METHOD AND SYSTEM FOR DELIVERY OF A FACSIMILE

Abstract: A method of delivering a facsimile, including: providing a printed form for entering a message thereon using a sensing device adapted to read coded data on the form; receiving, in a computer system, interaction data representing interaction of the sensing device with the coded data, the interaction data allowing the message to be electronically captured in the computer system; and tranmitting the message to a designated recipient address for facsimile delivery.

Description: METHOD AND SYSTEM FOR DELIVERY OF A FACSIMILE FIELD OF INVENTION The present invention relates generally to methods, systems and apparatus for interacting with computers by means of printed matter and sensing devices More particularly, the invention relates to delivery of a facsimile, utilizing such methods, systems and apparatus The invention has been developed primarily to allow a large number of distributed users to interact with networked information via printed matter and 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/AUOO/00520, PCT/AU00/00521 , PCT/AU00/00523, PCT/AU00/00524, PCT/AU00/00525, PCT/AU00/00526, PCT/AUOO/00527, PCT/AU00/00528, PCT/AU00/00529, PCT/AU00/00530, PCT/AU00/00531, PCT/AU00/00532, PCT/AUOO/00533, PCT/AU00/00534, PCT/AUOO/00535, PCT/AU00/00536, PCT/AUOO/00537, PCT/AU00/00538, PCT/AU00/00539, PCT/AU00/00540, PCT/AU00/00541 , PCT/AU00/00542, PCT/AUOO/00543, PCT/AU00/00544, PCT/AU00/00545, PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AU00/00556, PCT/AUOO/00557, PCT/AU00/00558, PCT/AU00/00559, PCT/AU00/00560, PCT/AUOO/00561, PCT/AU00/00562, PCT/AU00/00563, PCT/AU00/00564, PCT/AU00/00566, PCT/AU00/00567. PCT/AU00/00568, PCT/AU00/00569, PCT/AUOO/00570, PCT/AU00/00571 , PCT/AU00/00572, PCT/AUOO/00573, PCT/AU00/00574, PCT/AU00/00575, PCT/AU00/00576, PCT/AUOO/00577, PCT/AU00/00578, PCT/AUOO/00579, PCT/AU00/00581 , PCT/AU00/00580, PCT/AU00/00582, PCT/AU00/00587, PCT/AU00/00588, PCT/AUOO/00589, PCT/AUOO/00583, PCT/AU00/00593, PCT/AUOO/00590, PCT/AU00/00591 , PCT/AU00/00592, PCT/AU00/00594, PCT/AUOO/00595, PCT/AU00/00596, PCT/AUOO/00597, PCT/AUOO/00598, PCT/AU00/00516, and PCT/AU00/00517 The disclosures of these co-pending applications are incorporated herein by cross-reference BACKGROUND It is known to send a facsimile by writing or typing a message on a page and then feeding the page into a facsimile machine for scanning and subsequent transfer to a recipient machine OBJECT The present invention seeks to simplify the procedure for sending a facsimile by converting a written message directly into digital ink thereby obviating the need for scanning by a facsimile machine prior to transmission 0/72576 - 1a - SUMMARY OF INVENTION In accordance with the invention, there is provided a method of delivering a facsimile, including providing a printed form for entering a message thereon using a sensing device adapted to read coded data on the form, receiving, in a computer system, interaction data representing interaction of the sensing device with the coded data, the interaction data allowing the message to be electronically captured in the computer system, and transmitting the message to a designated recipient address for facsimile delivery Preferably, the message is delivered with a reply number for sending a return message, the reply number being valid for a predetermined time only A sender of the message may indicate on the form, using the sensing device, whether a reply number is to be transmitted with the message Preferably, the recipient address is entered on the form in writing, using the sensing device, and the writing RECTIFIED SHEET (RUEL 91) ISA EP - 2 - IS electronically captured and converted mto digital form to facilitate transmission of the message Alternatively the recipient address is selected from a document provided with an address list and associated user mteractive elements with which the sensmg device is adapted to mteract m order to select the address Preferably, the method further mcludes receivmg, m the computer system, mdicatmg data deπved form the coded data, regardmg the identity of the form and a position of the sensmg device relative to the form in order to identify the form and determme when the sensmg device is used to mteract with the form The method may further mclude receivmg, m the computer system, movement data regardmg movement of the sensmg device relative to the form, with the sensmg device preferably sensmg its movement relative to the form usmg the coded data The method may further mclude pπnting the form on a surface of a surface-defining structure and, at the same time, pπnting the coded data on the surface, with the coded data preferably bemg substantially invisible m the visible spectrum Preferably, the method mcludes retaining a retπevable record of the pnnted form, the form bemg retπevable usmg the identity data as contained m the coded data In another aspect, there is provided a system for delivering a facsimile, mcludmg a prmter for pπnting a form with coded data, a sensmg device for reading the coded data and transmitting mteraction data, representing mteraction of the sensmg device with the coded data, to allow for electromc capture of a message generated by moving the device relative to the form, and a computer system for receivmg the mteraction data from the device and transmitting the message to an address for facsimile delivery Preferably, the computer system is adapted to deliver the message with a reply number, valid for a predetermined time only and the computer syset preferably mcludes the reply number dependent upon a sender's instruction, indicated by mteraction of the device with an appropnate user mteractive element on the form Preferably, the computer system mcludes a fax application for receivmg and formatting the message for transmission to a fax server, the fax application further serving to allocate the reply number The coded data preferably serves to identify the form and a position of the sensmg device relative to the form, so that the computer system can receive movement data regardmg movement of the sensmg device relative to the coded data, m order to capture the message In that regard, the sensmg device preferably senses its own movement relative to the document usmg the coded data The sensmg device preferably also mcludes a markmg mb The pπnter is preferably arranged to pπnt the coded data on demand, at the same time as prmtmg the form on the surface-defining structure, with the coded data preferably bemg substantially invisible m the visible spectrum The system preferably mcludes a database for keepmg a retnevable record of the form, the form bemg retnevable usmg identity data, as included in its coded data BRIEF DESCRIPTION OF DRAWINGS Preferred and other embodiments of the mvention will now be descnbed, by way of non-limiting example only, with reference to the accompanying drawings, m which Figure 1 is a schematic of a the relationship between a sample pnnted netpage and its onlme page descnption, Figure 2 is a schematic view of a mteraction between a netpage pen, a netpage pnnter, a netpage page server, and a netpage application server, Figure 3 illustrates a collection of netpage servers and pnnters interconnected via a network, - 3 - Figure 4 is a schematic view of a high-level structure of a pnnted netpage and its onlme page descnption, Figure 5 is a plan view showing a structure of a netpage tag, Figure 6 is a plan view showing a relationship between a set of the tags shown m Figure 5 and a field of view of a netpage sensmg device m the form of a netpage pen, Figure 7 is a flowchart of a tag image processmg and decoding algonthm, Figure 8 is a perspective view of a netpage pen and its associated tag-sensing field-of-view cone, Figure 9 is a perspective exploded view of the netpage pen shown m Figure 8, Figure 10 is a schematic block diagram of a pen controller for the netpage pen shown m Figures 8 and 9, Figure 11 is a perspective view of a wall-mounted netpage pπnter, Figure 12 is a section through the length of the netpage pπnter of Figure 11 , Figure 12a is an enlarged portion of Figure 12 showing a section of the duplexed pπnt engmes and glue wheel assembly, Figure 13 is a detailed view of the ink cartndge, ink, an and glue paths, and pnnt engmes of the netpage pnnter of Figures 11 and 12, Figure 14 is a schematic block diagram of a pπnter controller for the netpage pπnter shown m Figures 11 and 12, Figure 15 is a schematic block diagram of duplexed pnnt engme controllers and Memjet™ printheads associated with the pπnter controller shown m Figure 14, Figure 16 is a schematic block diagram of the pπnt engine controller shown m Figures 14 and 15, Figure 17 is a perspective view of a smgle Memjet™ printing element, as used m, for example, the netpage pπnter of Figures 10 to 12, Figure 18 is a perspective view of a small part of an array of Mem et™ prmtmg elements, Figure 19 is a senes of perspective views illustrating the operating cycle of the Memjet™ pπnting element shown in Figure 13, Figure 20 is a perspective view of a short segment of a pagewidth Memjet™ pnnthead, Figure 21 is a schematic view of a user class diagram, Figure 22 is a schematic view of a pπnter class diagram, Figure 23 is a schematic view of a pen class diagram, Figure 24 is a schematic view of an application class diagram, Figure 25 is a schematic view of a document and page descnption class diagram, Figure 26 is a schematic view of a document and page ownership class diagram, Figure 27 is a schematic view of a 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 hyperlmk 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, - 4 - Figure 39 is a schematic view of a page server command element class diagram, Figure 40 is a schematic view of a resource descnption class diagram, Figure 41 is a schematic view of a favontes list class diagram, Figure 42 is a schematic view of a history list class diagram, Figure 43 is a schematic view of a subscnption delivery protocol, Figure 44 is a schematic view of a hyperlmk request class diagram, Figure 45 is a schematic view of a hyperlink activation protocol, Figure 46 is a schematic view of a form submission protocol, Figure 47 is a schematic view of a commission payment protocol, Figure 48 is a schematic view of a set of user mterface flow document icons, and Figure 49 is a schematic view of a set of user mterface page layout element icons, Figure 50 is a schematic view of a facsimile application structure, Figure 51 is a schematic view of a simple fax class diagram, Figure 52 is a schematic view of an e-mail user class diagram, Figure 53 is a schematic view of fax sending user mterface flow, Figure 54 is a schematic view of a fax composition form, Figure 55 is a schematic view of the reverse side of a fax composition form, Figure 56 is a schematic view of a first page a received fax, Figure 57 is a schematic view of a second page of a received fax, Figure 58 is a schematic view of fax contact registration user mterface flow, and Figure 59 is a schematic view of a fax contact registration form 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 necessanly embody all or even most of the specific details and extensions discussed below m relation to the basic system However, the system is descnbed m its most complete form to reduce the need for external reference when attempting to understand the context m which the preferred embodiments and aspects of the present invention operate In bnef summary, the preferred form of the netpage system employs a computer mterface m the form of a mapped surface, that is, a physical surface which contams references to a map of the surface mamtamed m a computer system The map references can be quened by an appropnate sensmg device Depending upon the specific implementation, the map references may be encoded visibly or invisibly, and defined m such a way that a local query on the mapped surface yields an unambiguous map reference both withm the map and among different maps The computer system can contam information about features on the mapped surface, and such information can be retneved based on map references supplied by a sensmg device used with the mapped surface The information thus retneved can take the form of actions which are initiated by the computer system on behalf of the operator in response to the operator's mteraction with the surface features In its preferred form, the netpage system relies on the production of, and human mteraction with, netpages These are pages of text, graphics and images pnnted on ordinary paper, but which work like mteractive web pages Information is encoded on each page usmg 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 - 5 - lnformation from the network or to signal preferences to a network server In one embodiment, text wntten by hand on a netpage is automatically recognized and converted to computer text m the netpage system, allowing forms to be filled m In other embodiments, signatures recorded on a netpage are automatically venfied, allowmg e-commerce transactions to be securely authorized As illustrated m Figure 1 , a pnnted netpage 1 can represent a mteractive form which can be filled m by the user both physically, on the pnnted page, and "electronically", via commumcation between the pen and the netpage system The example shows a "Request" form contammg name and address fields and a submit button The netpage consists of graphic data 2 pnnted usmg visible ink, and coded data 3 pnnted as a collection of tags 4 usmg invisible mk The corresponding page descnption 5, stored on the netpage network, descnbes the mdividual 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 mterpret mput via the netpage The submit button 6, for example, has a zone 7 which corresponds 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 in Figures 8 and 9 and descnbed m more detail below, works m conjunction with a netpage pnnter 601, an Internet-connected pnnting appliance for home, office or mobile use The pen is wireless and commumcates securely with the netpage pπnter via a short-range radio link 9 The netpage pπnter 601, a preferred form of which is shown in Figures 11 to 13 and descnbed m more detail below, is able to deliver, peπodically or on demand, personalized newspapers, magazines, catalogs, books and other publications, all prmted at high quality as mteractive netpages Unlike a personal computer, the netpage pπnter is an appliance which can be, for example, wall-mounted adjacent to an area where the morning news is first consumed, such as m a user's kitchen, near a breakfast table, or near the household's pomt of departure for the day It also comes m tabletop, desktop, portable and miniature versions Netpages pnnted at then pomt of consumption combme the ease-of-use of paper with the timeliness and interactivity of an mteractive medium As shown m Figure 2, the netpage pen 101 mteracts with the coded data on a pnnted netpage 1 and commumcates, via a short-range radio link 9, the mteraction to a netpage pπnter The pπnter 601 sends the mteraction to the relevant netpage page server 10 for mterpretation In appropnate cncumstances, 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 pnnted on the ongmating pnnter 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™) pnnters In the preferred form of this technology, relatively high-speed and high-quality prmtmg is made more affordable to consumers In its preferred form, a netpage publication has the physical charactenstics of a traditional newsmagazme, such as a set of letter-size glossy pages pnnted m full color on both sides, bound together for easy navigation and comfortable handling The netpage pπnter exploits the growing availability of broadband Internet access Cable service is available to 95% of households m the Umted States, and cable modem service offering broadband Internet access is aheady available to 20% of these The netpage pnnter can also operate with slower connections, but with longer delivery tunes and lower image quality Indeed, the netpage system can be enabled usmg existing consumer inkjet and laser pnnters, 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 mtranet In still other embodiments, the netpage system is hosted on a single computer or computer-enabled device, such as a pπnter Netpage publication servers 14 on the netpage network are configured to deliver print-quality publications - 6 - to netpage pnnters Penodical publications are delivered automatically to subscnbmg netpage pnnters via pointcasting and multicasting Internet protocols Personalized publications are filtered and formatted accordmg to mdividual user profiles A netpage pnnter can be configured to support any number of pens, and a pen can work with any number of netpage pnnters In the preferred implementation, each netpage pen has a umque identifier A household may have a collection of colored netpage pens, one assigned to each member of the family This allows each user to maintain a distinct profile with respect to a netpage publication server or application server A netpage pen can also be registered with a netpage registration server 11 and linked to one or more payment card accounts This allows e-commerce payments to be securely authorized 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 biometncs can also be used to venfy identity A version of the netpage pen mcludes fingerprint scanning, venfied m a similar way by the netpage registration server Although a netpage pnnter may deliver penodicals 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 penodicals 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 usmg 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 kmd of relationship between objects, l e between instances of classes A generalization relates actual classes, and can be understood m the following way if a class is thought of as the set of all objects of that class, and class A is a generalization of class B, then B is simply a subset of A The UML does not dnectly support second-order modelling - 1 e classes of classes Each class is drawn as a rectangle labelled with the name of the class It contams a list of the attnbutes of the class, separated from the name by a horizontal lme, and a list of the operations of the class, separated from the attnbute list by a horizontal lme In the class diagrams which follow, however, operations are never modelled An association is drawn as a 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", I 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 corresponding 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 (in the form of an open tnangle) at the generalization end When a class diagram is broken up mto multiple diagrams, any class which is duplicated is shown with a dashed outline m all but the mam diagram which defines it It is shown with attnbutes only where it is defined 1.1 NETPAGES Netpages are the foundation on which a netpage network is built They provide a paper-based user interface to published information and interactive services A netpage consists of a pnnted page (or other surface region) invisibly tagged with references to an onlme descnption of the page The online page descnption is mamtamed persistently by a netpage page server The page descnption descnbes the visible layout and content of the page, mcludmg text, graphics and images It also descnbes the mput elements on the page, mcludmg buttons, hyperlinks, and mput fields A netpage allows markings made with a - 7 - netpage pen on its surface to be simultaneously captured and processed by the netpage system Multiple netpages can share the same page descnption However, to allow mput through otherwise identical pages to be distinguished, each netpage is assigned a umque page identifier This page ID has sufficient precision to distinguish between a very large number of netpages Each reference to the page descnption is encoded m a pnnted tag The tag identifies the umque page on which it appears, and thereby indirectly identifies the page descnption The tag also identifies its own position on the page Charactenstics of the tags are descnbed m more detail below Tags are pnnted m infrared-absorptive mk 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 in the netpage pen, and the tag data is transmitted to the netpage system via the nearest netpage pnnter The pen is wireless and commumcates with the netpage pnnter via a short-range radio link Tags are sufficiently small and densely 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-correctably encoded to make them partially tolerant to surface damage The netpage page server maintains a umque page mstance for each pnnted netpage, allowmg it to maintain a distinct set of user-supplied values for mput fields m the page descnption for each pnnted netpage. The relationship between the page descnption, the page mstance, and the pnnted netpage is shown m Figure 4 The page mstance is associated with both the netpage pnnter which pnnted it and, if known, the netpage user who requested it 1.2 NETPAGE TAGS 1.2.1 Tag Data Content In a prefened form, each tag identifies the region in which it appears, and the location of that tag withm the region A tag may also contam flags which relate to the region as a whole or to the tag One or more flag bits may, for example, signal a tag sensmg device to provide feedback mdicative of a function associated with the immediate area of the tag, without the sensmg device havmg to refer to a descnption of the region A netpage pen may, for example, illuminate an "active area" LED when m the zone of a hyperlink As will be more clearly explained below, m a preferred embodiment, each tag contams an easily recognized mvanant structure which aids initial detection, and which assists m minimizing the effect of any warp mduced by the surface or by the sensmg process The tags preferably tile the entire page, and are sufficiently small and densely arranged that the pen can reliably image at least one tag even on a smgle click on the page It is important that the pen recognize the page ID and position on every mteraction with the page, smce the mteraction is stateless In a preferred embodiment, the region to which a tag refers comcides with an entire page, and the region ID encoded m the tag is therefore synonomous with the page ID of the page on which the tag appears In other embodiments, the region to which a tag refers can be an arbitrary subregion of a page or other surface For example, it can comcide with the zone of an mteractive element, in which case the region ID can directly identify the mteractive element Table 1 - Tag data - 8 - Each tag contams 120 bits of information, typically allocated as shown m Table 1 Assummg a maximum tag density of 64 per square mch, a 16-bit tag ID supports a region size of up to 1024 square mches Larger regions can be mapped continuously without mcreasmg the tag ID precision simply by usmg abutting regions and maps The 100-bit region ID allows 2 100 (-10 30 or a million tiilhon tnlhon) different regions to be umquely identified 1.2.2 Tag Data Encoding The 120 bits of tag data are redundantly encoded usmg a (15, 5) Reed-Solomon code This yields 360 encoded bits consisting of 6 codewords of 15 4-bit symbols each The (15, 5) code allows up to 5 symbol errors to be corrected per codeword, I e it is tolerant of a symbol error rate of up to 33% per codeword Each 4-bit symbol is represented m a spatially coherent way m the tag, and the symbols of the six codewords are mterleaved spatially withm the tag This ensures that a burst error (an enor affecting multiple spatially adjacent bits) damages a minimum number of symbols overall and a minimum number of symbols m any one codeword, thus maximising the likelihood that the burst error can be fully corrected 1.2.3 Physical Tag Structure The physical representation of the tag, shown m Figure 5, mcludes fixed target structures 15, 16, 17 and vanable data areas 18 The fixed target structures allow a sensmg device such as the netpage pen to detect the tag and fer 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 pnnted 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 surrounded by a "quiet area" of radius 16 dots Smce the quiet area is also contnbuted by adjacent tags, it only adds 16 dots to the effective diameter of the tag The tag mcludes six target structures A detection ring 15 allows the sensmg device to initially detect the tag The πng is easy to detect because it is rotationally mvanant and because a simple conection of its aspect ratio removes most of the effects of perspective distortion An 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 then immunity to noise The overall tag shape is cncular This supports, amongst other things, optimal tag packing on an irregular tnangular gnd In combmation with the cncular detection ring, this makes a cncular arrangement of data bits withm the tag optimal To maximise its size, each data bit is represented by a radial wedge m the form of an area bounded by two radial lmes and two concentnc cncular 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 concentnc symbol rings 18a to 18d m mterleaved fashion Symbols are allocated alternately m cncular progression around the tag The interleaving is designed to maximise the average spatial distance between any two symbols of the same codeword - 9 - 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 entne tag m its field of view no matter where m the region or at what onentation it is positioned The requned diameter of the field of view of the sensmg device is therefore a function of the size and spacmg of the tags Assummg a cncular tag shape, the minimum diameter of the sensor field of view is obtamed when the tags are tiled on a equilateral tnangular gnd, as shown m Figure 6 1.2.5 Tag Image Processing and Decoding The tag image processmg and decoding performed by a sensmg device such as the netpage pen is shown m Figure 7 While a captured image is bemg acquned from the image sensor, the dynamic range of the image is determined (at 20) The center of the range is then chosen as the binary threshold for the image 21 The image is then thresholded and segmented mto connected pixel regions (I e shapes 23) (at 22) Shapes which are too small to represent tag target structures are discarded The size and centroid of each shape is also computed Binary shape moments 25 are then computed (at 24) for each shape, and these provide the basis for subsequently locating target structures Central shape moments are by then nature mvanant of position, and can be easily made mvanant of scale, aspect ratio and rotation The πng target structure 15 is the first to be located (at 26) A πng has the advantage of bemg very well behaved when perspective-distorted Matchmg proceeds by aspect-normalizmg and rotation-normalizmg each shape's moments Once its second-order moments are normalized the πng is easy to recognize even if the perspective distortion was sigmficant The nng's oπgrnal 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 applymg the nng's normalizations to each shape's moments, and rotation-normalizmg the resulting moments Once its second-order moments are normalized the axis target is easily recognized Note that one thnd order moment is requned to disambiguate the two possible onentations of the axis The shape is deliberately skewed to one side to make this possible Note also that it is only possible to rotation-normalize the axis target after it has had the nng's normalizations applied, smce the perspective distortion can hide the axis target's axis The axis target's ongmal 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 then positions are computed based on then known spatial relationships to the nng and axis targets, the aspect and rotation of the πng, and the rotation of the axis Matchmg proceeds by applymg the nng's normalizations to each shape's moments Once then second-order moments are normalized the cncular perspective targets are easy to recognize, and the target closest to each estimated position is taken as a match The ongmal centroids of the four perspective targets are then taken to be the perspective-distorted comers 31 of a square of known size m tag space, and an eight-degree-of-freedom perspective transform 33 is inferred (at 32) based on solvmg the well-understood equations relatmg the four tag-space and lmage- space pomt pans The inferred tag-space to image-space perspective transform is used to project (at 36) each known data bit position m tag space mto image space where the real-valued position is used to bilmearly mterpolate (at 36) the four relevant adjacent pixels m the input unage 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 obtamed 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 in total Note that the codeword symbols are sampled m codeword order, so that codewords are implicitly de-mterleaved during the sampling process - 10 - The πng target 15 is only sought m a subarea of the image whose relationship to the image guarantees that the πng, if found, is part of a complete tag If a complete tag is not found and successfully decoded, then no pen position is recorded for the current frame Given adequate processmg power and ideally a non-minimal field of view 193, an alternative strategy mvolves seeking another tag m the current image The obtamed tag data mdicates the identity of the region contammg the tag and the position of the tag withm the region An accurate position 35 of the pen b m the region, as well as the overall onentation 35 of the pen, is then inferred (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 1.2.6 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 withm the tagged region, the location of the tag withm the region must be known This is given by a tag map, a function which maps each tag ID m a tagged region to a corresponding location The tag map class diagram is shown m Figure 22, as part of the netpage pnnter class diagram A tag map reflects the scheme used to tile the surface region with tags, and this can vary accordmg to surface type When multiple tagged regions share the same tilmg scheme and the same tag numbermg scheme, they can also share the same tag map The tag map for a region must be retπevable via the region ID Thus, given a region ID, a tag ID and a pen transform, the tag map can be retneved, the tag ID can be translated mto an absolute tag location withm the region, and the tag-relative pen location can be added to the tag location to yield an absolute pen location within the region 1.2.7 Tagging Schemes Two distinct surface coding schemes are of mterest, both of which use the tag structure descnbed earlier m this section The prefened coding scheme uses "location-mdicating" tags as aheady discussed An alternative coding scheme uses object-mdicating tags A location-mdicating tag contams a tag ID which, when translated through the tag map associated with the tagged region, yields a umque tag location withm the region The tag-relative location of the pen is added to this tag 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 descnption associated with the region Not only is the user mterface element itself identified, but a location relative to the user mterface element is identified Location-mdicating tags therefore tnvially support the capture of an absolute pen path m the zone of a particular user mterface element An object-mdicating 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 mdistingmshable Object-mdicating tags do not, therefore, support the capture of an absolute pen path They do, however, support the capture of a relative pen path So long as the position sampling frequency exceeds twice the encountered tag frequency, the displacement from one sampled pen position to the next withm a stroke can be unambiguously determined With either tagging scheme, the tags function m cooperation with associated visual elements on the netpage as user mteractive elements m that a user can mteract with the pnnted page using an appropnate sensing device in order for tag data to be read by the sensing device and for an appropnate response to be generated m the netpage system 1.3 DOCUMENT AND PAGE DESCRIPTIONS A preferred embodiment of a document and page descnption class diagram is shown m Figures 25 and 26 In the netpage system a document is descnbed at three levels At the most abstract level the document 836 has a hierarchical structure whose terminal elements 839 are associated with content objects 840 such as text objects, - 11 - text style objects, image objects, etc Once the document is pnnted on a pnnter with a particular page size and accordmg to a particular user's scale factor preference, the document is pagmated and otherwise formatted Formatted terminal elements 835 will m some cases be associated with content objects which are different from those associated with their conespondmg terminal elements, particularly where the content objects are style-related Each pnnted mstance of a document and page is also descnbed separately, to allow mput captured through a particular page mstance 830 to be recorded separately from mput captured through other instances of the same page descnption The presence of the most abstract document descnption on the page server allows a user to request a copy of a document without bemg forced to accept the source document's specific format The user may be requesting a copy through a pπnter 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 mterpret user actions on a particular pnnted page A formatted document 834 consists of a set of formatted page descnptions 5, each of which consists of a set of formatted terminal elements 835 Each formatted element has a spatial extent or zone 58 on the page This defines the active area of mput elements such as hyperlinks and mput fields A document mstance 831 conesponds to a formatted document 834 It consists of a set of page instances 830, each of which corresponds to a page descnption 5 of the formatted document Each page mstance 830 descπbes a smgle umque pnnted netpage 1, and records the page ID 50 of the netpage A page mstance is not part of a document mstance if it represents a copy of a page requested m isolation A page mstance consists of a set of terminal element instances 832 An element mstance only exists if it records mstance-specific information Thus, a hyperlink mstance exists for a hyperlink element because it records a transaction ID 55 which is specific to the page mstance, and a field mstance exists for a field element because it records mput specific to the page mstance An element mstance does not exist, however, for static elements such as textflows A terminal element can be a static element 843, a hyperlink element 844, a field element 845 or a page server command element 846, as shown m Figure 27 A static element 843 can be a style element 847 with an associated style object 854, a textflow element 848 with an associated styled text object 855, an image element 849 with an associated image element 856, a graphic element 850 with an associated graphic object 857, a video clip element 851 with an associated video clip object 858, an audio clip element 852 with an associated audio clip object 859, or a scnpt element 853 with an associated scnpt object 860, as shown m Figure 28 A page mstance has a background field 833 which is used to record any digital ink captured on the page which does not apply to a specific mput element In the preferred form of the mvention, a tag map 811 is associated with each page mstance to allow tags on the page to be translated mto locations on the page 1.4 THE NETPAGE NETWORK In a prefened embodiment, a netpage network consists of a distnbuted set of netpage page servers 10, netpage registration servers 11, netpage ID servers 12, netpage application servers 13, netpage publication servers 14, and netpage pnnters 601 connected via a network 19 such as the Internet, as shown in Figure 3 The netpage registration server 11 is a server which records relationships between users, pens, pnnters, applications and publications, and thereby authorizes vanous network activities It authenticates users and acts as a signing proxy on behalf of authenticated users m application transactions It also provides handwnting recogmtion 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 mstance, clients such as netpage pnnters send netpage mput dnectly to the appropnate page server The page server interprets any such mput relative to the - 12 - descnption of the conespondmg page A netpage ID server 12 allocates document IDs 51 on demand, and provides load-balancing of page servers via its ID allocation scheme A netpage pnnter uses the Internet Distnbuted Name System (DNS), or similar, to resolve a netpage page ID 50 mto the network address of the netpage page server handling the corresponding page mstance A netpage application server 13 is a server which hosts mteractive netpage applications A netpage publication server 14 is an application server which publishes netpage documents to netpage pnnters They are descπbed 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 concurrently on a smgle host, and a smgle server can be distnbuted over a number of hosts Some or all of the functionality provided by netpage servers, and m particular the functionality provided by the ID server and the page server, can also be provided directly m a netpage appliance such as a netpage pnnter, m a computer workstation, or on a local network 1.5 THE NETPAGE PRINTER The netpage pnnter 601 is an appliance which is registered with the netpage system and pnnts netpage documents on demand and via subscπption Each pπnter has a umque pπnter 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 contams no persistent storage As far as a user is concerned, "the network is the computer" Netpages function interactively across space and time with the help of the distnbuted netpage page servers 10, independently of particular netpage pnnters The netpage pπnter 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 unage objects, on the other hand, are typically shared with other subscnbers, and so are multicast to all subscnbers' pnnters and the appropnate page servers The netpage publication server optimizes the segmentation of document content mto pointcasts and multicasts After receivmg the pomtcast of a document's page layouts, the pnnter knows which multicasts, if any, to listen to Once the pnnter has received the complete page layouts and objects that define the document to be pnnted, it can pnnt the document The pnnter rastenzes and pnnts odd and even pages simultaneously on both sides of the sheet It contams duplexed pnnt engme controllers 760 and pnnt engmes utilizing Memjet™ printheads 350 for this purpose The prmtmg process consists of two decoupled stages rasterization of page descnptions, and expansion and printing of page images The raster image processor (RIP) consists of one or more standard DSPs 757 running m parallel The duplexed pπnt engme controllers consist of custom processors which expand, dither and pπnt page images m real time, synchronized with the operation of the pπntheads in the pnnt engmes Pnnters not enabled for IR prmtmg have the option to pnnt tags usmg IR-absorptive black ink, although this restncts tags to otherwise empty areas of the page Although such pages have more limited functionality than IR-pπnted pages, they are still classed as netpages A normal netpage pnnter pnnts netpages on sheets of paper More specialised netpage pnnters may pnnt onto more specialised surfaces, such as globes Each pnnter supports at least one surface type, and supports at least one tag tiling scheme, and hence tag map, for each surface type The tag map 811 which descπbes the tag tilmg scheme - 13 - actually used to pπnt a document becomes associated with that document so that the document's tags can be correctly mterpreted Figure 2 shows the netpage pnnter class diagram, reflecting printer-related information mamtamed by a registration server 11 on the netpage network A prefened embodiment of the netpage pnnter is descnbed 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 pnnters made with a wide range of digital printing technologies, mcludmg thermal inkjet, piezoelectnc Inkjet, laser electrophotographic, and others However, for wide consumer acceptance, it is desnable that a netpage pπnter have the following charactenstics • photographic quality color printing • high quality text pπnting • high reliability • low pnnter cost • low mk cost • low paper cost • simple operation • nearly silent printing • high printing speed • simultaneous double sided pπnting • compact form factor • low power consumption No commercially available printing technology has all of these charactenstics To enable to production of pnnters with these charactenstics, the present applicant has mvented a new pnnt technology, refened to as Memjet™ technology Memjet™ is a drop-on-demand Inkjet technology that incorporates pagewidth prmtheads fabncated usmg microelecfromechamcal systems (MEMS) technology Figure 17 shows a smgle printing element 300 of a Memjet™ pnnthead The netpage wallpnnter incorporates 168960 prmtmg elements 300 to form a 1600 dpi pagewidth duplex pnnter This pnnter simultaneously pnnts cyan, magenta, yellow, black, and infrared inks as well as paper conditioner and mk fixative The pnnting element 300 is approximately 110 microns long by 32 microns wide Anays of these prmtmg elements are formed on a silicon substrate 301 that incorporates CMOS logic, data transfer, timing, and dnve cncuits (not shown) Major elements of the pnnting element 300 are the nozzle 302, the nozzle run 303, the nozzle chamber 304, the flmdic 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 mk mlet 312 The active actuator beam pair 308 is mechanically joined to the passive actuator beam pair 309 at the j om 319 Both beams pans are anchored at then respective anchor pomts 310 and 311 The combmation of elements 308, 309, 310, 311, and 319 form a cantilevered electrothermal bend actuator 320 Figure 18 shows a small part of an anay of prmtmg elements 300, mcludmg a cross section 315 of a prmtmg element 300 The cross section 315 is shown without ink, to clearly show the ink mlet 312 that passes through the silicon wafer 301 Figures 19(a), 19(b) and 19(c) show the operating cycle of a Memjet™ pnnting element 300 - 14 - Figure 19(a) shows the quiescent position of the ink memscus 316 pnor to pπnting an mk droplet Ink is retained m the nozzle chamber by surface tension at the ink memscus 316 and at the flmdic seal 305 formed between the nozzle chamber 304 and the ink channel nm 306 While pnnting, the pnnthead CMOS cncuitry distnbutes data from the pnnt engme controller to the conect pπnting element, latches the data, and buffers the data to dnve the electrodes 318 of the active actuator beam pan 308 This causes an electncal cunent to pass through the beam pan 308 for about one microsecond, resulting m Joule heating The temperature mcrease resulting from Joule heating causes the beam pan 308 to expand As the passive actuator beam pan 309 is not heated, it does not expand, resulting m a stress difference between the two beam pans 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 1 (b) This mcreases the ink pressure, forcmg ink 321 out of the nozzle 302, and causing the ink memscus 316 to bulge The nozzle nm 303 prevents the ink memscus 316 from spreading across the surface of the nozzle chamber 304 As the temperature of the beam pans 308 and 309 equalizes, the actuator 320 returns to its ongmal position This aids m the break-off of the ink droplet 317 from the ink 321 m the nozzle chamber, as shown m Figure 19(c) The nozzle chamber is refilled by the action of the surface tension at the memscus 316 Figure 20 shows a segment of a pnnthead 350 In a netpage pnnter, the length of the pnnthead is the full width of the paper (typically 210 mm) m the direction 351 The segment shown is 04 mm long (about 02% of a complete pnnthead) When pπnting, the paper is moved past the fixed prmthead m the dnection 352 The pnnthead has 6 rows of mterdigitated pnnting elements 300, pnnting the six colors or types of ink supplied by the ink inlets 312 To protect the fragile surface of the pnnthead duπng operation, a nozzle guard wafer 330 is attached to the pnnthead substrate 301 For each nozzle 302 there is a conespondmg nozzle guard hole 331 through which the ink droplets are fired To prevent the nozzle guard holes 331 from becommg blocked by paper fibers or other debns, filtered an is pumped through the air inlets 332 and out of the nozzle guard holes duπng pnnting To prevent mk 321 from drying, 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, usmg its embedded controller 134, is able to capture and decode IR position tags from a page via an unage sensor The image sensor is a solid-state device provided with an appropnate filter to permit sensmg at only near-infrared wavelengths As descnbed m more detail below, the system is able to sense when the mb is m contact with the surface, and the pen is able to sense tags at a sufficient rate to capture human handwnting (I e at 200 dpi or greater and 100 Hz or faster) Information captured by the pen is encrypted and wnelessly transmitted to the pnnter (or base station), the pπnter or base station interpreting the data with respect to the (known) page structure The prefened embodiment of the netpage pen operates both as a normal markmg ink pen and as a non- markmg 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 unique pen ID 61 Figure 23 shows the netpage pen class diagram, reflecting pen-related rn ormation mamtamed by a registration server 11 on the netpage network When either mb is m contact with a netpage, the pen determmes its position and onentation relative to the page The mb is attached to a force sensor, and the force on the mb is mterpreted relative to a threshold to indicate whether the pen is "up" or "down" This allows a interactive element on the page to be 'clicked' by pressmg with the pen b, m order to request, say, information from a network Furthermore, the force is captured as a continuous value to - 15 - allow, say, the full dynamics of a signature to be venfied The pen determmes the position and onentation of its mb on the netpage by imaging, m the mfrared spectrum, an area 193 of the page m the vicinity of the mb It decodes the nearest tag and computes the position of the mb relative to the tag from the observed perspective distortion on the imaged tag and the known geometry of the pen optics Although the position resolution of the tag may be low, because the tag density on the page is mversely proportional to the tag size, the adjusted position resolution is quite high, exceedmg the minimum resolution requned for accurate handwnting recogmtion Pen actions relative to a netpage are captured as a senes of strokes A stroke consists of a sequence of time- stamped pen positions on the page, initiated by a pen-down event and completed by the subsequent pen-up event A stroke is also tagged with the page ID 50 of the netpage whenever the page ID changes, which, under normal cncumstances, is at the commencement of the sfroke Each netpage pen has a current selection 826 associated with it, allowing the user to perform copy and paste operations etc The selection is timestamped to allow the system to discard it after a defined time penod The cunent selection descπbes a region of a page mstance It consists of the most recent digital ink stroke captured through the pen relative to the background area of the page It is mterpreted m an application-specific manner once it is submitted to an application via a selection hyperlmk activation Each pen has a cunent mb 824 This is the mb last notified by the pen to the system In the case of the default netpage pen descnbed above, either the markmg black ink mb or the non-marking stylus mb is cunent Each pen also has a current 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 cunent mb Strokes captured through a pen are tagged with the current nib style When the strokes are subsequently reproduced, they are reproduced m the mb style with which they are tagged Whenever the pen is withm range of a pnnter with which it can communicate, the pen slowly flashes its "online" LED When the pen fails to decode a stroke relative to the page, it momentanly activates its "enor" LED When the pen succeeds m decoding a stroke relative to the page, it momentanly activates its "ok" LED A sequence of captured sfrokes is refened to as digital ink Digital ink forms the basis for the digital exchange of drawings and handwnting, for online recogmtion of handwnting, and for onlme venfication of signatures The pen is wireless and transmits digital mk 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 pnnter it buffers digital ink in internal memory, which has a capacity of over ten mmutes of continuous handwnting When the pen is once again withm range of a pnnter, it transfers any buffered digital ink A pen can be registered with any number of pnnters, but because all state data resides m netpages both on paper and on the network, it is largely lmmateπal which pnnter a pen is communicating with at any particular time A prefened 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 mdicatmg data is transmitted to - 16 - 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 corresponding page mstance 830 It then transmits the sfroke to the page server If the page was recently identified in an earlier sfroke, then the pnnter may aheady 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 sfroke from the pen, it retrieves the page descnption to which the sfroke applies, and determmes which element of the page descnption the stroke mtersects It is then able to mterpret 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 requnes 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 hyperlmk 1.7.1 Hyperlinks A hyperlink is a means of sending a message to a remote application, and typically elicits a pnnted response m the netpage system A hyperlink element 844 identifies the application 71 which handles activation of the hyperlink, a link ID 54 which identifies the hyperlink to the application, an "alias requned" flag which asks the system to mclude the user's application alias ID 65 in the hyperlink activation, and a descnption which is used when the hyperlink is recorded as a favoπte or appears m the user's history The hyperlink element class diagram is shown in Figure 29 When a hyperlink is activated, the page server sends a request to an application somewhere on the network The application is identified by an application ID 64, and the application ID is resolved m the normal way via the DNS There are three types of hyperlinks general hyperlinks 863, form hyperlinks 865, and selection hyperlinks 864, as shown m Figure 30 A general hyperlink can implement a request for a linked document, or may simply signal a preference to a server A form hyperlink submits the conesponding form to the application A selection hyperlink submits the cunent selection to the application If the current selection contams a single-word piece of text, for example, the application may return a smgle-page document givmg 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 conespondmg hyperlink mstance 862 records a transaction ID 55 which can be specific to the page mstance on which the hyperlink mstance appears The transaction ID can identify user-specific data to the application, for example a "shopping cart" of pendmg purchases mamtamed by a purchasing application on behalf of the user The system mcludes the pen's cunent selection 826 m a selection hyperlink activation The system mcludes the content of the associated form mstance 868 m a form hyperlink activation, although if the hyperlink has its "submit delta" attnbute set, only mput smce the last form submission is mcluded The system mcludes an effective return path in all hyperlink activations A hyperlinked group 866 is a group element 838 which has an associated hyperlink, as shown m Figure 31 When mput occurs through any field element m the group, the hyperlink 844 associated with the group is activated A hyperlinked group can be used to associate hyperlink behavior with a field such as a checkbox It can also be used, m conjunction with the "submit delta" attnbute of a form hyperlink, to provide continuous mput to an application It can - 17 - therefore be used to support a "blackboard" mteraction model, 1 e where mput is captured and therefore shared as soon as it occurs 1.7.2 Forms A form defines a collection of related mput fields used to capture a related set of mputs through a pnnted netpage A form allows a user to submit one or more parameters to an application software program running on a server A form 867 is a group element 838 m the document hierarchy It ultimately contams a set of terminal field elements 839 A form mstance 868 represents a pnnted mstance of a form It consists of a set of field instances 870 which conespond to the field elements 845 of the form Each field mstance has an associated value 871, whose type depends on the type of the corresponding field element Each field value records mput through a particular pnnted form mstance, l e through one or more pnnted netpages The form class diagram is shown m Figure 32 Each form mstance has a status 872 which mdicates whether the form is active, frozen, submitted, void or expned A form is active when first pnnted A form becomes frozen once it is signed A form becomes submitted once one of its submission hyperlinks has been activated, unless the hyperlink has its "submit delta" attribute set A form becomes void when the user mvokes a void form, reset form or duplicate form page command A form expnes when the time the form has been active exceeds the form's specified lifetime While the form is active, form mput is allowed Input through a form which is not active is mstead captured m the background field 833 of the relevant page mstance When the form is active or frozen, form submission is allowed Any attempt to submit a form when the form is not active or frozen is rejected, and mstead elicits an form status report Each form mstance is associated (at 59) with any form instances denved from it, thus providing a version history This allows all but the latest version of a form m a particular time penod to be excluded from a search All mput is captured as digital ink Digital ink 873 consists of a set of timestamped stroke groups 874, each of which consists of a set of styled strokes 875 Each stroke consists of a set of timestamped pen positions 876, each of which also includes pen onentation and mb force The digital ink class diagram is shown m Figure 33 A field element 845 can be a checkbox field 877, a text field 878, a drawing field 879, or a signature field 880 The field element class diagram is shown m Figure 34 Any digital ink captured m a field's zone 58 is assigned to the field A checkbox field has an associated boolean value 881, as shown m Figure 35 Any mark (a tick, a cross, a sfroke, a fill zigzag, etc ) captured m a checkbox field's zone causes a true value to be assigned to the field's value A text field has an associated text value 882, as shown in Figure 36 Any digital ink captured m a text field's zone is automatically converted to text via online handwnting recogmtion, and the text is assigned to the field's value Onlme handwnting recogmtion is well-understood (see for example Tappert, C , C Y Suen and T Wakahara, "The State of the Art in On-Line Handwnting Recogmtion", IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol 12, No 8, August 1990) A signature field has an associated digital signature value 883, as shown in 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 Online signature venfication is well-understood (see for example Plamondon, R and G Lorette, "Automatic Signature Venfication and Wnter Identification - The State of the Art", Pattern Recogmtion, Vol 22, No 2, 1989) A field element is hidden if its "hidden" attnbute is set A hidden field element does not have an input zone on a page and does not accept mput It can have an associated field value which is mcluded m the form data when the form contammg the field is submitted - 18 - "Editing" commands, such as stnke-throughs mdicatmg deletion, can also be recognized m form fields Because the handwnting recogmtion algonthm works "onlme" (l 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- wntten characters with relatively high accuracy, without a wnter-dependent frainmg phase A wnter-dependent model of handwnting is automatically generated over time, however, and can be generated up-front if necessary, Digital mk, as already stated, consists of a sequence of strokes Any sfroke which starts m a particular element's zone is appended to that element's digital ink stream, ready for mterpretation Any stroke not appended to an object's digital ink sfream is appended to the background field's digital ink sfream Digital ink captured m the background field is mterpreted as a selection gesture Cncumscnption of one or more objects is generally mterpreted as a selection of the cncumscnbed objects, although the actual mterpretation is application-specific Table 2 summanses these vanous pen interactions with a netpage Table 2 - Summary of pen interactions with a netpage 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 behavior The raw digital ink captured m every field is retained on the netpage page server and is optionally transmitted with the form data when the form is submitted to the application This allows the application to mtenogate the raw digital ink should it suspect the 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 fϊlled-in 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 receivmg (at 884) a sfroke from the pen, identifying (at 885) the page mstance 830 to which the page ID 50 m the stroke refers, retπevmg (at 886) the page descnption 5, identifymg (at 887) a formatted element 839 whose zone 58 the stroke mtersects, determining (at 888) whether the formatted element conesponds to a field element, and if so appending (at 892) the received stroke to the digital ink of the field value 871, interpreting (at 893) the accumulated digital mk of the field, and determining (at 894) whether the field is part of a hyperlinked group 866 and if so activating (at 895) the associated hyperlink, alternatively determining (at 889) whether the formatted element conesponds to a - 19 - hyperlink element and if so activating (at 895) the conespondmg hyperlink, altematively, in the absence of an mput field or hyperlink, appendmg (at 890) the received sfroke to the digital ink of the background field 833, and copymg (at 891) the received sfroke to the cunent selection 826 of the cunent pen, as mamtamed by the regisfration server Figure 38a shows a detailed flowchart of step 893 in the process shown m Figure 38, where the accumulated digital ink of a field is mterpreted according to the type of the field The process consists of determining (at 896) whether the field is a checkbox and (at 897) whether the digital ink represents a checkmark, and if so assignmg (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 assignmg (at 901) the converted computer text to the field value, altematively determining (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 regisfration server, creating (at 904) a digital signature of the contents of the corresponding form, also with the help of the registration server and usmg the pen owner's pnvate signature key relating to the correspondmg application, and assignmg (at 905) the digital signature to the field value 1.7.3 Page Server Commands A page server command is a command which is handled locally by the page server It operates directly on form, page and document instances A page server command 907 can be a void form command 908, a duplicate form command 909, a reset form command 910, a get form status command 911, a duplicate page command 912, a reset page command 913, a get page status command 914, a duplicate document command 915, a reset document command 916, or a get document status command 917, as shown m Figure 39 A void form command voids the conespondmg form mstance A duplicate form command voids the correspondmg form mstance and then produces an active pnnted copy of the cunent form mstance with field values preserved The copy contams the same hyperlink transaction IDs as the ongrnal, and so is mdistingmshable from the ongmal to an application A reset form command voids the conespondmg form instance and then produces an active pnnted copy of the form mstance with field values discarded A get form status command produces a pnnted report on the status of the conespondmg form mstance, mcludmg who published it, when it was pnnted, for whom it was pnnted, and the form status of the form mstance Smce a form hyperlink mstance contains a transaction ID, the application has to be mvolved m producing a new form mstance A button requesting a new form instance is therefore typically implemented as a hyperlink A duplicate page command produces a pnnted copy of the conespondmg page mstance with the background field value preserved If the page contams a form or is part of a form, then the duplicate page command is mterpreted as a duplicate form command A reset page command produces a pnnted copy of the correspondmg page mstance with the background field value discarded If the page contains 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 pnnted report on the status of the conesponding page mstance, including who published it, when it was pnnted, for whom it was pnnted, 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 pnnted m then native form, l e a checkmark appears as a standard checkmark graphic, and text appears as typeset text Only drawings and signatures appear m then ongmal form, with a signature accompanied by a standard graphic mdicatmg successful signature venfication A duplicate document command produces a pnnted copy of the correspondmg document mstance with - 20 - background field values preserved If the document contams any forms, then the duplicate document command duplicates the forms m the same way a duplicate form command does A reset document command produces a pnnted copy of the correspondmg document mstance with background field values discarded If the document contams any forms, then the reset document command resets the forms m the same way a reset form command does A get document status command produces a pnnted report on the status of the conespondmg document mstance, mcludmg who published it, when it was pnnted, for whom it was pnnted, and the status of any forms it contams If the page server command's "on selected" attribute is set, then the command operates on the page identified by the pen's current selection rather than on the page contammg the command This allows a menu of page server commands to be pnnted 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 dnectly by a user It can, however, be activated via a page server command embedded m a different page, if that page server command has its "on selected" attnbute set 1.8 STANDARD FEATURES OF NETPAGES In the prefened form, each netpage is pnnted with the netpage logo at the bottom to indicate that it is a netpage and therefore has mteractive properties The logo also acts as a copy button In most cases pressmg the logo produces a copy of the page In the case of a form, the button produces a copy of the entire form And m the case of a secure document, such as a ticket or coupon, the button elicits an explanatory note or advertismg page The default smgle-page copy function is handled dnectly by the relevant netpage page server Special copy functions are handled by linking the logo button to an application 1.9 USER HELP SYSTEM In a prefened embodiment, the netpage pnnter has a smgle button labelled "Help" When pressed it elicits a smgle page of information, mcludmg • status of pπnter connection • status of pnnter consumables • top-level help menu • document function menu • top-level netpage network directory The help menu provides a hierarchical manual on how to use the netpage system The document function menu mcludes the following functions • pnnt a copy of a document • pnnt a clean copy of a form • pnnt the status of a document A document function is initiated by simply 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 dnectory 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 desned document and route it to the user's pnnter Dependmg on the document - 21 - type, the publisher or the user pays the small "yellow pages" service fee The help page is obviously unavailable if the pnnter is unable to pnnt In this case the "error" light is lit and the user can request remote diagnosis over the network 2 PERSONALIZED PUBLICATION MODEL In the following descnption, news is used as a canonical publication example to illustrate personalization mechamsms m the netpage system Although news is often used m the limited sense of newspaper and newsmagazme news, the mtended scope m the present context is wider In the netpage system, the editonal content and the advertismg content of a news publication are personalized usmg different mechamsms The editonal content is personalized accordmg to the reader's explicitly stated and implicitly captured mterest profile The advertismg content is personalized accordmg to the reader's locality and demographic 2.1 EDITORIAL PERSONALIZATION A subscnber can draw on two kinds of news sources those that deliver news publications, and those that deliver news streams While news publications are aggregated and edited by the publisher, news sfreams are aggregated either by a news publisher or by a specialized news aggregator News publications typically conespond to traditional newspapers and newsmagazmes, while news sfreams can be many and vaned a "raw" news feed from a news service, a cartoon stnp, a freelance writer'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 sfreams selected dnectly by the reader, the server is able to place advertismg on pages over which it otherwise has no editonal control The subscnber builds a daily newspaper by selecting one or more contnbuting news publications, and creating a personalized version of each The resulting daily editions are pnnted and bound together mto a smgle newspaper The vanous members of a household typically express then 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", "Opmion", "Busmess", "Arts/Living", "Technology", and "Sports" The set of available sections is specific to a publication, as is the default subset The reader can extend the daily newspaper by creating custom sections, each one drawing on any number of news sfreams 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 (l e as a percentage) The reader also optionally expresses a preference for a large number of shorter articles or a small number of longer articles Each article is ideally wntten (or edited) m both short and long forms to support this preference An article may also be wntten (or edited) in different versions to match the expected sophistication of the reader, for example to provide children's and adults' versions The appropnate version is selected accordmg to the reader's age The reader can specify a "reading age" which takes precedence over then biological age The articles which make up each section are selected and pnoπtized by the editors, and each is assigned a useful lifetime By default they are delivered to all relevant subscnbers, m pnonty order, subject to space constraints m the subscnbers' editions - 22 - In sections where it is appropnate, the reader may optionally enable collaborative filtermg This is then applied to articles which have a sufficiently long lifetime Each article which qualifies for collaborative filtermg is pnnted with rating buttons at the end of the article The buttons can provide an easy choice (e g "liked" and "disliked'), making it more likely that readers will bother to rate the article Articles with high pnonties and short lifetimes are therefore effectively considered essential reading by the editors and are delivered to most relevant subscnbers The reader optionally specifies a serendipity factor, either qualitatively (e g do or don't surpnse me), or numencally A high serendipity factor lowers the threshold used for matchmg durmg collaborative filtermg A high factor makes it more likely that the conespondmg section will be filled to the reader's specified capacity A different serendipity factor can be specified for different days of the week The reader also optionally specifies topics of particular mterest within a section, and this modifies the pnonties assigned by the editors The speed of the reader's Internet connection affects the quality at which images can be delivered The reader optionally specifies a preference for fewer images or smaller images or both If the number or size of images is not reduced, then images may be delivered at lower 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 mvolves specifying whether units are impenal or metπc, a local timezone and time format, and a local currency, and whether the localization consist of in situ translation or annotation These preferences are denved 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 conespondmg text encoding, is a property of the publication and not a preference expressed by the user However, the netpage system can be configured to provide automatic franslation services m vanous guises 2.2 ADVERTISING LOCALIZATION AND TARGETING The personalization of the editonal content directly affects the advertismg content, because advertismg is typically placed to exploit the editonal context Travel ads, for example, are more likely to appear m a travel section than elsewhere The value of the editonal content to an advertiser (and therefore to the publisher) lies m its ability to attract large numbers of readers with the nght demographics Effective advertismg is placed on the basis of locality and demographics Locality determmes proximity to particular services, retailers etc , and particular mterests and concerns associated with the local community and environment Demographics determine general interests and preoccupations as well as likely spending patterns A news publisher's most profitable product is advertismg "space", a multi-dimensional entity determined by the publication's geographic coverage, the size of its readership, its readership demographics, and the page area available for advertismg In the netpage system, the netpage publication server computes the approximate multi-dimensional size of a publication s saleable advertising space on a per-section basis, taking mto account the publication's geographic coverage, the section's readership, the size of each reader's section edition, each reader's advertismg proportion, and each reader's demographic In companson with other media, the netpage system allows the advertismg space to be defined m greater detail, and allows smaller pieces of it to be sold separately It therefore allows it to be sold at closer to its true value - 23 - For example, the same advertismg "slot" can be sold m varying proportions to several advertisers, with mdividual readers' pages randomly receivmg the advertisement of one advertiser or another, overall preservmg the proportion of space sold to each advertiser The netpage system allows advertismg to be linked dnectly 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 arbifranly 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 dnectly capture advertismg Even though the advertismg aggregator is taking a proportion of advertismg revenue, publishers may find the change profit-neufral because of the greater efficiency of aggregation The advertismg aggregator acts as an intermediary between advertisers and publishers, and may place the same advertisement in multiple publications It is worth noting that ad placement m a netpage publication can be more complex than ad placement m the publication's traditional counterpart, because the publication's advertismg space is more complex While ignoring the full complexities of negotiations between advertisers, advertismg aggregators and publishers, the prefened form of the netpage system provides some automated support for these negotiations, mcludmg support for automated auctions of advertismg space Automation is particularly desnable for the placement of advertisements which generate small amounts of mcome, such as small or highly localized advertisements Once placement has been negotiated, the aggregator captures and edits the advertisement and records it on a netpage ad server Conespondmgly, the publisher records the ad placement on the relevant netpage publication server When the netpage publication server lays out each user's personalized publication, it picks the relevant advertisements from the netpage ad server Accordingly, a user may be provided with a netpages, which may more generally be refened to as a pnnted document with user mteractive elements, formatted in accordance with then own preferences, with additional content targeted specifically to demographics of the user The mteractive elements) relating to the targeted content allow the user to request further information relating to that content The targeted content may relate to advertismg matenal and the further information may be provided m the form of an advertismg brochure The manner m which the mteractive elements) are pnnted m the document and with which the sensmg device is used to mteract with the elements), to indicate a request for further information, are as descnbed above 2.3 USER PROFILES 2.3.1 Information Filtering The personalization of news and other publications relies on an assortment of user-specific profile information, mcludmg publication customizations • collaborative filtermg vectors contact details presentation preferences The customization of a publication is typically publication-specific, and so the customization information is mamtamed by the relevant netpage publication server A collaborative filteπng vector consists of the user's ratings of a number of news items It is used to conelate different users' mterests for the purposes of making recommendations Although there are benefits to maintaining a smgle collaborative filtermg vector independently of any particular publication, there are two reasons why - 24 - lt is more practical to maintain a separate vector for each publication there is likely to be more overlap between the vectors of subscnbers to the same publication than between those of subscnbers to different publications, and a publication is likely to want to present its users' collaborative filtermg vectors as part of the value of its brand, not to be found elsewhere Collaborative 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 m the same way The localization of advertismg relies on the locality indicated m the user's contact details, while the targeting of advertismg relies on personal information such as date of birth, gender, maπtal status, mcome, profession, education, or qualitative deπvatives 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, advertismg can be targeted on the basis of the demographic associated with the user's ZIP or ZIP+4 Code Each user, pen, pπnter, 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 regisfration purposes, a publisher is a special land of application provider, and a publication is a special kmd of application Each user 800 may be authorized to use any number of pnnters 802, and each pπnter may allow any number of users to use it Each user has a single default pnnter (at 66), to which penodical publications are delivered by default, whilst pages pnnted on demand are delivered to the pπnter through which the user is mteractmg The server keeps track of which publishers a user has authorized to pnnt to the user's default pnnter A publisher does not record the ID of any particular pπnter, but mstead resolves the ID when it is requned When a user subscnbes 808 to a publication 807, the publisher 806 (1 e application provider 803) is authorized to pπnt to a specified pπnter or the user's default pπnter 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 pπnter, then that pnnter recognizes any of the user's pens The pen ID is used to locate the correspondmg user profile mamtamed by a particular netpage registration server, via the DNS m the usual way A Web terminal 809 can be authorized to pnnt on a particular netpage pπnter, allowmg Web pages and netpage documents encountered durmg Web browsmg to be conveniently pnnted on the nearest netpage pnnter The netpage system can collect, on behalf of a pnnter provider, fees and commissions on mcome earned through publications pnnted on the provider's pnnters 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 m the precedmg paragraph), contact details 815, including name, address and telephone numbers, global preferences 816, including pnvacy, delivery and localization settings, any number of biometπc records 817, containing the user's encoded signature 818, fingerprint 819 etc, a handwnting model 819 automatically mamtamed by the system, and SET payment card accounts 821 with which e-commerce payments can be made 2.3.2 Favorites List A netpage user can maintain a list 922 of "favontes" - links to useful documents etc on the netpage network The list is mamtamed by the system on the user's behalf It is organized as a hierarchy of folders 924, a - 25 - prefenred embodiment of which is shown m the class diagram m Figure 41 2.3.3 History List The system maintains a history list 929 on each user's behalf, contammg links to documents etc accessed by the user through the netpage system It is organized as a date-ordered list, a preferred embodiment of which is shown in the class diagram m Figure 42 2.4 INTELLIGENT PAGE LAYOUT The netpage publication server automatically lays out the pages of each user's personalized publication on a section-by-section basis Smce most advertisements are m the form of pre-formatted rectangles, they are placed on the page before the editonal content The advertismg ratio for a section can be achieved with wildly varying advertismg ratios on mdividual pages withm the section, and the ad layout algoπthm exploits this The algoπthm is configured to attempt to co-locate closely tied editonal and advertismg content, such as placmg ads for roofing matenal specifically withm the publication because of a special feature on do-it-yourself roofing repans 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 sigmficant day-to-day vanations 2.5 DOCUMENT FORMAT Once the document is laid out, it is encoded for efficient distπbution and persistent storage on the netpage network The primary efficiency mechanism is the separation of information specific to a smgle user's edition and information shared between multiple users' editions The specific information consists of the page 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-foimatted text represented m the Extensible Markup Language (XML) usmg the Extensible Stylesheet Language (XSL) XSL provides precise confrol over text formatting mdependenfly of the region mto which the text is bemg set, which m this case is bemg provided by the layout The text object contams embedded language codes to enable automatic franslation, and embedded hyphenation hints to aid with paragraph formatting An unage 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 unage and graphic objects, linked textflow objects through which text objects flow, hyperlinks and mput fields as descπbed above, and watermark regions These layout objects are summaπzed m Table 3 The layout uses a compact format suitable for efficient distnbution and storage Table 3 - netpage layout objects • 26 - 2.6 DOCUMENT DISTRIBUTION As descnbed above, for purposes of efficient distnbution and persistent storage on the netpage network, a user-specific page layout is separated from the shared objects to which it refers When a subscnbed publication is ready to be distπbuted, the netpage publication server allocates, with the help of the netpage ID server 12, a umque ID for each page, page mstance, document, and document mstance The server computes a set of optimized subsets of the shared content and creates a multicast channel for each subset, and then tags each user-specific layout with the names of the multicast channels which will carry the shared content used by that layout The server then pomtcasts each user's layouts to that user's pnnter via the appropnate page server, and when the porntcasting is complete, multicasts the shared content on the specified channels After receivmg its pomtcast, each page server and pπnter 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 refened to by its page layouts The page servers persistently archive the received page layouts and shared content Once a pπnter has received all the objects to which its page layouts refer, the pπnter re-creates the fully- populated layout and then rasteπzes and pnnts it Under normal circumstances, the pnnter pnnts pages faster than they can be delivered Assummg a quarter of each page is covered with images, the average page has a size of less than 400KB The pπnter can therefore hold m excess of 100 such pages m its internal 64MB memory, allowmg for temporary buffers etc The pnnter pnnts at a rate of one page per second This is eqmvalent to 400KB or about 3Mbit of page data per second, which is similar to the highest expected rate of page data delivery over a broadband network Even under abnormal circumstances, such as when the pnnter runs out of paper, it is likely that the user will be able to replemsh the paper supply before the pnnter' s 100-page mtemal storage capacity is exhausted However, if the pnnter' s mtemal memory does fill up, then the pnnter will be unable to make use of a multicast when it first occurs The netpage publication server therefore allows pnnters to submit requests for re- multicasts When a cntical number of requests is received or a timeout occurs, the server re-multicasts the conespondmg shared objects Once a document is pnnted, a pnnter can produce an exact duplicate at any time by retrieving its page layouts and contents from the relevant page server 2.7 ON-DEMAND DOCUMENTS When a netpage document is requested on demand, it can be personalized and delivered m much the same way as a penodical However, smce there is no shared content, delivery is made dnectly 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 - 27 - designated netpage formatting server which reformats it as a netpage document A netpage formatting server is a special mstance of a netpage publication server The netpage formatting server has knowledge of vanous Internet document formats, mcludmg Adobe's Portable Document Format (PDF), and Hypertext Markup Language (HTML) In the case of HTML, it can make use of the higher resolution of the pnnted page to present Web pages m a multi-column format, with a table of contents It can automatically mclude all Web pages dnectly linked to the requested page The user can tune this behavior via a preference The netpage formatting server makes standard netpage behavior, mcludmg interactivity and persistence, available on any Internet document, no matter what its oπgm and format It hides knowledge of different document formats from both the netpage pnnter and the netpage page server, and hides knowledge of the netpage system from Web servers 2.8 BOOKS As may be appreciated from the above, the netpage system also allows for delivery of books The information is formatted usmg an appropnate server and the book is then pnnted at a netpage pnnter with appropnate coded data/tags to allow for user mteraction with a sensmg device, such as the netpage pen, m a manner descnbed above, m order to request further information relatmg to the contents of the book The further information is preferably pnnted on demand at the pnnter following a request for same Havmg books available for pπnting on the netpage system also means that users can obtain the latest bestsellers or rare "out-of-pπnt" (a soon-to-be-obsoleted term) editions on demand, pnnted m column format with a text size chosen by the user A typical 300-page paperback fits on as little as 40 sheets of Letter paper Slip-on covers are available for robust handling Titles which have outlived then copynght penod can be available for free Other titles can be heavily discounted for netpage delivery, smce publishers avoid the costs of pnnting, inventory storage, and delivery Colourful children's books reproduce immaculately When they've been loved to death, they can be pnnted agam, and agam Children's colonng-m books and puzzles are available just when they're needed on a rainy day 3 SECURITY 3.1 CRYPTOGRAPHY Cryptography is used to protect sensitive information, both m storage and m transit, and to authenticate parties to a transaction There are two classes of cryptography in widespread use secret-key cryptography and public-key cryptography The netpage network uses both classes of cryptography Secret-key cryptography, also referred to as symmefric cryptography, uses the same key to encrypt and decrypt a message Two parties wishing to exchange messages must first arrange to securely exchange the secret key Public-key cryptography, also refened 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 intended for the holder of the pnvate key Once encrypted usmg the public key, a message can only be decrypted usmg the pnvate key Thus two parties can securely exchange messages without first havmg to exchange a secret key To ensure that the pnvate key is secure, it is normal for the holder of the pnvate key to generate the key pan 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 venfying the hash agamst the message If the signature is appended to the - 28 - message, then the recipient of the message can venfy both that the message is genume and that it has not been altered m transit To make public-key cryptography work, there has to be a way to distnbute public keys which prevents impersonation This is normally done usmg certificates and certificate authonties A certificate authonty is a trusted thnd party which authenticates the connection between a public key and someone's identity The certificate authonty veπfies the person's identity by examining identity documents, and then creates and signs a digital certificate containing the person's identity details and public key Anyone who trusts the certificate authonty can use the public key m the certificate with a high degree of certainty that it is genume They just have to venfy that the certificate has mdeed been signed by the certificate authonty, whose public key is well-known In most transaction environments, public-key cryptography is only used to create digital signatures and to securely exchange secret session keys Secret-key cryptography is used for all other purposes In the following discussion, when reference is made to the secure transmission of information between a netpage pnnter and a server, what actually happens is that the pnnter obtams the server's certificate, authenticates it with reference to the certificate authonty, uses the public key-exchange key m the certificate to exchange a secret session key with the server, and then uses the secret session key to encrypt the message data A session key, by definition, can have an arbitraπly short lifetime 3.2 NETPAGE PRINTER SECURITY Each netpage pπnter is assigned a pan of umque identifiers at time of manufacture which are stored m read-only memory m the pπnter and m the netpage regisfration 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 pubhc/pnvate key pan It transmits the secret ID and the public key securely to the netpage registration server The server compares the secret ID against the pnnter' s secret ID recorded m its database, and accepts the regisfration if the IDs match It then creates and signs a certificate contammg the pnnter' s public ID and public signature key, and stores the certificate m the registration database The netpage registration server acts as a certificate authonty for netpage pnnters, smce it has access to secret information allowing it to venfy pnnter identity When a user subscnbes to a publication, a record is created in the netpage regisfration server database authorizing the publisher to pπnt the publication to the user's default pnnter or a specified pnnter 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, obtamed from the publisher's certificate stored m the regisfration database The netpage regisfration server accepts requests to add prmtmg authorizations to the database, so long as those requests are initiated via a pen registered to the pπnter 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 pnnters, and a pπnter can "know" a number of pens A pen commumcates with a pπnter via a radio frequency signal whenever it is withm range of the pπnter Once a pen and - 29 - pnnter are registered, they regularly exchange session keys Whenever the pen fransmits digital ink to the pπnter, the digital ink is always encrypted usmg the appropnate session key Digital ink is never transmitted m the clear A pen stores a session key for every pnnter it knows, mdexed by pπnter ID, and a pnnter stores a session key for every pen it knows, mdexed by pen ID Both have a large but fimte storage capacity for session keys, and will forget a session key on a least-recently-used basis if necessary When a pen comes withm range of a pπnter, the pen and pπnter discover whether they know each other If they don't know each other, then the pπnter determmes whether it is supposed to know the pen This might be, for example, because the pen belongs to a user who is registered to use the pπnter If the pπnter is meant to know the pen but doesn't, then it mitiates the automatic pen registration procedure If the pπnter 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 mitiates the regisfration procedure In addition to its public ID, the pen contams a secret key-exchange key The key-exchange key is also recorded the netpage regisfration server database at time of manufacture Duπng regisfration, the pen transmits its pen ID to the pπnter, and the pπnter fransmits the pen ID to the netpage registration server The server generates a session key for the pnnter and pen to use, and securely transmits the session key to the 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 fransmits the encrypted session key to the pen The pen stores the session key internally, mdexed by the pnnter ID Although a fake pen can impersonate a pen m the pen regisfration 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 regisfration 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 includes a facility to pπnt watermarks, but will only do so on request from publishers who are suitably authorized The publisher mdicates its authonty to pnnt watermarks m its certificate, which the pπnter is able to authenticate The "watermark" pπnting process uses an alternative dither matnx m specified "watermark" regions of the page Back-to-back pages contam minor-image watermark regions which comcide when pnnted The dither matnces used in odd and even pages' watermark regions are designed to produce an interference effect when the regions are viewed together, achieved by looking through the pnnted sheet The effect is similar to a watermark in 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 bmlt-m netpage copy mechanism descnbed 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 - 30 - status in the usual way The umque ID of a secure document is only valid for the lifetime of the document, and secure document IDs are allocated non-contiguously to prevent then prediction by opportunistic forgers A secure document venfication pen can be developed with bmlt-m feedback on venfication failure, to support easy point-of-presentation document venfication Clearly neither the watermark nor the user's photograph are secure m a cryptographic sense They simply provide a sigmficant obstacle to casual forgery Onlme document venfication, particularly usmg a venfication pen, provides an added level of secunty where it is needed, but is still not entirely immune to forgeπes 3.5 NON-REPUDIATION In the netpage system, forms submitted by users are delivered reliably to forms handlers and are persistently archived on netpage page servers It is therefore impossible for recipients to repudiate delivery E-commerce payments made through the system, as descnbed m Section 4, are also impossible for the payee to repudiate 4 ELECTRONIC COMMERCE MODEL 4.1 SECURE ELECTRONIC TRANSACTION (SET) The netpage system uses the Secure Electromc 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 authonty and are issued with certificates containing then public signature keys The certificate authonty venfies a cardholder's regisfration details with the card issuer as appropnate, and veπfies a merchant's registration details with the acquner as appropnate Cardholders and merchants store then respective pnvate signature keys securely on then computers Durmg the payment process, these certificates are used to mutually authenticate a merchant and cardholder, and to authenticate them both to the payment gateway SET has not yet been adopted widely, partly because cardholder maintenance of keys and certificates is considered burdensome Interim solutions which maintain cardholder keys and certificates on a server and give the cardholder access via a password have met with some success 4.2 SET PAYMENTS In the netpage system the netpage registration server acts as a proxy for the netpage user (l e the cardholder) m SET payment transactions The netpage system uses biometncs to authenticate the user and authorize SET payments Because the system is pen-based, the biometπc used is the user's on-lme signature, consisting of time- varying pen position and pressure A fingerprmt biometnc can also be used by designmg a fingerprmt sensor into 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 tune as the user's identity is venfied The biometnc is captured and stored m the regisfration 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 mf ormation to act as the user's proxy m any SET payment transaction When the user eventually supplies the biometπc to complete a payment, for example by signing a netpage order form, the pnnter securely fransmits the order information, the pen ID and the biometnc data to the netpage - 31 - regisfration server The server venfies the biometnc with respect to the user identified by the pen ID, and from then on acts as the user's proxy m completing the SET payment transaction 4.3 MICRO-PAYMENTS The netpage system mcludes a mechanism for micro-payments, to allow the user to be conveniently charged for pnnting low-cost documents on demand and for copying copynght documents, and possibly also to allow the user to be reimbursed for expenses incurred m pnnting advertismg matenal The latter depends on the level of subsidy already provided to the user When the user registers for e-commerce, a network account is established which aggregates micro- payments The user receives a statement on a regular basis, and can settle any outstandmg debit balance usmg the standard payment mechanism The network account can be extended to aggregate subscπption fees for penodicals, which would also otherwise be presented to the user m the form of 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 adding items from a pre-pnnted catalog page to the user's virtual "shopping cart" To protect the user's pnvacy, however, the umque user ID 60 known to the netpage system is not divulged to applications This is to prevent different application providers from easily conelating mdependenfly accumulated behavioral data The netpage regisfration 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 hyperlmk tagged with the "registered" attnbute, the netpage page server asks the netpage regisfration 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 independent 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 in 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 prefened embodiment of a resource descnption class diagram is shown in 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 Dublin Core metadata conforms to the World Wide Web Consortium (W3C) Resource Descnption Framework (RDF) A resource descnption may identify nghts holders 920 The netpage system automatically transfers copynght fees from users to nghts holders when users pπnt copynght content - 32 - 5 COMMUNICATIONS PROTOCOLS A commumcations protocol defines an ordered exchange of messages between entities In the netpage system, entities such as pens, pnnters and servers utilise a set of defined protocols to cooperatively handle user mteraction with the netpage system Each protocol is illustrated by way of a sequence diagram m which the horizontal dimension is used to represent message flow and the vertical dimension is used to represent time Each entity is represented by a rectangle contammg the name of the entity and a vertical column representing the lifeline of the entity Duπng the time an entity exists, the lifeline is shown as a dashed lme Durmg the time an entity is active, the lifeline is shown as a double lme Because the protocols considered here do not create or desfroy entities, lifelmes are generally cut short as soon as an entity ceases to participate m a protocol 5.1 SUBSCRIPTION DELIVERY PROTOCOL A prefened embodiment of a subscnption delivery protocol is shown m Figure 43 A large number of users may subscnbe to a penodical publication Each user's edition may be laid out differently, but many users' editions will share common content such as text objects and unage objects The subscnption delivery protocol therefore delivers document structures to mdividual pnnters via pomtcast, but delivers shared content objects via multicast The application (I e publisher) first obtams a document ID 51 for each document from an ID server 12 It then sends each document structure, mcludmg its document ID and page descnptions, to the page server 10 responsible for the document's newly allocated ID It mcludes its own application ID 64, the subscriber's alias ID 65, and the relevant set of multicast channel names It signs the message usmg its pnvate signature key The page server uses the application ID and alias ID to obtain from the registration server the conespondmg user ID 60, the user's selected pπnter ID 62 (which may be explicitly selected for the application, or may be the user's default pπnter), and the application's certificate The application's certificate allows the page server to venfy the message signature The page server's request to the registration server fails if the application ID and alias ID don't together identify a subscnption 808 The page server then allocates document and page mstance IDs and forwards the page descnptions, mcludmg page IDs 50, to the pnnter It mcludes the relevant set of multicast channel names for the pnnter to listen to It then returns the newly allocated page IDs to the application for future reference Once the application has distnbuted all of the document structures to the subscnbers' selected pnnters via the relevant page servers, it multicasts the vanous subsets of the shared objects on the previously selected multicast channels Both page servers and pnnters momtor the appropnate multicast channels and receive then requned content objects They are then able to populate the previously pomtcast document structures This allows the page servers to add complete documents to then databases, and it allows the pnnters to pnnt the documents 5.2 HYPERLINK ACTIVATION PROTOCOL A prefened embodiment of a hyperlink activation protocol is shown in 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 pπnter aheady knows the ID 61 of the pen from the pen connection protocol The pnnter determmes, via the DNS, the network address of the page server 10a handling the particular page ID 50 The address may already be m its cache if the user has recently mteracted with the same page The pnnter then forwards the pen ID, its own pnnter ID 62, the page ID and click location to the page server The page server loads the page descnption 5 identified by the page ID and determmes which mput - 33 - element's zone 58, if any, the click lies m Assummg the relevant mput element is a hyperlink element 844, the page server then obtains the associated application ID 64 and link ID 54, and determmes, 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 correspondmg user ID 60 from the registration server 11, and then allocates a globally umque hyperlink request ID 52 and builds a hyperlink request 934 The hyperlmk request class diagram is shown m Figure 44 The hyperlink request records the IDs of the requesting user and pπnter, and identifies the clicked hyperlink mstance 862 The page server then sends its own server ID 53, the hyperlink request ID, and the link ID to the application The application produces a response document accordmg to application-specific logic, and obtams a document ID 51 from an ID server 12 It then sends the document to the page server 10b responsible for the document's newly allocated ID, together with the 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 correspondmg user ID and prmter ID 62 The first page server rejects the request if the hyperlink request has expned or is for a different application The second page server allocates document mstance and page IDs 50, returns the newly allocated page IDs to the application, adds the complete document to its own database, and finally sends the page descnptions to the requesting pπnter The hyperlink mstance may include a meaningful transaction ID 55, m which case the first page server mcludes the transaction ID m the message sent to the application This allows the application to establish a transaction- specific context for the hyperlink activation If the hyperlink reqinres a user alias, 1 e its "alias requned" attnbute is set, then the first page server sends both the pen ID 61 and the hyperlink's application ID 64 to the registration server 11 to obtain not just the user ID conespondmg to the pen ID but also the alias ID 65 conespondmg to the application ID and the user ID It mcludes the alias ID m the message sent to the application, allowing the application to establish a user-specific context for the hyperlink activation 5.3 HANDWRITING RECOGNITION PROTOCOL When a user draws a sfroke on a netpage with a netpage pen, the pen commumcates the stroke to the nearest netpage pπnter The sfroke 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 sfroke path to the page server 10 in 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 sfroke to the text field's digital ink After a penod of inactivity m the zone of the text field, the page server sends the pen ID and the pendmg sfrokes to the registration server 11 for mterpretation The registration server identifies the user correspondmg to the pen, and uses the user's accumulated handwnting model 822 to mterpret the strokes as handwntten text Once it has converted the strokes to text, the regisfration 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 Assummg the mput element whose zone the stroke mtersects is a signature field 880, the page server 10 appends the stroke to the signature field's digital ink After a penod of inactivity m the zone of the signature field, the page server sends the pen ID 61 and the - 34 - pending sfrokes to the registration server 11 for venfication It also sends the application ID 64 associated with the form of which the signature field is part, as well as the form ID 56 and the current data content of the form The registration server identifies the user correspondmg to the pen, and uses the user's dynamic signature biometnc 818 to venfy the sfrokes as the user's signature Once it has venfied the signature, the regisfration 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 correspondmg user This allows a smgle form to capture multiple users' signatures 5.5 FORM SUBMISSION PROTOCOL A preferred embodiment of a form submission protocol is shown m Figure 46 Form submission occurs via a form hyperlmk 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 current data content of the form If the form contams any signature fields, then the application venfies each one by extracting the alias ID 65 associated with the conespondmg digital signature and obtaining the conespondmg certificate from the registration server 11 5.6 COMMISSION PAYMENT PROTOCOL A preferred embodiment of a commission payment protocol is shown m Figure 47 In an e-commerce envnonment, fees and commissions may be payable from an application provider to a publisher on chck-throughs, transactions and sales Commissions on fees and commissions on commissions may also be payable from the publisher to the provider of the pπnter The hyperlink request ID 52 is used to route a fee or commission credit from the target application provider 70a (e g merchant) to the source application provider 70b (l e publisher), and from the source application provider 70b to the pπnter provider 72 The target application receives the hyperlink request ID from the page server 10 when the hyperlink is first activated, as descπbed m Section 5 2 When the target application needs to credit the source application provider, it sends the application provider credit to the ongmal page server together with the hyperlink request ED The page server uses the hyperlink request ID to identify the source application, and sends the credit on to the relevant regisfration server 11 together with the source application ID 64, its own server ID 53, and the hyperlink request ID The registration server credits the conespondmg application provider's account 827 It also notifies the application provider If the application provider needs to credit the pnnter provider, it sends the pπnter provider credit to the ongmal page server together with the hyperlink request ID The page server uses the hyperlink request ID to identify the pπnter, and sends the credit on to the relevant regisfration server together with the pπnter ED The registration server credits the conespondmg pπnter provider account 814 The source application provider is optionally notified of the identity of the target application provider, and the pnnter provider of the identity of the source application provider 6. NETPAGE PEN DESCRIPTION 6.1 PEN MECHANICS Referring to Figures 8 and 9, the pen, generally designated by reference numeral 101, mcludes a housmg 102 m the form of a plastics moulding havmg walls 103 defining an mtenor space 104 for mounting the pen components The pen top 105 is m operation rotatably mounted at one end 106 of the housmg 102 A semi-transparent - 35 - cover 107 is secured to the opposite end 108 of the housmg 102 The cover 107 is also of moulded plastics, and is formed from semi-transparent matenal m order to enable the user to view the status of the LED mounted within the housmg 102 The cover 107 mcludes a mam part 109 which substantially sunounds the end 108 of the housmg 102 and a projecting portion 110 which projects back from the mam part 109 and fits withm a conespondmg slot 111 formed m the walls 103 of the housmg 102 A radio antenna 112 is mounted behmd the projecting portion 110, withm the housmg 102 Screw threads 113 surrounding an aperture 113A on the cover 107 are ananged to receive a metal end piece 114, mcludmg conespondmg screw threads 115 The metal end piece 114 is removable to enable ink cartndge replacement Also mounted withm 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 mk pen cartndge 118 with mb 119 and a stylus 120 with stylus mb 121 are mounted side by side withm the housmg 102 Either the ink cartndge mb 119 or the stylus mb 121 can be brought forward through open end 122 of the metal end piece 114, by rotation of the pen top 105 Respective slider blocks 123 and 124 are mounted to the ink cartndge 118 and stylus 120, respectively A rotatable cam banel 125 is secured to the pen top 105 m operation and ananged to rotate therewith The cam banel 125 mcludes a cam 126 m the form of a slot withm the walls 181 of the cam banel Cam followers 127 and 128 projecting from slider blocks 123 and 124 fit withm the cam slot 126 On rotation of the cam barrel 125, the slider blocks 123 or 124 move relative to each other to project either the pen mb 119 or stylus mb 121 out through the hole 122 m the metal end piece 114 The pen 101 has three states of operation By turning the top 105 through 90° steps, the three states are • Stylus 120 mb 121 out, • Ink cartndge 118 mb 119 out, and • Neither ink cartndge 118 mb 119 out nor stylus 120 mb 121 out A second flex PCB 129, is mounted on an electronics chassis 130 which sits withm the housmg 102 The second flex PCB 129 mounts an mfrared LED 131 for providmg infrared radiation for projection onto the surface An unage sensor 132 is provided mounted on the second flex PCB 129 for receivmg reflected radiation from the surface The second flex PCB 129 also mounts a radio frequency chip 133, which mcludes an RF transmitter and RF receiver, and a controller chip 134 for controlling operation of the pen 101 An optics block 135 (formed from moulded clear plastics) sits withm the cover 107 and projects an mfrared beam onto the surface and receives images onto the image sensor 132 Power supply wires 136 connect the components on the second flex PCB 129 to battery contacts 137 which are mounted within the cam banel 125 A terminal 138 connects to the battery contacts 137 and the cam barrel 125 A three volt rechargeable battery 139 sits withm the cam barrel 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 mfrared LED 143 and mfrared photodiode 144 for detecting displacement m the cam barrel 125 when either the stylus 120 or the ink cartndge 118 is used for writing, m order to enable a determination of the force bemg applied to the surface by the pen mb 119 or stylus nib 121 The IR photodiode 144 detects light from the IR LED 143 via reflectors (not shown) mounted on the slider blocks 123 and 124 Rubber gnp pads 141 and 142 are provided towards the end 108 of the housing 102 to assist gπpping 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 arranged to determme the position of its mb (stylus mb 121 or ink cartndge mb 119) by imaging, m the infrared spectrum, an area of the surface m the vicinity of the mb It records the location data from the nearest location tag, and is arranged to calculate the distance of the nib 121 or 119 from the location tab utilismg optics - 36 - 135 and controller chip 134 The controller chip 134 calculates the onentation of the pen and the nib-to-tag distance from the perspective distortion observed on the imaged tag Utilismg the RF chip 133 and antenna 112 the pen 101 can transmit the digital ink data (which is encrypted for secunty and packaged for efficient transmission) to the computing system When the pen is m range of a receiver, the digital ink data is transmitted as it is formed When the pen 101 moves out of range, digital ink data is buffered within the pen 101 (the pen 101 cncuitry mcludes a buffer arranged 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 illummation LED 131, the IR force sensor LED 143, and the force sensor photodiode 144 The pen controller chip 134 mcludes a controlling processor 145 Bus 146 enables the exchange of data between components of the controller chip 134 Flash memory 147 and a 512 KB DRAM 148 are also included An analog-to-digital converter 149 is arranged to convert the analog signal from the force sensor photodiode 144 to a digital signal An image sensor mterface 152 interfaces with the image sensor 132 A fransceiver controller 153 and base band cncmt 154 are also mcluded to mterface with the RF chip 133 which mcludes an RF cncuit 155 and RF resonators and mductors 156 connected to the antenna 112 The controlling processor 145 captures and decodes location data from tags from the surface via the image sensor 132, momtors the force sensor photodiode 144, controls the LEDs 116, 131 and 143, and handles short-range radio commumcation via the radio transceiver 153 It is a medium-performance (~40MHz) general-purpose RISC processor The processor 145, digital transceiver components (transceiver controller 153 and baseband cncmt 154), unage sensor mterface 152, flash memory 147 and 512KB DRAM 148 are integrated m a smgle controller ASIC Analog RF components (RF cncmt 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 Electromc 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 herein by reference) with an IR filter The controller ASIC 134 enters a quiescent state after a penod of inactivity when the pen 101 is not m contact with a surface It incorporates a dedicated cncmt 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 fransceiver communicates 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 In an alternative embodiment, the pen incorporates 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 pan of orthogonal accelerometers mounted m the normal plane of the pen 101 axis The accelerometers 190 are shown m Figures 9 and 10 m ghost outline The provision of the accelerometers enables this embodiment of the pen 101 to sense motion without reference to surface location tags, allowmg the location tags to be sampled at a lower rate Each location tag ED can then identify an object of mterest rather than a position on the surface For example, if the object is a user mterface mput - 37 - element (e g a command button), then the tag ID of each location tag withm the area of the mput element can dnectly identify the mput element The acceleration measured by the accelerometers m each of the x and y dnections is integrated 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 sfroke are calculated Although position mtegration accumulates enors m the sensed acceleration, accelerometers typically have high resolution, and the time duration of a stroke, over which errors accumulate, is short 7. NETPAGE PRINTER DESCRIPTION 7.1 PRINTER MECHANICS The vertically-mounted netpage wallpnnter 601 is shown fiilly assembled m Figure 11 It pnnts netpages on Letter/A4 sized media usmg duplexed 8V." Memjet™ pnnt 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 pnnt engmes 602 and 603 which pπnt both sides of a sheet simultaneously, m full color and with full bleed An mtegral binding assembly 605 applies a stπp of glue along one edge of each pnnted sheet, allowmg 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 pπnt engmes, has bladders or chambers for storing fixative, adhesive, and cyan, magenta, yellow, black and mfrared inks The cartndge also contams a micro an filter m a base molding The micro an filter interfaces with an an pump 638 mside the pπnter via a hose 639 This provides filtered an to the pπntheads to prevent ingress of micro particles mto the Memjet™ prmtheads 350 which might otherwise clog the prmthead nozzles By incorporating the an 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 pnnting and gluing 3000 pages (1500 sheets) Referring to Figure 12, the motorized media pick-up roller assembly 626 pushes the top sheet dnectly from the media fray past a paper sensor on the first pnnt engine 602 mto the duplexed Memjet™ pnnthead assembly The two Memjet™ pnnt engines 602 and 603 are mounted in an opposmg m-lme sequential configuration along the straight paper path The paper 604 is drawn mto the first pπnt engme 602 by mtegral, powered pick-up rollers 626 The position and size of the paper 604 is sensed and full bleed pπnting commences Fixative is pnnted simultaneously to aid drying m the shortest possible time The paper exits the first Memjet™ pnnt engine 602 through a set of powered exit spike wheels (aligned along the straight paper path), which act against a rubberized roller These spike wheels contact the 'wet' pnnted surface and continue to feed the sheet 604 mto the second Memjet™ pnnt engme 603 Referring to Figures 12 and 12a, the paper 604 passes from the duplexed pnnt engmes 602 and 603 into the binder assembly 605 The pnnted page passes between a powered spike wheel axle 670 with a fibrous support roller and another movable axle with spike wheels and a momentary action glue wheel The movable axle/glue assembly 673 is mounted to a metal support bracket and it is transported forward to interface with the powered axle 670 via gears by action of a camshaft A separate motor powers this camshaft The glue wheel assembly 673 consists of a partially hollow axle 679 with a rotating coupling for the glue supply hose 641 from the ink cartndge 627 This axle 679 connects to a glue wheel, which absorbs adhesive by capillary action through radial holes A molded housmg 682 sunounds the glue wheel, with an opening at the front Pivoting side moldmgs and sprung outer doors are attached to the metal bracket and h ge out sideways when the rest of the assembly 673 is thrust forward This action exposes the glue wheel through the front of the molded housmg 682 Tension springs - 38 - close the assembly and effectively cap the glue wheel duπng 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 controller consists of a controlling processor 750, a factory-installed or field-installed network mterface module 625, a radio transceiver (transceiver confroUer 753, baseband cncmt 754, RF cncmt 755, and RF resonators and mductors 756), dual raster image processor (RIP) DSPs 757, duplexed pnnt engme confrollers 760a and 760b, flash memory 658, and 64MB of DRAM 657, as illustrated m Figure 14 The controlling 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 pπnt engme confrollers 760 It consists of a medium-performance general-purpose microprocessor The controlling processor 750 commumcates with the pnnt engme confrollers 760 via a high-speed senal bus 659 The RIP DSPs rastenze and compress page descnptions to the netpage pπnter' s compressed page format Each pnnt engme controller expands, dithers and pnnts page images to its associated Memjet™ pnnthead 350 m real time (l e at over 30 pages per minute) The duplexed pnnt engme confrollers pπnt both sides of a sheet simultaneously The master pπnt engme controller 760a controls the paper transport and momtors ink usage m conjunction with the master QA chip 665 and the ink cartndge QA chip 761 The pnnter controller's flash memory 658 holds the software for both the processor 750 and the DSPs 757, as well as configuration data This is copied to mam memory 657 at boot time The processor 750, DSPs 757, and digital fransceiver components (transceiver controller 753 and baseband cncmt 754) are integrated m a smgle controller ASIC 656 Analog RF components (RF cncmt 755 and RF resonators and mductors 756) are provided m a separate RF chip 762 The network mterface module 625 is separate, smce netpage pnnters allow the network connection to be factory-selected or field-selected Flash memory 658 and the 2x256Mbit (64MB) DRAM 657 is also off-chip The pnnt engme controllers 760 are provided m separate ASICs A vanety of network mterface modules 625 are provided, each providmg a netpage network interface 751 and optionally a local computer or network mterface 752 Netpage network Internet interfaces mclude POTS modems, Hybπd Fiber-Coax (HFC) cable modems, ISDN modems, DSL modems, satellite transceivers, cunent and next- generation cellular telephone transceivers, and wireless local loop (WLL) transceivers Local interfaces mclude IEEE 1284 (parallel port), lOBase-T and 100Base-T Ethernet, USB and USB 2 0, IEEE 1394 (Fnewne), and vanous emergmg home networking interfaces If an Internet connection is available on the local network, then the local network mterface can be used as the netpage network mterface The radio fransceiver 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 hopping 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 pπnter uses the IrDA mterface for short-range commumcation with suitably configured netpage pens 7.2.1 RASTERIZATION AND PRINTING Once the mam processor 750 has received and venfied the document's page layouts and page objects, it runs the appropnate RIP software on the DSPs 757 The DSPs 757 rastenze each page descnption and compress the rastenzed page image The mam processor stores each compressed page image m memory The simplest way to load-balance multiple DSPs is to let each DSP - 39 - rastenze a separate page The DSPs can always be kept busy smce an arbifrary number of rastenzed pages can, in general, be stored in memory This strategy only leads to potentially poor DSP utilization when rastenzmg short documents Watermark regions m the page descnption 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 pnnted page contams coded netpage tags at a density of about six per mch Each tag encodes the page ED, tag ED, and control bits, and the data content of each tag is generated durmg rasterization and stored m the compressed page image The main processor 750 passes back-to-back page images to the duplexed pπnt engme confrollers 760 Each pπnt engme confroUer 760 stores the compressed page image m its local memory, and starts the page expansion and pπnting pipeline Page expansion and pnnting is pipelined because it is unpractical to store an entire 114MB bi-level CMYK+IR page image m memory 7.2.2 PRINT ENGINE CONTROLLER The page expansion and pnnting pipeline of the pnnt engme controller 760 consists of a high speed IEEE 1394 seπal 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 pπnt 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 pπnt engme controller pipeline Once the page has finished pπnting, the page just loaded is pnnted while another page is loaded The first stage of the pipeline expands (at 763) the JPEG-compressed contone CMYK layer, expands (at 764) the Group 4 Fax-compressed bi-level black layer, and renders (at 766) the bi-level netpage tag layer accordmg to the tag format defined in section 1 2, all m parallel The second stage dithers (at 765) the contone CMYK layer and composites (at 765) the bi-level black layer over the resulting bi-level CMYK layer The resultant bi-level CMYK+IR dot data is buffered and.formatted (at 767) for pnnting on the Memjet™ pnnthead 350 via a set of lme buffers Most of these line buffers are stored m the off-chip DRAM The final stage pnnts the six channels of bi-level dot data (mcludmg fixative) to the Memjet™ pnnthead 350 via the pnnthead interface 768 When several pnnt engme confrollers 760 are used m unison, such as m a duplexed configuration, they are synchronized via a shared lme sync signal 770 Only one pπnt engine 760, selected via the external master/slave pm 771, generates the lme sync signal 770 onto the shared lme The pnnt 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 controlling the stepper motors 675, 676 In the 8! " versions of the netpage pnnter, the two pπnt engmes each pnnts 30 Letter pages per minute along the long dimension of the page (11"), givmg a line rate of 8 8 kHz at 1600 dpi In the 12" versions of the netpage pnnter, the two pnnt engmes each pnnts 45 Letter pages per mmute along the short dimension of the page (8! "), givmg a lme rate of 10 2 kHz These lme rates are well within the operatmg frequency of the Memjet™ pnnthead, which m the cunent design exceeds 30 kHz 8 NETPAGE FACSIMILE This section descnbes facsimile message delivery through the netpage system - 40 - 8.1 APPLICATION DRAWING NOTATION Each application user mterface flow is illustrated as a collection of documents linked by command anows A command anow mdicates that the target document is pnnted as a result of the user pressmg the conespondmg command button on the source page Some command arrows are labelled with multiple commands separated by slashes Ct's), mdicatmg that any one of the specified commands causes the target document to be pnnted Although multiple commands may label the same command arrow, they typically have different side-effects In application terms, it is important to distinguish between netpage documents and netpage forms Documents contam pnnted information, as well as command buttons which can be pressed by the user to request further information or some other action Forms, m addition to behaving like normal documents, also contam mput fields which can be filled m by the user They provide the system with a data mput mechanism It is also useful to distinguish between documents which contam genenc information and documents which contam information specific to a particular mteraction between the user and an application Genenc documents may be pre-pnnted publications such as magazmes sold at news stands or advertismg posters encountered m public places Forms may also be pre-pnnted, mcludmg, for example, subscnption forms encountered m pre-pnnted publications They may, of course, also be generated on-the-fly by a netpage pnnter m response to user requests User-specific documents and forms are normally generated on the fly by a netpage pnnter m response to user requests Figure 48 shows a genenc document 990, a genenc form 991, a user- specific document 992, and a user-specific form 993 Netpages which participate m a user mterface flow are further descnbed by abstract page layouts A page layout may contam vanous lands of elements, each of which has a umque style to differentiate it from the others As shown m Figure 49, these mclude fixed information 994, vanable information 995, mput fields 996, command buttons 997, and draggable commands 998 When a user mterface flow is broken up mto multiple diagrams, any document which is duplicated is shown with dashed outlines m all but the mam diagram which defines it 8.2 NETPAGE FACSIMILE Referring firstly to Figure 50, a netpage facsimile (fax) application 500 allows a netpage user 501 to compose and send a simple two-page message to a remote fax machine 502 The fax application 500 optionally allows the fax recipient to send a reply to the netpage user, indicated by dashed line 503 usmg a one-time-use reply number The reply is delivered through the netpage pπnter through which the user submits the ongmal fax message The netpage electronic mail (e-mail) application 504 allows a netpage user to send a complex multi-page e- mail message to the remote fax machine 502, by addressing the e-mail message to a fax contact m the user's contact list Both applications 500,504 send faxes via a fax server 505, as illustrated m Figure 1 The fax server formats pages for fax delivery, renders them as bi-level bitmaps suitable for fax transmission, dials and connects to the remote fax machme via the telephone network, and encodes and transmits the bitmaps accordmg to the Group 3 or Group 4 fax protocol (ANSI/EIA 538-1988, Facsimile Coding Schemes and Coding Control Functions for Group 4 Facsimile Equipment, August 1988) depending on the capabilities of the remote fax machine 8.2.1 Simple Fax 8.2.1.1 Object Model The fax class diagram is shown m Figure 51 An outgomg fax 506, created by a netpage user 501, specifies the fax number 507 of the recipient, and consists of one or more pages, each of which records the digital mk of the conespondmg part of the message The outgomg fax also records the time it is sent The fax number is converted from hand-wntten text so that the fax server can dial the number to deliver the fax The message, however, is retained as digital ink so it is delivered exactly as wntten or drawn - 41 - If the user specifies that the recipient is allowed to reply, then the fax application allocates a umque onetime-use reply sequence number, records it m a pendmg fax reply 508, and enters the pendmg fax reply m a pendmg fax reply list 509 It uses the pendmg fax reply list to match mconung faxes 510 with pendmg replies The pendmg fax reply is associated with the pπnter 802 through which the outgomg fax is submitted, thus specifying where the subsequent mconung fax reply is to be delivered The pendmg fax reply has an expiry time, after which a reply is not accepted, to prevent abuse of reply numbers Once an mconung fax is received, the expiry time is adjusted backwards so that there is sufficient time for the recipient to immediately send additional pages m case of a transmission problem, but no future pages An mconung fax 510 consists of one or more pages 512, each of which records the bi-level bitmap of the correspondmg message It also records the time it is received 8.2.1.2 User Interface The fax sending user mterface flow is illustrated m Figure 53 The two sides of the fax composition form 513 are illustrated m Figures 54 and 55 To send a fax, the user obtams a blank composition form 513 from the netpage help page 514 or via the <blank form> button 515 on an existing composition form, fills m the recipient's fax number 516, checks the "allow reply" checkbox 517 if the recipient is to be allowed to reply, hand-wntes the message m the message field 518, and presses the <send> button 519 To send a two-page message, the user hand-wntes an additional part of the message m the message field on the back 520 of the form The fax application converts the hand-wntten fax number to text and sends the fax to the fax server 505 for delivery The format of the fax 530 received by the recipient is illustrated m Figures 56 and 57 The fax reply number 521 which appears on the received fax page consists of one of the fax server's mconung fax numbers followed by the reply sequence number It only appears if the recipient is allowed to reply The recipient replies by dialling the entire reply number The fax server captures the tone-dialled reply sequence number suffix and forwards it to the fax application 500 The application then uses it to identity the conespondmg pendmg fax reply and hence the appropnate netpage pπnter 8.2.2 E-mail Fax 8.2.2.1 Object Model E-mail fax is an extension of netpage e-mail An e-mail message is delivered to a remote fax machine 502 if one of the recipients of the e-mail is a fax user with a conespondmg fax number The e-mail user class diagram, extended to mclude the fax user, is shown m Figure 52 Each fax user 522 has a name 523, used to present the fax user m the netpage user's contact list, and a fax number 524 8.2.2.2 User Interface The fax contact regisfration user mterface flow is illustrated m Figure 58 The fax contact registration form 525 is illustrated m Figure 59 To register a new fax contact, the user obtams a blank regisfration form from the netpage help page 514 or via the <blank form> button 527 on an existing regisfration form, fills m the fax contact's name and fax number, and presses the <submιt> button 528 The e-mail application converts the hand-wntten name and fax number to text and adds the fax contact to the user's e-mail contact list It pnnts an updated contact list page showing the new entry To send an e-mail to a fax recipient, the user addresses the e-mail to a fax contact m the user's contact list CONCLUSION The present mvention has been descnbed with reference to a prefened embodiment and number of specific alternative embodiments However, it will be appreciated by those skilled in the relevant fields that a number of other embodiments, differing from those specifically descπbed, will also fall withm the spint and scope of the present - 42 - mvention Accordmgly, it will be understood that the mvention is not mtended to be Imuted to the specific embodiments descπbed m the present specification, mcludmg documents mcorporated by cross-reference as appropnate The scope of the invention is only limited by the attached claims

Claims: - 43 - CLAIMS 1 A method of delivering a facsimile, mcludmg providing a pnnted form for entering a message thereon usmg a sensmg device adapted to read coded data on the form, receivmg, m a computer system, mteraction data representing mteraction of the sensmg device with the coded data, the mteraction data allowmg the message to be elecfromcally captured in the computer system, and transmitting the message to a designated recipient address for facsimile delivery 2 A method as claimed m claim 1, wherem the message is delivered with a reply number for sending a return message, the reply number bemg valid for a predetermined time only 3 A method as claimed m claim 2, wherem a sender of the message mdicates on the form, usmg the sensmg device, whether a reply number is to be transmitted with the message 4 A method as claimed m claim 1 , wherem the recipient address is entered on the form m wnting, usmg the sensmg device, and the wnting is elecfromcally captured and converted mto digital form to facilitate transmission of the message 5 A method as claimed m claim 1 , wherem the recipient address is selected from a document provided with an address list and associated user mteractive elements with which the sensmg device is adapted to interact m order to select the address 6 A method as claimed m claim 1 , mcludmg receivmg, m the computer system, mdicatmg data denved from the coded data, regardmg the identity of the form and a position of the sensmg device relative to the form m order to identify the form and determme when the sensmg device is used to mteract with the form 7 A method as claimed m claim 6, mcludmg receivmg, m the computer system, movement data regardmg movement of the sensmg device relative to the form 8 A method as claimed m claim 7, mcludmg the sensmg device sensmg its movement relative to the form usmg the coded data 9 A method as claimed m claim 6, mcludmg pnnting the form on a surface of a surface-defining structure, and at the same time, pnnting the coded data on the surface 10 A method as claimed m claim 6 which mcludes pπnting the coded data to be substantially invisible m the visible spectrum 11 A method as claimed in claim 6, mcludmg retaining a retπevable record of the pnnted form, the form bemg retnevable usmg the identify data as contained m the coded data 12 A system for delivering a facsimile, mcludmg a pnnter for pnnting a form with coded data, a sensmg device for reading the coded data and transmitting mteraction data, representing mteraction of the sensing device with the coded data, to allow for electronic capture of a message generated by movmg the device relative to the form, and a computer system for receivmg the mteraction data from the device and transmitting the message to an address for facsimile delivery 13 A system as claimed m claun 12, wherem the computer system is adapted to deliver the message with a reply number, valid for a predetermined tune only 14 A system as claimed m claim 13, wherem the computer system includes the reply number dependent upon a sender's instruction, indicated by mteraction of the device with an appropnate user mteractive element on the form - 44 - 15 A system as claimed m claim 13, wherem the computer system mcludes a fax application for receivmg and formatting the message for transmission to a fax server, the fax application further servmg to allocate the reply number 16 A system as claimed m claim 12, wherem the coded data serves to identify the form and at least one pomt of the form 17 A system as claimed m claim 12, wherem the computer system is adapted to receive movement data regardmg movement of the sensmg device relative to the coded data, m order to capture the message 18 A system as claimed m claim 17, wherem the sensmg device senses its own movement relative to the document usmg the coded data 19 A system as claimed m claim 14, wherem the sensmg device mcludes a marking mb 20 A system as claimed m claim 14, wherem the document is pnnted on a surface of a surface-defining structure and wherem the pnnter pnnts the document on demand 21 A system as claimed m claim 19, wherem the pnnter is arranged to pnnt the coded data at the same time as pnnting the document on a surface-defining structure 22 A system as claimed m claim 19, wherem the coded data is substantially invisible m the visible spectrum 23 The system as claimed m claim 19, mcludmg a database for keeping a retnevable record of each document generated, each document bemg retnevable by usmg its identity, as mcluded m its coded data 24 The system as claimed m claim 14, wherem the prmter mcludes a binding means for binding the pnnted forni m the event the form mcludes a plurality of pages

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: H04N1
IPC codes: B41J2, B41J5, B41J13, B41J21, B41J29, B42C9, B42C19, B42D15, B65H29, B65H37, G06F3, G06F13, G06F17, G06F21, G06K9, G06K17, G06K19, G06Q10, G06Q30, G06Q50, G06T1, G06T11, G08C17, H04L9, H04N1