Patent Publication Number: US-2011073353-A1

Title: Conductive fabric and method for forming the same

Description:
FIELD 
     The present invention relates to a conductive fabric and a method for forming the same. More particularly, the present invention relates to a layered conductive fabric and a method for forming the same. 
     BACKGROUND 
     Fabrics in modern life are mostly used for being woven into normal clothing. Those fabrics have no additional function except for keeping warm and pursuing fashion. Recently, with the rapid growth of technology, more functions of the fabrics have been developed to increase the convenience of human life. For example, some of the fabrics are formed with some electronic components being attached thereon. Therefore, the clothing made of those fabrics with electronic components can be applied to many new fields. For example, LED lights can be used as indicators on the clothing for showing other people the ongoing direction or other applications. 
     However, it is complicated to attach the electronic components to the fabrics and detrimental to mass production accordingly. Moreover, one of the most important issues for those fabrics with electronic components attached thereon is to develop appropriate structures for insulation. Specifically, the fabrics must be conductive for those electronic components. Therefore, if the circuits are not insulted completely, those electronic components would be easily short with the human body and result in injury to the one who wear the clothing made of those fabrics. Accordingly, a better structure and manufacturing method for conductive fabrics is essentially needed. 
     SUMMARY 
     The present invention addresses the above needs by providing a conductive fabric and a method for forming the same. On account of a layered structure of the conductive fabric, the circuits of the fabrics can work well without causing any short circuit so that an electrical component can be attached onto it and function as well. 
     An objective of certain embodiments of the present invention is to provide a conductive fabric. The conductive fabric comprises a first layer and a second layer. The first layer has at least one first conductive thread and a plurality of first non-conductive threads. The at least one first conductive thread is woven within the plurality of first non-conductive threads. The second layer has at least one second conductive thread and a plurality of second non-conductive threads. The at least one second conductive thread is woven within the plurality of second non-conductive threads. The first layer is woven with the second layer and insulated from the second layer so that an electronic component can be attached to and electrically connect to the at least one first conductive thread of the first layer and the at least one second conductive thread of the second layer. 
     Another objective of certain embodiments of the invention is to provide a method for forming a conductive fabric. The method comprises: weaving at least one first conductive thread within a plurality of first non-conductive threads to form a first layer with at least one first cored yarn; weaving at least one second conductive thread within a plurality of second non-conductive threads to form a second layer with at least one second cored yarn; and weaving the first layer and the second layer with a plurality of third non-conductive threads. 
     Yet a further objective of certain embodiments of the invention is to provide a fabric circuit. The fabric circuit comprises at least one electronic component and a conductive fabric. The conductive fabric comprises a first layer and a second layer. The first layer has at least one first conductive thread and a plurality of first non-conductive threads, wherein the at least one first conductive thread is woven within the plurality of first non-conductive threads. The second layer has at least one second conductive thread and a plurality of second non-conductive threads. The at least one second conductive thread is woven within the plurality of second non-conductive threads. The first layer is woven with the second layer and insulated from the second layer so that an electronic component can be attached to and electrically connect to the at least one first conductive thread of the first layer and the at least one second conductive thread of the second layer. The at least one electronic component is attached to the conductive fabric and electrically connects to the at least one first conductive thread and the at least one second conductive thread. 
     The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. It is understood that the features mentioned hereinbefore and those to be commented on hereinafter may be used not only in the specified combinations, but also in other combinations or in isolation, without departing from the scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic view of a first example embodiment of the present invention; 
         FIG. 1B  is a schematic view of a first layer of an example embodiment of the present invention; 
         FIG. 1C  is a schematic view of a second layer of an example embodiment of the present invention; 
         FIG. 1D  is a cross-section view of the first layer from A to A′ in  FIG. 1B ; 
         FIG. 1E  is a cross-section view of the second layer from B to B′ in  FIG. 1C ; 
         FIG. 1F  is a cross-section view of a fabric circuit  1  from A to A′ in  FIG. 1A ; 
         FIG. 1G  is a cross-section view of the fabric circuit from B to B′ in  FIG. 1A ; 
         FIG. 2A  is a schematic view of a second example embodiment of the present invention; 
         FIG. 2B  is a cross-section view of a fabric circuit  1 ′ from C to C′ in  FIG. 2A ; 
         FIG. 3A  is a schematic view of a third example embodiment of the present invention; 
         FIG. 3B  is a schematic view of a fourth example embodiment of the present invention; 
         FIG. 4  is a schematic view of a fifth example embodiment of the present invention; and 
         FIG. 5  is a flowchart of a sixth example embodiment of the present invention. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular example embodiments described. On the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1A , it shows a fabric circuit  1  of a first embodiment of the present invention. The fabric circuit  1  can be integrated into one portion of any conventional fabrics or cloth to broaden the original functions thereof. Specifically, the fabric circuit  1  comprises a conductive fabric  2  and at least one electrical component  3  attached on the conductive fabric  2 . The conductive fabric  2  of this invention basically is a fabric capable of electrically connecting with any electrical component, such as light emitting diodes (LEDs), chips, or the like. 
     Referring to  FIG. 1B  and  FIG. 1C  simultaneously the conductive fabric  2  comprises a first layer  21  and a second layer  22 . The first layer  21  has, for example, but not limited to, four first conductive threads  210  and a plurality of first non-conductive threads  212 . The first conductive threads  210  are flexible and woven within the first non-conductive threads  212 . Similarly, the second layer  22  has, for example, but not limited to, four second conductive threads  220  and a plurality of second non-conductive threads  222 . The second conductive threads  220  are flexible and woven within the second non-conductive threads  222 . 
     It should be noted that the first conductive threads  210  and the second conductive threads  220  are made of any conductive fibers with electric conductivity, for example, but not limited to, stainless steel fibers, carbon fibers, sputtered silver, or their combinations. Moreover, the first conductive threads  210  and the second conductive threads  220  are flexible enough for be woven with any conventional fabrics or cloth. Further, the first non-conductive threads  212  of the first layer  21  and the second non-conductive threads  222  of the second layer  22  are all made of any non-conductive materials, for example, polyester, PET, cotton, pure polyurethane polymer, or their combinations. 
     More details of the first layer  21  are shown in  FIG. 1D  which is a cross-section view of the first layer  21  from A to A′ in  FIG. 1B . It can be seen clearly that the first non-conductive threads  212  are formed in a layered structure. Preferably, one portion of the first non-conductive threads  212  comprises a plurality of first covering portions  2120 . In this embodiment, four first covering portions  2120  existed in the layered structure and each of the first conductive threads  210  is covered by the corresponding first covering portion  2120  to form a first cored yarn  214 . Then, the first cored yarns  214  would be used to be woven with another portion of the first non-conductive threads  212  together to form the first layer  21 . It is noted that the cored yarn is a basic conductive unit of the conductive fabric with a good insulation property, and the cored yarn is flexible and could be easily wound around a shuttle so that the cord yarn could be easily adopted in any conventional textile machinery. 
     Similarly,  FIG. 1E  is the cross-section view of the second layer  22  from B to B′ in  FIG. 1C .  FIG. 1E  illustrates the details of the second layer  22  just the same as the details of the first layer  21 . The second non-conductive threads  222  are formed in a layer structure as well and one portion of the second non-conductive threads  222  comprise four second covering portions  2220  covering the four second conductive threads  220  respectively and form four second cored yarn  224  existed therein. Then, the second cored yarns  224  would be used to be woven with another portion of the second non-conductive threads  222  together to form the second layer  22 . 
     As described above, the first and the second conductive threads  210 ,  220  are woven or knit within the first and the second non-conductive threads  212 ,  222  to form the first layer  21  and the second layer  22  respectively. Moreover, other manufacturing methods would be applied to form the layered structure, such as embroidery or printing, or the like. Furthermore, the first layer  21  could be woven or embroidery with the second layer  22  together to form the fabric circuit  1  wherein the first layer  21  is insulated from the second layer  22 . To enhance the insulation between the fabric circuit  1  with the human body, the conductive fabric  2  can further comprise at least one insulation layer for covering one of the first layer  21  and the second layer  22 . As the preferred embodiment shown in  FIG. 4 , there are two insulation layers  41 ,  42  for covering the first layer  21  and the second layer  22  individually. The insulation layer could be coated or printed or adhesive to the first and the second layers  21 ,  22  by any non-conductive material. More details will be described in the following. 
     In a preferred embodiment, the conductive fabric  2  further comprises a plurality of third non-conductive threads  232  for weaving the first layer  21  and the second layer  22  together and insulating therebetween, as shown in  FIG. 1F  and  FIG. 1G  which are the cross-section views of the fabric circuit  1  in  FIG. 1A . Particularly, the third non-conductive threads  232  could be formed as a layered structure between the first layer  21  and the second layer  22 . The third non-conductive threads  232  are made of any non-conductive material, for example, polyester, PET, cotton, pure polyurethane polymer, or their combinations, so that the first layer  21  would be completely insulated from the second layer  22 . 
     Furthermore, in this embodiment, the first layer  21  and the second layer  22  are woven together as mentioned above while the first cored yarns  214  and the second cored yarns  224  in the conductive fabric  2  are configured in warps and wefts form as shown in  FIG. 1A . Therefore, there are many junctions formed by intersecting the first cored yarns  214  and the second cored yarns  224 . The junctions distributed on the conductive fabric  2  are arranged in a matrix or an array or any other configurations. 
       FIGS. 1A ,  1 F and  1 G illustrate a top view and two cross-section views of the fabric circuit  1 . The electronic component  3  can be attached to a position adjacent to any junction of the fabric circuit  1 . Specifically, the electronic component  3  has two leads  31  which are used for being attached onto the conductive fabric  2 . Particularly, two conductive sewing threads  24  are used for sewing the leads  31  of the electronic component  3  onto one position which has a small offset d with a specific junction of the conductive fabric  2 , and each of the leads  31  of the electronic component  3  electrically connects to one of the first conductive threads  210  and one of the second conductive threads  220  respectively near the junction. Similarly, the conductive sewing threads  24  are made of any conductive fibers with electric conductivity, for example, but not limited to, stainless steel fibers, carbon fibers, sputtered silver, or their combinations. 
     Similar with sewing buttons onto cloth, the electronic component  3  could be sewn onto the conductive fabric  2  by any conventional sewing machine. Therefore, both the conductive fabric  2  and the fabric circuit  1  can be manufactured by any conventional textile machinery and/or sewing machine in a mass production manner. 
     The electronic component  3  can be detachably attached to and electrically connect to one of the first conductive threads  210  of the first layer  21  and one of the second conductive threads  220  of the second layer  22  systematically, and the electronic component  3  can function well when the first conductive threads  210  and the second conductive threads  220  are electrically connected to the power system (not shown). Moreover, when the fabric circuit  1  is arranged in a matrix circuit, the electronic components  3 , such as LEDs, can be driven by any conventional control code for different specific applications, such as entertainments, indicating, signaling. It should be noted that the sewing threads  24  can electrically connect the first and the second conductive threads  210 ,  220  with the leads of the electronic component  3  directly driven by the sewing machine needle puncturing through the first layer  21  and the second layer  22  several times. 
       FIG. 2A  and  FIG. 2B  illustrate a fabric circuit  1 ′ of a second embodiment. In this embodiment, the first cored yarns  214  of the first layer  21  and the second cored yarns  224  of the second layer  22  are woven in parallel. The other features of the fabric circuit  1 ′ are similar with those of the fabric circuit  1 . Hence, the details of the structure of the fabric circuit  1 ′ will not be further described. 
     Based on the disclosure above, another two example fabric matrixes can be accomplished.  FIG. 3A  and  FIG. 3B , illustrate a third example embodiment and a fourth example embodiment of aspects of this invention respectively. A plurality of electronic components  3  are attached to each position adjacent to the junction of the fabric circuit  1  and the fabric circuit  1 ′. In certain embodiments, if the electronic components  3  comprise several LEDs, the different lighting patterns on the fabric circuit  1  and the fabric circuit  1 ′ can be accomplished. 
     A fifth example embodiment of aspects of the present invention is illustrated in  FIG. 4 . The conductive fabric  2  comprises two insulation layers  41 ,  42  for covering the first layer  21  and the second layer  22  individually. The other elements are the same with those described in the aforesaid. The two insulation layers  41 ,  42  are used to enhance the insulation between the fabric circuit  1  and the human body. The other details of this embodiment are similar with the abovementioned. 
     A sixth example embodiment of aspects of the present invention is a method for forming a conductive fabric which is similar to the conductive fabrics  2 ,  2 ′ as described above. Referring to  FIG. 5 , a flowchart of an example method according to an embodiment of the present invention is provided. In step  501 , at least one first conductive thread is woven within a plurality of first non-conductive threads to form a first layer with at least one first cored yarn. Particularly, some of the first non-conductive threads are used for covering the at least one first conductive thread to form the at least one first cored yarn. And if there is more than one first cored yarn, rests of the first non-conductive threads are then used for weaving the first cored yarns together. 
     In step  502 , at least one second conductive thread is woven within a plurality of second non-conductive threads to form a second layer with at least one second cored yarn. Similarly, some of the second non-conductive threads are used for covering the at least one second conductive thread to form the at least one second cored yarn. If there is more than one second cored yarn, rests of the second non-conductive threads are then used for weaving the second cored yarns together. 
     In step  503 , the first layer and the second layer are woven together with a plurality of third non-conductive threads. Specifically, the third non-conductive threads are woven into a layer between the first layer and the second layer, and then weaving the first layer and the second layer together at the same time. 
     Finally, step  504  is optionally for providing two insulation layers for covering the first layer and the second layer individually. Similar to the third non-conductive threads which are used for insulating and weaving the first layer and the second layer, the two insulation layers can be woven onto the first layer and the second layer respectively. 
     The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is, therefore, desired that the present disclosure and embodiments be considered in all respects as illustrative and not restrictive. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.