THE PRESENT INVENTION relates to a toy or educational device and seeks to provide a novel toy or educational device which will retain the attention of a person using the toy or educational device.

According to one aspect of this invention there is provided a toy or educational device comprising a substrate carrying printing, sensor means adapted to sense where a finger touches the substrate and a voice synthesizer formed integrally with the device adapted to emit a sound corresponding to the sound of a human voice in response to the substrate being touched.

Preferably the sensor is carried by a second substrate located under the said substrate which is adapted to be touched.

In one embodiment the substrate is the board for a board game, the board carrying the said voice synthesizer.

In an alternative embodiment the substrate forms a page in a book, the book carrying the voice synthesizer.

Preferably, in this embodiment, the voice synthesizer is mounted in the spine of the book.

According to another aspect of this invention there is provided a toy or educational device comprising a substrate carrying printing sensor means carried on the substrate adapted to sense where a finger touches the substrate and means formed integrally with, or associated with, the device adapted to emit a predetermined sound in

response to a finger touching the substrate in a predetermined area.

In one embodiment the sensor comprises a grid of intersecting mutually insulated conductive elements, means being provided to interrogate the elements to determine when a finger is in contact with or immediately adjacent said grid and to locate the position of the finger.

In a preferred embodiment the sensor comprises an elongate conductive path provided on the substrate, means being provided to respond to a finger touching or immediately adjacent the conductive path.

Preferably the conductive path is provided with a plurality of enlarged areas or "icons" intermediate its ends.

Advantageously the sensor is over-printed with a conductive ink.

In one embodiment apertures or holes are formed in parts of the conductive ink overlying selected regions of the conductive path. In a further embodiment the conductive path is visible and forms an integral part of an illustration.

In certain embodiments the conductive path is laminated within the substrate.

According to another aspect of this invention there is provided a sensor adapted to sense where a finger touches a substrate, the sensor comprising an elongate conductive path provided on the substrate, means being provided to determine the point at which, along said

elongate path, a finger touches the conductive path or is brought into close proximity with the conductive path.

Preferably the conductive path is visible and forms part of an illustration present upon the substrate, means being provided to determine the position of a finger touching the conductive path due to the impedance as determined from each end of the conductive path.

Alternatively the conductive path is an elongate path provided with a plurality of enlarged areas or "icons", means being provided to determine, by measuring the impedance at each end of the path, which icon is being touched by a finger, or adjacent which icon a finger is located.

Preferably the conductive path is substantially covered with non-conductive ink forming an illustration or the like. In certain embodiments the said conductive ink is provided with one or more apertures aligned with selected parts of the conductive path.

Preferably the conductive path is printed on the substrate. Preferably the conductive path is laminated within the substrate.

Advantageously the substrate forms part of a book or part of the board of a board game.

According to another aspect of this invention there is provided a toy or educational device or greeting card comprising a book, card or magazine carrying printing and carrying sensor means adapted to sense where a finger touches a page of the book, and means adapted to emit a

predetermined audible response to a page of the book or magazine being touched within a predetermined area.

The means to emit said predetermined audible response may comprise a voice synthesizer.

The sensor means may comprise a capacitive sensor means or a resistive sensor means. The sensor may comprise one or more elongate conductive paths provided on the book, means being provided to respond to a finger touching or immediately adjacent the or each conductive path.

One embodiment of the invention may comprise a book or magazine wherein the sensor means comprise one or more conductive tracks mounted on or adjacent the outer cover of the book or magazine. Alternatively the sensor means may be mounted on a plurality of pages within the book or magazine, each page provided with a sensor means carrying at least one conductive track which forms the sensor means.

In one embodiment of the invention a computer is provided adapted to display a predetermined image in response to a page of the book or magazine being touched at a predetermined area.

Means, including a plug and socket connection may be provided for physically connecting the book or magazine to the computer, but alternatively the book or magazine is provided with means adapted to transmit a signal in response to a page of the book or magazine being touched at a predetermined area, the computer or the like being provided with means adapted to receive and process the signal transmitted by the book or magazine. The transmitting means may comprise optical transmitting means.

although, in a modified embodiment, may comprise alternate electro-magnetic transmitting means.

According to a further aspect of this invention there is provided a toy or educational device comprising a book carrying printing, sensor means carried on the book and mounted on or adjacent the back cover of the book to sense where a finger touches a page, to identify the page and subsequently to sense where a finger touches one of the selected plurality of predetermined areas on the page, and means associated with the book to emit a predetermined sound in response to a page of the book being touched at a predetermined area.

The means associated with the book may be mounted on the book, for example, being contained within a housing which is mounted in a cover of the book or mounted within the spine of the book, but alternatively the means associated with the book may be separated from the book, means being provided to pass signals from the book to the said means associated with the book. An electrical connection, including a plug and socket, extend between the book and the said means associated with the book. Alternatively, the book may be provided with means adapted to transmit signals in response to a finger touching a predetermined area on a page of the book, the said means associated with the book being provided with means adapted to receive signals.

In such an arrangement, the signals may be indicative of the area of the page that has been touched, and the said means associated with the book may contain a memory storing signal as appropriate to be passed to sound generating means when each area is touched. Alternatively the signals are directly representative of the sound to be

emitted, the means associated with the book being arranged so that the received signal is passed directly to the sound emitting means, the book carrying memory storing data corresponding to the audible signals to be generated when any predetermined area of a page is touched.

According to another aspect of this invention there is provided a toy or educational device comprising a book or magazine, the book carrying printing, and carrying sensor means adapted to sense where a finger touches a page of the book, means being provided to transmit data indicative of where a finger touches a page of the book to a separate housing, the separate housing containing or being associated with memory means and being adapted to emit a predetermined audible message in response to a predetermined area of a predetermined page of the book being touched. The memory may comprise ROM or RAM, which may be replaceable. Alternatively the memory may comprise a tape or disc, the housing containing or being associated with a tape player or disc reader.

According to another aspect of this invention there is provided a toy or educational device comprising a book carrying printing and carrying sensor means adapted to sense where a finger touches one of a plurality of predetermined areas on each of a plurality of pages, means being provided to transmit signals from the book indicative of where a finger touches a page to a radio or television receiver assembly, the assembly being adapted to receive and store further transmitted signals, and being adapted to pass the stored signals selectively to an audio output or an audio-visual output under the control of the said signals transmitted from the book. Preferably the said receiver is provided with means adapted to receive signal segments which are preceded by a code identifying signal

segments, the receiver comprising decoding means, memory means, a processor and an audio or audio/visual output, the arrangement being such that when a code is received, the code is decoded and the process passes the following signal either to memory or to the audio or audio/visual output.

Alternatively the receiver assembly is adapted to receive signals on a plurality of channels, the signal from one channel being fed directly to the audio or audio/visual output and signals from the other channels being fed to memory. The channels may be time-multiplexed channels.

The receiver may be adapted to receive control signals, the receiver being adapted to pass the control signals to the memory, in such a way that the control signals can control the functioning of the process.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which

FIGURE 1 is a perspective view, with parts thereof cut away, of a book in accordance with the invention,

FIGURE 2 is a view of a conductive track which forms part of the book of Figure 1,

FIGURE 3 is a view of an alternative form of conductive track which forms part of the book of Figure 1,

FIGURE 4 is a view of another form of conductive track which forms part of the book of Figure 1,

FIGURE 5 is a perspective view of another embodiment of a book in accordance with the invention,

FIGURE 6 is a view of the book of Figure 5 opened to reveal the rear cover of the book,

FIGURE 7 illustrates another book in accordance with the invention, similar to that of Figure 5, with an associated item of equipment,

FIGURE 8 illustrates another book, similar to that of Figure 5, and further associated equipment, and

FIGURE 9 illustrates another book, similar to that of Figure 5, with further associated equipment.

The invention will be described initially with reference to an embodiment of the invention which is in the form of a book 1. The book has, as is conventional, outer covers 2,3 inter-connected by a spine 4, and carries a number of pages 5. Some of the pages, such as the illustrated page on the left-hand side of the book 6, carry text, whereas some pages, such as the page 7 on the left- hand side of the book may carry pictures or illustrations. Of course, a page carrying illustrations may also carry printed text.

In the illustrated embodiment of the invention the page 7 carrying the illustration, carries a picture of a house 8 having a chimney 9, and a door 10, there being two bushes 11,12 located in the front of the house.

As can be seen from Figure 1, a housing 13 is secured to the spine of the book. The housing 13 may have a different location, and may, for example, be embedded in

one of the outer covers of the book. The housing 13 contains a micro-processor or the like, associated with an appropriate memory and a speech synthesizer, and a battery. The housing is accessible to enable the battery to be replaced. The speech synthesizer may be adapted truly to synthesise speech from data provided from the micro¬ processor or may produce recorded sound which has been digitised, the micro-processor storing, in an associated memory, digital data relating to the recorded sound. In each case the speech synthesizer is associated with a transducer, such as a Piezo electric transducer and the effect of the speech synthesizer is to cause the transducer to emit sound which is recognisable, by the human ear, as speech. The housing 13 is provided with apertures to permit sound from the transducer to be emitted from the housing, and the housing is positioned so that a person using the book can readily hear sound from the transducer.

A sensor arrangement is provided as will be described hereinafter in greater detail, which responds to a finger touching part of the illustration, which can effectively control the speech synthesizer.

It is envisaged, therefore, that the book may provide a printed instruction, present in the text either on the page shown to the left-hand side of the .book, page 5, or the page shown at the right-hand side of the book, page 6, which, for example, instructs a person reading the book to touch the house. If the house is touched the speech synthesizer will issue a message confirming that the correct item has been touched. Thus the speech synthesizer may emit sound corresponding to the words "Yes, that is the house - well done!". However, if the house is not touched the speech synthesizer may emit sound corresponding to the words "That was not the house -

try again!". It will be appreciated that the speech synthesizer may emit sounds corresponding to various messages depending upon the content of the illustrations present in the book.

It is to be appreciated that each page of the book which carries illustrations which are intended to be touched in the manner described above may carry a sensor which is such that when a predetermined area of the page is touched, for example the area carrying the page number, the voice synthesizer is activated with a specific message providing instructions as to what the person reading the book is to do. Thus, in the example set out above, when the page number is initially touched an instruction may be given "Can you put your finger on the house?". Depending upon whether the reader of the book puts his/her finger on the house or on some other part of the illustration, then an appropriate message may be given by the voice synthesizer. When all the required parts of the picture have been touched correctly, the voice synthesizer may give a message such as "Now proceed to the next page".

In the example given thus far the book would be intended for reading by relatively young people, and the illustration might be considered, for example, to be an illustration of the home of Snow White, the two bushes in front of the house being respectively the red rose-bush and the white rose-bush. However, it is to be appreciated that a book of the type being described may find many valuable applications as an educational device. The illustration may, therefore, be a cross-sectional view of a biological specimen, and the person reading the book may be required to identify the various parts of the specimen by touching the appropriate parts of the specimen when requested so to do. Indeed, it is envisaged that the page carrying the

sensors (which will be described hereinafter) need not necessarily carry an illustration, but may carry printed material. For example the page may carry a mathematical problem and three or four possible answers to the problem. The person reading the book may be asked to touch an answer believed to be the correct answer. Depending upon which answer is touched, the voice synthesizer will be able to provide valuable information to the person using the book.

Many other uses for the general arrangement described herein may readily be devised.

Turning now to Figure 2 of the accompanying drawings, there is illustrated a conductive track applied to the illustrated page 6 of the book of Figure 1. The track 20 is an elongate track which is formed of a conductive material printed on to the page. Many conductive inks are available for this purpose. The track 20 is of elongate form and comprises various thin track elements 21, and various enlarged areas or "icons" 22,23,24,25.

It can be seen that one enlarged area 24 is located where the page number is printed on the book. The other enlarged areas have a shape corresponding to and a position corresponding to the house 8 and the two bushes 11 and 12. It is envisaged that the track will be printed on the page initially, and then the illustration will be printed on top of the track. The illustration may totally mask the track and the illustration may be formed of non-conductive ink. In such an embodiment, therefore, a person looking at the printed page would not necessarily realise that the conductive track was present on the page. The two ends of the conductive track 20 are connected, by appropriate

wires, to the micro-processor contained within the housing 5.

The effect of a finger touching one of the "icons" mentioned above, is to apply a capacitive coupling to earth to that icon. Because of the nature of the track 20 the resistance between one end of the track and that particular icon has a predetermined value and a resistance between that particular icon and the other end of the track has a predetermined value. Therefore, by determining the impedance of the path from each end of the path, it is possible to determine precisely which icon is being touched or pointed-at, at any particular instant.

Figure 3 illustrates a modified of conductive track, which corresponds to the" track 20 of Figure 2, but instead of having one large icon 22 for the house, separate icons are provided for the chimney 26 and the door 27 of the house. If a track of this type is used it is envisaged that the device may be adapted to work not on capacitive coupling, but on actual touching of the conductive track. Thus, in this case, the illustration printed on top of the track would be of electrically resistive ink, but certain "holes" would be left in the illustration where the conductive track is exposed to view. These holes may correspond with part of the chimney and part of the door of the house. Also, of course, holes would be provided associated with the two bushes. It is envisaged, therefore, in this embodiment of the invention that a person may be invited to touch the chimney of the house. If a finger is pressed against the part of the illustration corresponding to the chimney of the house the finger will touch the conductive track. This has the effect of applying an earth potential to the appropriate icon on the track. Again, by measuring the impedance of the track from

each end of the track, it is possible to determine which icon is being touched.

Whilst in the embodiments of the invention described above, the conductive track is applied to the page and subsequently an illustration is applied to the page which substantially masks the conductive track, it is possible that the conductive track may form part of the illustration, especially if the illustration is a "line" illustration or incorporates lines.

Thus, as shown in Figure 4, the conductive track 29 may be an elongate track which forms a substantial part of the periphery of the house and each of the bushes. Of course, these various components of the illustration have to be inter-connected, but a suitable route for the inter¬ connecting parts of the conductive track may no doubt be found within a typical illustration. Thus the part of the illustration itself may be formed of the conductive track, and other parts of the illustration may be formed from the same conductive ink, these parts of the illustration not being in electrical contact with the illustrated conductive track. However, non-conductive ink may be preferred for the remaining ■parts of the illustration. In use of this embodiment a person using the book must be invited to touch the edge of the house or the edge of the bush, for example, but again when the conductive track is touched, the point at which the track is touched is brought to earth potential, and by determining the impedance from each end of the track, it is possible to determine the precise location of the point at which the track is touched.

The various impedance measuring functions mentioned above can be performed automatically by the micro-processor in a straightforward manner.

Whilst the invention has thus far been described with reference to a sensor of a particular type provided in a page of a book, it is to be appreciated that other types of sensor may be used. For example, a sensor comprising rows and columns of conductive tracks, which are insulated from each other, (which thus comprises a grid of intersecting mutually insulated elements) may be used, so that wherever a finger is placed on the illustration it is possible for the sensor to determine the position of the finger. One possible disadvantage of a sensor of this type is that a very large number of connections have to be made between the ends of the conductive rows and columns and the micro-processor. The embodiment described above utilises only two connections between the track on each page and the micro-processor.

Instead of the sensor comprising conductive tracks printed on the page, the sensor may comprise elements laminated within the page. The elements may be printed on thin sheets of paper, and the sheets may then be adhered to one another to form thick pages with the conductive elements sandwiched or laminated in the centre of the page, thus protecting the conductive elements and also rendering the conductive elements practically invisible.

Instead of having a separate sensor incorporated in each page which is intended to be touched, a single sensor could be provided in one page which would be adequate to locate a finger touching that page or a finger touching one of several pages located on top of that page. Thus, a sensor may be provided, for example, every tenth page within the book. Such a sensor should preferably be a capacitative sensor, since it will not be possible for the sensor to be touched by the person using the book. In this embodiment of the invention it would, of . course, be

preferable for the page numbers present on the pages of the book each to have a unique location so that when a person touches the page number of a specific page their finger is in a unique position thus enabling the sensor and the associated micro-processor to identify accurately the number of the page in use.

Figure 5 illustrates a book 30 which comprises a second embodiment of the invention, and Figure 6 illustrates the book 30 open to reveal the interior of the rear cover of the book.

In this embodiment of the invention the rear cover of the book is provided with a sensor array. The sensor array, as illustrated, comprises a plurality of conductive areas 31 of a relatively large size at diverse positions on the inside of the rear cover of the book and the plurality of smaller areas 32 located in a row adjacent the top of the rear cover of the book. The conductive areas are all connected by appropriate conductive tracks to circuitry within a housing 33 which is embedded in the back of the book. The conductive areas may be on a single elongate track, like the track of Figures 2 and 3.

The housing 33 contains a battery, and part of the cover of the housing may be readily removable to permit replacement of the battery. The housing 33 also contains a memory and a speech synthesizer of the type described above, together with an appropriate micro-processor or the like. The speech synthesizer is associated with Piezo electric transducer located within the housing adjacent part of the housing 33 which is provided with apertures 34 which permit sound from the transducer to emanate from the housing 33.

It is to be appreciated that a corresponding sensor array, including areas corresponding to the areas 31 and areas corresponding to the areas 32, may be provided on the inside of a front cover of the book, with the conductive areas of that array also being connected to the circuitry within the housing 33.

It can be observed, from Figure 5, that when the book is opened, various marks 35 are provided on the exposed pages, substantially aligned with the areas 32 of the sensor array. A person using the book must place a finger on each of the marks 35 simultaneously, and the presence of the fingers is detected capacitatively by the sensor array. Thus, when the book is open, as illustrated in Figure 5, when a finger is placed adjacent each of the two marks 35, effectively the fingers are located adjacent two of the conductive elements 32. The presence of the fingers adjacent those two elements will be detected, and the micro-processor contained within the housing 33 will then be able to determine precisely which page of the book is open. Each page is provided with a unique combination of marks 35.

It can be seen that in this example the book is provided with illustrations 36 which are substantially aligned with the areas 31 of the sensor array. When any one of the illustrations 36 is touched by a finger, that finger will be detected capacitatively as being adjacent a specific one of the conductive areas 31 of the sensor array, and the micro-processor contained within the housing 33 will be able to determine an audible message which is to be effectively transmitted to the user of the book through the transducer that forms part of the speech synthesizer within the housing 33.

It is envisaged that when a book is opened at a specific page, the person using the book will touch the marks 35 to indicate to the micro-processor which page is open. The micro-processor then may issue an audible instruction for the person using the book to perform a certain act, for example, touching one of the illustrations present in the book, or the text of the book may provide the instruction. When a person touches an illustration, an appropriate response is generated by the micro-processor and transmitted through the speech synthesizer.

The book of Figures 5 and 6 presents an advantage over the book of Figure 1 in that only a single sensor array, provided in the covers of the book, need be provided and only this single array need be connected to the housing containing the micro-processor. In the embodiment of Figure l the signal tracks present on each page of the book need be connected to the micro-processor, which involves a significant amount of relatively complex wiring, whereas in the embodiment of Figures 5 and 6 only one sensor array is connected to the circuitry, which means that the wiring is relatively simple. Of course the sensors may be provided in pages located at the beginning and end of the book, instead of being in the actual covers of the book.

It is to be appreciated that, whilst in the fore¬ going description reference has been made to a book, having an outer cover and a plurality of pages, the book may be a very simple publication and may even simply comprise a Greetings Card or the like. The Greetings Card may invite the recipient to touch various parts of an image present on the Greetings Card, and in response to different parts of the image being touched, different audible messages will be given by the Greetings Card.

Whilst, in the embodiments described above, the micro-processor, the associated memory, and the voice synthesizer have all been mounted on the book, so that the book, together with all these components, is manufactured and sold as a single integral entity, Figure 7 illustrates a modified embodiment of the invention which incorporates a book very similar to that illustrated in Figure 5 with the exception that the housing 33 is not provided with a transducer, but instead is provided with an exposed light- emitter 37. Associated with the book is a separate housing 38 which is provided with a light detector 39 and a transducer which is located adjacent an apertured region 40 of the housing 38 to permit sound to emanate from the housing 38.

In the embodiment of Figure 7 it is envisaged that the back of the book will be provided with a sensor array comprising the conductive areas 31 and 32 as described with reference to Figure 6. Contained within the housing 33 is a micro-processor and a memory arrangement. When the micro-processor wishes an audible signal to be generated, the appropriate signals are appropriately encoded and are passed to the light-emitter, the signals being emitted as encoded light. The encoded light is detected by the detector 39, and is passed to a voice synthesizer within the housing 38. The appropriate sound emanates from the housing through the apertures 40.

Because the voice synthesizer and the transducer are not present on the book it is possible to use the housing 38 with a plurality of different books. This means that,- from an economic point of view, the quality of the voice synthesizer and the transducer may be enhanced, since a single voice synthesizer and transducer may be used with a relatively large number of books.

Whilst, in the embodiment of Figure 7, the effective link between the book and the housing 38 is described as being an optical link, other types of link could be utilised such as a link involving electro-magnetic radiation, in which case the book would be provided with a low power radio transmitter and the housing 38 would be provided with a radio receiver, or even a wire may be provided which extends from the housing 38 and plugs into the book or which extends from the book and plugs into the housing 38. If this expedient is adopted it is possible that the book may be totally passive and not include a power source such as a battery, the necessary power being supplied to the book through the wire and plug-and-socket connection.

The embodiment of Figure 7 may be further modified, with the housing 33 present on the book not containing any "memory" containing information concerning the audible messages to be emanated. Thus the housing 33 would simply contain an appropriate circuit to determine which page of the book is open and precisely where a finger is touching the page, the circuit being adapted to transmit appropriately coded information to the housing 38. The housing 39 would then be provided with means to receive an appropriate "memory" containing the various messages to be transmitted. This may be in the form of a plug-in ROM (Read Only Memory) which is supplied together with the book and which is plugged into an appropriate socket within the housing 38 whenever the specific book is to be used, or may comprise another conventional data storage medium such as a tape cassette, or a magnetic or optical disc, which is supplied to the book and which is inserted into an appropriate tape-player, or disc-reader which is associated with the housing 38. One advantage of using this expedient would be that a much greater amount of data could be

available for use at an economic price, than if the data is stored in integrated circuit memory which is mounted on the book.

It will thus be appreciated that the transducer may be mounted on the book or off the book, and the necessary memory which stores the alternate audible messages that may be generated may be present on the book or off the book. Also, it is to be appreciated that the memory may be integrated circuit memory, in the form of ROM or RAM, or may be other types of data recording and reproducing means, such as tape or disc.

Whilst the invention has been described with reference to an embodiment in the form of a book, it is to be appreciated that the invention may find other applications and thus a sensor as described and an associated micro-processor and voice synthesizer combination may be embodied in a board used to play a board game. In such an embodiment the sensor would be responsive to various playing areas on the board being touched, and would then issue instructions appropriate for the board game in question. For example, the game may be of the type where a player has to perform a forfeit. The game board may thus include a "forfeit" square and when a person has to pay a forfeit he or she touches the square and the voice synthesizer gives out a message indicating precisely what the forfeit will be.

Whilst, in the description of the various embodiments given above reference has been made to a voice synthesizer, which operates to produce an audible sound which is recognisable as human speech, in alternative embodiments a sound generator may be provided which emits other predetermined sounds.

Figure 8 illustrates another embodiment of a book in accordance with the invention, corresponding broadly to the book of Figure 5. The housing 33 is provided with a socket adapted to receive a plug 41 which is connected to a computer arrangement 42.

The housing 33 contains sufficient circuitry to enable signals to be sent, through the plug 41, to the computer 42 indicating where a finger is touching a specific page of the book. The computer 42 is illustrated as being provided with a monitor 43 and is adapted to receive a disc 44 containing data corresponding to the particular book. It is thus envisaged that a book will be provided together with a disc containing data, and the disc can be inserted in a computer, such as the computer 42, which is physically connected to the book. The data present on the disc inserted in the computer may take a wide variety of forms, but will relate to matter present within the book. The arrangement may be used as a teaching aid, with the computer initially issuing an instruction, either visual or audible, for a pupil to find a specific item of subject matter in the book, thus requiring the pupil to open the book at the correct page, and touch the marks 35 indicating precisely where the book has been opened and then touching an appropriate illustration, the computer then providing further appropriate visible or audible messages.

Alternatively, the book may be more in the form of a "magazine" and may relate to a computer game.

In modified versions of this embodiment the book or magazine may be connected to the computer by an optical or electro-magnetic link, of the type described above with reference to Figure 7.

Figure 9 illustrates a further embodiment of the invention which is primarily suitable for use as a teaching aid, particularly where no adequately qualified teacher is present. The book 30, as in the embodiment of Figure 8, is provided with a socket present in the housing 33 adapted to receive a plug 45 which is connected to a radio receiver assembly 46. The housing 33 contains sufficient circuitry to send, through the socket-and-plug connection 45, to the radio receiver 46, signals representative of where a finger is present on a page of the book. Alternatively the links between the book and the assembly 46 may be an optical or an electro-magnetic link as described with reference to Figure 7.

The radio receiver assembly 46 is adapted to receive signals through an antenna 47, the received signals being de-modulated by a demodular 48 and then passed to a de-coder 49. The de-coded signals are fed to a processor 50. Signals from the processor 50 may either be stored in a memory 51 or may be fed directly to an audio output 52 depending upon the coding that precedes each signal received. Thus the combination of the de-coder and the processor determine whether any particular signal is stored in memory, or is fed directly to the audio output. The audio output may pass, for example, to an ear-piece or pair of headphones for the person using the book, if the book is to be used in a classroom situation, or may be passed to a loud speaker.

It is envisaged that, when the apparatus of Figure 9 is to be used as a teaching aid, initially a plurality of signals, preceded by appropriate codes, will be transmitted and will be stored in the memory 51. Subsequently a further signal will be transmitted, with an appropriate code, which would pass directly to the audio

output. This signal will comprise an instruction to a person using the book to touch a specific area of the book. Depending upon which area is touched, one of the signals stored in the memory will be passed, by the processor, to the audio output. One of the signals stored in the memory may be a "central" signal, which effectively controls the processor, causing the signals in the appropriate part of the memory to be transferred to the audio output wherever a specific sensor of the sensor array is activated. This control signal will be up-dated from time-to-time.

It is conceivable that if, for example, a double- side band receiver is utilised, the signals to be stored in the memory may be transmitted simultaneously with the initial signal that is passed to the audio output providing the instruction. While the signals may be preceded by a code, as described above, to enable the receiver assembly to identify which signals are to be stored in which areas of memory, and which signals are to be passed immediately to the audio output, in a modified embodiment the different signals may be provided on different channels, such as time multiplexed channels.

It is also envisaged that, in a modified embodiment of Figure 9, instead of a radio receiver 46 being utilised, a television receiver could be utilised. In such an arrangement, audio visual signal preceded by an appropriate code would be stored in a memory 51 which might be embodied by a read-write optical disc or an audio tape arrangement. When part of the book is touched in response to an instruction, the appropriate audio visual signal would be played.

Whilst, in the description given above, various techniques have been disclosed for identifying the page at

which a book is opened, an alternative technique, it is envisaged, could be used. In this technique a separate strip of sensors would be provided mounted on the cover of the book adjacent the pages when the pages are open. The strip would be located so that when the book is open the strip is not covered by any one of the pages, but is accessible, and can be directly touched by a finger. Because the sensor can be touched directly by a finger, the sensor can have relatively fine resolution.

It is envisaged that each page of the book will carry a mark, such as an arrow or the like, printed on the book adjacent the edge of the page which is in the region of the sensor. When the book is opened a person will touch the sensor at the position indicated by the arrow, consequently providing an accurate indication of the page at which the book is opened. It is, of course, conceivable that it will be necessary for there to be two marks, such as two arrows, with the sensor strip being touched at the two positions indicated by the two arrows, if there are a large number of pages in the book.

Referring now to Figure 10, which illustrates schematically apparatus for playing a board game, a board 60 is provided which presents an upper playing surface 61. Playing pieces, such as the playing piece 62 are intended for use with the board.

Embedded in the board 60, about the periphery of the board, is a large coil 62 made of low resistance material, such as copper wire. A current is fed into this coil to induce current into the playing pieces such as the playing piece 62. Each playing piece, such as the playing piece 62, contains a resonant circuit in which a current flows when induced in the circuit from the coil 62.

Two sets of elongate sensor coils are provided within the board 60. The first set of sensor coils, comprising the coils 63 (only two of which are shown) , comprise elongate coils which extend transversely of the board in parallelism. The second set of coils, 64, only two of which are shown, are elongate coils extending longitudinally of the board in parallelism. Each coil may be connected in opposite polarity to the adjacent coils of the set of coils to which the coil belongs. The complementary coil pairs combine to reject background interference.

Any signals from a resonant circuit present in a playing piece such as the playing piece 62 resting on the surface of the board 60 will induce a field into the sensor coils in the vicinity of the playing piece. Thus the position of each playing piece can be determined.

It is preferred that each playing piece 62 incorporates a ferrite core, with the base of each playing piece being constituted by the end of the ferrite material, surrounded by a coil forming part of the resonant circuit. In this way a strong flux is generated when the resonant circuit of the playing piece resonates, this strong flux being induced into the sensor coils present in the board.

The board is associated with an output device 65, which can comprise a voice synthesizer, a tape player, a CD player, a CD ROM or a C.D.I.

It is to be understood that in the foregoing description whenever reference is made to position of the "finger" being detected, a similar technique may be utilised to detect the presence of other objects, such as playing pieces or the like. It is also to be appreciated

that in the foregoing description reference has been made to a voice synthesizer, the voice synthesizer may be replaced by an audio CD, or a CD ROM or C.D.I. It is possible that, when such a CD system is used, in response to the detection of a finger on a book or a playing piece on a board, information from the CD may be down-loaded into a memory carried on the book or on the board, that memory being associated with sound generating means present on the book or on the board.

Of course, information from the CD system may be utilised to produce not only sound but also pictures.

It is to be understood that whilst the various components described above may be interconnected by wires, there may be some other form of link between the components such as an infra-red link or a radiation link.