Patent Application
20140177137
1. Field of the Invention
The present invention relates to a touch panel and, more particularly, to a touch panel having a reduced wiring area, in which the wiring region of the touch panel is much narrower as compared with the conventional touch panels.
2. Description of the Prior Art: In recent years, touch-sensing human-machine interface devices, such as touch panels, have been widely used in a broad variety of electrical and electronic devices, including global positioning system (GPS) devices, personal digital assistants (PDAs), cellular phones, and Hand-held PCs, in place of traditional input devices (such as a keyboard or a computer mouse). This structural innovation not only improves the communication between human and machine, but saves space by eliminating traditional input devices. As a result, the saved space can be utilized for accommodating a display panel which in turn provides the user a pleasant experience on displaying image data.
When a finger (or other electrically conductive objects) touches the touch-sensing device 1, the touch causes a capacitance change among the sensing electrodes 12. The capacitance change is then transmitted to the external detection circuits via the peripheral wires 13 and the external detection circuits determine the location of the finger touch by sensing the capacitance change.
With the rapid development of the fabrication technology for display panels and the increasing need for large-size display screens, the current designs for display panels tend to have narrower borders as compared to the display panels produced before. As a consequence, the layout design for the peripheral wires becomes extremely challenging due to a significant decrease in the border widths of display panels. Some of the conventional approaches to address the layout design are summarized below:
1. Narrower wire widths are used to reduce the wiring area. This approach, however, may increase the wire resistance, causing an increase in voltage drop across the wires and an interference with signal transmission. Moreover, it is difficult and cost-ineffective to produce display panels with narrower wires and this approach would easily reduce the production yield.
2. The peripheral wires are overlapped on the transparent conductive substrate, thereby reducing the wiring area. However, this approach may increase the risks of causing interference and short-circuit between the peripheral wires.
Therefore, there is a need for a better layout architecture compared to the conventional approaches, in which the peripheral wires are readily disposed within a narrow border region without causing interference between the wires.
An object of the invention is to provide a touch panel having a reduced wiring area, in which the wiring region of the touch panel is much narrower as compared with the conventional touch panels.
In order to achieve the object described above, the touch panel according to the invention comprises a first transparent substrate, and an upper sensing pattern, a plurality of upper metallic wires, a lower sensing pattern, a plurality of lower metallic wires and a shielding member, all disposed on the first transparent substrate. The shielding member is arranged between the upper metallic wires and the lower metallic wires.
By virtue of the structural arrangement described above, the upper metallic wires and the lower metallic wires can be arranged in a manner overlapping with each other without causing interference between the wires. The invented touch panel has a reduced wiring area, in which the wiring region is minimized. The invented touch panel is also advantageous in preventing misreading of touch signals due to an unintentional direct contact between the wiring region with human body.
The above and other objects, features and effects of the invention will become apparent with reference to the following description of the preferred embodiments taken in conjunction with the accompanying drawing, in which:
The first transparent substrate 21 is formed with a visual region 211 and a wiring region 212 disposed around the outer periphery of the visual region 211. The first transparent substrate 21 includes an upper surface 213 and a lower surface 214 opposite to the upper surface 213.
The upper sensing pattern 22 comprises a plurality of upper sensing series 221 arranged in a first direction and resides in the visual region 211 of the first transparent substrate 21. According to the embodiment disclosed herein, the upper sensing pattern 22 is disposed on the upper surface 213 of the first transparent substrate 21.
The upper metallic wires 23 are disposed in the wiring region 212 of the first transparent substrate 21 and electrically connected to the upper sensing series 221 of the upper sensing pattern 22, respectively.
The lower sensing pattern 24 comprises a plurality of lower sensing series 241 arranged in a second direction and alternate to the upper sensing series 221 of the upper sensing pattern 22. The lower sensing pattern 24 is disposed in the visual region 211 and formed on the lower surface 214 of the first transparent substrate 21.
The lower metallic wires 25 are disposed in the wiring region 212 of the first transparent substrate 21 and electrically connected to the lower sensing series 241 of the lower sensing pattern 24. The lower metallic wires 25 are formed on the lower surface 214 of the first transparent substrate 21.
The shielding member 26 are disposed in the wiring region 212 and formed on the upper surface 213 of the first transparent substrate 21 and arranged between the upper metallic wires 23 and the lower metallic wires 25. The shielding member 26 comprises a conductive layer 261, a grounded wire 262 connected to the conductive layer 261, and an insulation layer 263 disposed on the conductive layer 261. The upper metallic wires 23 are disposed atop the insulation layer 263. In a more preferred embodiment, the conductive layer 261 is made of transparent conductive material and fabricated concurrently with the upper sensing pattern 22.
By virtue of mounting the shielding member 26 between the upper metallic wires 23 and the lower metallic wires 25, the upper metallic wires 23 and the lower metallic wires 25 can be arranged on the opposite sides of the first substrate 21 in a manner overlapping with each other, thereby preventing the occurrence of interference between the upper metallic wires 23 and the lower metallic wires 25. The invented touch panel 2 has a reduced wiring area, in which the wiring region 212 is minimized. The invented touch panel 2 is also advantageous in preventing misreading of touch signals due to an unintentional direct contact between the wiring region 212 with human body. According to the second preferred embodiment shown in
According to the third preferred embodiment shown in
According to the fourth preferred embodiment shown in
The first transparent substrate 21 is optionally coated with a protective layer 29, according to the fifth preferred embodiment shown in
In conclusion, the touch panel disclosed herein can surely achieve the intended objects and effects of the invention by virtue of the structural arrangement described above. While the invention has been described with reference to the preferred embodiments above, it should be recognized that the preferred embodiments are given for the purpose of illustration only and are not intended to limit the scope of the present invention and that various modifications and changes, which will be apparent to those skilled in the relevant art, may be made without departing from the spirit of the invention and the scope thereof as defined in the appended claims.
