1. Field of the Invention
The invention relates in general to a touch display device, a driving method thereof and a manufacturing method thereof, and more particularly, to a touch display device that utilizes a conductive layer of a display panel and a transparent layer on the display panel as touch sensing devices, a driving method and a manufacturing method thereof.
2. Description of the Related Art
A conventional touch display device is formed by directly adhering a touch panel to a display panel by an optical adhesive. Thus, the overall thickness and the weight of the panel are greater than those of one single display panel, adding to a load in user portability. In a current touch panel integrated with a touch function, a newly added touch sensing circuit utilizes transparent electrode blocks that are not connected to one another as driving electrodes and sensing electrodes. Indium tin oxide (ITO), having moderate electric conductivity, is generally adopted for transparent electrodes. Therefore, not only the value of received touch sensing signals is affected but also the sensitivity of touch sensing devices is limited.
The primary object of the present invention is to provide a touch display device that simultaneously reduces the thickness and the weight of a display panel integrated with a touch function without degrading functions of the display panel.
To achieve the above object, the present invention provides a touch display device. The touch display device includes a first substrate, a conductive layer and a first transparent layer. The conductive layer is disposed on the first substrate, and includes a plurality of metal lines. The metal lines extend along a first direction, and are insulated from one another. The first transparent layer is disposed on the conductive layer, and includes a plurality of first electrode strips. The first electrode strips extend along the first direction, and individually overlap with at least one of the metal lines in a second direction substantially perpendicular to the substrate. The first electrode strips are disposed between a plurality of second electrode strips and the metal lines. The second electrode strips extend along a third direction different from the first direction, and are disposed above the first transparent layer. The second electrode strips form capacitance coupling with the metal lines via the first electrode strips to perform touch sensing.
To achieve the above object, the present invention further provides a driving method of a touch display device. The touch display device includes a plurality of metal lines, a plurality of first electrode strips and a plurality of second electrode strips. The metal lines and the first electrode strips extend along a first direction, the first electrode strips individually overlap with at least one of the metal lines in a second direction of the display device substantially perpendicular to the substrate, and the second electrode strips extend along a third direction different from the first direction. In a display period, a display signal is transmitted to at least one of the metal lines, and a common voltage signal is transmitted to at least one of the first electrode strips. In a touch control period, a touch driving signal is transmitted to at least one of metal lines, at least one of the first electrode strips correspond to the at least one of the metal lines is kept floating, and a sensing signal is received from the second electrode strip corresponding to the at least one of the metal lines.
To achieve the above object, a manufacturing method of a touch display device is provided. A first substrate is provided. A conductive layer is formed on the first substrate. The conductive layer includes a plurality of metal lines, which extend along a first direction and are insulated from one another. A first transparent layer is formed on the conductive layer. The first transparent layer includes a plurality of first electrode strips. The first electrode strips extend along the first directly, and individually overlap with at least one of the metal lines in a second direction substantially perpendicular to the first substrate. A plurality of second electrode strips are formed on the first transparent layer. The second electrode strips extend along a third direction different from the first direction, and form capacitance coupling with the metal lines via the first electrode strips to perform touch sensing.
In the touch display device of the present invention, the metal lines may be utilized to transmit touch display signals including touch driving signal and pixel voltage signals or pixel switch signals. Therefore, in addition to serving as conducting lines that the display panel uses for transmitting pixel voltage signals or pixel switch signals, the metal lines can also form touch sensing devices with the second electrode strips. As such, a touch electrode layer for transmitting touch signals can be omitted in the touch display device of the present invention, thereby effectively reducing the thickness and the manufacturing costs of the touch display device. Further, in the present invention, with the first electrode strips disposed between the metal lines and the second electrode strips, coupling capacitance between the metal lines and the second electrode strips can be increased, and the touch sensitivity of the touch sensing devices can also be enhanced.
The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
Referring to
The touch display device 100 may further includes a plurality of second electrode strips 114, which extend along a third direction D3 different from the first direction D1. The first electrode strips 112 are disposed between the second electrode strips 114 and the metal lines 108. The metal lines 108 disposed along the first direction D1 may couple with the second electrode strips 114 disposed along the third direction D3 via the first electrode strips 112 to form touch sensing devices. In the embodiment, the touch display device 100 may further include a second substrate 106 that is disposed opposite the first substrate 104. Further the second electrode strips 114 are disposed on an outer surface of the second substrate 106.
The touch display device 100 may selectively further include a plurality of switches 116 disposed on an inner surface of the first substrate 104 in the border region 102b and facing the second substrate 106. Each of the switches 116 has one end electrically connected to one of the electrode strips 112, and the other end electrically connected to the same signal pad 118 to provide a common voltage. More specifically, each of the switches 116 may be a first thin film transistor. The first thin film transistors have their drains respectively electrically connected the first electrode strips 112, their gates electrically connected to a control pad 120 to control the turning on/off of the first thin film transistors, and their sources electrically connected to the signal pad 118.
It should be noted that, when the touch display device performs a touch function, the control pad 120 does not provide a voltage signal to the gates of the first thin film transistors corresponding to the touch function, in a way that the first thin film transistors are in a turn-off state, and the first electrode strips 112 electrically connected to the first thin film transistors 112 are in a floating state. Accordingly, the first electrode strips 112 are insulated from one another, and are allowed to respectively couple with the metal lines 108 to further change the voltages of the first electrode strips 112 with the signals of the metal lines 108. Further, the first electrode strips 112 may also couple with the second electrode strips 114, such that the second electrode strips 114 may form capacitance coupling with the metal lines 108 via the first electrode strips 112 to achieve touch sensing. When the touch display device 100 performs the display function, the control pad 120 provides a turn on voltage to the gates of the first thin film transistors to turn on the first thin film transistors. Thus, the common voltage provided by the signal pad 118 is provided to all of the first electrode strips 112 via the first thin film transistors to have the first electrode strips 112 serve as common electrodes.
In the embodiment, the display panel 102 may be a liquid crystal display (LCD) panel. For example, the display panel 102 is formed by an array substrate 122, the first transparent layer 110, a liquid crystal layer 124 and a color filter substrate 126. The display panel 102 may also be other types of array display panels, e.g., an organic light-emitting diode (OLED) display panel. The array substrate 122 and the color filter substrate 126 are disposed opposite each other, with the liquid crystal layer 124 disposed between the array substrate 122 and the color filter substrate 126. The array substrate 122 may include the first substrate 104 and a pixel element layer 128. The pixel element layer 128 may include the conductive layer 105, and the conductive layer 105 may be formed by any conductive layer in the pixel element layer 128. In the embodiment, the metal lines 108 may serve as data lines of the pixel element layer 128. In the above situation, for example, the first direction D1 may be the vertical direction, and the third direction D3 may be the horizontal direction. In addition to the metal lines 108, the pixel element layer 128 may further include a plurality of gate lines 130, a plurality of second thin film transistors 132 and a second transparent layer 134. The gate lines 130 transmit pixel switch signals to turn on/off the corresponding second thin film transistors 132, and are staggered with and insulated from the metal lines 108. The second thin film transistors 132 are in an array arrangement, and are correspondingly disposed at intersections of the gate lines 130 and the metal lines 108. Each of the second thin film transistors 132 may include a gate 136, a gate insulation layer 138, a source 142 and a drain 144. Each of the gates 136 is connected to one corresponding gate line 130. That is, the gates 136 of the second thin film transistors 132 of the same row are electrically connected to the same gate line 130. In the embodiment, the gates 136 and the gate lines 130 are formed by a first metal pattern layer M1. The gate insulation layer 138 covers inner surfaces of the first metal pattern layer M1 and the first substrate 104. The sources 142 and the drains 144 are disposed on the gate insulation layer 138, and are disposed correspondingly at two sides of the gates 136. Further, the sources 142 are electrically connected to one of the metal lines 108. That is, the sources 142 of the second thin film transistors 132 of the same row are electrically connected to the same metal line 108. In the embodiment, the sources 142, the drains 144 and the metal lines 108 may be formed by the conductive layer 105. For example, the conductive layer 104 may be the second metal pattern layer, or be formed by another conductive material. Instead of the exemplary type above, the second thin film transistors 132 of the present invention may be another type, e.g., top gate thin film transistors.
The pixel element 128 further includes an insulation layer 146. The insulation layer 146 is disposed between the first transparent layer 110 and the second transparent layer 134, and electrically insulates the first transparent layer 110 and the second transparent layer 134. The first transparent layer 110 and the second transparent layer 134 may be formed by a transparent conductive material, e.g., ITO or indium zinc oxide (IZO). In the embodiment, the second transparent layer 134 may include a plurality of pixel electrodes 148, which are respectively electrically connected to the drains 144 of the second thin film transistors 132. The first transparent layer 110 may further include a plurality of third electrode strips 150 as common electrodes. At least every two of the third electrode strips 150 are disposed between any two adjacent first electrode strips 112, and are located right above the pixel electrodes 148. As a gap is present between any two adjacent third electrodes 150, when a frame is displayed, an electric field formed by the pixel voltages of the pixel electrodes 148 may penetrate through the gap to form a lateral (horizontal) electric field with the common voltages of the third electrode strips 150 to drive liquid crystal particles of the liquid crystal layer 124. In another embodiment, the touch display device 100 may further include a plurality of switches. These switches switch the third electrode strips to a floating state when the touch display device 100 performs a touch function, and switch the third electrode strips to connect to a common voltage when the touch display device 100 performs a display function. These switches may be formed by a third film transistor.
The color filter substrate 126 may include the second substrate 106, a black pattern layer 152 and a plurality of color filter plates 154. The liquid crystal layer 124 is disposed between the first substrate 104 and the second substrate 106. The black pattern layer 152 and the color filter plates 154 are disposed between the liquid crystal layer 124 and the second substrate 106. The black pattern layer 152 includes a black matrix, and shields the second thin film transistors 132, the metal lines 108 and the gate lines 130 formed by the first metal pattern layer M1 and the conductive layer 105. Further, the black pattern layer 152 has a plurality of openings 152a disposed correspondingly to the pixel electrodes 148, respectively. The color filter plates 154 are disposed on the second substrate 106 of the openings 152a.
Details of a driving method of the touch display device 100 are given below. The driving method simultaneously provides functions of image display and touch sensing. Referring to
In step S10, in the display period DT, a display signal F is transmitted to at least one of the metal lines 108, and a common voltage signal Vcom is transmitted to at least one of the first electrode strips 112.
In step S12, in the touch control period TT, a touch driving signal T is transmitted to at least one of the metal lines 108 serving as first touch electrodes, at least one of the first electrode strips 112 corresponding to the at least one of the metal lines 108 is kept floating, and a sensing signal Rx is received from at least one of the second electrode strips 114 serving as second touch electrodes and corresponding to the metal line 108.
In the display period DT in step S10, as the metal lines 108 of the embodiment are data lines, the display signal F is a pixel voltage signal. That is, in the display period DT, the pixel voltage signal is transmitted to at least one of the metal lines 108, and pixel switch signals G1 to Gn are transmitted to at least one of the gate lines 130 to turn on the corresponding second thin film transistor 132 such that the pixel electrode 148 corresponding to the second thin film transistor 132 is allowed to have the corresponding pixel voltage. Meanwhile, the common voltage signal Vcom transmitted to the first electrode strips 112 is also transmitted to the third electrode strips 150, and has the common voltage in the display period DT. Thus, a lateral electric field is formed between the pixel electrodes 148 and the first electrode strips 112 as well as the third electrode strips 150 to enable the touch display device 100 to display a frame. More specifically, the common voltage signal Vcom transmitted to the first electrode strips 112 is provided by the signal pad 118 to be transmitted to the first electrode strips 112 via the switches 116.
In the touch control period TT in step S12, the pixel switch signals G1 to Gn are no longer transmitted to the gate lines 130 to turn off the corresponding second thin film transistor 132. At this point, the signal transmitted to at least one of the metal lines 108 is changed to the touch driving signal T, and the step of keeping the first electrode strip 112 corresponding to the at least one of the metal lines 108 floating includes turning off the switches 116 to stop transmitting the common voltage signal Vcom to the first electrode strips 112, such that at least one of the first electrode strips 112 is kept in a floating state. Further, the touch driving signal T may be simultaneously or sequentially transmitted to different metal lines 108, and the first electrode strip 112 corresponding to the metal line 108 that transmits the touch driving signal T, i.e., the first electrode strip 112 that overlaps the metal line 108 and/or the adjacent first electrode strip 112, is also in a floating state, thereby preventing the first electrode strip(s) 112 from affecting the displayed frame. The first electrode strips 112 may be coupled to the corresponding metal lines 108, and generate signals along with the change in the touch driving signal T. Meanwhile, according to the sensing signal Rx sensed by the second electrode strips 114, it may be determined whether the touch display device 100 is touched or approached by an object, and a position of the object may then be detected. In another embodiment, the third electrode strips 150 may also be kept floating in the touch control period TT.
In the embodiment, the display period DT is the time that the display panel 102 uses to display one frame, and so the touch display device 100 may transmit the touch driving signal T to the metal lines 108 and receive the sensing signal between different display periods DT in which different frames are displayed. In another embodiment, the touch control period TT may be an interval between periods of any two adjacent pixel switches signals G1 to Gn. That is, the display period DT may be divided into two periods, which may respectively correspond to different pixel switch signals G1 to Gn of a same frame. Further, the touch control period TT is also located therein to prevent the touch driving signal T from interfering with the displayed frame.
It should be noted that, the touch driving signals T and the pixel voltage signals F of the embodiment may be integrated into one touch display signal TD, which is the pixel voltage signal F in the display period DT and the touch driving signal T in the touch control period TT. Accordingly, the metal lines 108 serving as data lines may transmit the pixel voltage signals F in the display period DT to serve as conducting wires for transmitting the pixel voltage signal F of a displayed frame, and transmit the touch driving signal T in the touch control period TT to serve as driving electrodes that touch sensing devices use to transmit the touch driving signal T. Therefore, the touch electrode layer for transmitting the touch driving signal T can be omitted in the touch display device 100 of the embodiment, thereby effectively reducing the thickness as well as manufacturing costs of the touch display device 100. Further, in the touch display device 100 of the present invention, the first electrode strips 112 are disposed between the metal lines 108 and the second electrode strips 114 to enhance the touch sensitivity of the touch sensing devices.
The present invention further provides a manufacturing of the touch display device 100. Referring to
In step S100, the first substrate 104 is provided.
In step S102, the conductive layer 105 is formed on the first substrate 104. The conductive layer 105 includes a plurality of metal lines 108, which extend along the first direction D1 and are insulated from one another.
In step S104, the first transparent layer 110 is formed on the conductive layer 105. The first transparent layer 110 includes a plurality of first electrode strips 112. The first electrode strips 112 extend along the first direction D1, and individually overlap with the metal lines 108 in a second direction D2 substantially perpendicular to the first substrate 104.
In step S106, a plurality of second electrode strips 114 are formed on the first transparent layer 110. The second electrode strips 114 extend along the third direction D3 different from the first direction D1, and form capacitor coupling with the metal lines 108 via the first electrode strips 112 to perform touch sensing.
Referring to
Referring to
Referring to
It should be noted that, the touch display device of the present invention is not limited to be implemented as the foregoing embodiments. Other embodiments are to be described below. For the sake of simplicity and to emphasize the differences between the embodiments or the variations, the same elements are represented by the same denotations and associated details are omitted herein.
Details of a driving method of the touch display device 200 according to the embodiment of the present invention are given below. The driving method simultaneously supports functions of image display and touch sensing. Referring to
In step S20, in the display period DT, pixel switch signals G1 to Gn are transmitted to at least one of the metal lines 202, a pixel voltage signal F is transmitted to at least one of the data lines, and a common voltage signal Vcom is transmitted to the first electrode strips 112 and the third electrode strips 150 to cause the touch display device 200 to display a frame.
In step S22, in the touch control period TT, a touch driving signal T is transmitted to the at least one of the metal lines 202 serving as the first touch electrodes, at least one of the first electrode strips 112 corresponding to the at least one of the metal lines 202 is kept floating, and a sensing signal Rx is received from at least one of the second electrode strips 114 corresponding to the metal line 202 and serving as second touch electrodes.
Compared to the first embodiment, as the metal lines 202 of the embodiment are gate lines, the display signal transmitted to the metal lines 202 is the pixel switch signals G1 to Gn. Further, the pixel voltage signal F is transmitted to the data lines 204. Therefore, in the driving method of the embodiment, the touch driving signals T and the pixel switch signals G1 to Gn are integrated into touch display signals TD1 to TDn, which are the pixel switch signals G1 to Gn in the display period DT and the touch driving signals T in the touch control period TT. Further, the touch display signals TD1 to TDn are transmitted via the metal lines 202. Accordingly, the metal lines 202 serving as gate lines may transmit the pixel switch signals G1 to Gn in the display period DT to serve as conducting lines of the pixel switch signals G1 to Gn of the second thin film transistors 132, and transmit the touch driving signals T in the touch control period TT to serve as driving electrodes that the touch sensing devices use to transmit the driving signals T. In the embodiment, the data lines 204 transmit the pixel voltage signals F in the display period DT, and do not transmit signals in the touch control period TT. Details of driving the first electrode strips 112, the second electrode strips 114 and the third electrode strips 150 are the same as those of the first embodiment, and shall be omitted herein.
In conclusion, in the touch display device of the present invention, the metal lines may be utilized to transmit touch display signals including touch driving signals and pixel voltage signals or pixel switch signals. Thus, the metal lines not only can serve as conducting lines that the display panel uses to transmit the pixel voltage signals or the pixel switch signals, but also can respectively form touch electrode pairs with the second electrode strips by the coupled first electrode strips that are kept floating. It should be noted that, the first touch electrodes and the second touch electrodes of the present invention refer to a sequence of assigning the terms, and are not for limiting a stacking sequence of the electrodes on the display device or an operation sequence of the touch driving method, or electrode functions for transmitting touch signals or receiving sensing signals sensed. Accordingly, the touch electrode layer for transmitting touch signals can be omitted in the touch display device of the present invention to further effectively reduce the thickness and the manufacturing costs of the touch display device. Further, in the present invention, with the first electrode strips disposed between the metal lines and the second electrode strips, coupling capacitance between the metal lines and the second electrode strips can be increased, and the touch sensitivity of the touch sensing devices can also be enhanced.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
Number | Date | Country | Kind |
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103142447 | Dec 2014 | TW | national |
This application claims the benefit of U.S. Provisional Application Ser. No. 62/043,430, filed Aug. 29, 2014, and Taiwan Application Serial No. 103142447, filed Dec. 5, 2014, the subject matter of which is incorporated herein by reference.
Number | Date | Country | |
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62043430 | Aug 2014 | US |