Abstract:
A capacitive touch panel has two basal plates, an adhesive ring and a dot spacer. Each of the two basal plates has a working surface and an outer rim. One basal plate further has a conductive area, a peripheral area and a metal wiring area. The peripheral area is defined between the outer rim and the conductive area. The adhesive ring is made with a reusable adhesive agent and clamped between the peripheral areas of the basal plates without contacting the conductive area. The dot spacer is clamped between the basal plates and positioned within the conductive area. The adhesive ring, being a reusable adhesive agent, does not stick fast to the conductive area and thus allows a manufacturer to accurately align the basal plates during manufacture and thus to raise yield rate.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a capacitive touch panel, especially to a capacitive touch panel allowing fine adjustment of two basal plates in a manufacture process of the same and thus capable of preventing interference between the two basal plates. 
         [0003]    2. Description of the Prior Art 
         [0004]    Conventional touch panels are categorized into capacitive-type, resistance-type, sound-wave-type and optic-type due to their mechanisms. Capacitive touch panels are most popular among the aforementioned four kinds of conventional touch panels for overcoming the shortcoming of resistance-type touch panel that requires pressing of a user to operate, which generate unwanted scratches easily. Capacitive touch panels, on the contrary, are operated more with touching than pressing. 
         [0005]    Capacitive touch panels are further categorized into superficial capacitive touch panels and projective capacitive touch panels, wherein the former is operated with single-point touching while the latter allows multiple-point touching. 
         [0006]    A capacitive touch panel may comprise one basal panel or two basal panels. For example, Taiwan utility model application No. 98223215, filed on Dec. 11, 2009 discloses a projective capacitive touch panel comprising two basal panels. 
         [0007]    A conventional capacitive touch panel comprising two basal panels comprises two basal plates and an optic adhesive agent. At least one basal plate comprises an indium tin oxide (ITO) conductive area and a metal wiring area. The ITO conductive area comprises crossing-over patterns of ITO. The crossing-over patterns are formed on a surface of the conductive area. For example, as shown in Taiwan utility model No. M379118, the crossing patterns of ITO may be multiple diamond-shaped conductive pads. Spaces are formed between the conductive pads. The conductive pads of one basal plate correspond to the spaces of the other basal plate in order to prevent interference due to overlapping conductive pads. 
         [0008]    The metal wiring area is for connection of the ITO conductive area and a flexible circuit board. The optic adhesive agent is applied on a surface of at least one basal plate. The optic adhesive agent combines the two basal plates after being heated and thus a conventional capacitive touch panel is obtained. 
         [0009]    Accurate alignment of the two basal plates, which is usually achieved with multiple aligning steps, is indispensable for a qualified capacitive touch panel free from interference due to overlapping of the crossing-over patterns of the two basal plates. However, current human-handed or mechanical means hardly align the two basal plates in a single-step operation. Once the optic adhesive, even before heating, is applied to the basal plates, removing the optic adhesive destroys the ITO conductive area or generates bubbles within the optic adhesive. Multiple aligning steps often disrupt or destroy the ITO conductive area, as well as generate bubbles that may interfere with electrical signals for capacitive computing. The multiple aligning steps, which are usually unavoidable during manufacture of a conventional capacitive touch panel, significantly lower yield rate of conventional capacitive touch panels. 
         [0010]    To overcome the shortcomings, the present invention provides a capacitive touch panel to mitigate or obviate the aforementioned problems. 
       SUMMARY OF THE INVENTION 
       [0011]    The main objective of the invention is to provide a capacitive touch panel allowing fine adjustment of two basal plates in a manufacture process of the same and thus capable of preventing interference between the two basal plates. 
         [0012]    The capacitive touch panel in accordance with the present invention has two basal plates, an adhesive ring and a dot spacer. 
         [0013]    Each of the two basal plates has a working surface and an outer rim. One basal plate further has a conductive area, a peripheral area and a metal wiring area. The peripheral area is defined between the outer rim and the conductive area. 
         [0014]    The adhesive ring is made with a reusable adhesive agent and clamped between the basal plates within the peripheral areas and without contacting the conductive area. 
         [0015]    The dot spacer is clamped between the basal plates and positioned within the conductive area. 
         [0016]    The adhesive ring, being a reusable adhesive agent, does not stick fast to the conductive area and thus allows a manufacturer to accurately align the basal plates during manufacture and thus to raise yield rate. 
         [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 an exploded perspective view of a first embodiment of a capacitive touch panel in accordance with the present invention; 
           [0019]      FIG. 2  is an exploded perspective view of a second embodiment of a capacitive touch panel in accordance with the present invention; 
           [0020]      FIG. 3  is a top view of the capacitive touch panel in  FIG. 2 ; 
           [0021]      FIG. 4  is a sectional side view of the capacitive touch panel in  FIG. 2 ; 
           [0022]      FIG. 5  is an exploded perspective view of a third embodiment of a capacitive touch panel in accordance with the present invention; and 
           [0023]      FIG. 6  is a top view of the capacitive touch panel in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    With reference to  FIG. 1 , a first embodiment of a capacitive touch panel in accordance with the present invention comprises two basal plates  10 ,  20 , an adhesive ring  30 , a dot spacer  40  and an insulated ink layer  50 . 
         [0025]    Each of the two basal plates  10 ,  20  comprises a working surface and an outer rim. One basal plate  10  further comprises a conductive area  11 , a peripheral area and a metal wiring area  12 . The conductive area  11  is defined on the working surface of the basal plate  10  and comprises multiple conductive pads  111 . The conductive pads  111  are made of ITO. The peripheral area is defined between the outer rim and the conductive area  11 . The metal wiring area  12  is defined on the working surface of the basal plate  10  and connects to the conductive area  11 . The metal wiring area  12  comprises multiple silver wires  121 . 
         [0026]    The insulated ink layer  50  is attached to the peripheral area of the other basal plate  20  for insulating the metal wiring area  12  from external interference. With reference to  FIG. 4 , the first embodiment of the capacitive touch panel comprises an electromagnetic shielding layer  13  and a silicon dioxide protection layer  23 . The electromagnetic shielding layer  13  is attached to a bottom surface of one basal plate  10  that constitute a bottom portion of the capacitive touch panel. The silicon dioxide protection layer  23  is attached to a top surface of the other basal plate  20  positioned upon the foregoing basal plate  10  and constituting an upper portion of the capacitive touch panel. 
         [0027]    The adhesive ring  30  may be made with a reusable adhesive agent is selected from the group consist of hydrogel, uv-curing glue, backing adhesive and pressure-sensitive adhesive. The adhesive ring  30  is clamped between the basal plates  10 ,  20  within the peripheral areas and without contacting the conductive area  11 . 
         [0028]    The dot spacer  40  is clamped between the basal plates  10 ,  20  and positioned within the conductive area  11 . 
         [0029]    A method for making the first embodiment of the capacitive touch panel comprises the following steps. 
         [0030]    a) The first step is preparing two basal plates  10 ,  20 . Each of the basal plates  10 ,  20  comprises a working surface and an outer rim. One basal plate  10  further comprises a conductive area  11 , a peripheral area and a metal wiring area  12 . The conductive area  11  is defined on the working surface of the basal plate  10 . The peripheral area is defined between the outer rim and the conductive area  11 . The metal wiring area  12  is defined on the working surface of the basal plate  10  and connected to the conductive area  11 . The conductive area  11  comprises multiple conductive pads  111 . The metal wiring area  12  comprises multiple silver wires  121 . An insulated ink layer  50  is attached to the peripheral area of the other basal plate  20 . 
         [0031]    b) The second step is applying a reusable adhesive to the peripheral area of at least one basal plate  10  without contacting the conductive area  11 . The reusable adhesive may be a hydrogel, a uv-curing glue, a backing adhesive or a pressure-sensitive adhesive. A dot spacer  40  is attached to the conductive area  11  of the basal plate  10 . 
         [0032]    c) The third step is to combining the basal plates  10 ,  20  with their working surfaces facing each other. 
         [0033]    d) The forth step is aligning the basal plates  10 ,  20 . In the current embodiment, a perpendicular aligning device is employed to engage the basal plates  10 ,  20 . A pressure is applied to the outer rims of the basal plates  10 ,  20  to force accurate alignment of the same. 
         [0034]    e) The fifth step is hot-pressing the combined basal plates  10 ,  20  to harden the reusable adhesive and obtain an adhesive ring  30  as hardened reusable adhesive. 
         [0035]    A capacitive touch penal of the first embodiment is obtained with the foregoing steps. 
         [0036]    With reference to  FIGS. 2 to 4 , a second embodiment of a capacitive touch panel comprises two basal plates  10 ,  20 , an adhesive ring  30  and a dot spacer  40 . 
         [0037]    Each of the two basal plates  10 ,  20  comprises a working surface, an outer rim, a conductive area  11 ,  21 , a peripheral area and a metal wiring area  12 ,  22 . Each conductive area  11 ,  21  is defined on the working surface of the basal plate  10 ,  20  and comprises multiple conductive pads  111 ,  211 . The conductive pads  111 ,  211  are made of ITO. The shapes and conformation of the conductive pads  111 ,  211  are sophisticatedly designed so that the spaces between the conductive pads  111  of one basal plate  10  correspond to the conductive pads  211  of the other basal plate  20 . 
         [0038]    The peripheral area of each basal plate  10 ,  20  is defined between the outer rim and the conductive area  11 ,  21  of the same basal plate  11 ,  21 . The metal wiring area  12 ,  22  of each basal plate  10 ,  20  is defined on the working surface of the same basal plate  10 ,  20  and connects to the conductive area  11 ,  21 . Each metal wiring area  12 ,  22  comprises multiple silver wires  121 ,  221 . 
         [0039]    With reference to  FIG. 4 , the first embodiment of the capacitive touch panel comprises an electromagnetic shielding layer  13  and a silicon dioxide protection layer  23 . The electromagnetic shielding layer  13  is attached to a bottom surface of one basal plate  10  that constitutes a bottom portion of the capacitive touch panel. The silicon dioxide protection layer  23  is attached to a top surface of the other basal plate  20  positioned upon the foregoing basal plate  10  and constituting an upper portion of the capacitive touch panel. 
         [0040]    The adhesive ring  30  may be made with a reusable adhesive agent is selected from the group consisting of hydrogel, uv-curing glue, backing adhesive and pressure-sensitive adhesive. The adhesive ring  30  is clamped between the peripheral areas of the basal plates  10 ,  20  without contacting the conductive areas  11 ,  21 . 
         [0041]    The dot spacer  40  is clamped between the basal plates  10 ,  20  and positioned within the conductive areas  11 ,  21 . The dot spacer  40  divides the conductive areas  11 ,  21  of the two basal plates  10 ,  20  and insulates the two basal plates  10 ,  20 . 
         [0042]    A method for making the second embodiment of the capacitive touch panel comprises the following steps. 
         [0043]    a) The first step is preparing two basal plates  10 ,  20 . Each of the two basal plates  10 ,  20  comprises a working surface, an outer rim, a conductive area  11 ,  21 , a peripheral area and a metal wiring area  12 ,  22 . Each conductive area  11 ,  21  is defined on the working surface of the basal plate  10 ,  20  and comprises multiple conductive pads  111 ,  211 . The conductive pads  111 ,  211  are made of ITO. The peripheral area of each basal plate  10 ,  20  is defined between the outer rim and the conductive area  11 ,  21  of the same basal plate  11 ,  21 . The metal wiring area  12 ,  22  of each basal plate  10 ,  20  is defined on the working surface of the same basal plate  10 ,  20  and connects to the conductive area  11 ,  21 . Each metal wiring area  12 ,  22  comprises multiple silver wires  121 ,  221 . 
         [0044]    b) The second step is applying a reusable adhesive to the peripheral area of at least one basal plate  10 ,  20  without contacting the conductive area  11 ,  21 . The reusable adhesive may be a hydrogel, a uv-curing glue, a backing adhesive or a pressure-sensitive adhesive. 
         [0045]    c) The third step is clamping a dot spacer  40  between the conductive areas  11 ,  21  of the basal plates  10 ,  20 . 
         [0046]    d) The forth step is combining the basal plates  10 ,  20  with their working surfaces facing each other. 
         [0047]    e) The fifth step is aligning the basal plates  10 ,  20 . In the current embodiment, a perpendicular aligning device is employed. The basal plates  10 ,  20  are engaged in the perpendicular aligning device. Each of the basal plates  10 ,  20  has a rim. A pressure is applied to rims of the basal plates  10 ,  20  to force alignment of the same. 
         [0048]    f) The sixth step is hot-pressing the combined basal plates  10 ,  20  to harden the reusable adhesive and obtain an adhesive ring  30  as hardened reusable adhesive. 
         [0049]    A capacitive touch penal of the second embodiment is obtained with the foregoing steps. 
         [0050]    With reference to  FIGS. 5 and 6 , a third embodiment of a capacitive touch panel comprises two basal plates  10 ,  20 , an adhesive ring  30 , a dot spacer  40  and an insulated ink layer  50 . 
         [0051]    Each of the two basal plates  10 ,  20  comprises a working surface, an outer rim, a conductive area  11 ,  21 , a peripheral area and a metal wiring area  12 ,  22 . Each conductive area  11 ,  21  is defined on the working surface of the basal plate  10 ,  20  and comprises multiple conductive pads  111 ,  211 . The conductive pads  111 ,  211  are made of ITO. The peripheral area of each basal plate  10 ,  20  is defined between the outer rim and the conductive area  11 ,  21  of the same basal plate  11 ,  21 . The metal wiring area  12 ,  22  of each basal plate  10 ,  20  is defined on the working surface of the same basal plate  10 ,  20  and connects to the conductive area  11 ,  21 . Each metal wiring area  12 ,  22  comprises multiple silver wires  121 ,  221 . 
         [0052]    With reference to  FIG. 4 , the first embodiment of the capacitive touch panel comprises an electromagnetic shielding layer  13  and a silicon dioxide protection layer  23 . The electromagnetic shielding layer  13  is attached to a bottom surface of one basal plate  10  that constitute a bottom portion of the capacitive touch panel. The silicon dioxide protection layer  23  is attached to a top surface of the other basal plate  20  positioned upon the foregoing basal plate  10  and constituting a upper portion of the capacitive touch panel. 
         [0053]    The adhesive ring  30  may be made with a reusable adhesive agent is selected from the group consist of hydrogel, uv-curing glue, backing adhesive and pressure-sensitive adhesive. The adhesive ring  30  is clamped between the peripheral areas of the basal plates  10 ,  20  without contacting the conductive areas  11 ,  21 . 
         [0054]    The dot spacer  40  is clamped between the basal plates  10 ,  20  and positioned within the conductive areas  11 ,  21 . The dot spacer  40  divides the conductive areas  11 ,  21  of the two basal plates  10 ,  20  and insulates the two basal plates  10 ,  20 . 
         [0055]    The insulated ink layer  50  is attached to the peripheral area of one basal plate  20 , wherein the basal plate  20  is preferred to be one that constitutes a upper portion of the capacitive touch panel. The conductive area  21  of the basal plate  20  comprises a rim. The insulated ink layer  50  contacts the rim of the conductive area  21 . The insulated ink layer  50  may instead be attached to the peripheral area of the other basal plate  10  that constitutes a bottom portion of the capacitive touch panel. 
         [0056]    A method for making the third embodiment of the capacitive touch panel is similar to the aforementioned method for making the second embodiment, wherein the current method differs from the method for making the second embodiment by further comprising an additional step before combining the basal plates  10 ,  20 . The additional step is applying the insulated ink layer  50  between the adhesive ring  30  and one basal plate  20 . The insulated ink layer  50  is attached to the peripheral area of one basal plate  20  and contacts a rim of the conductive area  21  of the basal plate  20 . 
         [0057]    The scope of the present invention covers any capacitive touch panel comprising two basal plates  10 ,  20 . With the aforementioned structure of the capacitive touch penal in accordance with the present invention, accurate alignment of the two basal plates  10 ,  20  may be easily achieved, which prevents interference of the conductive areas  11 ,  21  of the two basal plates  10 ,  20 . The foregoing advantages of the present invention help raise the quality of capacitive touch penal products as well as yield rate of the same. 
         [0058]    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 features of the invention, the disclosure is illustrative only. Changes may be made in the details, 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.