Patent Description:
<CIT> discloses an electronic book comprising printed circuitry.

The invention is described in the appended claims.

Non-limiting examples will now be described with reference to the accompanying drawings, in which:.

<FIG> shows an exploded view of printed circuitry <NUM> comprising a digitally printed switch <NUM>. The printed switch <NUM> comprises a first contact element <NUM> which is digitally printed using conductive print agent on a first substrate portion <NUM>, and a second contact element <NUM> which is digitally printed using conductive print agent on a second substrate portion <NUM>. The substrate portions <NUM>, <NUM> may be provided on the same or different substrates, which may be any type of substrate, for example comprising paper, card, plastic, or the like. The switch <NUM> further comprises an interposed digitally printed spacer element <NUM>, which is overprinted on at least one of the first and the second substrate portions <NUM>, <NUM>. In this example, the black lines of the contact elements <NUM>, <NUM> and the spacer element <NUM> indicate the presence of a print agent. For example, the surface area/spatial extent of the spacer element may at least partially overlie the surface area and/or spatial extent of the first and/or second contact element <NUM>, <NUM>.

While the exploded view shows the elements <NUM>-<NUM> separately, in practice the elements <NUM>-<NUM> would be closely stacked.

In this example, the first contact element <NUM> comprises a broken conductive track which is formed of interleaved, but unconnected, conductive fingers. The second contact element <NUM> comprises a plurality of printed bars, and the arrangement is such that, when pressed together, the bars, which are arranged to be substantially orthogonal to the fingers, connects the fingers together. However, numerous alternative designs could be used to form the contact elements <NUM>, <NUM>.

The conductive print agent, which may for example comprise an ink comprising carbon particles such as carbon-nanotubes or graphene, or other conductive particles such as metallic particles, may be printed in one or more layers. In some examples, the number of layers is selected so as to provide a predetermined electrical characteristic such as conductivity. For example, <NUM>, <NUM>, <NUM>, <NUM> or more layers may be provided and/or the cross section of the lines of the contact elements <NUM>, <NUM> may be selected so as to provide a threshold conductivity.

The printed spacer element <NUM> may be printed using one or more layers any print agent such as liquid ink, paste, or power toner, which has a relatively high resistance. For example, this may comprise a cyan, yellow or magenta ink (which may comprise electronic ink comprising charged particles suspended in a carrier fluid) of a standard set of colorants.

In this example, the spacer element <NUM> comprises a border <NUM> and dispersed dots 116a-e. In practice, the design (including the height, which may be determined by the number of layers) of the spacer element <NUM> may vary. The design of the spacer element <NUM> may be so as to allow the first and second contact elements <NUM>, <NUM>, when urged together, to contact one another, but also such that the first and second contact elements <NUM>, <NUM> are generally held apart. Thus, the design of the spacer element <NUM> may depend on features such as the rigidity of the substrate on which the contact element <NUM>, <NUM> are printed, the achievable height of the printed elements, and the like.

In one example, a first spacer element <NUM> is printed so as to overlie the region of a substrate on which the first contact element <NUM> is provided and a second spacer element <NUM> is printed so as to overlie the region of a substrate on which the second contact element <NUM> is provided. In some examples, it may be more efficient to print two spacer elements <NUM> of a first number of layers than one spacer element of double the number of layers, which would provide the same spacing between the contact elements <NUM>, <NUM>.

In some examples, the first and second substrate portions <NUM>, <NUM> may be part of a folded continuous substrate, or may have been printed on a single substrate, which was then cut. In other examples, the first and second substrate portions <NUM>, <NUM> may be taken from different substrates, in some examples having been printed on different substrate sheets.

Such circuitry <NUM> may be efficiently printed. While in the past, combinations of non-printed and printed elements have been used form circuits, by printing all of the elements of the switch <NUM> including the nonconductive spacer element <NUM>, the production process may be simplified.

In some examples, the printed circuitry <NUM> may be printed using 'liquid toners', which comprise toner particles suspended in a carrier fluid, for example using a liquid electrophotographic printer, or LEP. An LEP comprises a photoconductive surface which may be selectively charged such that liquid toner adheres thereto with an intended pattern. This pattern may be partially dried to form a print layer which is transferred to a substrate. In some such examples, a plurality of print layers may be transferred to a substrate in a single transfer operation. For example, a plurality of layers of print agent (which may comprise different print agent types, for example comprising one or more layers formed in conductive ink (for example forming the contact elements <NUM>, <NUM>) and one or more layers formed of an insulating ink (for example providing the spacer element <NUM>) may be transferred to a substrate in a single operation.

As noted above, the switch is a digitally printed switch. Digital printing methods do not rely on printing plates, printing screens, or the like, and can deposit toners, inks and the like onto substrates in an adaptable manner. The printed image may be formed based on instructions derived from a data file describing the image, for example a digital representation of the image. For example, digital printing processes include inkjet printing (in which nozzles selective dispense drops print agents onto a substrate), laser, electrophotographic and/or xerographic printing (in which light is used to selectively discharge a charged surface such that charged toner particles are attracted thereto in a pattern, which may be formed on or transferred to a substrate), and the like. The switch <NUM> of <FIG> may be printed by any such printing apparatus.

In some examples, as set out in greater detail below, media content may be printed on a substrate bearing a contact element. In some examples, a contact element <NUM>, <NUM> may be printed on a first side of a media sheet and media content may be printed on a second side of the media sheet.

<FIG> shows another example of printed circuitry <NUM>. The printed circuitry comprises a printed switch <NUM>, which in some examples may comprise a digitally printed switch, and may be substantially as described above in relation to <FIG>. In this example, there is a first conductive path 202a and second conductive path 202b connecting respectively to the first and second contact element <NUM>, <NUM>. The first and second conductive paths 202a, 202b extend over fold lines in respective first and second substrates 204a, 204b. This means that, when the first and second substrates 204a, 204b face one another with the contact elements <NUM>, <NUM> facing one another, contact points to the first and second contact elements <NUM>, <NUM> are readily accessible on the reverse of the first and second substrates 204a, 204b. In some examples, the first and second conductive paths 202a, 202b may be laterally offset, such that they are not aligned in the vertical direction of the Figure (and are therefore not in direct galvanic contact even when the substrates 204a, 204b are in face to face contact, although a galvanic connection may be formed via the switch <NUM>). In this example, both contact elements <NUM>, <NUM> are overprinted with a spacer element <NUM>.

While in this example, one conductive path <NUM> is associated with each contact element <NUM>, <NUM>, this need not be the case in examples. In other examples, both of the conductive paths <NUM> may be associated with one of the first and the second contact element <NUM>, <NUM>. In the example shown, in which one conductive path <NUM> is associated with each of the first and the second contact elements <NUM>, <NUM>, then the conductive tracks may extend either side of the 'sandwich' of the substrates 204a, 204b.

In this example, the contact elements <NUM>, <NUM> are thicker than the conductive paths <NUM>, but this need not be the case in all examples.

In other examples, the first and second contact elements <NUM>, <NUM> may be printed on the same side of the substrate, which may be folded to arrange the contact elements <NUM>, <NUM> face to face. In such examples (or in examples in which the he first and second contact elements <NUM>, <NUM> are printed on different substrates), the edges of the substrate(s) may be misaligned so as to result in an overhang on one edge. In some such examples, at least one conductive track may extend into the region of the overhang such that it can be readily engaged without folding the substrate. In some examples, both conductive tracks may extend from one contact element <NUM>, <NUM> into the region of the overhang.

<FIG> shows a schematic side view of an example of an electronic media item <NUM>. The electronic media item may comprise any physical item which is capable of providing delivering information such as media content to an end user, and may comprise part of a larger item. For example, the media item may a book, magazine, pamphlet, packaging, poster or the like. The electronic media item <NUM> comprises an electronic device <NUM> and a digitally printed switch <NUM> to actuate the first electronic device <NUM>. The printed switch <NUM> comprises a first conductive contact element <NUM> digitally printed on a first media sheet portion <NUM>, and a second conductive contact element <NUM> which is printed on a second media sheet portion <NUM>. A digitally printed non-conductive printed spacer element <NUM> is interposed between the first and second contact elements <NUM>, <NUM> and is overprinted on a media sheet portion on which at least one of the first and second contact elements <NUM>, <NUM> is printed (i.e. on at least one of the first and second media sheet portions <NUM>, <NUM>).

A media sheet may for example comprise a discrete piece of a substrate such as a paper, card, plastic, glass, fabric or the like. Sheets may be defined before or after printing. For example, a 'web' or elongate stretch of a substrate may be printed and cut into sheets, or the sheets may be individually printed. The first media sheet portion <NUM> and the second media sheet portion <NUM> may be provided on the same or different media sheets. In some examples, a media sheet may be folded to form the electronic media item <NUM> and/or the electronic media item <NUM> may comprise a plurality of printed sheets.

The printed media item <NUM> further comprises a first conductive path <NUM> connecting the electronic device to the first contact element <NUM> and a second conductive path <NUM> connecting the electronic device <NUM> to the second contact element <NUM>. In some examples, the conductive paths <NUM>, <NUM> may be printed conductive paths (which may be digitally printed conductive paths), however, in this example, they comprise wires which connect to the electronic device <NUM>. While in this example, the conductive path <NUM>, <NUM> connect to different contact elements <NUM>, <NUM>, they could connect to the same contact element <NUM>, <NUM>. In addition, as is described in greater detail below, in some examples both contact elements may connect to two conductive paths <NUM>, <NUM>.

Media content (i.e. information which is directed towards a user, for example as images, words, patterns and the like) may be printed on at least one reverse side of the first and second media sheet portions <NUM>, <NUM> to the contact elements <NUM>, <NUM>. In some examples, content may provide an indication of where the printed switch <NUM> lies. By printing media content on the reverse side, an interactive book, leaflet or the like may be produced in a simple manner, as separate fabrication of the content pages and the circuitry is not required, and instead these fabrication processes may be combined in a 'double sided' printing exercise. In some examples, the media content may be digitally printed media content.

<FIG>, which are useful for understanding the invention, show substrate sheets 400a-g which may combined to form an interactive book. Each substrate sheet <NUM> is printed with at least one digitally printed contact element <NUM>, each of which has an overlying, digitally printed, spacer element <NUM>. Some of the sheets 400b-g are also printed with conductive paths <NUM> which extend from the contact elements <NUM> towards a fold line 408a-g, and which terminate with widened regions <NUM> (labelled on <FIG> only) which extend across the fold line <NUM> of that sheet <NUM>.

To assemble an interactive book, it is intended that each sheet <NUM> is to be folded along the fold line 408a-g with the contact elements <NUM> on the outside of the folded page, and the folded substrate sheets <NUM> may then be stacked on top of one another, such that the lower half of the sheet 400a shown in <FIG> contacts the upper half of the sheet 400b in <FIG>, the lower half of the sheet 400b shown in <FIG> contacts the upper half of the sheet 400c in <FIG>, and so on. The folded halves of adjacent sheets <NUM> which bear the contact elements <NUM> may be glued together, in some examples by applying adhesive such that it does not overlie the contact elements <NUM> (and, in some examples, the widened regions <NUM>, although in other examples, the widened regions may be coated with conductive adhesive).

In this example, the upper half of the substrate sheet 400a in <FIG> shows printed content which is intended to indicate the location of an underlying printed switch (in this example, a speech bubble), and the folded sheet 400a may be glued shut. In general, however, such printed media content may be printed on the reverse side of each sheet <NUM>, such that the sheets <NUM> may be opened along their fold lines <NUM> to reveal the content.

In this example, the printed conductive tracks <NUM> are substantially provided on the upper half of each substrate sheet 400b-g and each substrate sheet <NUM> comprises, in the region of the fold line <NUM>, the widened region <NUM> which extends beyond the fold line <NUM>, and which terminates the conductive tracks <NUM> on each page. When the sheets <NUM> are folded and a stack is formed, the widened regions <NUM> will align, allowing electrical signals to pass up and down via the 'spine' region of the assembled stack. More generally, once the stack is formed, a region of conductive track <NUM> (in this example, the widened region <NUM>) spans the fold line <NUM> on one media sheet <NUM> and is to contact with a region of conductive print agent on another media sheet <NUM>. While in this example all the widened regions <NUM> are provided on all sheets 400b-g, this need not be the case: the widened regions <NUM> serve as 'page to page' contact elements, each sheet <NUM> may bear those widened regions <NUM> to pass a signal from that sheet <NUM> and from any sheet <NUM> above it in the stack, and may not bear any widened region <NUM> for a signal which is intended to originate further down the stack.

As briefly noted above, in some examples, the widened regions <NUM> may be left clear of adhesive when forming a stack. However, in other examples, a conductive adhesive may be used in this region.

Some conductive print agents are relatively brittle and can crack or flake when flexed. Providing widened regions <NUM> which extend either side of the fold line <NUM> means that, even in the event that folding (and in some examples, opening and closing a book when formed) causing some cracking or flaking, it is likely that sufficient print agent will remain on the page to ensure a galvanic connection across the fold line <NUM>.

Considering <FIG>, when the pages are stacked, the contact element <NUM> on the sheet 400a shown in <FIG> will overly the contact element <NUM> on the sheet 400b shown in <FIG>. Pressing the region overlying the contact element <NUM> (which, if the sheet 400a of <FIG> is glued shut, comprises pressing the region of the speech bubble) may cause the switch formed by those two contact elements <NUM> to close, overcoming the air gap provided by the spacer element, and a signal may be generated at the widened region <NUM> shown in <FIG> which is second from the right (assuming a power supply is connected to the right-most widened region). Each successive page has another actuatable switch, generating signals at successive widened regions <NUM>.

While in this example, there is provided one switch per sheet <NUM>, there may be a plurality of switches on a page, and/or at least one page may have no switch.

As can be seen in <FIG>, the final sheet <NUM> comprises an upper half <NUM> bearing a contact element <NUM> which is overprinted with a spacer element <NUM>, the upper half <NUM> also bearing tracks <NUM> and widened regions <NUM>, which extend over the fold line <NUM> into a lower half <NUM>. The lower half <NUM> also comprises printed tracks <NUM> leading from each widened region <NUM> to contact points <NUM>. When the sheets <NUM> are stacked, at least one electronic device may be provided in the marked region <NUM>. In one example, each contact point <NUM> may be associated with a different electronic device, such as a screen, a light source, a speaker, etc. In some examples, a power supply, for example a battery, may also be provided and actuating a switch by pressing on a region of a substrate overlying a contact element may connect the power supply to the device.

As noted above, the conductive features may be printed with either one layer or several layers one on top of the other to provide a higher conductivity. The spacer element <NUM> may be printed with one or several layers to create an intended spacing.

In another example, the electronic device may comprise a controller, for example a microcontroller. The controller may for example comprise multiple inputs (for example, multiple input pins), which may result in the controller controlling a separate electronic device to carry out particular actions. For example, as a result of a signal at a first contact point, a speaker may be controlled to play a first sound and as a result of a signal at a second contact point, a speaker may be controlled to play a second sound. The sounds (or other responses to signals) may be encoded and held in a memory.

The sheets <NUM> may be paper, which may be a relatively heavy paper (for example, <NUM>-<NUM> microns thick) or card. In other examples, the sheets <NUM> may comprise a plastic, fabric, or some other material. In some examples, different sheets <NUM> may comprise different substrate types. The sheets <NUM> may be formed (e.g. cut from a larger sheet or web) before or after printing.

<FIG> shows an equivalent circuit <NUM> to the assembled stack shown in <FIG>, with each pair of contact elements illustrated as a switch.

<FIG> show an embodiment of the invention, in which each switch can actuate two contact points. Each of <FIG> show a substrate sheet 600b-f printed on one side with conductive print agent providing contact elements <NUM> overprinted with spacer elements <NUM> on both the upper and lower halves thereof, whereas <FIG> and <FIG> show sheets 600a, <NUM> printed contact elements <NUM> overprinted with spacer elements <NUM> on one of the lower and upper halves respectively. As described in relation to <FIG>, the sheets 600a-g are intended to be folded along a fold line 608a-g with the contact elements <NUM> on the outside of the folded sheets <NUM>, and the folded substrate sheets <NUM> are intended to be stacked on top of one another, such that the lower half of the substrate shown in <FIG> contacts the upper half of the substrate in <FIG>, the lower half of the substrate sheet 600b shown in <FIG> contacts the upper half of the substrate in <FIG>, and so on. The fold lines <NUM> may be aligned in forming the stack. The sides of adjacent substrates which bear contact elements <NUM> may then be glued together, in some examples by applying adhesive such that it does not overlie the contact elements <NUM> and the widened regions <NUM> (although in other examples, conductive adhesive may be used over the widened regions).

In this example, and in contrast with <FIG>, on the sheets 600b, d, f and <FIG>, <FIG> and <FIG>, the contact elements <NUM> on each half of each sheet has conductive tracks <NUM> associated therewith, whereas in <FIG> and <FIG>, the top half of the substrate sheets 600c, e are provided with conductive tracks <NUM> and the bottom half of the substrate sheets 600c, e do not have such tracks.

In this example, there are four widened regions 610a-d on each sheet <NUM>, providing a connection to four contact points 612a-d on the last substrate sheet <NUM>. One of the contact points 612d provides a common connection and each of the other contact points may be activated or not, leading to a <NUM> bit coded signal. In this example, the electronic component comprises a controller <NUM> which is capable of controlling one or more additional electronic devices, in this example a speaker <NUM>, as shown on <FIG>. In some examples a power source such as a battery may be provided.

Considering two sheets 600b and 600c, these may be stacked such that the bottom half of sheet 600b faces the upper half of sheet 600c. Thus, the contact point <NUM> on the lower half of sheet 600b will overlie the contact point <NUM> of the upper half of sheet 600c. Applying pressure to this region of the stacked sheets <NUM> will cause a signal to be generated at the second contact point 612b from the left from the signal generated by the circuit of the lower half of sheet 600b in <FIG> and will also cause a signal to be generated at the third contact point 612c from the left from the signal generated by the circuit of the upper half of sheet 600c in <FIG>. Such a signal may therefore be encoded as <NUM>, as indicated on the Figures (while this information may be printed feature of the sheets, this need not be the case in all examples).

Therefore, in this example, a total of six different signals, noted in the Figures adjacent to the relevant contact elements <NUM> (but may not be printed on the sheets in all examples) may be provided by four contact points <NUM>, and four widened regions <NUM> (bearing in mind that the <NUM> signal is not used as this is the 'unactivated' state and in this example the <NUM> signal is not accessible). This in turn means that the widened regions <NUM> may each occupy a larger proportion of the fold line and/or more signals may be provided without reducing the size of the widened regions <NUM> unduly. Given the tendency for some conductive agents to crack or flake in the region of a fold line <NUM>, this may assist in maintaining the integrity of the galvanic connection across the fold line.

<FIG> shows an equivalent circuit <NUM> to the assembled stack shown in <FIG>.

It may therefore be seen that, in the example of <FIG> and <FIG>, for an electronic printed media item, there is, for at least some of the printed switches, a first conductive path connecting the electronic device to a first contact element and a second conductive path connecting the electronic device to the second contact element of the switch, as well as a third conductive path connecting the first contact element to a first input of the electronic device to the first contact element and a fourth conductive path connecting the second contact element to a second input of the electronic device. However, others of the printed switches connect to exactly one of the inputs (in such examples, exactly one of the bits is set to <NUM>). The when the first and second contact elements are pressed together, two completed circuits may be formed: a first circuit comprising the electronic device (which may include a power source, such as a battery), the contact elements and the first and third conductive paths, and a second circuit comprising the electronic device, the contact elements and the second and fourth conductive paths. In other words, in some examples, as a result of pressing two contact elements together, two inputs may be provided to an electronic device.

<FIG> shows an example of electronic printed media item, in this example comprising an interactive book <NUM> comprising a speaker <NUM>, which in this example extends through a cut-out in the pages. The pages of the book <NUM> may be formed as set out in <FIG> or <FIG>.

<FIG> is an example of a method, which may be a method of printing pages for an electronic printed media item. Block <NUM> comprises generating a plurality of media sheets by (i) printing a plurality of contact elements, conductive paths and contact regions in conductive print agent, such that the conductive paths galvanically connect at least one contact element to a printed contact region, and (ii) overprinting at least one contact element with a spacer element using non-conducting print agent. The plurality of media sheets may be formed before or after printing. For example, a single media sheet or web may be printed and cut to form the plurality of sheets of block <NUM>. The printing may comprise digital printing.

For example, this block may result in a printed sheet <NUM>, <NUM> as shown in <FIG> or <FIG>.

The printing may be carried out so as to apply a plurality of print agent layers for one or both of the conductive and the non-conductive printed features.

Block <NUM> comprises folding the media sheets such that the fold line passes through the printed contact region. In some examples, the printed contact region may comprise a widened region <NUM>, <NUM> as described above.

Block <NUM> comprises forming a stack of folded media sheets such that a portion of the contact region on a first side of a fold line on a first media sheet contacts a contact region on a second media sheet and, in some examples, a contact region on a second side of a fold line on the first media sheet contacts a contact region on a third media sheet, and a contact element of the first sheet faces a contact element of the second sheet. In some examples, sides with facing contact elements may be glued together. In some examples, the glue or adhesive may be applied so as to leave the contact elements uncovered thereby. The fold lines may be aligned.

In some examples, the contact elements printed in block <NUM> are printed on respective first faces of the media sheets and the method may further comprise printing media content on a second side of at least one media sheet. In some examples, the media content may be indicative of where the electronic switches are located. In some examples, the contact elements, conductive paths and spacer elements printed in block <NUM> are printed to a substrate in a single operation. For example, the layer may be built up on an intermediate transfer member of an offset printer such as an LEP and applied to the substrate as an assembled stack.

In some examples, the method may further comprise connecting at least one contact region to an electronic apparatus. The electronic apparatus may for example comprise at least one of a controller, a speaker, a light source, a display screen, processing circuitry, power supply and a memory. The connection may be via an additional printed conductive path and/or via the contact regions of a plurality of printed sheets.

While the method, apparatus and related aspects have been described with reference to certain examples, various modifications, changes, omissions, and substitutions can be made without departing from the spirit of the present disclosure. It is intended, therefore, that the method, apparatus and related aspects be limited only by the scope of the following claims and their equivalents. It should be noted that the above-mentioned examples illustrate rather than limit what is described herein, and that those skilled in the art will be able to design many alternative implementations without departing from the scope of the appended claims. Features described in relation to one example may be combined with features of another example.

The word "comprising" does not exclude the presence of elements other than those listed in a claim, "a" or "an" does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims.

Claim 1:
An electronic printed media item comprising:
a first electronic device (<NUM>) and a first printed switch (<NUM>) to actuate the first electronic device (<NUM>),
the first printed switch (<NUM>) comprising:
a first digitally printed conductive contact element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) printed on a first media sheet portion;
a second digitally printed conductive contact element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) printed on a second media sheet portion; and
a digitally printed spacer element (<NUM>) interposed between the first and second conductive contact elements (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and overprinted on a media sheet portion on which at least one of the first and second conductive contact elements (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is printed,
the electronic printed media item characterised by comprising:
a first conductive path (<NUM>, <NUM>, <NUM>) connecting the first electronic device (<NUM>) to the first conductive contact element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>);
a second conductive path (<NUM>, <NUM>, <NUM>) connecting the first electronic device (<NUM>) to the second conductive contact element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>);
a third conductive path (<NUM>, <NUM>, <NUM>) connecting the first conductive contact element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to a first input of the first electronic device (<NUM>); and
a fourth conductive path (<NUM>, <NUM>, <NUM>) connecting the second conductive contact element (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) to a second input of the first electronic device (<NUM>).