Abstract:
A touch panel including a first substrate, a second substrate, a sealant, a liquid crystal layer, a main spacer, a first sensing spacer, a second sensing spacer, a first opposite electrode and a second opposite electrode is provided. The first substrate has a central area and a peripheral area. The second substrate is disposed opposite to the first substrate. The first sensing spacer is disposed on the central area and between the first and the second substrates. The second sensing spacer is disposed on the peripheral area and between the first and the second substrates. There&#39;s a first sensing gap between the first sensing spacer and the first opposite electrode disposed corresponding to the first sensing spacer. There&#39;s a second sensing gap between the second sensing spacer and the second opposite electrode disposed corresponding to the second sensing spacer. The first sensing gap is larger than the second sensing gap.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority benefit of Taiwan application serial no. 97132792, filed on Aug. 27, 2008. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a display panel, and particularly relates to a touch panel. 
         [0004]    2. Description of Related Art 
         [0005]    At present, a display is one of the most popular among various consumers&#39; optoelectronic products. As display technology advances, the use of displays is making our life more convenient than ever. Hence, the design of touch panels, especially, has become the representative of convenience. By directly touching the display frame, a user may utilize various functions of the touch panel, which simplifies the complexity of operating the touch panel. 
         [0006]    Generally speaking, touch panels are categorized into two types, plug-in type and built-in type, according to the structures thereof. A built-in type product is usually thinner and lighter than a plug-in type product. Hence, built-in type touch panels are commonly applied in all kinds of portable electronic devices. 
         [0007]      FIG. 1A  is a cross-sectional view illustrating a portion of a conventional built-in touch panel. Referring to  FIG. 1A , a built-in touch panel  100  includes a first substrate  110 , a second substrate  120 , a liquid crystal layer  140 , a main spacer  150 , a sensing spacer  160 , an opposite electrode  170 , a transparent conductive layer  182 , a shielding layer  184 , a plurality of color filter layers  184 ′, a protective layer  186 , a first metal layer M 1 , a gate insulating layer GI′, an amorphous silicon layer AS, and a second metal layer M 2 . 
         [0008]    The second substrate  120  is disposed opposite to the first substrate  110 . The liquid crystal layer  140  and the main spacer  150  are arranged between the first substrate  110  and the second substrate  120 . The sensing spacer  160  is disposed on the second substrate  120 . The opposite electrode  170  is arranged on the first substrate  110  and corresponds to the sensing spacer  160 , wherein the opposite electrode  170  is disposed on the protective layer  186  and contacts the protective layer  186 . The transparent conductive layer  182  is disposed on the second substrate  120  and covers the main spacer  150  and the sensing spacer  160 . 
         [0009]    Generally speaking, the main spacer  150  and the sensing spacer  160  are formed by performing a photomask process, so as to simultaneously complete the fabrication of the main spacer  150  and the sensing spacer  160 . However, because of the limitation of the photolithography process, the discrepancy between the height of the sensing spacer  160  and the height of the main spacer  150  is small or none. 
         [0010]    Referring to  FIG. 1A , when the built-in touch panel  100  is not touched, the shortest distance between the transparent conductive layer  182  covering the sensing spacer  160  and the opposite electrode  170  is a sensing gap g′. When the user touches the built-in touch panel  100 , an electrical change is generated by the contact of the transparent conductive layer  182  covering the sensing spacer  160  and the opposite electrode  170 . Thereby, the built-in touch panel  100  determines the area touched by the user. 
         [0011]    In the conventional built-in touch panel  100 , the sensing gap g′ remains the same or almost the same in every area. When the user touches an area having lower sensitivity, the user needs to apply larger stress so that the transparent conductive layer  182  on the sensing spacer  160  may contact the opposite electrode  170 , i.e. to make the sensing gap g′ become 0. However, the transparent conductive layer  182  may be broken if the user applies excessive stress to the built-in touch panel  100 , as indicated by the breaking position B 1  and B 2  in  FIG. 1B . 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention provides a touch panel having sensing spacers of various heights disposed therein for enhancing the touch sensitivity of a low-sensitive area in the touch panel. 
         [0013]    The present invention further provides a touch panel comprising sensing gaps of various sizes for enhancing the touch sensitivity of a low-sensitive area in the touch panel. 
         [0014]    The present invention further provides a touch panel using an organic conductive material to fabricate a sensing spacer for varying the height of the sensing spacer and the size of a sensing gap. 
         [0015]    The present invention provides a touch panel including a first substrate, a second substrate, a sealant, a liquid crystal layer, a main spacer, a first sensing spacer, a second sensing spacer, a first opposite electrode, and a second opposite electrode. The first substrate has a central area and a peripheral area, and the second substrate is disposed opposite to the first substrate. The sealant is disposed on the peripheral area for bonding the first and the second substrates. The liquid crystal layer, the main spacer, the first sensing spacer, and the second sensing spacer are arranged between the first and the second substrates. The first sensing spacer is disposed on the central area, and the second sensing spacer is disposed on the peripheral area. A first sensing gap is arranged between the first sensing spacer and the first opposite electrode disposed corresponding to the first sensing spacer. A second sensing gap is arranged between the second sensing spacer and the second opposite electrode disposed corresponding to the second sensing spacer. The first sensing gap is larger than the second sensing gap. 
         [0016]    The present invention further provides a touch panel including a first substrate, a second substrate, a sealant, a liquid crystal layer, a main spacer, a first sensing spacer, and a second sensing spacer. The first substrate has a central area and a peripheral area, and the second substrate is disposed opposite to the first substrate. The sealant is disposed on the peripheral area for bonding the first and the second substrates. The liquid crystal layer, the main spacer, the first sensing spacer, and the second sensing spacer are arranged between the first and the second substrates. The first sensing spacer is disposed on the central area and the second sensing spacer is disposed on the peripheral area. The second sensing spacer is higher than the first sensing spacer. 
         [0017]    The present invention further provides a touch panel including a first substrate, a second substrate, a sealant, a liquid crystal layer, a main spacer, and a sensing spacer. The second substrate is disposed opposite to the first substrate. The sealant is used for bonding the first and the second substrates. The liquid crystal layer and the main spacer are disposed between the first substrate and the second substrate. The sensing spacer is disposed on the first substrate or the second substrate, and may be formed by multiple organic conductive layers. 
         [0018]    In an embodiment of the present invention, at least one of the first sensing spacer and the second sensing spacer is formed by multiple organic conductive layers. 
         [0019]    In an embodiment of the present invention, at least one of the first opposite electrode and the second opposite electrode is formed by multiple organic conductive layers. 
         [0020]    In an embodiment of the present invention, the first sensing gap or the second sensing gap ranges from 0.3 μm to 0.8 μm. 
         [0021]    In an embodiment of the present invention, at least one of the first sensing spacer and the second sensing spacer has a spherical top or a blunt top. 
         [0022]    In an embodiment of the present invention, the first sensing spacer and the second sensing spacer are disposed on a transparent conductive layer and contact the transparent conductive layer. 
         [0023]    In an embodiment of the present invention, the touch panel further comprises a first shielding layer, a second shielding layer, and a third shielding layer disposed on the second substrate. In an embodiment, the first shielding layer, the second shielding layer, and the third shielding layer are arranged corresponding to the first sensing spacer, the second sensing spacer, and the main spacer respectively. 
         [0024]    In an embodiment of the present invention, the touch panel further comprises a protective layer and a plurality of transparent electrodes. The protective layer disposed on the first substrate and the transparent electrodes disposed on the protective layer are arranged to correspond to the first sensing spacer and the second sensing spacer respectively. In a preferable embodiment, the first opposite electrode and the second opposite electrode are separately disposed on the transparent electrodes. 
         [0025]    In an embodiment of the present invention, a material of the organic conductive layer may be selected from a group of poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS), polyaniline, polypyrrole, polythiophene, polyacetylene, polyphenyl, polyfuran, polyselenophene, isothianaphthene, polyphenylsulfide, polystyrene, polythienylstyrene, polynaphthalene, polyanthracene, polypyrene, polyazulene, phthalocyanine, pentacene, hemicyanine dye, and 3,4-polyethylene dioxythio phene (PEDT), but the present invention is not limited thereto. 
         [0026]    According to the present invention, the sensing spacers in the touch panel may be fabricated by performing an inkjet process, so as to vary the heights of different sensing spacers simultaneously. Moreover, the present invention may apply the sensing spacers of different heights to overcome the problem that the peripheral area of the touch panel has lower touch sensitivity. From another aspect, the touch sensitivity of the peripheral area in the touch panel may also be enhanced by forming sensing gaps of different sizes. By the means mentioned above, the present invention not only helps to improve the low touch sensitivity of the peripheral area in the touch panel but also prevents the breaking of the transparent conductive layer caused by excessive stress from the user. 
         [0027]    To make the above features and advantages of the present invention more comprehensible, several embodiments accompanied with drawings are described in detail as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
           [0029]      FIG. 1A  is a cross-sectional view illustrating a portion of a conventional built-in touch panel. 
           [0030]      FIG. 1B  is a cross-sectional view illustrating a portion of the built-in touch panel in  FIG. 1A  damaged by excessive stress. 
           [0031]      FIG. 2A  is a cross-sectional view illustrating a portion of a touch panel in the first embodiment of the present invention. 
           [0032]      FIG. 2B  is a cross-sectional view illustrating a portion of a touch panel in the second embodiment of the present invention. 
           [0033]      FIG. 3A  is a cross-sectional view illustrating a portion of a touch panel in the third embodiment of the present invention. 
           [0034]      FIG. 3B  is a cross-sectional view illustrating a portion of a touch panel in the fourth embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0035]      FIG. 2A  is a cross-sectional view illustrating a portion of a touch panel in the first embodiment of the present invention. Referring to  FIG. 2A , a touch panel  200  of the embodiment includes a first substrate  210 , a second substrate  220 , a sealant  230 , a liquid crystal layer  240 , a main spacer  250 , a sensing spacer  260 , a transparent electrode  290 , and an opposite electrode  270 . 
         [0036]    A pixel array is disposed on the first substrate  210 , wherein the pixel array includes a plurality of active elements, a plurality of scanning lines, a plurality of data lines DL, and a plurality of pixel electrodes. In order to facilitate the illustration of the embodiment, only one data line DL is illustrated in  FIG. 2A  and the other elements are omitted. Persons with ordinary skill in the art should understand the actual positions and functions of the omitted elements. Hence, the details thereof are not described here. As shown in  FIG. 2A , the data line DL is disposed above a gate insulating layer GI. The second substrate  220  is disposed opposite to the first substrate  210 . The sealant  230  is used for bonding the first substrate  210  and the second substrate  220 . The liquid crystal layer  240  and the main spacer  250  are disposed between the first substrate  210  and the second substrate  220 . The sensing spacer  260  is arranged on the second substrate  220 . 
         [0037]    According to a preferable embodiment, the opposite electrode  270  and the transparent electrode  290  are disposed on the first substrate  210  and arranged corresponding to the sensing spacer  260 , as shown in  FIG. 2A . The opposite electrode  270  is above the data line DL and the gate insulating layer GI, and the transparent electrode  290  is arranged between the opposite electrode  270  and the date line DL, but the present invention is not limited thereto. Any designer may dispose the opposite electrode  270  above the scanning lines (not shown) or other suitable elements, or dispose the opposite electrode  270  between the transparent electrode  290  and the data line DL, the scanning lines, or other elements to meet the requirements of products. 
         [0038]    In a preferable embodiment, the transparent electrode  290  and the opposite electrode  270  are electrically connected for transmitting an electrical change or a sensing signal generated by a contact of the sensing spacer  260  and the opposite electrode  270  caused by a user touching the touch panel  200 . In addition, the designer may vary a pattern of the opposite electrode  270  per the requirements of products to substitute for the functions of the transparent electrode  290 , and further simplify the fabricating process. 
         [0039]    Referring to  FIG. 2A , a transparent conductive layer  282  is disposed on the second substrate  220 , and the sensing spacer  260  is disposed on the transparent conductive layer  282  and contacts the transparent conductive layer  282 . In a preferable embodiment, shielding layer  284  are disposed on the second substrate  220  and arranged corresponding to the sensing spacer  260  and the main spacer  250  respectively. Moreover, pluralities of color filter layers  284 ′ are disposed on the second substrate  220 . The color filter layers  284 ′ and the shielding layer  284  are arranged alternately. Further, a protective layer  286  is disposed on the first substrate  210 , and the opposite electrode  270  is disposed on the protective layer  286  and contacts the protective layer  286  or the transparent electrode  290  on the protective layer  286 . 
         [0040]    As shown in  FIG. 2A , the transparent conductive layer  282  may be electrically connected with the sensing spacer  260  and electrically insulated from the opposite electrode  270  when not operating. When the user touches the touch panel  200 , an electrical change is generated by a contact of the sensing spacer  260  and the opposite electrode  270 . Thereby, the touch panel  200  determines the area touched by the user. In brief, the sensing spacer  260  and the opposite electrode  270  are respectively disposed on the second substrate  220  and the first substrate  210  to correspond to each other, so as to sense the touched area in the touch panel  200 . 
         [0041]    The sensing spacer  260  may be formed by multiple organic conductive layers  260   c.  The organic conductive layers  260   c  are usually formed by a conductive material having softer texture for easing a force which occurs when the sensing spacer  260  contacts the opposite electrode  270 . 
         [0042]    According to a preferable embodiment, a material of the organic conductive layers  260   c  may be selected from a group of poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS), polyaniline, polypyrrole, polythiophene, polyacetylene, polyphenyl, polyfuran, polyselenophene, isothianaphthene, polyphenylsulfide, polystyrene, polythienylstyrene, polynaphthalene, polyanthracene, polypyrene, polyazulene, phthalocyanine, pentacene, hemicyanine dye, and 3,4-polyethylene dioxythio phene (PEDT), but the present invention is not limited thereto. 
         [0043]    Because the sensing spacer  260  is formed by the organic conductive material having softer texture, an ink-jet process may be applied to sequentially form the sensing spacer  260  on the second substrate  220 . In addition, through controlling the volume and times of jetting the organic conductive material in each ink-jet process, the height of the sensing spacer  260  may be controlled to reach a predetermined value or fall within a predetermined range. 
         [0044]    As shown in  FIG. 2A , a first ink-jet process is performed on the second substrate  220  to form one organic conductive layer  260   c  having a height d. Then, a second ink-jet process is performed to form another organic conductive layer having the height d. Thus, the height is  2   d  in total. Accordingly, after four times of the ink-jet process, four organic conductive layers  260   c  having a total height of  4   d  are formed. In this embodiment, the sensing spacer  260  is formed by the four organic conductive layers  260   c,  and the height of the sensing spacer  260  is  4   d.    
         [0045]    In practice, the organic conductive layers  260   c  are not restricted to four layers. The designer may vary the volume and times of jetting the organic conductive material during the ink-jet process based on the requirements of products, so as to control the number and height of the organic conductive layers  260   c.  Moreover, other fabricating methods or ink-jet controlling processes may also be used to form the sensing spacer  260  as long as the shape or height of the sensing spacer  260  can be controlled. Persons with ordinary skill in the art may adjust the height of the organic conductive layer  260   c  formed in each ink-jet process according to their requirements. 
         [0046]    According to a preferable embodiment, the aforesaid material of the organic conductive layers  260   c  and the aforesaid ink-jet process may be combined to fabricate the opposite electrode  270 , so that the height of the opposite electrode  270  may meet the requirements of design, but the present invention is not limited thereto. Generally speaking, the opposite electrode  270  may be a single-layer conductive layer which may be formed by an inorganic conductive material. The present invention is not limited to the aforesaid material of the organic conductive layers  260   c.    
         [0047]    The sensing spacer  260  may also be disposed on the first substrate  210 , and the opposite electrode  270  may be disposed on the second substrate  220  to correspond to the sensing spacer  260 , wherein the sensing spacer  260  is formed by the organic conductive material, as shown in  FIG. 2B . 
         [0048]      FIG. 2B  is a cross-sectional view illustrating a portion of a touch panel in the second embodiment of the present invention. Referring to  FIG. 2B , the sensing spacer  260  is disposed above the protective layer  286  and the transparent electrode  290 , and electrically contacts the transparent electrode  290 . Additionally, the opposite electrode  270  or the transparent electrode  290  may also be formed by the inorganic conductive material instead of the organic conductive material. The organic conductive material has been described in the above, and thus the details thereof are omitted here. 
         [0049]    In this embodiment, the use of the organic conductive material may be combined with the ink-jet process or other fabricating processes to fabricate the sensing spacer  260 . Thereby, the height of the sensing spacer  260  may be easily varied. Moreover, the use of the organic conductive material may also be combined with the ink-jet process or other fabricating processes to form the opposite electrode  270 , so as to further adjust the height of the opposite electrode  270 . 
         [0050]      FIG. 3A  is a cross-sectional view illustrating a portion of a touch panel in the third embodiment of the present invention. Referring to  FIG. 3A , a touch panel  300  of this embodiment includes the first substrate  210 , the second substrate  220 , the sealant  230 , the liquid crystal layer  240 , the main spacer  250 , a first sensing spacer  360   a,  a second sensing spacer  360   b,  a first opposite electrode  370   a,  a second opposite electrode  370   b,  a transparent conductive layer  382 , a first shielding layer  384   a,  a second shielding layer  384   b,  a third shielding layer  384   c,  a first transparent electrode  390   a,  a second transparent electrode  390   b,  and a protective layer  386 . 
         [0051]    The first substrate  210  has a central area  312  and a peripheral area  314 . Further, a pixel array is disposed on the first substrate  210 , wherein the pixel array includes a plurality of active elements, a plurality of scanning lines, a plurality of data lines DL, and a plurality of pixel electrodes. To facilitate the illustration, only the data lines DL are shown in  FIG. 3A  and other elements are omitted. Persons having ordinary skill in the art should understand the actual positions and functions of the omitted elements. Hence, the details thereof are not described here. As shown in  FIG. 3A , the data lines DL are arranged above the gate insulating layer GI. 
         [0052]    The second substrate  220  is disposed opposite to the first substrate  210 . The sealant  230  is disposed on the peripheral area  314  for bonding the first substrate  210  and the second substrate  220 . The liquid crystal layer  240 , the main spacer  250 , the first sensing spacer  360   a,  and the second sensing spacer  360   b  are all arranged between the first substrate  210  and the second substrate  220 . 
         [0053]    In this embodiment, the first sensing spacer  360   a  and the second sensing spacer  360   b  are disposed on the second substrate  220 , wherein the first sensing spacer  360   a  and the main spacer  250  are arranged in the central area  312 , and the second sensing spacer  360   b  is arranged in the peripheral area  314 . The first opposite electrode  370   a  and the first transparent electrode  390   a  are disposed on the central area  312  of the first substrate  210  and correspond to the first sensing spacer  360   a.  The second opposite electrode  370   b  and the second transparent electrode  390   b  are disposed on the peripheral area  314  of the first substrate  210  and correspond to the second sensing spacer  360   b,  wherein the peripheral area  314  usually surrounds the central area  312 . 
         [0054]    The first opposite electrode  370   a,  the first transparent electrode  390   a,  the second opposite electrode  370   b,  and the second transparent electrode  390   b  are all disposed above the data lines DL and the gate insulating layer GI. The first transparent electrode  3   90   a  and the second transparent electrode  390   b  are respectively disposed between the first opposite electrode  370   a  and the second opposite electrode  370   b  and the corresponding data lines DL. However, the designer may dispose the first opposite electrode  370   a  and the second opposite electrode  370   b  above the scanning lines (not shown) or other suitable elements, or alternatively dispose the first opposite electrode  370   a  and the second opposite electrode  370   b  between the first transparent electrode  390   a  and the second transparent electrode  390   b  and the data lines DL, the scanning lines, or other elements to meet the requirements of products. 
         [0055]    In a preferable embodiment, the first transparent electrode  390   a  and the second transparent electrode  390   b  are electrically connected with the first opposite electrode  370   a  and the second opposite electrode  370   b  respectively for transmitting the electrical changes or sensing signals generated by the contact of the first sensing spacer  360   a  and the first opposite electrode  370   a  and the contact of the second sensing spacer  360   b  and the second opposite electrode  370   b  when the user touches the touch panel  300 . Additionally, the designer may vary the patterns of the first opposite electrode  370   a  or the second opposite electrode  370   b  per the requirements of products to substitute for the functions of the first transparent electrode  390   a  or the second transparent electrode  390   b,  and further simplify the fabricating process. 
         [0056]    In this embodiment, the transparent conductive layer  382  is disposed on the second substrate  220 , and the first sensing spacer  360   a  and the second sensing spacer  360   b  are disposed on the transparent conductive layer  382  and contact the transparent conductive layer  382 . The first shielding layer  384   a,  and the second shielding layer  384   b,  and the third shielding layer  384   c  are disposed on the second substrate  220  and correspond to the first sensing spacer  360   a,  the second sensing spacer  360   b,  and the main spacer  250  respectively. Furthermore, pluralities of color filter layers  384  are disposed on the second substrate  220 . The color filter layers  384  and the shielding layers  384   a,    384   b,  and  384   c  are arranged alternately. The protective layer  386  is disposed on the first substrate  210 . The first opposite electrode  370   a  and the second opposite electrode  370   b  are disposed on the protective layer  386  and contact the protective layer  386  or contact the first transparent electrode  390   a  and the second transparent electrode  390   b  on the protective layer  386 . 
         [0057]    As shown in  FIG. 3A , the transparent conductive layer  382  may be electrically connected with the first sensing spacer  360   a  and the second sensing spacer  360   b,  and respectively electrically insulated from the first opposite electrode  370   a  and the second opposite electrode  370   b  when not operating. When the user touches the central area  312  of the touch panel  300 , the touch panel  300  determines the touched area according to the electrical change generated by the contact of the first sensing spacer  360   a  and the first opposite electrode  370   a.  Similarly, when the user touches the peripheral area  314  of the touch panel  300 , the touch panel  300  determines the touched area based on the electrical change generated by the contact of the second sensing spacer  360   b  and the second opposite electrode  370   b.    
         [0058]    The first sensing spacer  360   a,  the second sensing spacer  360   b,  the first opposite electrode  370   a,  and the second opposite electrode  370   b  may all be formed by multiple organic conductive layers  260   c.  Generally speaking, the organic conductive layers  260   c  usually have softer texture for reducing the force generated when the first sensing spacer  360   a  contacts the first opposite electrode  370   a  (or when the second sensing spacer  360   b  contacts the second opposite electrode  370   b ), so as to reduce the possibility and degree of damaging the transparent conductive layer  382  or other structures. The organic conductive layers  260   c  may be formed by the materials described in the first embodiment, but the present invention is not limited to the use of these organic conductive materials. 
         [0059]    In view of the above, because the first sensing spacer  360   a  and the second sensing spacer  360   b  are formed by the organic conductive material having softer texture, the ink-jet process may be used to form the first sensing spacer  360   a  and the second sensing spacer  360   b  on the second substrate  220 . As shown in  FIG. 3A , the first sensing spacer  360   a  may be formed by four organic conductive layers  260   c,  and the second sensing spacer  360   b  may be formed by five organic conductive layers  260   c.  In other words, the height of the first sensing spacer  360   a  is  4   d  and the height of the second sensing spacer  360   b  is  5   d.  The height  5   d  of the second sensing spacer  360   b  is larger than the height  4   d  of the first sensing spacer  360   a.    
         [0060]    In practice, the organic conductive layers  260   c  are not restricted to four or five layers. The designer may vary the volume and times of jetting the organic conductive material during the ink-jet process based on the requirements of products, so as to control the number and height of the organic conductive layers  260   c.  Moreover, other fabricating methods or other ink-jet controlling processes may also be applied to form the first sensing spacer  360   a  and the second sensing spacer  360   b  as long as the shapes or heights of the first sensing spacer  360   a  and the second sensing spacer  360   b  can be controlled. For instance, the height of the organic conductive layer  260   c  formed in each ink-jet process may also be varied. 
         [0061]    In addition, the shape that the organic conductive material is formed on the second substrate  220  may also be adjusted by using the ink-jet process. As shown in  FIG. 3A , the first sensing spacer  360   a  and the second sensing spacer  360   b  both have spherical tops. However, the tops of the first sensing spacer  360   a  and the second sensing spacer  360   b  may also be blunt tops. Herein, the spherical tops or blunt tops of the first sensing spacer  360   a  and the second sensing spacer  360   b  help to ease the force which occurs when the first sensing spacer  360   a  contacts the first opposite electrode  370   a  (or when the second sensing spacer  360   b  contacts the second opposite electrode  370   b ). 
         [0062]    One or both of the first sensing spacer  360   a  and the second sensing spacer  360   b  may be selected to have the spherical top or the blunt top. That is to say, at least one of the first sensing spacer  360   a  and the second sensing spacer  360   b  has the spherical top or the blunt top. Moreover, the designer may dispose the first sensing spacer  360   a  and the second sensing spacer  360   b  on the second substrate  200  by performing other fabricating methods according to the requirements of products. Hence, the present invention is not limited to the use of the ink-jet process. 
         [0063]    From another aspect, a first sensing pad g 1  is arranged between the first sensing spacer  360   a  and the first opposite electrode  370   a,  and a second sensing gap g 2  is arranged between the second sensing spacer  360   b  and the second opposite electrode  370   b.  The first sensing gap g 1  is correlated to the height of the first sensing spacer  360   a,  and the second sensing gap g 2  is correlated to the height of the second sensing spacer  360   b.    
         [0064]    To be more specific, because the main spacer  250  may maintain a gap D between the first substrate  210  and the second substrate  220 , the first sensing gap g 1  is enlarged when the height of the first sensing spacer  360   a  decreases. On the contrary, the first sensing gap g 1  is narrowed when the height of the first sensing spacer  360   a  increases. In practice, the gap D does not remain the same in every area. Therefore, the second sensing gap g 2  may also be smaller than the first sensing gap g 1 . 
         [0065]    However, the touch panel  300  has different touch sensitivities in different areas. Because the sealant  230  is disposed on the peripheral area  214 , the deformation flexibility of the peripheral area  214  is constrained by the sealant  230 . Therefore, the peripheral area  214  has lower deformation flexibility and sensitivity than that of the central area  312 . To enhance the sensitivity of the peripheral area  214 , the second sensing spacer  360   b  may be disposed close to the second opposite electrode  370   b.  In other words, the height  5   d  of the second sensing spacer  360   b  is larger or the second sensing gap g 2  is smaller. The first sensing spacer  360   a  may be disposed away from the first opposite electrode  370   a,  i.e. the height  4   d  of the first sensing spacer  360   a  is smaller or the first sensing gap g 1  is larger. 
         [0066]    As shown in  FIG. 3A , the second sensing spacer  360   b  may be formed by the organic conductive layers  260   c  having the total height of  5   d,  and the distance between the second sensing spacer  360   b  and the second opposite electrode  370   b  is the second sensing gap g 2 . Further, the first sensing spacer  360   a  may be formed by the organic conductive layers  260   c  having the total height of  4   d,  and the distance between the first sensing spacer  360   a  and the first opposite electrode  370   a  is the first sensing gap g 1 . 
         [0067]    Because the second opposite electrode  370   b  on the peripheral area  314  is closer to the second sensing spacer  360   b  and the first opposite electrode  370   a  on the central area  312  is away from the first sensing spacer  360   a,  the first sensing gap g 1  is larger than the second sensing gap g 2 . On the other hand, there are also other reasons influencing the relationship between the first sensing gap g 1  and the second sensing gap g 2 , the present invention is not limited the reasons. In a preferable embodiment, the range of the first sensing gap g 1  or the second sensing gap g 2  falls between 0.3 μm and 0.8 μm. Thereby, the touch panel  300  has favorable touch sensitivity. 
         [0068]    According to a preferable embodiment, the first sensing spacer  360   a,  the second sensing spacer  360   b,  the first opposite electrode  370   a,  and the second opposite electrode  370   b  are all formed by multiple organic conductive layers  260   c,  but the present invention is not limited thereto. That is to say, this embodiment does not require a photomask and photolithography process to form the first sensing spacer  360   a,  the second sensing spacer  360   b,  the first opposite electrode  370   a,  and the second opposite electrode  370   b.  Moreover, the use of the ink-jet process helps to vary the heights of the first sensing spacer  360   a,  the second sensing spacer  360   b,  the first opposite electrode  370   a,  and the second opposite electrode  370   b.    
         [0069]    The first sensing spacer  360   a  and the second sensing spacer  360   b  may also be disposed on the first substrate  210 , and the first opposite electrode  370   a  and the second opposite electrode  370   b  may be disposed on the second substrate  220  to respectively correspond to the first sensing spacer  360   a  and the second sensing spacer  360   b,  wherein the first sensing spacer  360   a  and the second sensing spacer  360   b  are formed by the organic conductive material, as shown in  FIG. 3B . 
         [0070]      FIG. 3B  is a cross-sectional view illustrating a portion of a touch panel in the fourth embodiment of the present invention. It is known from  FIG. 3B  that the first sensing spacer  360   a  and the second sensing spacer  360   b  are respectively arranged above the first transparent electrode  390   a  and the second transparent electrode  390   b  of the protective layer  286 , and contact the first transparent electrode  390   a  and the second transparent electrode  390   b.    
         [0071]    In other embodiments, one of the first sensing spacer  360   a  and the second sensing spacer  360   b  may be selected to be formed by the organic conductive layers  260   c,  and one of the first opposite electrode  370   a  and the second opposite electrode  370   b  may be selected to be formed by the organic conductive layers  260   c.  In a word, at least one of the first sensing spacer  360   a  and the second sensing spacer  360   b  is formed by the organic conductive layers  260   c.  Similarly, at least one of the first opposite electrode  370   a  and the second opposite electrode  370   b  is formed by the organic conductive layers  260   c.    
         [0072]    In addition, this embodiment may make use of the ink-jet process to dispose the first, the second sensing spacers  360   b,    360   b  or the first, the second opposite electrodes  370   a,    370   b  on the first substrate  210  or the second substrate  220 . It is certain that other suitable methods may also be adapted to form the first, the second sensing spacers  360   a,    360   b  or the first, the second opposite electrodes  370   a,    370   b.  The present invention is not intended to limit the forming methods thereof. 
         [0073]    It is known from the above that the touch sensitivity of the peripheral area  314  may be enhanced by making the first sensing gap g 1  larger than the second sensing gap g 2 . In other embodiment, any persons having ordinary skill in the art may dispose the first sensing spacer  360   a  on the first substrate  210  (disposing the first opposite electrode  370   a  on the second substrate  220 ) and dispose the second sensing spacer  360   b  on the second substrate  220  (disposing the second opposite electrode  370   b  on the first substrate  210 ), so as to make the first sensing gap g 1  larger than the second sensing gap g 2 . Alternatively, the first sensing spacer  360   a  may be disposed on the second substrate  220  (disposing the first opposite electrode  370   a  on the first substrate  210 ) and the second sensing spacer  360   b  may be disposed on the first substrate  210  (disposing the second opposite electrode  370   b  on the second substrate  220 ) to achieve the same effect. 
         [0074]    To solve the problem that the peripheral area  314  has low touch sensitivity, this embodiment makes the first sensing gap g 1  in the touch panel  300  larger than the second sensing gap g 2 , and thereby improves the touch sensitivity of the peripheral area  314 . In addition, the first sensing spacer  360   a  or the second sensing spacer  360   b  has the spherical top or blunt top which serves as a buffer between the first sensing spacer  360   a  or the second sensing spacer  360   b  and the first opposite electrode  370   a  or the second opposite electrode  370   b  for preventing the breaking or damage to the transparent conductive layer  382  or other structures caused by excessive stress. 
         [0075]    In conclusion, the embodiments mentioned above of the present invention make use of the organic conductive material to form the sensing spacers, which is adapted for adjusting the sensing spacers. As a consequence, the touch sensitivity of certain areas having worse sensitivity in the touch panel is enhanced, and the touch panel can have uniform touch sensitivity. Different products may include sensing spacers of different heights, but the present invention is not required to change photomask for different products during the production. Moreover, using the organic conductive material to form the opposite electrodes facilitates the adjustment of the sensing gaps. Therefore, the sizes of the sensing gaps may be varied more flexibly. Because the organic conductive material has softer texture in some embodiments, the possibility of damaging the touch panel is also greatly reduced. 
         [0076]    Although the present invention has been disclosed by the above embodiments, they are not intended to limit the present invention. Anybody with ordinary knowledge in the art may make some modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the protection range of the present invention falls in the appended claims.