GB2487580A

GB2487580A - Sheet for user interface with capacitive sensing elements

Info

Publication number: GB2487580A
Application number: GB1101511.2A
Authority: GB
Inventors: Kate Jessie Stone
Original assignee: Novalia Ltd
Current assignee: Novalia Ltd
Priority date: 2011-01-28
Filing date: 2011-01-28
Publication date: 2012-08-01
Also published as: GB201101511D0

Abstract

A sheet 1 comprises a substrate 2, a set of conductive elements 3 distributed across the substrate, a set of conductive terminals 4 disposed on the substrate for interfacing to a surface- or edge-mounted device or connector and network of conductive tracks 5 running between the elements and the terminals. The tracks are arranged such that conductive elements are interconnected. The sheet can be adapted by breaking selected tracks, for example by cutting or punching slit or holes 13 in the sheet, to provide a customized sheet for a user interface with functioning elements in suitable positions. The conductive elements, terminals and tracks can be printed using conductive ink. The conductive elements 13 can be pads for a capacitive touch sensing and the sheet can be a printed article such as a poster, calendar, book, product packaging, game or greeting card.

Description

User interface

Field of the invention

The present invention relates to a user interface particularly, but not exclusively, comprising capacitive sensing elements.

Background

Sensing elements, such as capacitive sensing elements, are increasingly being incorporated into printed articles, such as books, posters and greeting cards, to allow printed articles to become more interactive. Examples of interactive printed articles are described in GB 2 464 537 A, \XTO 2004 077286 A, WO 2007 035115 A and DE 1993 4312672 A.

Summary

The present invention seeks to facilitate incorporation of conductive elements, particularly capacitive sensing elements, into printed articles, such as posters, to provide a user interface.

According to a first aspect of the present invention there is provided a sheet comprising a substrate, a set of conductive elements distributed across the substrate, a set of conductive terminals disposed on the substrate for interfacing to a surface-or edge-mounted device or connector and a network of conductive tracks running between the elements and the terminals, the tracks arranged such that the conductive elements are interconnected.

Thus, the sheet can he produced in relatively large numbers and then customised in smaller numbers by breaking selected tracks, for example by cutting or punching the sheet, to provide a customised sheet for a user interface with functioning elements in suitable positions.

The conductive elements, conductive terminals and/or conductive tracks may comprise conductive ink or foil. The conductive ink may he a carbon-based ink.

The conductive ink may be a metal-based conductive ink, such as a silver-or copper-based conductive ink. The foil may comprise aluminium, copper, gold or silver.

The conductive elements, conductive terminals and/or conductive tracks may comprise a conductive polymer. The conductive elements, conductive terminals and/or conductive tracks may comprise a transparent conductive material.

The conductive elements may comprise conductive pads. Each conductive element may comprise a layer of conductive material having a solid block pattern.

The conductive elements may have substantially the same shape or pattern and/or the same size.

The conductive elements may be distributed uniformly across the substrate in at least one direction or in at least two orthogonal directions. This can help to make the sheet generic. The set of conductive elements comprises an array of conductive elements. The set of conductive elements may comprise a rectangular array of conductive elements.

The set of conductive elements may comprise at least tO conductive elements, at least 10 conductive elements or at least 30 conductive elements.

The substrate may have a face having a surface area, A, and the conductive elements are disposed in a sub-area, A', of at least 0.5xA, at least 0.6xA, at least 0.7xA or at least 0.8xA. This can help to make the sheet generic.

Each conductive element may cover a surface area of at least 100 nim2, at least 200 mm2, at least 400 mm2 or at least 600 mm2.

The network of conductive tracks may include an array of conductive tracks. The network of conductive tracks may be a rectangular array of conductive tracks.

A first set of tracks may be divided into groups, each group comprising at least two parallel tracks, and separation between groups of tracks may be larger than separation between tracks in a group. A second group of tracks may be divided into groups, each group comprising at least two parallel tracks and separation between groups of tracks is larger than separation between tracks in a group, wherein the first set of tracks and the second set of tracks cross. Each group comprises between 2 and 10 tracks or between 3 and 5 tracks, or each group may comprise 3 tracks.

The conductive tracks may include a set of tracks which connect the conductive elements to other conductive tracks.

At least two conductive tracks, at least three conductive tracks, at least four conductive tracks or four conductive tracks may connect each conductive element to other conductive tracks.

The conductive elements may be arranged in rows and columns and at least some of conductive tracks may be arranged in rows and columns interposed between rows and columns of conductive elements.

The substrate may comprise a fibre-based material, such as paper or card. The substrate may comprise paper, card or plastic. The substrate may comprise a laminate.

According to a second aspect of the present invention there is provided a sheet comprising a substrate, an array of conductive elements distributed across the substrate, a set of conductive terminals for interfacing to a surface-or edge-mounted device and an array of crossing conductive tracks running between the elements and terminals, the tracks arranged such that conductive elements are interconnected.

According to a third aspect of the present invention there is provided a user interface comprising the sheet, wherein at least one of the conductive tracks includes a break.

The break may comprises a slit or a slot passing through the at least one track and, optionally, through the substrate. The silt or slot may break more than one track.

According to a fourth aspect of the present invention there is provide an article including the user interface.

The article may be a printed article. The article may be a poster, calendar, book, product packaging (such as a carton or secondary packaging), game or greeting card.

According to a fifth aspect of the present invention there is provided a method comprising providing the sheet and interrupting (e.g. cutting or punching) at least one conductive track so as to isolate at least one conductive element and at least one terminal from other elements and/or terminals.

Interrupting the at least one track may comprise cutting slits or slots the substrate.

Interrupting the at least one track may comprise laser cutting the track.

Interrupting the at least one track need not break or cut the substrate.

Brief Description of the Drawings

Certain embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a user interface sheet supporting a plurality of sensing elements in accordance with the present invention; Figure 2 illustrates a first pattern for selecting certain sensing elements; Figure 3 illustrates a second pattern for selecting certain sensing elements; Figure 4 illustrates functioning and non-functioning sensing elements; Figure 5 illustrates interactive printed matter using a customised user interface sheet; Figure 6 illustrates printing process; and Figure 7 illustrates a cutting process.

Detailed Description of Certain Embodiments

Referring to Figure 1, a customisable or generic user interface sheet I in accordance with the present invention is shown.

The sheet I comprises a substrate 2 which supports a plurality of conductive elements 3 distributed across the substrate 2, a set of terminals 4 and a plurality of conductive tracks 5 running between the conductive elements 3 and the terminals 4.

As \vill be explained in more detail later, the sheet 1 can be adapted by breaking one or more tracks S to form a customised or specific user interface 1' (Figure 2), 1" (Figure 3) having a required number of operable conductive elements 3 in appropriate positions.

The substrate 2 comprises an electrically insulating material and is flexible. In this example, the substrate 2 comprises a sheet of thick paper or card having a weight, for example, of about 100 to about 200 g/m2. The sheet 2 may be heavier, for example, having a weight of up to 330 g/m2 or more. However, plastics materials, such as polyethylene terephthalate (PET), can be used. In some embodiments, the substrate 2 may he rigid or stiff. For example, the substrate 2 may comprise paperboard, cardboard, hardboard or thick plastic.

In this example, the sheet I has dimensions, a X b, of 297)( 420 mm,i.e. A3 as defined by International Standards Organization (ISO) 216. However, the sheet I can be larger, for example A0, Al or A2, or smaller, for instance, A4 or A5. The sheet 1 can have other metric sizes, such as B-series (ISO 216) or C-series (ISO 269) format. The sheet 1 can have an American National Standards Institute (ANSI) size, for example ANSI A or "Letter" size, other inch-based paper size (such as folio, quarto etc.), an Architectural size or other defined paper-size. Non-standard sizes can be used.

As shown in Figure 1, the conductive elements 3 take the form of circular conductive pads, i.e. conductive discs. The conductive elements 3 are configured for capacitive sensing, i.e. capacitive touch or proximity sensing, and have a diameter of about 30 mm. Thus, the conductive elements 3 are also referred to herein as sensing elements. In some examples, the conductive elements 3 provide a set terminals for a surface-mounted light source (e.g. LED), sensor or actuator. The conductive elements 3 are substantially the same shape and have the same size.

The conductive elements 3 comprise conductive ink, such as carbon-based conductive ink or a metal-based conductive ink, for example a silver-or copper-based conductive ink, and are formed by printing. The conductive elements 3 need not be circular, but can take other shapes, for example ovals, rectangles and other (regular or irregular) polygonal shapes. The conductive elements 3 need not be solid blocks of conductive material, but can include holes or slots. The conductive elements 3 may be smaller or larger, for example, having areal dimensions (for example diameter, width, length etc) of at least about 5 mm.

The conductive elements 3 can be configured for other forms of sensing, such as resistive touch sensing, i.e. touch switches. Suitable forms of touch switches are described in GB 2 462 287 A, which is incorporated herein by reference.

The conductive elements 3 need not comprise conductive ink. For example, in some embodiments, the conductive elements 3 may comprise metal foil, for example formed by hot or cold foil stamping or by etching metallised sheets. The foil may comprise aluminium, copper, gold or silver.

The conductive elements 3 are arranged across the sheet I having a substantially uniform distribution and/or uniform size.

In this example, the conductive elements 3 are arranged in a periodic rectangular array having seven rows (m 7) and six columns (n 6). The rows and columns are arranged orthogonally, in this case perpendicularly, with respect to each other.

As shown in Figure 1, rows are shown running parallel to the x-axis and columns are shown running parallel to the y-axis. The first three columns contain six elements 3 and the second three columns contain seven elements 3, i.e. three elements in the last row are omitted. This helps to provide space in a corner 6 of the sheet for the terminals 5. The number of rows and columns (m, n) may be lower or higher. The conductive elements 3 can be arranged differently, e.g. in a hexagonal array, in an angular array etc. The conductive elements 3 need not be periodic, but can have different spacing, e.g. between a first and second rows and between second and third rows. The conductive elements 3 can be arranged randomly on the substrate 2.

As shown in Figure 1, the conductive tracks 5 are joined at nodes 7. The nodes 7 have at least three branches. As shown in Figure 1, some nodes 7 have three branches, in the form of a T'-shape, and some nodes 7 have four branches, in the form of a cross shape.

The terminals 4 are arranged in the corner 6 (in this case, the lower left corner) of the sheet 1. The terminals 4 are positioned away from the edges 8, 82 of the sheet, e.g. at least 10 mm. In this example, there are seven terminals 4. Fewer or more terminals may be provided. The terminals 4 are grouped in an interface region 9 for io interfacing with a surface-mounted device 10 (Figure 5). In this example, the terminals 4 are arranged in a row. However, the terminals 4 can be arranged in other regular, e.g. along sides or a rectangle, or other well-defined positions, for example within an area of between about 10 mm2 and about 200 mm2. Terminals 4 may be arranged into two or more groups spaced apart.

The terminals 4 preferably comprise the same material as the conductive elements 3 and/or conductive tracks 5. Thus, they can be formed in the same stage, which helps simplify manufacture. In this example, the terminals 4 comprise conductive int The conductive tracks 5 can be divided in several types.

Most of the conductive tracks 5A' 5B (herein referred to as "shared tracks" or "common tracks") cover large distances across the sheet and are arranged in sets.

In this example, each set comprises three tracks. However, fewer tracks, for example, one or two tracks, or more tracks, for instance four, five, six, seven, eight, nine, ten or more tracks, can be used. In general, if the number of tracks in a set is higher, then the more complex routing pattern between sensing elements 3 and terminals 4 can be used.

As shown in Figure 1, the common tracks 5A' 5B are arranged in a periodic rectangular array running parallel to the same directions as the rows and columns of the array of conductive pads 3, i.e. along x-and y-axes.

Some of the conductive tracks 5 (herein referred to as "access tracks") connect the conductive elements 3 to the shared tracks 5A' 5B and are arranged around each conductive element 3. This allows each conductive element 3 to be accessed from different sides or directions. In this example, four, single access tracks 5 are arranged in a cross-shape around each conductive element 3. However, sets of access tracks 5 comprising two or more track can be used. Moreover, a conductive element 3 can be accessed by fewer or more sets of access tracks 5. For example, each conductive element 3 can be accessed by only one set of access tracks 5 (which may contain one, two or more sets of tracks). Furthermore, a conductive element 3 can be accessed from other directions, e.g. by access tracks 5 running in -10 -a direction which is not parallel to the common tracks 5A' 5B' for example diagonally.

Some of the conductive tracks 5 (herein referred to as "terminal tracks") connect the terminals 4 to the shared tracks 5M 5. In this example, a single terminal track is used to communicate with each terminal 4. However, two or more tracks can he used.

The tracks 5 preferably comprise the same material as the conductive elements 3 and/or terminals 4. The tracks 5 have a line width of at least 100 tim, preferably at least 500 im and more preferably at least 1 mm.

The sheet 1 can be manufactured in large numbers, for example, in thousands, tens of thousands or more.

For example, the conductive elements 3, terminals 4 and tracks 5 can be formed using a printing process, such as screen printing, ink jet printing, fiexography or offset printing. The conductive elements 3, terminals 4 and tracks S may comprise a silver-based conductive ink. Suitable conductive inks are available from Sun Chemical Corporation, Parsippany, New Jersey, USA. Other forms of conductive ink can be used, such as a copper-based conductive ink or some other metallic-based conductive ink, or a carbon-based conductive ink.

Once the sheets I have been manufactured, smaller numbers of sheets, for example one, a few, tens, hundreds, thousands or more, can he customised by hand or by machine, by breaking one or more of the tracks 5.

The tracks 5 may be broken by cutting or punching the sheet 1, by creasing the sheet I or by cutting, etching, ablating, scribing or scratching the tracks 5. For Jo example, the tracks S may he broken using laser ablation or laser cutting.

Interrupting the tracks 5 need not cut through the underlying sheet.

-11 -Referring to Figure 2, a first pattern which can be used to customise the sheet us shown.

Figure 2 shows a plurality of slits 11 are cut in the sheet I which select first, second, third, fourth, fifth, sixth and seventh conductive pads 2, 33, 34, 3, 6, 37. The slits 11 may be cut, for example, using a form cutter, rotary die cutter or laser. The slits 11 are generally longer than the separation between conductive pads 3 and are herein referred to as "long" or "continuous" lines.

As shown in Figure 2, the slits 11 are generally chosen to isolate at least one continuous route from a pad 3, through at least one access track 5, at least one continuous path of shared tracks 5A' 5B' through at least one terminal track 5, to a terminal 4.

In this example, the lines 11 sever multiple shared tracks 5A. 5B and/or access tracks 5c and form a plurality of tab-like strips 12 which are each attached at one end to the rest of the sheet 1.

Referring to Figure 3, a second pattern which can be used to customise the sheet I is shown.

Figure 3 shows a plurality of slits 13 are cut which are used to select the first, second, third, fourth, fifth, sixth and seventh conductive pads 2, 33, 34, 35, 6, 37.

The slits 12 are generally shorter than the separation between conductive pads 3 and are herein referred to as "short" cut lines or "perforated" lines.

The second pattern severs the same tracks as the first pattern. However, rather than forming tab-like strips, the second pattern leaves the strips attached to the rest of the sheet at more than one point. Thus, the sheet is more robust and easier to handle. For example, strips are less likely to be torn off or folded over.

A combination of long and short cut lines can be used.

-12 -Pads which are no longer capable of functioning may be removed from the sheet 1, for example, to reduce stray capacitances.

Figure 4 shows the first, second, third, fourth, fifth, sixth and seventh conductive pads 33, 3, 33, 34, 35, 3, 37 selected to be function as sensing elements. Other, non-functioning conductive pads are shown in chain.

By changing the pattern of lines 11, 12, different conductive elements 3 can be chosen to function. Thus, the sheet 1 (Figure 1) can be customised so that different numbers of elements 3 in different positions can be chosen. These can be used with different posters or other printed matter.

Referring to Figure 5, a customised sheet 1', 1" can he placed behind a poster 13 or other printed matter having indicia 14 printed thereon and so provide a user interface. The functioning elements 3, 37, 33, 34, 3, 6, 37 are aligned with corresponding indicia 14. A device 9 is mounted to the sheet 1', 1" which alone or in conjunction with other circuitry can provide audio and/or visual output.

This arrangement allows a manufacturer (e.g. a printer, a converter etc) to incorporate a user interface more easily into printed matter, such as a poster, calendar, book, carton or other product packaging, game, greeting card or the like.

For example, manufacturer need not have any specialist kno\vledge for handling or printing conductive inks. This arrangement can also he used for prototyping.

Referring to Figures 6, the sheet I is formed by printing the conductive elements 3, terminals 4 and tracks S on the substrate 2 using a printer 15. Screen printing, ink jet printing, flexography or offset printing can be used. Individual sheets 1 may be printed. Alternatively, a roll-to-roll process can be used and sheets 1 can be cut from a printed roll (not shown).

Referring to Figure 7, the customised sheet 1', 1" is formed using a converting process for example by cutting or punching slits or holes 11, 12 in the sheet using a tool or machine 16. Sheets I may be customised individually. Alternatively, a roll- -13 -to-roll process can be used and customised sheets I', 1" can be cut from the printed roll (not shown).

It will be appreciated that many modifications may be made to the embodiments hereinbefore described.

For example, the conductive tracks need not be straight, but can be curved or wavy.

Different segments of the line can have different shapes. -14-

Claims

Claims 1. A sheet comprising: a substrate; a set of conductive elements distributed across the substrate; a set of conductive terminals disposed on the substrate for interfacing to a surface-or edge-mounted device or connector; and a network of conductive tracks running between the elements and the terminals, the tracks arranged such that the conductive elements are interconnected.
2. A sheet according to claim 1, wherein the conductive elements comprises conductive pads.
3. A sheet according to claim I or 2, wherein the conductive elements comprise layer of conductive material having a solid block pattern.
4. A sheet according to any preceding claim, wherein the conductive elements, conductive terminals and/or conductive tracks comprise conductive ink.
5. A sheet according to any preceding claim, wherein the conductive elements are distributed uniformly across the substrate in at least one direction and, optionally, distributed uniformly across the substrate in at least two orthogonal directions.
6. A sheet according to any preceding claim, wherein the set of conductive elements comprises an array of conductive elements.
7. A sheet according to any preceding claim, wherein the set of conductive elements comprises a rectangular array of conductive elements.
8. A sheet according to any preceding claim, wherein the set of conductive elements comprises at least 10 conductive elements, at least 10 conductive elements or at least 30 conductive elements.

-15 -
9. A sheet according to any preceding daim, wherein the substrate has a face having a surface area, A, and the conductive elements are disposed in a sub-area, A', of at least 0.5xA, at least 0.6xA, at least 0.7xA or at least 0.8xA.
10. A sheet according to any preceding claim, wherein each conductive element covers a surface area of at least 100 mm2, at least 200 mm2, at least 400 mm2 or at least 600 mm2
ii. A sheet according to any preceding claim, wherein the network of conductive tracks includes an array of conductive tracks.
12. A sheet according to any preceding daim, wherein the network of conductive tracks in a rectangular array of conductive tracks.
13. A sheet according to any preceding daim, wherein a first set of tracks are divided into groups, each group comprising at least two parallel tracks, wherein separation between groups of tracks is larger than separation between tracks in a group.
14. A sheet according to claim 13, wherein each group comprises between 2 and tracks or between 3 and 5 tracks, or each group comprises 3 tracks.
15. A sheet according to daim 13 or 14, wherein a second group of tracks are divided into groups, each group comprising at least two parallel tracks wherein separation between groups of tracks is larger than separation between tracks in a group, wherein the first set of tracks and the second set of tracks cross.
16. A sheet according to any preceding claim, wherein the conductive tracks include a set of tracks which connect the conductive elements to other conductive tracks.-16 -
17. A sheet according to claim 16, wherein at least two conductive tracks, at least conductive three tracks, at least four conductive tracks or four conductive tracks connect each conductive element to other conductive tracks.
18. A sheet according to any preceding claim, wherein the conductive elements are arranged in rows and columns and wherein at least some of conductive tracks are arranged in rows and columns interposed between rows and columns of conductive elements.
19. A sheet comprising a substrate, an array of conductive elements distributed across the substrate, a set of conductive terminals for interfacing to a surface-or edge-mounted device and an array of crossing conductive tracks running between the elements and terminals, the tracks arranged such that conductive elements are interconnected.
20. A user interface comprising a sheet according to any preceding claim, wherein at least one of the conductive tracks includes a break.
21. A user interface according to claim 20, wherein the break comprises a slit or a slot passing through the at least one track and, optionally, through the substrate.
22. A user interface according to claim 21, wherein the slit or slot breaks more than one track.
23. An article comprising a user interface according to any one of claims 20 to 22.
24. An article according to claim 23, which is a poster.Jo
25. An article according to claim 23, which is a greeting card.
26. An article according to claim 23, which is a book.-17 -
27. An article according to claim 23 which is product packaging.
28. An article according to claim 23, which is a game.
29. A method comprising: providing a sheet according to any one of claims I to 19; and interrupting at least one conductive track so as to isolate at least one conductive element and at least one terminal from other elements and/or terminals.
30. A method according to claim 29, wherein interrupting at least one track comprises cutting slits or slots the track and, optionally, substrate.