of an account server that is linked to the information server and one or more electronic bank accounts, for receiving the payment from the second party and for providing the payment to the first party Where the second party is a supplier of goods and/or services and the second information or the third information allows the user to purchase those goods and/or services at respective predetermined purchase pnces, it is prefeπed that the calculation means is responsive to the monetary value of the purchases completed by the users for detemumng the payment That is, the system provides a vanety of options for calculating the payment mcludmg a combmation of a flat fee for each purchase, a fixed proportion of the purchase pπce for the goods and/or services that are purchased, and a proportion of the purchased pnce of the goods and/or services that are purchased, where that proportion is different for particular goods and/or services It will be appreciated that the system accommodates a plurality of second parties and a plurality of respective second information and third information that is denved from those parties Preferably, the quantum of the payments made by the respective second parties is contingent upon one or more of the following charactenstics of the second party geographic location, quantity of purchases completed in a given time penod, and relative geographic location with respect to the user As bnefly foreshadowed above, it is prefeπed that the identifier is a tag although, m practice, it is usually embodied as a plurality of tags spaced apart on the respective pπnted medium In other embodiments, however, the identifier is a character string that the user provides to the module to obtam the third information In this case, the string preferably includes a sequence of numbers that are manually keyed mto the module However, m alternative embodiments the string is scanned by sensor means that are manually operated by the user In some embodiments, the account server automates the payments and provides the parties to the transactions with all the necessary reporting and summanes to substantiate the quantum of the payments Preferably, the account server generates a disable signal if the payment calculated as payable by the second party is not made available or paid withm a predetermined time, where the generation of the disable signal prevents the module from obtaining the first or the second information which is denved from that second party That is, an automated debtor system is applied Preferably, all parties to the transaction have electronic bank accounts that are accessible to the account server for effecting the necessary transactions The system also allows the parties, and importantly the second party or the advertiser, to obtain an - 43 - mdication of the success of the advertismg by monitoring one or more of the following the number of times that the users designate the second information, the number and or value of sales that are achieved through the users designating the second information, and the cost savings gamed through the use of onlme selling over that of shop front retailing Where the second information is a link to a third party, the identifier is related to that second information such that designation by the user of the second lnfoimation results m designation of the identifier which, m turn, ensures that the third information mcludes either or both of further ---formation about the goods and/or services bemg offered for use and/or sale by the third party or mstructions as to how the user should proceed to effect that use and/or a purchase of those goods and or services of the third party Preferably, the second party obtains an indication of the success of the link by monitoring one or more of the number or proportion of users selecting the click-through, and the number or proportion of users purchasing or makmg use of the goods and or services of the third party It will be appreciated that the monitoring allows the parties to accurately estimate the cost/benefit achieved by the advertismg and, hence to plan for future promotions or advertismg campaigns In other embodiments the first information mcludes advertismg denved from a third party and the calculation means determines the quantum of a payment that is made by the third party to the first party In some cases the advertismg is solicited by the user, while m others the advertismg is unsolicited The system also allows the first party to preferentially display of the advertismg to the user While m the above embodiments the prmted media are generated by the user's pnnter module, as an alternative, or m addition to this, the pπnted media are selectively generated at a remote pnnter and subsequently provided to the user for viewmg Some more specific examples follow and are descnbed with reference to Figures 1 to 3 8.2.1.1 Advertising Fees This embodiment allows the publisher, who publishes to the on-demand prmters, to receive advertismg fees on advertismg placed withm the publication This provides a profitable role for the publisher, and allows the publisher to attract readers by bemg able to provide them with subsidised or free publications In some embodiments the publisher automatically delivers the publication to a subscπbmg user's prmter on a peπodic basis For example, m the case of the publisher bemg an onlme newspaper, an updated publication is provided to the user's pnnter each weekday morning at a predetermined time This time will default to a non-peak processing time for the publisher However, the user can specify the time, and may be coordinated with the normal ns g time of the user In other embodiments, the publication is delivered to a user's pnnter ad hoc at the user's request Preferably, the publication is prmted as mteractive paper As illustrated m Figure 48, this embodiment operates as follows The advertiser, which is indicated generally by reference numeral 42, places an advertisement 501 with the publisher 41 The publisher 41 eventually prints the advertisement, as represented by aπow 502, on the user's on-demand pnnter 44 This pnntmg occurs typically as part of one of the publisher's publications and results m one or more pπnted pages 1 that contam the publication, mcludmg the advertismg The publisher 41 charges the advertiser 42 an agreed advertismg fee, as represented by aπow 503 The advertiser pays the publisher the advertismg fee, as represented by aπow 504 For practical purposes, advertismg fees are negotiated, mvoiced and settled m bulk In some embodiments - 44 - the fees are part of a wider advertismg agreement 8.2.1.2 Click-Through Fees This embodiment allows a publisher who publishes on mteractive paper to receive click-through fees on advertismg placed withm its publications This provides a profitable role for a publisher who publishes on mteractive paper, and allows the publisher to attract readers by bemg able to provide them with subsidised or free publications As illustrated in Figure 49, the embodiment operates as follows An advertiser 42 places a hyperlink 505 with a publisher 41 The publisher 41 eventually prints the hyperlink, as represented by aπow 506, and typically as part of one of the publisher's publications The result is one or more prmted pages 1 bemg created that contam the publication, mcludmg the hyperlink When a user 40 selects the hyperlink, as represented by aπow 507, for example to request a linked document from the advertiser, the advertiser 42 is notified, as represented by aπow 508 The advertiser 42 pays the publisher 41 an agreed click-through fee 509 For practical purposes, click-through fees are negotiated, mvoiced and settled m bulk In some embodiments the fees are part of a wider advertismg agreement 8.2.1.3 Sales Commissions This embodiment allows a publisher who publishes on mteractive paper to receive commissions on sales initiated through advertismg placed withm its publications This provides a profitable role for a publisher who publishes on mteractive paper, and allows the publisher to attract readers by being able to provide them with subsidised or free publications As illustrated m Figure 50, this embodiment operates as follows A merchant 43 places a hyperlink, as represented by aπow 510, with a publisher 41 The publisher 41 eventually prints the hyperlink, as represented by aπow 511, typically as part of one of the publisher's publications The result is one or more prmted pages 1 bemg created that contam the publication, mcludmg the hyperlink When a user 40 clicks on the hyperlink to request a linked document from the merchant 43, the merchant is notified When the user 40 eventually makes an onlme purchase via the linked document (or via a document obtained via the linked document), the merchant 43 is notified The merchant 43 pays the publisher 41 an agreed commission on the sale Preferably, the sales commission is a fixed fee However, other embodiments make use of a commission that is based on the value of the sale For practical purposes, sales commissions are negotiated, mvoiced and settled m bulk, and are often part of wider advertising agreements 8.2.2 Netpage Printer Provider In broad terms, this embodiment mcludes a system for providmg to a user pπnted information obtained from a remote source m the form of the onlme publication The system mcludes a user module in the form of an mteractive pnnter for interfacing the user with the onlme publication The module is responsive to the user requesting first information from the publication, which may be the publication itself, for generating a first prmted medium that displays to the user the first information together with second information The second ---formation is the advertismg information that is denved from the advertiser Identifier means, m the form of the prmter module, applies an identifier to the first prmted medium such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user third information Calculation means, m the form of the onlme publisher's server, is responsive to the module for determinmg a payment to be made by the advertiser to the pnnter provider In practice, the - 45 - advertiser would pay the online publisher and, m the case where the pnnter provider was different to the publisher, the publisher would provide a payment to the pnnter provider As a default, the payment is a predetermmed function of the number of reproductions of the pπnted publication that are generated That is, where the second party is an advertiser m the publication the payment is a predetermmed function of the circulation achieved by the publication This allows the advertiser to pay for the actual circulation achieved, and the publisher to be rewarded for mcreasmg that circulation The payment mcludes, m some embodiments, another component m addition to or as a substitute for the above For example, where the second information is associated with the second party the payment is a predetermmed function of the number of second pπnted media generated So, where the second party is an advertiser the payment is increased for successful hits on their specific advertismg The payment is, m other embodiments, a predetermmed function of both the number of prmted publications generated that display the first information and the number of second pπnted media generated that display the second information Where the second party is a supplier of goods and/or services, the first information or the second information is usually arranged to allow the user to purchase those goods and or services at a predetermmed purchase pnce In turn, the payment is calculated as a predetermmed function of the purchase pπce of the goods and/or services actually purchased by the user For some items the user will desire to obtam further information about the goods and/or services pnor to proceeding further Accordingly, m some embodiments the module is responsive to the designation of the identifier by the user for accessing advertismg, technical or other information about particular goods and/or services of the second party In these embodiments the calculation means is responsive to the designation of the identifier for determinmg the payment If required, however, the calculation means is responsive only to the designation of the identifier for deteπrurung the payment such that the advertiser pays the publisher only for successful links to the advertismg information Some more specific examples follow and are descnbed with reference to Figures 4 to 6 8.2.2.1 Commissions on Advertising Fees In this embodiment the provider of an mteractive pnnter receives a percentage of advertismg fees earned directly through the pnnter This provides a profitable role for a provider of mteractive prmters, and allows the provider to attract users by partially or fully subsidising the capital and runmng costs of each user's pnnter As illustrated m Figure 51 , the system is operates as follows A pnnter provider 72 provides a user with a pnnter 45 While m this embodiment the provider 72 retains ownership of the pnnter, m other embodiments that ownership resides with the respective users An advertiser 42 places an advertisement, as represented by aπow 520, with a publisher 41 The publisher 41 eventually prints the advertisement on the pnnter 45, typically as part of one of the publisher's publications The result is one or more pπnted pages 1 bemg created that contam the publication, mcludmg the advertisement The publisher 41 charges the advertiser 42 an agreed advertismg fee, as represented by aπow 523 The advertiser 42 pays the publisher 41 the advertismg fee, as represented by aπow 524 The publisher 41 pays the pnnter provider 72 an agreed commission on the advertismg fee, as represented by aπow 525 8.2.2.2 Commissions on Click-Through Fees In another embodiment, the provider of an mteractive pnnter receives a percentage of click-through fees - 46 - eamed directly through the prmter This provides a profitable role for the provider of mteractive prmters, and allows the provider to attract users by partially or fully subsidising the capital and runmng costs of each user's pnnter As illustrated m Figure 52, the system operates as follows The pnnter provider 72 provides the user 40 with a pnnter 45 An advertiser 42 places a hyperlink with a publisher 41 The publisher eventually prints the hyperlink, typically as part of one of the publisher's publications The result is one or more pπnted pages 1 bemg created that contain the publication, mcludmg the hyperlink When the user 40 clicks on the hyperlink, as it is represented on the mteractive paper, for example to request a linked document from the advertiser 42, the advertiser is notified The advertiser 42 pays the publisher 41 an agreed click-through fee The publisher 41 pays the pnnter provider 72 an agreed commission on the click-through fee 8.2.2.3 Commissions on Sales Commissions This embodiment allows the provider of an mteractive pnnter to receive a percentage of sales commissions earned directly through the pnnter This provides a profitable role for the provider of mteractive prmters, and allows the provider to attract users by partially or fully subsidising the capital and runmng costs of each user's pnnter As illustrated m Figure 53, this embodiment operates as follows The pnnter provider 72 provides the user 40 with a pnnter 45 An advertiser m the form of a merchant 43 places a hyperlink with a publisher 41 The publisher 41 eventually prints the hyperlink, typically as part of one of the publisher's publications The result is one or more prmted pages 1 bemg created that contam the publication, mcludmg the hyperlink When the user 40 clicks on the hyperlink to request a linked document from the merchant 43, the merchant is notified The "click" occurs through use of the mteractive paper When the user 40 eventually makes an onlme purchase via the linked document (or via a document obtained via the linked document), the merchant 43 is notified The merchant 43 pays the publisher 41 an agreed commission on the sale The publisher 41 pays the pnnter provider 72 an agreed commission on the sales commission 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 spint and scope of the present mvention Accordingly, it will be understood that the mvention is not mtended to be limited to the specific embodiments descnbed m the present specification, mcludmg documents mcorporated by cross-reference as appropπate The scope of the mvention is only limited by the attached claims

Claims: - 47 - C LAI MS 1 A system for providmg a user with a pπnted publication from a first party, the system mcludmg a publication source for storing publication data representative of the publication, the publication data mcludmg first information about a second party, a user pnnter module for interfacing the user with the publication source, the module bemg responsive to the user requesting the pπnted publication for reproducmg the prmted publication on a prmted medium for viewing by the user, identifier means for applying an identifier to the pnnt medium such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user second information, and calculation means bemg responsive to the module for determinmg a payment that is made by the second party to the first party 2 A system accordmg to claim 1 wherem the payment is a predetermmed function of the number of reproductions of the pπnted publication that are generated 3 A system accordmg to claim 2 wherem the second party is an advertiser m the publication and the payment is a predetermmed function of the circulation achieved by the publication 4 A system accordmg to claim 1 wherem the second information is associated with the second party and the payment is a predetermmed function of the number of second pπnted media generated 5 A system accordmg to claim 4 wherem the second party is an advertiser and the payment is increased for successful hits on their specific advertismg 6 A system according to claim 1 wherem the payment is a predetermmed function of both the number of prmted publications generated that display the first information and the number of second pπnted media generated that display the second information 7 A system according to claim 1 wherem the second party is a supplier of goods and/or services and the first information or the second information allows the user to purchase those goods and/or services at a predetermmed purchase pπce 8 A system according to claim 7 wherem the payment is a predetermmed function of the purchase pnce of the goods and or services actually purchased by the user 9 A system accordmg to claim 1 wherem the module is responsive to the designation of the identifier by the user for accessmg advertismg information about particular goods and/or services of the second party 10 A system accordmg to claim 9 wherem the calculation means is responsive to the designation of the identifier for determinmg the payment 11 A system accordmg to claim 10 wherem the calculation means is responsive only to the designation of the identifier for determinmg the payment such that the advertiser pays the publisher only for successful links to the advertismg information 12 A system for providmg a user with a pπnted publication from a first party, the system mcludmg a publication source computer for storing electronic publication data representative of the publication, the publication data mcludmg first information about a second party, a user pnnter module for interfacing the user with the publication source, the module bemg responsive to the user requesting the prmted publication for reproducmg the prmted publication on a pπnted medium for viewmg by the user, an identifier device for applymg an identifier to the prmted medium such that designation of the identifier by the user results m the module generating a second prmted medium that displays to the user second information, and - 48 - an account computer bemg responsive to the module for determinmg a payment that is made by the second party to the first party 13 A system accordmg to clam 12 wherem the user pnnter module and the identifier device are contained withm a smgle housing 14 A system accordmg to claim 13 wherem the identifier device applies the identifier to the surface of a medium as it is bemg produced by the pnnter module 15 A system accordmg to claim 14 wherem the identifier is pπnted on the medium 16 A system accordmg to claim 15 wherem the identifier is pπnted with ink that does not substantially reflect light m the visible spectrum 17 A method for providmg a user with a prmted publication from a first party, the method mcludmg the steps of storing publication data representative of the publication on a publication source, the publication data mcludmg first information about a second party, interfacing the user with the publication source via a user pnnter module, the module bemg responsive to the user requesting the pπnted publication for reproducmg the prmted publication on a pπnted medium for viewmg by the user, applying an identifier to the prmt medium with identifier means such that designation of the identifier by the user results m the module generating a second prmted medium that displays to the user second information, and bemg responsive to the module with calculation means for determinmg a payment that is made by the second party to the first party 18 A method accordmg to claim 17 wherem the payment is a predetermmed function of the number of reproductions of the pnnted publication that are generated 19 A method accordmg to claim 18 wherem the second party is an advertiser m the publication and the payment is a predetermmed function of the circulation achieved by the publication 20 A method accordmg to claim 17 wherem the second information is associated with the second party and the payment is a predetermmed function of the number of second pnnted media generated 21 A method accordmg to claim 20 wherem the second party is an advertiser and the payment is increased for successful hits on their specific advertismg 22 A method accordmg to claim 17 wherem the payment is a predetermmed function of both the number of pnnted publications generated that display the first information and the number of second pnnted media generated that display the second information 23 A method accordmg to claim 17 wherem the second party is a supplier of goods and/or services and the first information or the second information allows the user to purchase those goods and/or services at a predetermmed purchase pπce 24 A method accordmg to claim 23 wherem the payment is a predetermmed function of the purchase pnce of the goods and or services actually purchased by the user 25 A method accordmg to claim 17 wherem the module is responsive to the designation of the identifier by the user for accessmg advertismg information about particular goods and/or services of the second party 26 A method according to claim 25 wherem the calculation means is responsive to the designation of the identifier for determmmg the payment 27 A method accordmg to claim 26 wherem the calculation means is responsive only to the designation of the identifier for determinmg the payment such that the advertiser pays the publisher only for successful links to the - 49 - advertismg information 28 A method for providmg a user with a pπnted publication from a first party, the method mcludmg the steps of storing electronic publication data representative of the publication on a publication source computer, the publication data mcludmg first ---formation about a second party, interfacing the user with the publication source computer with a user pnnter module, the module bemg responsive to the user requesting the pπnted publication for reproducmg the pπnted publication on a pπnted medium for viewmg by the user, applymg an identifier to the pπnt medium with an identifier device such that designation of the identifier by the user results m the module generating a second pπnted medium that displays to the user second lnfom-ation, and bemg responsive to the module with an account computer for determining a payment that is made by the second party to the first party 29 A method accordmg to claim 30 wherem the user pnnter module and the identifier device are contained withm a smgle housing 30 A method accordmg to claim 29 wherem the identifier device applies the identifier to the surface of a medium as it is bemg produced by the pnnter module 31 A method according to claim 30 wherem the identifier is pnnted on the medium 32 A method accordmg to claim 31 wherem the identifier is pnnted with ink that does not substantially reflect light m the visible spectrum

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