The invention relates to textiles incorporating electrical conductors for driving electronic components such as light emitting diodes. In particular, though not exclusively, the invention relates to textiles with integrated electrode layouts which may be obtained by weaving. Such textiles are useful for providing flexible displays.
Flexible display technology permits the development of, among other things, wearable electronics incorporating displays and multi-colour display textiles for ambient lighting and other effects. Flexible and foldable displays increase the portability and versatility of such displays.
One method of creating flexible and foldable displays is by incorporating light emitting elements such as Light Emitting Diodes (LEDs) into woven textiles. Conductive elements such as fibres or printed tracks may be provided on or in the textile to conduct electrical signals to the LEDs. Ideally, such displays are capable of addressing individual LEDs, maintaining a textile-like quality in the support material and securely attaching the LEDs to the support.
WO 03/095729 discloses a woven article having plural weave layers comprising a plurality of electrically insulating and/or electrically conductive yarn in the warp and a plurality of electrically insulating and/or electrically conductive yarn in the weft interwoven with the yarn in the warp. An electrical function is provided by circuit carriers disposed in cavities in the woven article which include electrical contacts for connecting to the electrically conductive yarn in the warp and/or weft. The circuit carriers may be “functional yarn”, which includes an elongated electrical and/or electronic substrate on which are disposed one or more electrical conductors and a plurality of electrical and/or electronic devices that connect to one or more of the electrical conductors.
WO 04/100111 discloses a flexible display device comprising a material support of woven threads including electrically conducting threads, discrete electroluminescent sources soldered to the conductive threads and a control and power supply for individually addressing the electroluminescent sources. The woven threads are electrically insulated from one another by a polymer cladding. Directly addressable surface mounted LEDs are placed and soldered at intersections of threads along the warp and weft. Soldering to the threads can be achieved through melting the polymer coating without damage to the rest of the textile.
GB 2396252 discloses a textile comprising surface mounted LEDs which are individually encapsulated. LEDs are placed on to a textile member with at least two electrically conductive tracks and fixed with electrically conductive adhesive. The electrically conductive textile tracks may be a woven, non-woven, knitted or stitched series of electrically conductive fibres or yarns incorporated into the textile structure. A matrix layout is disclosed where two textile members with electrically conductive tracks are positioned at right angles to each other. LEDs are positioned at the junction of these conductive tracks with one end of the LED attached to the upper fabric and the other end of the LED attached to the lower fabric by means of a small window in the upper fabric.
The above referenced prior art discloses various means of providing textile-like substrates with light emitting elements attached. There are however a number of problems associated with prior art solutions. The light emitting elements may be required to be attached to flexible non-textile substrates, which are then woven into the textile. Alternatively, the woven textile may be woven with or sewn on to a non-conducting substrate such as a polymer sheet to provide support and insulation. Both of these approaches result in a diminished textile look and feel. Further, the prior art does not teach how to form a fully textile matrix electrode layout within one textile piece, but relies on, for example in the case of GB 2396252, two textile members with electrically conductive tracks being positioned at right angles to each other.
A further approach to making an improved textile “look and feel” is by the use of an electrically conductive yarn having an outer insulating layer. This insulating layer prevents yarns in the warp and weft direction from electrically shorting, but results in a need for removal of the layer prior to connection being made to any surface mounted components. This removal process may result in damage to the surrounding textile and limits the types of non-conducting surrounding yarns which can be used.
This invention provides a solution to some or all of the above problems. A fully flexible textile is disclosed with separately addressable light-emitting elements which retains a textile look and feel and ensures the required conductive yarns are insulated from each other without a need for electrically insulating coatings.
It is an object of the invention to provide a fully textile electrode layout allowing passive and active matrix addressing of devices attached thereto.
According to a first aspect, the present invention provides a textile formed from interwoven electrically conductive and non-conductive yarns comprising: a multi-layer warp comprising electrically conductive and non-conductive yarns; and a weft comprising electrically conductive and non-conductive yarns, at least some of the electrically conductive weft yarns crossing selected electrically conductive warp yarns without electrical contact therebetween by being separated from the electrically conductive warp yarns by at least one non-conductive warp yarn in each layer of the multi-layer warp, in which a first pair of electrical connection points is provided on a first surface of the textile by means of a loop of conductive weft yarn traversing from a second surface of the textile to the first surface and back, and a proximal portion of a conductive warp yarn.
According to a second aspect, the present invention provides a textile formed from interwoven electrically conductive and non-conductive yarns, comprising: a multi-layer warp comprising electrically conductive and non-conductive yarns; and a weft comprising electrically conductive and non-conductive yarns, at least some of the electrically conductive weft yarns crossing selected electrically conductive warp yarns without electrical contact therebetween by being separated from the electrically conductive warp yarns by at least one non-conductive warp yarn in each layer of the multi-layer warp, in which the multi-layer warp comprises only two layers of yarns.
According to another aspect, the present invention provides a method of forming a textile according to either of the first and second aspects.
Embodiments of the present invention will now be described by way of example and with reference to the accompanying drawings in which:
a and 10b illustrate: (a) a plan view; and (b) a cross-sectional view along a weft axis, of the single sided matrix textile of
a illustrates a schematic view of an arrangement of warp and weft yarns in a two-layer textile for a matrix of mono-colour LEDs;
b illustrates a schematic view of an arrangement of warp and weft yarns in a two-layer textile for a matrix of bi-colour LEDs;
c illustrates a schematic view of an arrangement of warp and weft yarns in a two-layer textile for a matrix of tri-colour LEDs;
d illustrates a schematic view of an arrangement of warp and weft yarns in a three-layer textile for a matrix of mono-colour LEDs;
e illustrates a schematic view of an arrangement of warp and weft yarns in a three-layer textile for a matrix of bi-colour LEDs;
f illustrates a schematic view of an arrangement of warp and weft yarns in a three-layer textile for a matrix of tri-colour LEDs;
a illustrates a schematic view of connections for an active matrix containing driver integrated circuits within the weaving layout of
b illustrates a detail schematic view of a single driver integrated circuit of
The woven textile has a multilayer structure, and is preferably made with at least a double layer structure. The textile may be woven from yarns in a first direction, which may be termed the warp direction, interwoven with yarns aligned in a second direction, which may be termed the weft direction. Yarns in the weft direction traverse the yarns in the warp direction. The warp and weft directions are transverse to one another and preferably substantially orthogonal to one other.
It is to be understood that the terms “warp” and “weft” are used simply in relation to the directions lengthwise and crosswise on a textile sheet, but are not necessarily used to imply any limitation on a method of fabricating a textile on a weaving loom.
The term “multi-layer warp” is used to encompass a textile in which a plurality of layers of warp yarns are used to weave a single textile piece, being distinct from multi-layer textiles formed from separately woven pieces.
Optoelectronic devices can be attached to the textile on either or both faces. Such devices can have two, three, four or more electrodes that need to be connected to the textile. Exemplary embodiments will be given for one-, two- and three-colour light emitting diodes (LEDs), however the principles outlined are intended to be suitable for other types of devices. Besides light emitting modules, any suitable kind of electronic component may be attached, such as sensors, actuators, driver integrated circuits and the like. In the case of two- and three-colour LEDs, shared anodes will be indicated.
Different types of yarns and/or fibres may be used: electrically conductive yarns and electrically non-conductive yarns. Both types of yarn may be of single or multifilament type. If using multi-filament yarns, a degree of twist may be necessary in the yarn in order to prevent short circuits between adjacent multi-filament yarns due to electrical connections between stray single yarn filaments. Conductive yarns according to the invention are defined as those which have an electrically conductive material on at least an outer surface of the yarn. Such yarns may be of various types of construction, and may for example have an internal core of another material. The internal core may include a non-conductive material. Non-conductive yarns according to the invention are defined as having at least a non-conducting outer surface, and may be made entirely from non-conductive material or may have a conductive core.
Any suitable fibres or yarns may be used for the conductive and non-conductive yarns. For example, copper, stainless steel or silver plated polyamide fibres may be used for the conductive yarns. Nylon, cotton or polyester fibres could be used for the non-conductive yarns.
A number of weave structures are possible based on the type of LED to be used, for example whether the LED is to be a single or multiple (bi/tri) colour type. The number of layers in the weave structure may depend on the type and grade of yarn used and the pitch of the weave. Preferably the number of layers in the warp direction is two, but more layers may be used without departing from the scope of the invention. In the illustrated embodiments, only one layer in the weft direction is shown, but more than one layer may be used without departing from the scope of the invention.
Referring to
In
The weave shown in
It is to be understood that the non-conducting weft yarns 101 in all embodiments and examples described herein do not necessarily follow the same paths as the conducting weft yarns as they are woven around and between conducting and non-conducting warp yarns.
The electrically conductive weft yarn 13 in
Two successive traversals of a conductive weft yarn through the textile, in which the conductive weft yarn 13 passes around at least one warp yarn in at least one, and preferably all, layers of the multi-layer warp, forms a loop 20. In
These examples are also in the form of double layer weaves containing a first layer of warp yarns 24 and a second layer of warp yarns 25, with an interlacing conductive weft yarn 23. In these double-sided matrix arrangements both the first layer 24 and second layer 25 of warp yarns contain conductive warp yarns 21. These conductive warp yarns 21 are also disposed on alternating faces 26, 27 of the textile in the first layer 24 and the second layer 25 respectively of the multi-layer warp, which in this example has only two layers. The weave structure in
In order to allow connection of multiple colour LEDs to the woven fibre matrix extra conductive warp yarns are needed, one for each cathode. Again, adjacent conductive warp yarns are separated by at least one interposing non-conductive warp yarn so that there is no electrical contact between adjacent conductive warp yarns, and between the conductive warp yarns and the interlacing conductive weft yarns. Adjacent conductive weft yarns are also separated by at least one non-conductive weft yarn 101 (shown further in
Extending the above illustrated arrangements of the weave structure permits tri-colour LEDs to be attached to the textile. In this case, for a single sided matrix the textile will preferably have at least a 1×7 twill weave, and for a double sided matrix the textile will preferably have at least a 7×7 twill weave. It is to be understood that the examples of weave structures given above contain only the minimum number of conductive and non-conductive yarns necessary in each case. Further non-conductive warp yarns and weft yarns can be included in the weave structure without altering the functionality of the textile.
Similarly, it will be understood that further conductive yarns may be incorporated. Where two conductive yarns (warp or weft) are positioned adjacent one another in the weave, they may be considered as electrically equivalent to a single conductive yarn but of twice the current carrying capacity.
Conductive crossovers may be required to connect the yarns that conduct the electrical signals such that driver electronics can be connected, for example by means of a parallel array connector. One exemplary conductive crossover 63 is illustrated in
The electrically conductive crossover 63 of
The bypass 73 of
To prevent the conductive weft yarns 62, 71 from coming loose, floats 81 may be incorporated into the weave as illustrated in
a and 10b illustrate schematically a plan view and a cross-section view along the weft direction of an example textile sheet for creating the electrode array of the embodiment of
Illustrated in
a illustrates an example of a two-layer weave with mono-colour pixels. Connection regions 156a for attachment of LEDs are indicated. Within each connection region 156a are situated an anode connection point 166a and a cathode connection point 165a, formed from a conductive warp yarn and conductive weft yarn respectively.
b illustrates an example of a two-layer weave with bi-colour pixels. Connection regions 156b for attachment of LEDs are indicated. Within each connection region 156b are situated a shared anode connection point 166a and two cathode connection points 165b, formed from a conductive warp yarn and adjacent conductive weft yarns respectively.
c illustrates an example of a two-layer weave with tri-colour pixels. Connection regions 156c for attachment of LEDs are indicated. Within each connection region 156c are situated a shared anode connection point 166c and three cathode connection points 165c, formed from a conductive warp yarn and adjacent conductive weft yarns respectively.
d illustrates an example of a three-layer weave with mono-colour pixels. Connection regions 156d for attachment of LEDs are indicated. Within each connection region 156d are situated an anode connection point 166d and a cathode connection point 165d, formed from a conductive warp yarn and conductive weft yarn respectively.
e illustrates an example of a three-layer weave with bi-colour pixels. Connection regions 156e for attachment of LEDs are indicated. Within each connection region 156e are situated a shared anode connection point 166e and two cathode connection points 165e, formed from a conductive warp yarn and adjacent conductive weft yarns respectively.
f illustrates an example of a three-layer weave with tri-colour pixels. Connection regions 156f for attachment of LEDs are indicated. Within each connection region 156f are situated a shared anode connection point 166f and three cathode connection points 165f, formed from a conductive warp yarn and adjacent conductive weft yarns respectively.
f illustrates connection regions 156f equivalent to the connection regions 156 of
Illustrated in
In the passive array of
In order to overcome the problem of passive matrix arrays, which result in a dim display illumination, active matrix addressing can instead be used. Such an active matrix is illustrated in
a represents the situation where every pixel is switched by a corresponding driver integrated circuit 185. An alternative and possibly more efficient arrangement may involve more than one pixel per driver integrated circuit 185, or even one driver integrated circuit per row.
The three-colour passive matrix array of
The textile of the embodiments and examples described herein may, in addition to electronic components such as LEDs, incorporate a radio frequency antenna comprising woven conductive yarns in electrical connection with and for remote communication with the electronic components. The antenna may be in the form of a coil comprising electrically conducting warp and weft yarns. Remote communication may be enabled via the driving circuitry. The antenna may be used to provide a communications link with remote control equipment. Such remote control equipment may provide signals to the antenna, which signals can then be translated by the driving circuitry into other signals, which other signals then drive the electronic components attached to the textile. Alternatively, or in addition, the antenna may transmit signals from the textile to the remote control equipment. Such transmitted signals may comprise information received by the driving circuitry from one or more electronic components attached to the textile, such as temperature, light or other sensors.
Other embodiments are within the scope of the appended claims.
Number | Date | Country | Kind |
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05104703.3 | May 2005 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2006/051716 | 5/30/2006 | WO | 00 | 11/26/2007 |