Abstract:
A touch panel has a test point formed on one end of each of the wires formed inside the touch panel and connected to a circuit board. The test point is larger than a wire diameter of the wires and serves to be contacted by a probe of a test instrument. Even if the probe is similar to the wires in width, the wires are not cut and broken by the probe. Accordingly, after the wires of the touch panel are tested by a probe-type test instrument, the touch panel can still operate normally without having the fault arising from the broken wires inadvertently cut by a probe.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is related to a touch panel, and more particularly to a touch panel having test points being accessible and wider than a wire. 
         [0003]    2. Description of the Related Art 
         [0004]    Touch panels can be categorized into capacitive type, resistive type, surface acoustic wave (SAW) type and the infrared type based on the applied technologies. The capacitive touch panels and the resistive touch panels have greater market share than the other two types. What the capacitive touch panels in common with the resistive touch panels pertains to a conductive glass formed by indium tin oxide (ITO) and serving as a sensor unit. On the other hand, the capacitive touch panels differ from the resistive touch panels in that the capacitive touch panels generate a capacitive variation while the resistive touch generates a voltage variation at which the conductive glass is touched. Regardless of what type of variation, a signal resulting from the variation is outputted to a controller through a plurality of wires connected to the conductive glass. The controller can calculate the coordinates of a location being touched in accordance with the signal. 
         [0005]    Usually, after finishing fabrication of the capacitive touch panels and the resistive touch panels, a test must be performed to check if each wire is electrically connected with the conductive glass. The test instrument currently available for such test pertains to a probe type instrument. Such test instrument has a plurality of probes serving to be respectively contacted with the wires when the test is conducted. Thus, the instrument can be electrically connected with the wires to determine if a signal generated by the conductive glass is transmitted to the corresponding wire. 
         [0006]    As the wire size of the wires of the foregoing touch panels is relatively small and is close to a diameter of the probe, some of the wires are oftentimes poked and broken by the probe of the test instrument during testing. In this regard, it happens that the test result of a touch panel indicates a normal connection between the conductive glass and the controller while the touch panel actually fails to perform normally later due to the broken wires therebetween jabbed by the probe. 
       SUMMARY OF THE INVENTION 
       [0007]    A first objective of the present invention is to provide a single substrate touch panel having test points being greater than a wire diameter of wires. 
         [0008]    To achieve the foregoing objective, the touch panel has a substrate. The substrate has a top surface, a bottom surface, a sensor unit and a plurality of wires. The sensor unit is formed on the top surface. The wires are mounted on the top surface of the substrate and formed by a conductive material. One end of each one of the wires is connected to the sensor unit and the other end has a test point being wider than the wire. 
         [0009]    Preferably, the end of each one of the wires having the test point is formed on the top surface of the substrate. 
         [0010]    Preferably, the end of each one of the wires having the test point further extends to the bottom surface of the substrate so that the test points are formed on the bottom surface of the substrate. 
         [0011]    A second objective of the present invention is to provide a dual substrate touch panel having test points being wider than a wire. 
         [0012]    To achieve the foregoing objective, the touch panel has a lower substrate and an upper substrate. The lower substrate has a top surface, a bottom surface, a lower sensor unit and at least one lower wire. The lower sensor is formed on the top surface. The at least one lower wire is mounted on the top surface of the lower substrate and formed by a conductive material. One end of each one of the at least one lower wire is connected to the lower sensor unit and the other end and has a first test point being wider than the lower wire. 
         [0013]    The upper substrate has a top surface, a bottom surface, an upper sensor unit and at least one upper wire. The upper sensor is formed on the bottom surface. The at least one upper wire are mounted on the bottom surface of the upper substrate and formed by a conductive material. One end of each one of the at least one upper wire is connected to the upper sensor unit and the other end extends to the lower substrate and has a second test point formed on the lower substrate and being wider than the upper wire. 
         [0014]    Preferably, the end of each one of the at least one upper wire having the second test point and the at least one lower wire having the first test point is formed on the top surface of the lower substrate. 
         [0015]    Preferably, the end of each one of the at least one upper wire having the second test point and the at least one lower wire having the first test point further extends to the bottom surface of the lower substrate so that the first test point of the at least one lower wire and the second test point of the at least one upper wire and are formed on the bottom surface of the lower substrate. 
         [0016]    Given a test point formed on one end of each one of the wires, the upper wires and the lower wires for the probe of a test instrument to contact with and being wider than the wires, the upper wire and the lower wire, the test points can be prevented from being cut and broken by the probe having a similar size to those wires. The issue that conventional touch panels are faulty for sake of broken wires being tested by the probe of the test instrument can be solved accordingly. Besides, the test points capable of being formed on the top surface or the bottom surface of the substrate facilitate the test points to be accessible to the probe. 
         [0017]    Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a perspective view of a first embodiment of a touch panel in accordance with the present invention; 
           [0019]      FIG. 2  is a perspective view of a second embodiment of a touch panel in accordance with the present invention; 
           [0020]      FIG. 3  is an exploded perspective view of a third embodiment of the touch panel in accordance with the present invention; 
           [0021]      FIG. 4  is a perspective view of the touch panel in  FIG. 3 ; 
           [0022]      FIG. 5  is a perspective view of a fourth embodiment of a touch panel in accordance with the present invention; 
           [0023]      FIG. 6  is an exploded perspective view of a fifth embodiment of the touch panel in accordance with the present invention; and 
           [0024]      FIG. 7  is an exploded perspective view of a sixth embodiment of a touch panel in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    A touch panel in accordance with the present invention is characterized by a test point formed on one end of each one of wires formed in the touch panel for transmitting signals. Such characteristic can be applied to touch panels which are built based on various touch panel technologies, such as single substrate projected capacitive technology, dual substrate resistive technology, dual substrate projected capacitve technology, or dual substrate matrix capacitive technology. Embodiments associated with the aforementioned touch panel technologies are given as follows. 
         [0026]    With reference to  FIG. 1 , being a single substrate projected capacitive touch panel, a first embodiment of a touch panel in accordance with the present invention has a substrate  10 , a sensor unit  20  and a plurality of wires  30 . 
         [0027]    The substrate  10  has a top surface  11  and a bottom surface  12 . The sensor unit  20  is formed on the top surface  11  and has a plurality of first conductive layers  21  and a plurality of second conductive layers  22 . The first conductive layers  21  parallelly align in a first direction. Each one of the first conductive layers  21  has a plurality of sensing areas  211  and a connection port  212 . The sensing areas  211  are serially connected. The connection port  212  of each one of the first conductive layers  21  is formed on an edge of an outermost sensing area  211  of the first conductive layer  21  in the first direction, and is formed by a conductive material. The second conductive layers  22  are formed on an unfilled space defined by the first conductive layers  21  and parallelly align in a second direction that is perpendicular to the first direction. Each one of the second conductive layers  22  has a plurality of sensing areas  221  and a connection port  222 . The sensing areas  221  are serially connected. All of the sensor areas  221  are formed by ITO and are semi-rhombic for the bordering sensing areas  221  and rhombic between the bordering sensing areas  221 . The connection port  222  of each one of the second conductive layers  22  is formed on an edge of an outermost sensing area  221  of the second conductive layer  22  in the second direction, and is formed by a conductive material. 
         [0028]    The wires  30  are formed on the top surface  11  of the substrate  10  and are made from a conductive material. A count of the wires  30  corresponds to that of the connection ports  212 ,  222  on the first conductive layer  21  and the second conductive layer  22 . One end of each one of the wires  30  is connected to one of the connection ports  212 ,  213 , and the other end has a test point  31  being wider than the wires  30 . In the first embodiment, the test points  31  are formed on the top surface of the substrate  10 . 
         [0029]    With reference to  FIG. 2 , in a second embodiment of a touch panel being a single substrate projected capacitive touch panel, one end of each one of the wires  30  further extends through a side edge of the substrate  10  and to the bottom surface  12  of the substrate  10 , and has a test point  31  being wider than the wire  30 . Therefore, the test points  31  are formed on the bottom surface  12 . 
         [0030]    With reference to  FIGS. 3 and 4 , being a double substrate resistive touch panel, a third embodiment of a touch panel has a lower substrate  40 , an upper substrate  50 , a lower sensor unit  60 , an upper sensor unit  70 , an insulation layer  91 , a separation layer  92 , at least one lower wire  81  and at least one upper wire  82 . 
         [0031]    The lower substrate  40  has a top surface  411  and a bottom surface  412 . The upper substrate  50  has a top surface  511  and a bottom surface  512 . The bottom surface  512  of the upper substrate  50  faces the top surface  411  of the lower substrate  40 . The lower sensor unit  60  is formed on the top surface  411  of the lower substrate  40  and has a lower conductive layer  61  formed by ITO. 
         [0032]    The upper sensor unit  70  is formed on the bottom surface  512  of the upper substrate  50  and has an upper conductive layer  71  formed by ITO. The insulation layer  91  is frame-shaped, matches the size of the upper substrate  50 , is mounted between the upper substrate  50  and the lower substrate  40 , and is overlapped on the upper substrate  50 . The separation layer  92  is mounted between the upper substrate  50  and the lower substrate  40  and within the insulation layer  91 . 
         [0033]    As a size of the lower substrate  40  is greater than that of the upper substrate  50 , one end portion on the top surface  411  of the lower substrate  40  protrudes beyond a boundary of the upper substrate  50 . Given a 5-wire resistive touch panel as an example, four lower wires  81  are formed on the top surface  411  of the lower substrate  40 . One end of each one of the lower wires  81  is formed on the lower conductive layer  61 , and the other end is formed on the exposed end portion and has a first test point  811  being wider than the lower wire  81 . The upper substrate  50  has only one upper wire  82  formed thereon. One end of the upper wire  82  is formed on the upper conductive layer  71 , and the other end extends to the exposed end portion on the top surface  411  of the lower substrate  40  through an edge of the insulation layer  91  abutting the exposed end portion. A second test point  821  is formed on the end of the upper wire  82  on the lower substrate  40  and is wider than the upper wire  82 . In the third embodiment, the first test points  811  and the second test point  821  are formed on the top surface of the lower substrate  40 . 
         [0034]    With reference to  FIG. 5 , a fourth embodiment of a touch panel is a double substrate resistive touch panel and is similar to the third embodiment of the double substrate resistive touch panel. In the fourth embodiment, the size of the lower substrate  40  matches that of the upper substrate  50 . One end of the upper wire  82  having the second test point  821  further extends to the bottom surface  412  of the lower substrate  40  through the insulation layer  91 , the lower conductive layer  61  and an edge of the lower substrate  40 . One end of the lower wire  81  having the first test point  811  extends to the bottom surface  412  of the lower substrate  40  through the edge of the lower substrate  40 . In the fourth embodiment, the first test points  811  and the second test point  821  are formed on the bottom surface  412  of the lower substrate  40 . 
         [0035]    With reference to  FIG. 6 , being a projected capacitive panel, a fifth embodiment of a touch panel in accordance with the present invention has a lower substrate  40 A, an upper substrate  50 A, a lower sensor unit  60 A, an upper sensor unit  70 A, an insulation layer  91 A, a plurality of lower wires  81 A, and a plurality of upper wires  82 A. Each one of the lower substrate  40 A and the upper substrate  50 A has a top surface  411 A,  511 A and a bottom surface  412 A,  512 A. The bottom surface  512 A of the upper substrate  50 A faces the top surface  411 A of the lower substrate  40 A. The lower sensor unit  60 A is formed on the top surface  411 A of the lower substrate  40 A and has a plurality of lower conductive layers  62 . The lower conductive layers  62  parallelly align in a first direction. Each one of the lower conductive layers  62  has a plurality of lower sensing areas  621  and a lower connection port  622 . The lower sensing areas  621  are serially connected and formed by ITO and are semi-rhombic for the bordering lower sensing areas  621  and rhombic between the bordering lower sensing areas  621 . The lower connection port  622  of each one of the lower conductive layers  62  is formed on an edge of an outermost sensing area  621  of the lower conductive layer  62  in the first direction, and is formed by a conductive material. The upper sensor unit  70 A is formed on the bottom surface  512 A of the upper substrate  50 A and has a plurality of upper conductive layers  72 . The upper conductive layers  72  parallelly align in a second direction that is perpendicular to the first direction. Each one of the upper conductive layers  72  has a plurality of upper sensing areas  721  and an upper connection port  722 . The upper sensing areas  721  are serially connected and formed by ITO and are semi-rhombic for the bordering upper sensing areas  721  and rhombic between the bordering upper sensing areas  721 . The upper connection port  722  of each one of the upper conductive layers  72  is formed on an edge of an outermost sensing area  721  of the upper conductive layer  72  in the second direction, and is formed by a conductive material. 
         [0036]    The insulation layer  91 A matches the size of the upper substrate  50 A, is mounted between the upper substrate  50 A and the lower substrate  40 A, and is overlapped on the upper substrate  50 A. 
         [0037]    When a size of the lower substrate  40 A is larger than that of the upper substrate  50 A as shown in  FIG. 6 , one end portion on the top surface  411 A of the lower substrate  40 A protrudes beyond a boundary of the upper substrate  50 A. The lower wires  81 A are formed on the top surface  411 A of the lower substrate  40 A and the count of the lower wires  81 A corresponds to that of the lower connection ports  622 . One end of each one of the lower wires  81 A is connected with the corresponding lower connection port  622 . The other end is formed on the exposed end portion and has a first test point  811 A being wider than the lower wire  81 A. The upper wires  82 A are formed on the bottom surface  512 A of the upper substrate  50 A and the count of the upper wires  82 A corresponds to that of the upper connection port  722 . One end of each one of the upper wires  82 A is connected with the corresponding upper connection port  722 . The other end extends to the exposed end portion on the top surface  411 A of the lower substrate  40 A through an edge of the insulation layer  91 A abutting the exposed end portion. A second test point  821 A is formed on the end of each one of the upper wire  82 A on the lower substrate  40 A and is wider than the upper wire  82 A. In the fifth embodiment, the first test points  811 A and the second test points  821 A are formed on the top surface  411 A of the lower substrate  40 A. 
         [0038]    Despite not shown in  FIG. 6  due to the similarity as in  FIG. 5 , when the size of the lower substrate  40 A matches that of the upper substrate  50 A, the end of the upper wire  82 A having the second test point  821 A extends to the bottom surface  412 A of the lower substrate  40 A through the insulation layer  91 A, the lower conductive layer  62  and an edge of the lower substrate  40 A. The second test point  821 A is wider than the upper wire  82 A. The end of the lower wire  81 A having the first test point  811 A extends to the bottom surface  412 A of the lower substrate  40 A through the edge of the lower substrate  40 A. The first test point  811 A is wider than the upper wire  81 A. When the lower substrate  40 A matches the upper substrate  50 A in size, the first test points  811 A and the second test points  821 A are formed on the bottom surface  412 A of the lower substrate  40 A. 
         [0039]    With reference to  FIG. 7 , being a matrix capacitive touch panel, a sixth embodiment of a touch panel in accordance with the present invention has a lower substrate  40 B, an upper substrate  50 B, a lower sensor unit  60 B, an upper sensor unit  70 B, an insulation layer  91 B, a plurality of lower wires  81 B, and a plurality of upper wires  82 B. Each one of the lower substrate  40 B and the upper substrate  50 B has a top surface  411 B,  511 B and a bottom surface  412 B,  512 B. The bottom surface  512 B of the upper substrate  50 B faces the top surface  411 B of the lower substrate  40 B. The lower sensor unit  60 B is formed on the top surface  411 B of the lower substrate  40 B and has a plurality of juxtaposed lower conductive layers  63 . The lower conductive layers  63  are rectangular, align in a first direction, and are formed by ITO. Each one of the lower conductive layers  63  has a lower connection port  631 . The lower connection port  631  is formed on one side of the corresponding lower conductive layer  63  that is perpendicular to the first direction and is made from a conductive material. The upper sensor unit  70 B is formed on the bottom surface  512 B of the upper substrate  50 B and has a plurality of juxtaposed upper conductive layers  73 . The upper conductive layers  73  are rectangular, align in a second direction that is perpendicular to the first direction, are formed by ITO, and are intersected with the lower conductive layers  63  in a form of columns and rows of a matrix. Each one of the upper conductive layers  73  has an upper connection port  731 . The upper connection port  731  is formed on one side of the corresponding upper conductive layer  73  that is perpendicular to the second direction and is made from a conductive material. 
         [0040]    The insulation layer  91 B matches the size of the upper substrate  50 B, is mounted between the upper substrate  50 B and the lower substrate  40 B, and is overlapped on the upper substrate  50 B. 
         [0041]    When a size of the lower substrate  40 B is larger than that of the upper substrate  50 B as shown in  FIG. 7 , one end portion on the top surface  411 B of the lower substrate  40 B protrudes beyond a boundary of the upper substrate  50 B. The lower wires  81 B are formed on the top surface  411 B of the lower substrate  40 B and the count of the lower wires  81 B corresponds to that of the lower connection ports  622 . One end of each one of the lower wires  81 B is connected with the corresponding lower connection port  631 . The other end is formed on the exposed end portion and has a first test point  811 B being wider than the lower wire  81 B. The upper wires  82 B are formed on the bottom surface  512 B of the upper substrate  50 B and the count of the upper wires  82 B corresponds to that of the upper connection ports  731 . One end of each one of the upper wires  82 B is connected with the corresponding upper connection port  731 . The other end extends to the exposed end portion on the top surface  411 B of the lower substrate  40 B through an edge of the insulation layer  91 B abutting the exposed end portion. A second test point  821 B is formed on the end of the upper wire  82 B on the lower substrate  40 B and is wider than the upper wire  82 B. In the sixth embodiment, the first test points  811 B and the second test points  821 B are formed on the top surface  411 B of the lower substrate  40 B. 
         [0042]    Despite not illustrated in  FIG. 7  due to the similarity as in  FIG. 5 , when the size of the lower substrate  40 B matches that of the upper substrate  50 B, the end of the upper wire  82 B having the second test point  822 B extends to the bottom surface  412 B of the lower substrate  40 B through the insulation layer  91 B, the lower conductive layer  63  and an edge of the lower substrate  40 B and has a second test point  822 B being wider than the upper wire  82 B. The end of the lower wire  81 B having the first test point  811 B extends to the bottom surface  412 B of the lower substrate  40 B through the edge of the lower substrate  40 B. The first test point  811 B is wider than the upper wire  81 B. When the lower substrate  40 B matches the upper substrate  50 B in size, the first test points  811 B and the second test points  821 B are formed on the bottom surface  412 B of the lower substrate  40 A. 
         [0043]    The touch panel of the present invention has a test point formed on one end of each one of the wires, the upper wires and the lower wires. Those test points are available for the probe of test instrument to contact with. As the test points are wider than the wires, the upper wires and the lower wires, the test points are not poked and broken by the probe having a similar size to those wires. Accordingly, the present invention can prevent the issue that conventional touch panels are faulty due to broken wires after the wires are tested by a probe-type test instrument. Moreover, being exposed, the test points of the present invention are located on the bottom surface of the lower substrate or on a portion of the top surface of the lower substrate protruding beyond the upper substrate. Therefore, when the test points are further connected with a circuit board for outputting signals, the circuit board is unnecessarily sandwiched between the upper substrate and the lower substrate, securing a tight bonding of the upper and lower substrates and preventing a reduced touch sensitivity caused by air penetrating from the gaps between the circuit board and the upper substrate as well as between the circuit board and the lower substrate. 
         [0044]    Besides, after test, the test points can be integrated with a circuit of a machine (for example: touch TV, mobile phone, e-book and the like) without having to worry about finding a place for placing and integrating the circuit board. 
         [0045]    Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.