Touch device and an electrostatic shielding method thereof

The present disclosure provides a touch device comprising at least one first conductive axis, a plurality of second conductive units, a plurality of bridging structures and an insulating layer. The first conductive axis has a plurality of openings in which the second conductive units are located respectively. There is a space existed between each of the second conductive units and the corresponding first conductive axis. Each of the majority of the bridging structures are electrically connected to every two adjacent second conductive units in two adjacent first conductive axes. The insulating layer is located between the bridging structure and the first conductive axis. The insulating layer has a plurality of holes exposing the second conductive units respectively, and the bridging structures connect to the second conductive through the holes. In addition, the disclosure also provides an electrostatic shielding method of touch device.

BACKGROUND OF THE INVENTION

This Application claims the benefit of the People's Republic of China Application No. 201210198144.3, filed on Jun. 15, 2012 and No. 201310188334.1, filed on May 21, 2013.

FIELD OF THE INVENTION

The present disclosure relates to touch technology, more particularly to a touch device and an electrostatic shielding method thereof.

DESCRIPTION OF THE RELATED ART

Presently, due to personal digital assistants (PDA), mobile phones, notebook computers, tablet personal computers, and other portable electronic products need to be thin in thickness and also, light in weight, the traditional input devices, such as keyboards or mouse, have to be replaced with other input devices. Especially, when the need for tablet personal computers has greatly increased, a touch panel has become one of the key components used in electronic products as an interface for data communication.

When a conventional touch device sends or receives signals, an extra shielding layer is added into the structure of the touch device for preventing touch signals from signal interference caused by other external electronic devices, based on the electrostatic shielding theory, the extra shielding layer can increase the anti-interference ability of the touch device. However, the addition of such a shielding layer tends to increase the integral thickness of the touch device, accompanying with a relatively higher manufacturing cost and more complicated manufacturing process.

SUMMARY OF THE DISCLOSURE

The present disclosure provides a touch device and an electrostatic shielding method thereof.

The disclosure provides a touch device comprising at least one first conductive axis, a plurality of second conductive units, a plurality of bridging structures and an insulating layer. The first conductive axis has a plurality of openings in which the second conductive units are located respectively. There is a space existed between each of the second conductive units and the corresponding first conductive axis. Each of the majority of the bridging structures are electrically connected to every two adjacent second conductive units in two adjacent first conductive axes. The insulating layer is located on the positions between the budging structure and the first conductive axis. The insulating layer has a plurality of holes exposing the second conductive units respectively, and the bridging structures connect to the second conductive through the holes. Upon a driving signal received by the second conductive units, the first conductive axis is connected to a grounding potential or a fixed potential, so as to conduct electrostatic shielding for the second conductive units.

The disclosure also provides an electrostatic shielding method of touch device. The method comprises steps of: driving a first conductive axis to detect the output signals of the first axis and acquire first information concerning touch position in the first direction; second, connecting the first conductive axis to it grounding potential or a fixed potential so as to conduct electrostatic shielding for second conductive axes; third, driving the second conductive axes to detect the output signals of the second axes and acquire second information concerning touch position in the second direction; finally, combining the first information and the second information concerning touch position in the first direction and the information concerning touch position in the second direction to calculate coordinates of touch positions.

The first conductive axes used for sensing touch positions can also be used as a shielding layer without the manufacture of an extra shielding layer, thus reduce the integral thickness and the manufacturing cost of the touch device, and further, simplify the manufacturing process, and, meanwhile, enable the touch device to have anti-interference function.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To provide a better understanding of the present disclosure to a person skilled in the art, preferred embodiments are detailed as follows. The preferred embodiments of the present disclosure are illustrated in the accompanying drawings with numbered elements to clarify the contents and effects to be achieved.

Those of ordinary skill in the art will recognize that the figures are only for illustration and the figures may not be to scale. The scale may be further modified according to different design considerations. On referring to the words “up” or “down” that describe the relationship between components in the text, it is well known to a person skilled in the art that these words refer to relative positions that can be inverted to obtain a similar structure, and these structures should therefore not be precluded from the scope of the claims in the present disclosure.

FIGS. 1˜6are schematic diagrams of the structures of a touch device in accordance with the first embodiment of the disclosure. With reference toFIGS. 1˜6, the touch device1comprises at least one first conductive axis20, a plurality of second conductive units32, a plurality of bridging structures62and an insulating layer50. The first conductive axis20has a plurality of openings22in which the second conductive units32are located respectively, wherein there is a space23existed between each of the second conductive units32and the corresponding first conductive axis20to make the second conductive units32insulated to the corresponding first conductive axis20. Each of the majority of the bridging structures62(bridging structures62such as located between the first conductive axes20) is electrically connected to every two adjacent second conductive units32in two adjacent first conductive axes20. The insulating layer50is located between the bridging structures62and the first conductive axes20, and in other embodiments, part of the insulating layer50may be also located between the bridging structures62and the second conductive units32, to make the bridging structures62electrically insulated to the first conductive axes20. The insulating layer50has a plurality of holes52exposing the second conductive units32respectively, and the bridging structures62electrically connect to the second conductive units32through the holes52. Upon a driving signal (not shown in Figs.) received by the second conductive units32, the first conductive axis20is connected to a grounding potential or a fixed potential, so as to conduct electrostatic shielding for the second conductive units32.

According to the touch device provided in the embodiment of the disclosure, the following content describes the components of the touch device respectively according to their formation steps, but the structure of the touch device is not limited to such formation steps.

With further reference toFIG. 1, the touch device provided in the preferred embodiment of the disclosure also comprises a substrate10on which the first conductive axes20and the second conductive units32are disposed. Furthermore, the substrate10is delimited as a touch area12and a peripheral area14. The plurality of first conductive axes20and the plurality of second conductive units32are disposed in the touch area12. The first conductive axes20with the plurality of openings22are arranged in parallel along a first direction (for example, along Y axis). The second conductive units32are located in the openings22, without intersecting or contacting with the first conductive axes20. In this embodiment, the material of the substrate10can be selected from transparent materials such as glass, polymethylmethacrylate (PMMA), polyvinylchloride (PVC), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), and poly-styrene (PS) etc. The materials of the first conductive axes20and the second conductive units32can include various transparent conductive materials, for instance, indium tin oxide (ITO), aluminum zinc oxide (AZO), indium tin zinc oxide (ITZO), zinc oxide, cadmium oxide, hafnium oxide (HfO), indium gallium zinc oxide (InGaZnO), indium gallium zinc magnesium oxide (InGaZnMgO), indium gallium magnesium oxide (InGaMgO) or indium gallium aluminum oxide (InGaAlO) and so on. The first conductive axes20, the second conductive units32and the openings22are roughly in rectangular shape, but their shapes can be designed according to the specific requirements, for example, the shapes of the second conductive units32and the openings22can also be round, rhombic and orthohexagonal etc. The periphery of the second conductive units32are surrounded by the corresponding first conductive axes20. Moreover, the sequential order of manufacturing the first conductive axes20and the second conductive units32is not limited in this embodiment, and can also be firmed in a same step simultaneously or in two steps respectively.

As shown inFIG. 2, a plurality of first conductive wires42are formed within the touch area12and the peripheral area14to electrically connect with the first conductive axes20. A plurality of second conductive wires44are formed only within the peripheral area14and will electrically connect to the second conductive axes that will be formed in the subsequent process. The first conductive wires42and the second conductive wires44are also connected to an external microprocessor (not shown) for transmitting the touch signals to the microprocessor or for receiving driving signals, a grounding potential and/or a fixed potential from the microprocessor. The materials of the first conductive wires42and the second conductive wires44can be selected from metals such as aluminium, copper, silver or the above-mentioned transparent conductive materials. When the first conductive wires42and the second conductive wires44are of the same material as of the first conductive axes20and the second conductive units32, they can be formed simultaneously with the manufacture of the first conductive axes20and the second conductive units32. It should be noted that at this moment the second conductive wires44are not electrically connected to the second conductive units32yet.

Next, an insulating layer is formed within the touch area12and covers the first conductive axes20and may be partial of the second conductive units32. From the top view of patterns on the insulating layer alone, a plurality of holes52are existed in the middle area of the insulating layer50, as shown inFIG. 3A. After the insulating layer50covers the touch area12, as shown inFIG. 3B, the holes52will expose the second conductive units32respectively for being contact holes to let the bridging structures62electrically connect with the second conductive units32later. In this embodiment, the insulating layer50adopts a variety of non-conductive materials such as Polyimide (PI), SiO2, SiN. SiON and SiC and so on. After the insulating layer50is formed, the second conductive units32will be exposed and the first conductive axis20will be covered by the insulating layer50, in other embodiment, the partial first conductive wires42and second conductive wires44will be exposed.

Next, bridging structures are formed on the insulating layer50, at this moment the top view of the touch device of this disclosure is as shown inFIG. 4, whereasFIG. 5is a cross-sectional schematic diagram of the structure along the cross-hatching II′ inFIG. 4. With reference toFIGS. 4 and 5, each of the majority of the bridging structures62, showing arch shape from a lateral side, crosses over the insulating layer50and electrically connects every two adjacent second conductive units32in two adjacent first conductive axes20to make the second conductive units32connect serially to form a plurality of second conductive axes30. And each of the minority of the bridging structures62also extend towards the peripheral area14and are electrically connected to the second conductive wires44, via this connection the touch signals of the second conductive axes30are transmitted to the external microprocessor. Since the first conductive axes20surround the second conductive units32, the first conductive axes20can function as a shielding layer of the second conductive units32, that is, when the second conductive units32are driven by receiving the driving signals from the external microprocessor, the first conductive axes20may be controlled by the external microprocessor to connect to the grounding potential or the fixed potential for effectively shielding the interference of the outside signals to the second conductive axes30, thus reducing the extent of signal interference of the integral touch device. Moreover, since the first conductive axes20of this disclosure is not only used to sense touch positions but also function as a shielding layer, there is no necessity of manufacturing an extra shielding layer and thus, the integral thickness of touch device can be reduced, thereby simplifying manufacture process and saving costs and enabling the touch device to have anti-interference function.

Finally, as shown inFIG. 6, a protective layer70can be overlaid and disposed on the first conductive wires42, the second conductive wires44and the bridging structures62to protect the components stacked-up on the substrate10from vapour and oxygen in the air. The material of the protective layer70comprises inorganic materials such as silicon nitride, silicon oxide and silicon oxynitride, and organic materials, for example, acrylic resin or other suitable materials.

Further, the touch device provided in the embodiment of this disclosure can also comprise at least a display unit (not shown) located underneath the substrate. The display unit can be liquid crystal display (LCD) or other optical assemblies. There is no shielding layer that exists between the substrate and the display unit, while the first conductive axes, used for sensing touch positions, function simultaneously as a shielding layer for shielding the signal interference of the display unit or other optical assemblies to the touch device. In view thereof, the integral thickness of touch device can be reduced, with lower costs and simplified manufacturing process.

This disclosure can be applied to manufacture various touch devices such as mobile phone, personal digital assistant or satellite navigation system etc., as for other applications, printed circuit board or flexible printed circuit can be used to manufacture the touch device of the disclosure.

In this embodiment the first conductive axes20are arranged in parallel along a first direction (for example, along Y axis), and the second conductive axes30, formed by connecting the second conductive units32serially with the bridging structures62, are arranged in parallel along a second direction (for example, along X axis). The first direction may be perpendicular to the second direction, but is not limited herein, and the arrangement can be accorded with the actual requirements.

Compared with the conventional touch devices, the touch device provided in this disclosure does not require an extra shielding layer to be manufactured, as the conductive axis can be used for sensing, touch positions and also, function as a shielding layer, thereby reducing the integral thickness of the touch device and the manufacturing costs and simplifying the manufacturing process. The interference of outside electronic signals can thus be decreased and the stability of the touch device can be improved.

The following text will make illustration for different embodiments about the touch device of this disclosure, and for simplifying the description, the following text is primarily aimed at the specification of different points concerning various embodiments, the same points will be referred to the embodiments and not be repeated again. In addition, the same components of various embodiments of this disclosure are marked with the identical labels to facilitate mutual contrast among different embodiments.

FIG. 7is a cross-sectional diagram of the partial structure in accordance with the second preferable embodiment of the disclosure. With reference toFIG. 7, the points of difference from the first embodiment are that the bridging structures62are disposed on the substrate10, that is, the touch device2has a substrate10on which the bridging structures62are formed first and then covered with an insulating layer50to expose at least a part of bridging structures62. Subsequently, a plurality of first conductive axes20and a plurality of second conductive units32surrounded by the first conductive axes20are formed. When the second conductive units32are formed, they contact with the bridging structures62underneath via the holes of the insulating layer50, that is, every two adjacent second conductive units32in two adjacent first conductive axes20are electrically connected via a bridging structure62. The second conductive units32are conducted mutually to be further connected in series for forming a second conductive axis. Finally, a protective layer70is overlaid and disposed on the first conductive axes20and the second conductive units32, in this process the touch device2of the second preferable embodiment of this disclosure is completed. Since most of the bridging structures62are covered with the insulating layer50, the bridging structures62can be concealed underneath the insulating layer50to increase the aesthetic extent of the touch device from the top angle of the touch device. Similarly this embodiment can also be applied to manufacture various different products, and the materials of the components used in the embodiment are the same as the first preferable embodiment, but the same is not repeated again.

FIG. 8is a top-view schematic diagram of the structure in accordance with the third embodiment of the disclosure. The point of difference from the first preferred embodiment are that the first conductive axis of the touch device3is divided into two axes respectively as the first left-side conductive axis24and the first right-side conductive axis26separated from each other, and the intermediate region between the first left-side conductive axis24and the first right-side conductive axis26is defined as an opening-hole area28in which the second conductive units32are located respectively, wherein there is a space29existed between each of the second conductive units32and the corresponding first left-side conductive axis24and between the second conductive units32and the corresponding first right-side conductive axis26to make the second conductive units32insulated to the corresponding the first left-side conductive axis24and the first right-side conductive axis26. In this embodiment, since a previous first conductive axis is divided into two axes respectively connected with the conductive wire42aand the conductive wire42b, the measurement accuracy for the first direction direction in this embodiment) can be further increased. The first left-side conductive axis24and the first right-side conductive axis26surround the second conductive units32to realize the shielding function, which has the same advantages as the first embodiment of this disclosure.

FIGS. 9˜11are respectively top-view schematic diagrams of the partial structures of other three embodiments in accordance with the first embodiment of this disclosure.FIGS. 9˜11only show a part of first conductive axes and a second conductive unit. The points of difference from the first embodiment of this disclosure are that the second conductive units of various embodiments are patterned conductive units to promote the transmittance of the integral touch device. With reference toFIG. 9, the second conductive units previously in rectangular shape are replaced by the second conductive units34of this embodiment pattern presenting in S shape along a horizontal direction. With reference toFIG. 10, the second conductive units previously in rectangular shape are replaced by the second conductive units36of this embodiment pattern presenting in S shape along a vertical direction. As for the way of formation of the second conductive units of S shape in the embodiment patterns ofFIGS. 9˜10, the second conductive units of rectangular shape are formed firstly via lithography and etching process and a plurality of strip openings are etched on these conductive units, or the second conductive units arranged in S shape are formed by direct printing process. With reference toFIG. 11, the central part of the second conductive units38of this embodiment has a plurality of small holes. The materials of the components used in the foregoing embodiment patterns are the same as the first embodiment, but is not limited herein. The foregoing embodiments changing variably can improve the transmittance of the integral touch device. Of course, the foregoing different patterning embodiments can also be integrated with the second or third embodiments, which are not limited to the variation of the first embodiment.

The touch device of this disclosure is not limited to the structure or the method described in the foregoing embodiments. Provided that the first conductive axis and the second conductive axis are located on a same layer, and that the bridging structures are located on another layer, and that the first conductive axis can function as a shielding layer simultaneously, all these belong to the scope covered by this disclosure.

According to the touch devices provided by the foregoing embodiments, the embodiment of this disclosure also provides an electrostatic shielding method of the said touch devices.FIG. 12is a flow chart of the electrostatic shielding method for the touch device of this disclosure. With reference toFIG. 12, the electrostatic shielding method for the touch device provided by the embodiment of this disclosure specifically includes the following steps:

S1: Driving a first conductive axis and detecting the output signals of the first conductive axis, especially via a first conductive wire corresponding to the first conductive axis, to acquire first information concerning touch position in a first direction.

S2: Connecting the first conductive axis to a grounding potential or a fixed potential (such as a 5V voltage). In this step, the first conductive axis, being connected to the grounding potential or the fixed potential, also performs electrostatic shielding function for the second conductive axis so as to reduce the interference of outside noise signals to subsequent detection of the output signals from a second conductive wire.

S3: Driving a second conductive axis and detecting the output signals from the second conductive axis, especially via a second conductive wire corresponding to the second conductive axis, to acquire second information concerning touch position in a second direction.

S4: Combining the first and the second information concerning touch positions in the first and second directions to calculate the coordinate of the touch position.

In the foregoing embodiment, the signal generated by driving the first conductive axis and the second conductive axis is an alternating signal such as impulse signal or sine-wave signal. The output signals from the first conductive wire and the second conductive wire can be self-capacitance variable quantity caused by touch.

The electrostatic shielding method for the touch device of the foregoing embodiment is that the first conductive axis can be used to sense touch positions and also, function as a shielding layer, thereby reducing the interference of outside electronic signals and improving the detection accuracy for touch positions.

While certain embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the disclosure. Therefore, it is to be understood that the present disclosure has been described by way of illustration and not limitations.