Patent Publication Number: US-2015062065-A1

Title: Touch sensitive device

Description:
BACKGROUND 
     This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Applications: Application No. 201310386952.7, filed on Aug. 30, 2013, Application No. 201310447222.3, filed on Sep. 27, 2013, and Application No. 201310621196.1, filed on Nov. 29, 2013, in the China Intellectual Property Office, disclosures of which are incorporated herein by references. 
     1. Technical Field 
     The present disclosure relates touch sensitive devices, particularly to a three-dimensional touch sensitive device. 
     2. Description of Related Art 
     In recent years, various electronic apparatuses such as mobile phones, car navigation systems have advanced toward high performance and diversification. There is continuous growth in the number of electronic apparatuses equipped with optically transparent touch panels in front of their display devices such as liquid crystal panels. 
     A user of such electronic apparatus operates it by pressing a touch panel with a finger or a stylus while visually observing the display device through the touch panel. Thus a demand exists for such touch panels which superior in visibility and reliable in operation. Different types of touch panels, including a resistance-type, a capacitance-type, an infrared-type and a surface sound wave-type have been developed. A conventional capacitance-type touch panel usually includes an insulative substrate such as a glass plate, a transparent conductive layer such as an indium tin oxide (ITO) layer, and a plurality of electrodes. However, the touch panel is a two-dimensional touch sensitive device, and cannot detect the pressure of the finger of user. 
     What is needed, therefore, is to provide a touch sensitive device which can overcome the short come described above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a schematic view of one embodiment of a touch sensitive device. 
         FIG. 2  is a schematic view of one embodiment of a touch sensitive device. 
         FIG. 3  is a schematic view of one embodiment of a touch sensitive device. 
         FIG. 4  is a schematic view of one embodiment of a touch sensitive device. 
         FIG. 5  is a schematic view of one embodiment of a touch sensitive device. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
     References will now be made to the drawings to describe, in detail, various embodiments of the touch sensitive devices. 
     Referring to  FIG. 1 , a touch sensitive device  100  of one embodiment includes a touch module  110 , and a display module  120 . The touch module  110  and the display module  120  are stacked with and spaced from each other. The distance between the touch module  110  and the display module  120  can be selected according to need. In one embodiment, the touch module  110  and the display module  120  are overlapped with each other. The touch module  110  covers the display module  120 . 
     The touch module  110  is a self inductance capacitance-type touch module. The touch module  110  includes a first transparent conductive layer  112 , a plurality of electrodes (not shown) located on at least one side of and electrically connected with the first transparent conductive layer  112 , a protection layer  118  covering the first transparent conductive layer  112 . In one embodiment, the touch module  110  is a super-thin touch panel consisting of the first transparent conductive layer  112 , the protection layer  118 , and the plurality of electrodes. The first transparent conductive layer  112  is located on and in direct contact with a surface of the protection layer  118  facing the display module  120 . 
     The first transparent conductive layer  112  is a carbon nanotube layer. The carbon nanotube layer includes a single carbon nanotube film or a plurality of stacked carbon nanotube films. In one embodiment, first transparent conductive layer  112  is a carbon nanotube film with resistance anisotropy. Thus, the first transparent conductive layer  112  has good mechanical strength and flexibility and can have greater deformation without being destroyed. 
     The carbon nanotube film is a substantially pure structure consisting of a plurality of carbon nanotubes, with few impurities and chemical functional groups. The carbon nanotube film is a free-standing structure. The term “free-standing structure” includes, but is not limited to, the property that the carbon nanotube film can sustain the weight of itself when it is hoisted by a portion thereof without any significant damage to its structural integrity. Thus, the carbon nanotube film can be suspended by two spaced supports. The majority of carbon nanotubes of the carbon nanotube film are joined end-to-end by van der Waals force therebetween so that the carbon nanotube film is a free-standing structure. The carbon nanotubes of the carbon nanotube film can be single-walled, double-walled, or multi-walled carbon nanotubes. The diameter of the single-walled carbon nanotubes can be in about 0.5 nm to about 50 nm. The diameter of the double-walled carbon nanotubes can be in about 1.0 nm to about 50 nm. The diameter of the multi-walled carbon nanotubes can be in about 1.5 nm to about 50 nm. 
     The carbon nanotubes of the carbon nanotube film are oriented along a preferred orientation. That is, the majority of carbon nanotubes of the carbon nanotube film are arranged to substantially extend along the same direction and in parallel with the surface of the carbon nanotube film. Each adjacent two of the majority of carbon nanotubes of the carbon nanotube film are joined end-to-end by van der Waals force therebetween along the extending direction. A minority of dispersed carbon nanotubes of the carbon nanotube film may be located and arranged randomly. However, the minority of dispersed carbon nanotubes have little effect on the properties of the carbon nanotube film and the arrangement of the majority of carbon nanotubes of the carbon nanotube film. The majority of carbon nanotubes of the carbon nanotube film are not absolutely form a direct line and extend along the axial direction, some of them may be curved and in contact with each other in microcosm. Some variations can occur in the carbon nanotube film. Because the electric conductivity of the carbon nanotubes along the axial direction is much better than the electric conductivity along the radial direction, and the majority of the carbon nanotubes of the carbon nanotube film are substantially arranged to extend along the same direction, the carbon nanotube film is conductivity anisotropy. 
     The carbon nanotube film can be made by the steps of: growing a carbon nanotube array on a wafer by chemical vapor deposition (CVD) method; and drawing the carbon nanotubes of the carbon nanotube array to from the carbon nanotube film. During the drawing step, the carbon nanotubes are joined end-to-end by van der Waals attractive force therebetween along the drawing direction. The width of the carbon nanotube film can be in a range from about 1 millimeter to 10 centimeters, and the thickness of the carbon nanotube film can be in a range from about 0.5 nanometers to 150 micrometers. The carbon nanotube film has the smallest resistance along the drawing direction and the greatest resistance along a direction perpendicular to the drawing direction. Thus, the carbon nanotube film is resistance anisotropy. Furthermore, the carbon nanotube film can be etched or irradiated by laser. After being irradiated by laser, a plurality of parallel carbon nanotube conductive strings will be formed and the resistance anisotropy of the carbon nanotube film will not be damaged because the carbon nanotube substantially extending not along the drawing direction are removed by burning. Each carbon nanotube conductive string comprises a plurality of carbon nanotubes joined end-to-end by van der Waals attractive force. 
     In one embodiment, the carbon nanotube film includes a plurality of successively oriented carbon nanotube segments joined end-to-end by van der Waals attractive force therebetween. Each carbon nanotube segment includes a plurality of carbon nanotubes parallel to each other, and combined by van der Waals attractive force therebetween. The carbon nanotubes in the carbon nanotube film are oriented along a preferred orientation. 
     The free-standing carbon nanotube film can be drawn from a carbon nanotube array and then placed on the protection layer  118  directly. Because of the adhesive properties of the drawn carbon nanotube film, the carbon nanotube film can be attached on the protection layer  118  firmly. The carbon nanotube film can also be fixed on the protection layer  118  by an adhesive layer such as an optically clear adhesive (OCA) layer. The optically clear adhesive layer is located between the protection layer  118  and the carbon nanotube film. 
     The plurality of electrodes are located at one side of the first transparent conductive layer  112  and spaced from each other. The plurality of electrodes are arranged along a direction perpendicular with the extending direction of the carbon nanotubes of the first transparent conductive layer  112 . The plurality of electrodes can be made of material such as metal, carbon nanotube, conductive silver paste, or transparent conductive oxide (TCO), and can be made by etching a metal film, etching an TCO film, or printing a conductive silver paste. The metal can be silver, tin, copper, or platinum. The material of the TCO film can be ITO, indium zinc oxide (IZO), aluminum zinc oxide (AZO), zinc oxide (ZnO) or tin oxide (TO). In one embodiment, the plurality of electrodes are made of metallic carbon nanotubes. 
     The protection layer  118  is made of a transparent and flexible material such as polycarbonate (PC), polymethyl methacrylate acrylic (PMMA), polyimide (PI), polyethylene terephthalate (PET), polyethylene (PE), polyether polysulfones (PES), polyvinyl polychloride (PVC), benzocyclobutenes (BCB), polyesters, or acrylic resin. The size and shape of the protection layer  118  can be selected according to need. In one embodiment, the thickness of the protection layer  118  is in a range from about 100 micrometers to about 500 micrometers. In one embodiment, the protection layer  118  is a flat PET plate with a thickness of 150 micrometers. The protection layer  118  is located the surface of the first transparent conductive layer  112  adjacent to the user. 
     The touch module  110  is flexible because all the first transparent conductive layer  112 , the protection layer  118  and the plurality of electrodes are flexible. 
     The display module  120  can be can any type display having a second transparent conductive layer  122 , such as a liquid crystal display (LCD), a field emission display (FED), electroluminescent display (ELD), vacuum fluorescent display (VFD), organic light emitting diode (OLED) display, cathode ray tube (CRT) display, electronic ink (E-ink) display, or electronic paper display (EPD). The surface of the display module  120  can be a flat or curved surface. The display module  120  can play other function at the same time. In one embodiment, the display module  120  is a liquid crystal display. 
     In one embodiment, the display module  120  is an electronic paper display. The electronic paper display can be micro-capsule type electrophoretic display, micro cup type electrophoretic display, gyricon bead type electrophoretic display, or partition type electrophoretic display. 
     The electronic paper display includes a low electrode plate, an electrophoretic medium layer, and an upper electrode plate stacked in that order. The electrophoretic medium layer is sandwiched between the low electrode plate and the upper electrode plate. The upper electrode plate includes an upper plate and the second transparent conductive layer  122  located on a surface of the upper plate adjacent to the electrophoretic medium layer. The low electrode plate includes a low plate and a plurality of pixel electrodes located on a surface of the low plate adjacent to the electrophoretic medium layer. The electrophoretic medium layer is in direct contact with the second transparent conductive layer  122  and the plurality of pixel electrodes. The surface of the upper plate away from the electrophoretic medium layer is used as a display surface adjacent to user. 
     The can be made of transparent flexible materials or transparent rigid materials such as glass, quartz, diamond, plastic or any other suitable material. The second transparent conductive layer  122  is transparent with a light transmittance greater than 70%, especially greater than 90%. The low electrode plate further includes a plurality of thin film transistors electrically connected to and used to control the plurality of pixel electrodes. The electrophoretic medium layer includes bistable electronic ink medium. In one embodiment, the electrophoretic medium layer includes a plurality of micro-capsules. Each micro-capsule packages a plurality of first electrophoresis ion and a plurality of second electrophoresis ion. 
     The low plate and the upper plate are optional. For example, the electronic paper display module  120  and the touch module  110  can use a common plate. 
     The second transparent conductive layer  122  is a component of the display module  120  and directly integrated in the display module  120 . That is, the second transparent conductive layer  122  is an inherent transparent conductive layer of the display module  120 . The material of the second transparent conductive layer  122  can be selected according to need, such as ITO, carbon nanotubes. The thickness of the second transparent conductive layer  122  can be in a range from about 50 micrometers to about 300 micrometers. The second transparent conductive layer  122  can be a patterned or an un-patterned. In one embodiment, the second transparent conductive layer  122  is a continuous un-patterned ITO film with a thickness in a range from about 50 micrometers to about 300 micrometers, such as 125 micrometers. Furthermore, the other necessary component of the display module  120  is not described in the disclosure and can be selected according to need. 
     Furthermore, an insulative support  130  is located between the touch module  110  and the display module  120  to insulate the touch module  110  and the display module  120  from each other. 
     As shown in  FIG. 1 , the insulative support  130  can be two strip shaped insulative elements or an insulative frame located on the periphery of two opposite surfaces of the touch module  110  and the display module  120 . Thus, a space (not labeled) is defined by the insulative support  130 , the touch module  110  and the display module  120 . The strip shaped insulative elements or the insulative frame can be made of elastic material or rigid material such as glass, quartz, diamond, plastic. In one embodiment, the insulative support  130  is an insulative frame made of elastic material with a Young&#39;s modulus smaller than the Young&#39;s modulus of the OCA layer. 
     As shown in  FIG. 2 , the insulative support  130  can be a continuous insulative layer made of elastic material with a Young&#39;s modulus smaller than the Young&#39;s modulus of the OCA layer. The continuous insulative layer is in direct contact with the two opposite surfaces of the touch module  110  and the display module  120 . The shape and size of the continuous insulative layer is the same as the shape and size of the two opposite surfaces of the touch module  110  and the display module  120 . 
     The first transparent conductive layer  112  and the second transparent conductive layer  122  function as a touch pressure sensing unit together. Because the insulative support  130  is located between first transparent conductive layer  112  and the second transparent conductive layer  122 , the distance between the first transparent conductive layer  112  and the second transparent conductive layer  122  is changeable under a pressure. When a touch is applied on the touch module  110  by a finger, the touch module  110  will detect the capacitance change of the first transparent conductive layer  112  and determine the position of the touch. When a pressure is applied on the touch module  110  by the finger, the distance between the first transparent conductive layer  112  and the second transparent conductive layer  122  will be changed. Thus, the capacitance between the first transparent conductive layer  112  and the second transparent conductive layer  122  will be changed. The pressure can be determined according to the capacitance change between the first transparent conductive layer  112  and the second transparent conductive layer  122 . The apparatus having the touch sensitive device  100  will perform a function according to the pressure. 
     Referring to  FIG. 3 , a touch sensitive device  200  of one embodiment includes a touch module  210 , and display module  220 . The touch module  210  and the display module  220  are stacked with and spaced from each other. 
     The touch sensitive device  200  is similar to the touch sensitive device  100  above except that the touch module  210  is a mutual inductance capacitance-type touch module. The touch module  210  includes a first transparent conductive layer  212 , a common substrate  214 , a third transparent conductive layer  216 , a protection layer  218 , a plurality of first electrodes (not shown), and a plurality of second electrodes. The first transparent conductive layer  212 , the common substrate  214 , the third transparent conductive layer  216 , and the protection layer  218  are stacked with each other in that order. The first transparent conductive layer  212  and the third transparent conductive layer  216  are located on two opposite surfaces of the common substrate  214 . The protection layer  218  covers the third transparent conductive layer  216  and can be bonded to the third transparent conductive layer  216  by an OCA layer. The plurality of first electrodes are located on at least one side of and electrically connected with the first transparent conductive layer  212 . The plurality of second electrodes are located on at least one side of and electrically connected with the third transparent conductive layer  216 . 
     The first transparent conductive layer  212  is the same as the first transparent conductive layer  112  above. In one embodiment, the first transparent conductive layer  212  is a single carbon nanotube film. 
     The common substrate  214  is made of a transparent and flexible material such as polycarbonate (PC), polymethyl methacrylate acrylic (PMMA), polyimide (PI), polyethylene terephthalate (PET), polyethylene (PE), polyether polysulfones (PES), polyvinyl polychloride (PVC), benzocyclobutenes (BCB), polyesters, or acrylic resin. The thickness, size and shape of the common substrate  214  can be selected according to need. In one embodiment, the common substrate  214  is a flat PET plate with a thickness of 2 millimeters. The size and shape of the common substrate  214  is substantially the same as the size and shape of the first transparent conductive layer  212  and the third transparent conductive layer  216 . 
     The third transparent conductive layer  216  can be a transparent conductive film with resistance anisotropy, such as a patterned TCO film, graphene film, carbon nanotube film, or metal mesh. In one embodiment, the third transparent conductive layer  216  a patterned ITO film with a thickness in a range from about 50 micrometers to about 300 micrometers, such as 125 micrometers. 
     The protection layer  218  and the display module  220  can be the same as the protection layer  118  and the display module  120  above. Furthermore, an insulative support  230  is located between the touch module  210  and the display module  220  to insulate the touch module  210  and the display module  220  from each other. The insulative support  230  is the same as the insulative support  130  above. The working principle of the touch sensitive device  200  is the same as the touch sensitive device  100  above. 
     Referring to  FIG. 4 , a touch sensitive device  300  of one embodiment includes a touch module  310 , display module  320 , and a fourth transparent conductive layer  340 . The touch module  310 , the fourth transparent conductive layer  340  and the display module  320  are stacked with each other. In one embodiment, the touch module  310 , the fourth transparent conductive layer  340  and the display module  320  are overlapped with each other. The fourth transparent conductive layer  340  is located between the touch module  310  and the display module  320 . The fourth transparent conductive layer  340  is located on and in direct contact with a surface of the display module  320  and spaced from the touch module  310 . 
     The touch sensitive device  300  is similar to the touch sensitive device  100  above except that a fourth transparent conductive layer  340  is located between the touch module  310  and the display module  320  and spaced from the touch module  310 . 
     The touch module  310  includes a first transparent conductive layer  312 , a plurality of electrodes (not shown) located on at least one side of and electrically connected with the first transparent conductive layer  312 , a protection layer  318  covering the first transparent conductive layer  312 . In one embodiment, the touch module  310  is a super-thin touch panel. The first transparent conductive layer  312  and the fourth transparent conductive layer  340  function as a touch pressure sensing unit together. The display module  320  is the same as the display module  120  above. 
     The fourth transparent conductive layer  340  can be a TCO film, graphene film, carbon nanotube film, or metal mesh. The fourth transparent conductive layer  340  can be patterned or un-patterned. In one embodiment, the fourth transparent conductive layer  340  is a continuous un-patterned ITO film with a thickness in a range from about 50 micrometers to about 300 micrometers, such as 125 micrometers. In one embodiment, the fourth transparent conductive layer  340  is a patterned carbon nanotube film having carbon nanotubes extending along a direction perpendicular with the extending direction of the carbon nanotubes of the first transparent conductive layer  312 . 
     Furthermore, an insulative support  330  is located between the first transparent conductive layer  312  and the fourth transparent conductive layer  340  to insulate the first transparent conductive layer  312  and the fourth transparent conductive layer  340  from each other. The insulative support  330  is in direct contact with the first transparent conductive layer  312  and the fourth transparent conductive layer  340 . Thus, the first transparent conductive layer  312  and the fourth transparent conductive layer  340  are only insulated by the insulative support  330 . The insulative support  330  is the same as the insulative support  130  above. 
     When a touch pressure is applied on the touch module  310  by the finger, the distance between the first transparent conductive layer  312  and the fourth transparent conductive layer  340  will be changed, and the capacitance between the first transparent conductive layer  312  and the fourth transparent conductive layer  340  will be changed. The pressure can be determined according to the capacitance change between the first transparent conductive layer  312  and the fourth transparent conductive layer  340 . 
     Referring to  FIG. 5 , a touch sensitive device  400  of one embodiment includes a touch module  410 , display module  420 , and a fifth conductive layer  440 . The touch module  410 , the display module  420 , and the fifth conductive layer  440  are stacked with each other. In one embodiment, the touch module  410 , the display module  420 , and the fifth conductive layer  440  are overlapped with each other. The display module  420  is located between the touch module  410  and the fifth conductive layer  440 . 
     The touch sensitive device  400  is similar to the touch sensitive devices  100 ,  200  above except that a fifth conductive layer  440  is located on the surface of the display module  420  away from the touch module  410 . The fifth conductive layer  440  can be a transparent conductive layer described above or an opaque conductive layer such as a metal film, conductive ceramic film, a conductive polymer film, or a conductive silver paste layer. The fifth conductive layer  440  can be a patterned or an un-patterned. In one embodiment, the fifth conductive layer  440  is a continuous un-patterned aluminum film with a thickness in a range from about 50 micrometers to about 300 micrometers, such as 125 micrometers. 
     The display module  420  includes a second transparent conductive layer  422 . The second transparent conductive layer  422  is the same as the second transparent conductive layer  122  above. The second transparent conductive layer  422  is a component of the display module  420  and directly integrated in the display module  420 . The second transparent conductive layer  422  is adjacent to the fifth conductive layer  440 . 
     The touch module  410  can be a self inductance capacitance-type touch module, a mutual inductance capacitance-type touch module or other type of touch module. The display module  420  is the same as the display module  120  above. In one embodiment, the display module  420  is an electronic paper display, and the plurality of pixel electrodes are used as the second transparent conductive layer  422 . The plurality of pixel electrodes are inherent transparent conductive layer of the display module  420  and integrated in the display module  420 . 
     Furthermore, an insulative support  430  is located between the fifth conductive layer  440  and the display module  420  to insulate the fifth conductive layer  440  and the second transparent conductive layer  422  from each other. The insulative support  430  is the same as the insulative support  130  above. When the insulative support  430  is two strip shaped insulative elements or an insulative frame, the insulative support  430  is located on the periphery of the display module  420 . The fifth conductive layer  440  should be a free-standing structure, such as a metal plate, or formed on a surface of a free-standing plate such as a glass plate. A space (not labeled) is defined by the insulative support  430 , the fifth conductive layer  440  and the display module  420 . In one embodiment, the insulative support  430  is a continuous insulative layer made of elastic material with a Young&#39;s modulus smaller than the Young&#39;s modulus of the OCA layer, and the fifth conductive layer  440  is located on and in direct contact with the surface of the insulative support  430  away from the display module  420 . In one embodiment, the display module  420  is an electronic paper display, and the low plated of the display module  420  is used as the insulative support  430 . 
     The fifth conductive layer  440  and the second transparent conductive layer  422  function as a touch pressure sensing unit together. The working principle of the touch pressure sensing unit of touch sensitive device  400  is the same as the working principle of the touch pressure sensing unit of the touch sensitive device  100 . 
     The touch module  410  and the display module  420  can be in direct contact with or spaced from each other. In one embodiment, the touch module  410  and the display module  420  are bonded together and insulated from each other by a rigid insulative layer therebetween. 
     Furthermore, the touch module  410  can be omitted if the touch position is not needed to be determined. The touch sensitive device  400  consists of the display module  420 , the insulative support  430 , and the fifth conductive layer  440 . 
     It is to be understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Any elements described in accordance with any embodiments is understood that they can be used in addition or substituted in other embodiments. Embodiments can also be used together. Variations may be made to the embodiments without departing from the spirit of the disclosure. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure. 
     Depending on the embodiment, certain of the steps of methods described may be removed, others may be added, and the sequence of steps may be altered. It is also to be understood that the description and the claims drawn to a method may include some indication in reference to certain steps. However, the indication used is only to be viewed for identification purposes and not as a suggestion as to an order for the steps.