TWI403941B - Touch panel display device - Google Patents

Abstract

The present invention relates to a touch panel display device. An upper substrate of the touch panel display device includes a common voltage layer. A lower substrate of the touch panel display device includes a plurality of scanning lines and a touch-sensing module. The touch-sensing module includes a plurality of touch-sensing readout line, a plurality of touch-sensing elements and a judgement module. A resistance of the touch-sensing element alters according to a variation of an electric field between the touch-sensing element and the common voltage layer. A voltage or a current of the touch-sensing readout line alters according to a resistance of the touch-sensing element. The judgement module connects to the touch-sensing readout lines and determines a touch-sensing position according to a position of the scanning line and a position of the touch-sensing readout line whose voltage or current changed.

Description

Touch display

The invention relates to a touch sensing module and a touch display integrated with the touch sensing module in the touch display.

With the maturity of touch technology, the touch application products available in the market are very wide, and the growth of the touch panel display market in the future is expected. The conventional touch panel is mainly divided into an external capacitive type and an externally mounted resistive type. However, regardless of any of the above methods, a touch panel module must be added to the display surface of the display module, thereby causing a touch display product. Certain effects, such as increasing the total thickness and weight of the display, reducing the brightness and contrast of the display, increasing the difficulty of production integration and thus increasing the cost.

In order to solve the aforementioned problems, related manufacturers of flat panel displays are competing to develop integrated flat panel displays with touch sensing functions, such as in-cell light sensing touch panels proposed by Pat Green Planar Systems (Adi Abileah, Willem Den Boer, Terrance Larsson, Tom Baker, Scott Robinson, Roy Siegel, Noah Fickenscher, Brent Leback, Terry Griffin, Beaverton, OR, USA, Integrated Optical Touch Panel in a 14.1" AMLCD, SID 2004) is an example. The technology used in the cell light-sensing touch panel utilizes the a-Si layer of the thin film transistor (TFT) inside the touch display to easily change the light leakage current of the output according to the intensity of the light, and thus, when the user When the hand blocks the light from the external environment, the thin film transistor outputs different currents to determine the position of the user's hand, thereby achieving the effect of determining the touch position. However, the above-mentioned light-sensitive touch panel has two main ones. technical problem:

1) The light-sensitive touch panel transmits brightness of external ambient light The change in the position of the touch is recognized. Therefore, there is a relatively high requirement for the brightness of the ambient light, for example, there is no sensing effect in a low-brightness environment.

2) The thin film transistor inside the light-sensitive touch panel is exposed to external ambient light for a long period of time. After a period of use, the thin film transistor may degrade and continuously generate leakage current, which is easy to control or read after long-term use. A misjudgment occurred in the judgment.

In order to solve the technical problem that the in-cell light-sensitive display uses limited environmental light intensity variation and is prone to malfunction, the present invention provides a touch display that can be used in various environments and is less prone to malfunction.

The invention provides a touch display comprising an upper substrate and a substrate disposed opposite the upper substrate. The upper substrate includes a common electrode layer, and the lower substrate includes a plurality of scan lines, a plurality of data lines insulated from the scan lines, and a touch sensing module. The touch sensing module includes a plurality of touch data reading lines, a plurality of touch reading elements, and a touch determining module. The plurality of touch data reading lines are respectively spaced apart from the data lines; the touch reading element is disposed at an intersection of the touch data reading line and the plurality of scanning lines. Each touch reading component is a double-ended component, and the first end is electrically connected to one of the touch data reading lines, and the second end is electrically connected to one of the scan lines. The touch sensing element changes its own equivalent resistance according to the electric field change between the touch sensing element and the common electrode layer, so that the voltage or the output current of the touch data reading line changes. The touch determination module is electrically connected to each touch data read line, and determines the touch position according to the position of the touch data read line and the position of the scanned scan line according to the voltage or the output current.

The invention provides a touch display comprising an upper substrate and a substrate disposed opposite the upper substrate. The upper substrate includes a common electrode layer, and the lower substrate includes a plurality of scan lines, a plurality of data lines insulated from the scan lines, and a touch sensing module. The touch sensing module includes a plurality of touch data reading lines, a plurality of touch switch transistors, a plurality of touch reading elements, and a touch determining module. The plurality of touch data reading lines are respectively spaced apart from the data lines; each touch switch transistor includes a gate, a source and a drain. The gate is electrically connected to the scan line; the source is electrically connected to the touch data read line. The touch reading component is disposed at an intersection of the touch data read line and the plurality of scan lines, and each of the touch read elements is a double end element, and the first end is electrically connected to one of the scan lines The second end is electrically connected to the drain of the touch switch transistor. The touch sensing element changes its own equivalent resistance according to the electric field change between the touch sensing element and the common electrode layer, so that the voltage or output current of the touch data reading line changes; the touch determination module and each strip The touch data reading line is electrically connected, and the touch position is determined according to the position of the touch data read line and the position of the scanned scan line which are changed according to the voltage or the output current.

Compared with the conventional technology, the invention achieves the technical effect of the touch position sensing by the resistance induction type, and therefore can solve the technique of using the in-cell light-sensitive display with the limitation of the ambient light intensity variation and the malfunction. problem.

Please refer to FIG. 1 , which is a partial structural diagram of a first embodiment of a touch display device according to the present invention. The touch display 1 includes an upper substrate 20, a lower substrate 10, and a liquid crystal layer (not shown) between the sealing clips. The upper substrate 20 An upper substrate body 21 and a black matrix 22, a common electrode 23, and a color filter 24 formed on an inner surface of the upper substrate body 21 opposite to the lower substrate 10 are included. The black matrix 22 is a non-transmissive grid that is disposed between the color filters to separate the color filters. The common electrode 23 is plated on the outermost surface of the upper substrate 20 with respect to the lower substrate 10.

The lower substrate 10 includes a lower substrate body 11 and a light shielding layer 1848, an insulating layer (not labeled), a sensing layer 1842, and an ohmic contact layer 1846 are sequentially stacked from the lower substrate body 11 toward the upper substrate body 21. , a connector 1844 and a protective layer (not labeled). The sensing layer 1842 is fabricated using amorphous silicon (a-Si) which is a standard process for display control transistors. In order to avoid the phenomenon that the sensing layer 1842 generates a light leakage current due to exposure to ambient light, the layout position of each sensing layer 1842 may correspond to the black matrix 22. In order to prevent the photosensitive layer 1842 from being irradiated by the light generated by the backlight module of the touch display 1 to cause a photoinduced leakage current phenomenon, the subsequent touch determination error is made before the sensing layer 1842 is formed. First, a light shielding layer 1848 corresponding to the sensing layer 1842 is first laid out by using a gate metal layer of the display control transistor standard process. The insulating layer, the sensing layer 1842, the ohmic contact layer 1846, the connecting member 1844, and the protective layer are then laid on the light shielding layer 1848 in the order of the standard process steps of the display control transistor.

Please refer to FIG. 2 together for a partial schematic diagram of the equivalent circuit of the touch display 1. The lower substrate body 11 is further provided with a plurality of scanning lines 12, a plurality of data lines 14, a plurality of sub-pixel control modules 16, a plurality of touch sensing modules 18 and a touch determining module 19.

Each sub-pixel control module 16 is sandwiched between two adjacent scan lines 12 and two adjacent data lines 14; each sub-pixel control module 16 includes a display control transistor (not labeled) and A sub-pixel electrode (not shown). An electric field is formed between the common electrode 23 and each of the sub-pixel electrodes of the lower substrate 10 to control molecular rotation of the liquid crystal layer. The display control transistor is located at an intersection of the scan line 12 and the data line 14, and is electrically connected to the adjacent scan line 12, the data line 14, and the sub-pixel electrode. The material of the sub-pixel electrode is a transparent conductive film such as ITO (indium tin oxide), IZO (indium zinc oxide) or the like. A driving control module (not shown) is connected to each of the scanning lines 12 and the data lines 14 to control the switching state of each display control transistor and the voltage change of the connected sub-pixel electrodes.

The plurality of touch sensing modules 18 include a plurality of touch data reading lines 182 and a plurality of touch reading elements 184. The plurality of touch data reading lines 182 are spaced apart from the plurality of data lines 14 . The touch reading component 184 is located at the intersection of the touch data reading line 182 and the partial scanning line 12, and the touch sensing component 184 is a resistive sensing element having two terminals. The two terminals are electrically connected to the touch data read line 182 and the scan line 12 respectively. Each touch-reading component 184 of the present embodiment mainly includes a sensing layer 1842 and two connecting members 1844. The layout area and shape of the sensing layer can be set in conjunction with the adjacent sub-pixel control module 16. For example, the sensing layer 1842 can be in the shape of a strip and adjacent to the scan line 12 or the data line 14 disposed at one of the two ends of the sensing layer 1842 and the touch data reading line 182 by the connecting member 1844. The scan line 12 is electrically connected; the connector 1844 can be fabricated using the source/dual metal layer of the display control transistor standard process. In order to make the connector 1844 and the induction The connection between the layers 1842 forms a lower junction resistance or avoids the formation of a non-ohmic contact pattern, and an ohmic contact layer 1846 is interposed between the connector 1844 and the sensing layer 1842, the ohmic contact Layer 1846 is a doped amorphous germanium (n+ a-Si) process in the standard process of display control transistor.

The touch determination module 19 is electrically connected to each of the touch data read lines 182, and determines one or some touches according to the difference between the voltage level or the output current of each touch data read line 182. Whether the corresponding position of the touch reading element 184 on the data reading line 182 is touched and pressed. In an implementation manner, the touch determination module 19 of the embodiment may include a comparison circuit electrically connected to each touch data reading line 182, and the comparison circuit is configured to find the difference between the generated voltage or the output current. The touch data reading line 182; the touch determining module 19 further includes a touch reading chip electrically connected to the comparing circuit, and the comparison judgment result of the comparing circuit is read, and the driving control wafer die is matched with the driving The signals of the group are determined, and it is determined whether the corresponding positions of the touch reading elements 184 on the touch data reading lines 182 having the voltage or current difference are touched.

Please refer to FIG. 3 together for a partial structural diagram of the touch display 1 of the present invention when it is subjected to pressure. In use, in order to enable the output display to maintain the display function, the drive control module inputs a voltage pulse square wave to the scan line 12 one by one in a scanning manner, wherein the drive control module scans the scan frequency of each scan line 12 It is 60Hz, 120Hz...etc. One end of each touch reading element 184 in this embodiment is respectively connected to one of the scanning lines 12; therefore, when the user presses and touches the upper substrate 20, the partial area of the upper substrate 20 is deflected toward the lower substrate. The direction of 10 moves closer to the free conductive charge in the sensing layer 1842 of the touch reading element 184 corresponding to the position The concentration is concentrated by the attraction of the common electrode 23, thereby changing the equivalent resistance across the sensing layer 1842. The foregoing common electrode 23 can attract the accumulation of the free conduction charge of the sensing layer 1842 because the electric field of the common electrode 23 and the lower substrate 10 forms an electric field, for example, the common electrode 23 can also be shielded from the light. The layer 1848 forms an electric field, so when the position of the common electrode 23 is relatively close to the sensing layer 1842, the equivalent resistance of the sensing layer 1842 changes due to the change of the electric field; when the sensing layer 1842 is sensed, When the scanning line 12 is in the input voltage pulse period, the touch sensing element 184 connected to the scanning line 12 changes the touch data reading line 182 connected to the touch reading element 184 due to the resistance change. Voltage level or output current. Therefore, the touch determination module 19 can determine the position to be touched according to the position of the touch data read line 182 that changes the voltage level or the output current and the position of the scan line 12 that is scanned. In other words, the scan period of the scan line 12 is a read voltage for the touch read element 184, so that the touch read element 184 changes the output due to the touch when the read voltage is input. The voltage or output current to the touch data read line 182.

Preferably, the touch data read line 182 connected to each of the touch read elements 184 is connected to the low level voltage source connected to the scan line 12. Therefore, before the scan line 12 is not scanned, the first end point and the second end point of the touch reading element 184 are equipotential, and the current flowing through the sensing layer 1842 of the touch reading element 184 is zero. When the scan line 12 is selected such that the voltage of the scan line 12 changes from a low level voltage to a high level voltage, the first end point and the second end point of the touch reading element 184 have a voltage difference, so that there is a current. Output. At this time, if the area of the touch reading element 184 is not touched, the output current of the touch reading element 184 is relatively relatively high. If the corresponding area of the touch reading element 184 is touched, the output current of the touch reading element 184 is relatively large. By comparing the magnitude of the output current, the touch can be known. Whether the area in which the reading element 184 is located is touched. In addition, the number of the touch reading elements 184 of the embodiment is not limited, and the number of the touch reading elements 184 may be the same as or less than the number of the data lines 14 and each The number of the touch-reading elements 184 connected to the scan line 12 may be the same or less than the number of the display control transistors; wherein the number of the touch-sensing modules 18 and the touch-reading elements 184 is such that the touch The display has better aperture ratio, yield and cost, and vice versa, it has a relatively sensitive touch sensing effect.

Please refer to FIG. 4 , which is a partial structural diagram of a second embodiment of the touch display of the present invention. The difference is that the light-shielding layer 1848 is not disposed under the sensing layer 1842 of the touch-reading element 184 of the touch display device 2, and thus, the sensing layer 1842 of the embodiment may continue to be accepted. The backlight module (not shown) of the touch display can be used to modulate the light of the backlight module and reduce the impedance of the sensing layer 1842, so that the area required for the sensing layer 1842 can be reduced. Or the size can increase the aperture ratio and display brightness of the touch display.

Please refer to FIG. 5 , which is a partial structural diagram of an equivalent circuit of a third embodiment of the touch display of the present invention. The difference between the touch sensing device 384 and the touch data reading line 382 is connected to one touch switch transistor 388. The drain/source of the touch switch transistor 388 is respectively connected to the touch reading component 384 and the touch data reading line 382, and the gate of the touch switch transistor 388 The gate is connected to the touch The scan line 32 to which the component 384 is connected is read. The purpose of the touch switch transistor 388 is to stabilize the voltage and output current of the touch data read line 382, because each touch data read line 382 of the first embodiment is connected to many different ones. The plurality of touch reading elements 384 of the scan line 32, and the touch data read line 382 may still be in each scan line 32 when the touch display is not touch-pressed. During the scanning, the leakage current is output to the touch data reading line 382 to affect the interpretation result of the touch determination module 39. After the touch switch transistor 388 is added, each touch sensing component 384 transmits the touch sensing result to the corresponding touch data reading line 382 only during the scanning period of the connected scan line 32. Therefore, the background noise of the touch data reading line 382 can be greatly reduced, and the problem of the judgment error of the touch determination module 39 can be further improved.

To further illustrate, another main purpose of adding the touch switch transistor 388 is to allow the potential of the touch data read line 382 to be freely adjusted. When the scan line 32 connected to a touch switch transistor 388 is not When the scanning is selected, the touch switch transistor 388 is turned off, so there is no leakage current, so the problem of the leakage current is completely solved, and the circuit designer can have more adjustment space to select the touch data to read. Take the voltage level of line 382.

Please refer to FIG. 6 , which is a partial structural diagram of an equivalent circuit of a fourth embodiment of the touch display of the present invention. Compared with the first, second, and third embodiments, the difference is that each of the touch read elements 484 is connected to one of the scan lines 42 and is connected to a voltage source VDD. 489 provides the read voltage, and the voltage level of the voltage source 489 is not limited, and may be output to the touch determination module 49 according to requirements, such as layout convenience. The signal strength changes and so on. Thus, the signal outputted to the touch data read line 482 is no longer limited by the highest voltage of the scan line 42, and can be adjusted according to the foregoing requirements.

1, 2, 3‧‧‧ touch display

24‧‧‧Color filters

10‧‧‧lower substrate

11‧‧‧ Lower substrate body

12, 32, 42‧‧‧ scan lines

14‧‧‧Information line

16‧‧‧Subpixel Control Module

162‧‧‧Display control transistor

182,382,482‧‧‧ touch data reading line

18‧‧‧Touch sensor module

1842‧‧‧Sense layer

184, 384, 484‧‧‧ touch reading components

1846‧‧‧Ohm contact layer

1844‧‧‧Connecting parts

188, 388‧‧‧ touch switch transistor

1848‧‧‧Lighting layer

19, 39, 49‧‧‧ Touch judgment module

VDD‧‧‧voltage source

21‧‧‧Upper substrate body

20‧‧‧Upper substrate

23‧‧‧Common electrode

22‧‧‧Black matrix

FIG. 1 is a partial schematic structural view of a first embodiment of a touch display device according to the present invention.

2 is a partial schematic view of an equivalent circuit of the touch display shown in FIG.

FIG. 3 is a schematic structural view of the touch display shown in FIG. 1 when it is pressed.

4 is a partial structural schematic view of a second embodiment of the touch display of the present invention.

FIG. 5 is a partial schematic diagram of an equivalent circuit of a third embodiment of the touch display of the present invention.

6 is a partial schematic view showing an equivalent circuit of a fourth embodiment of the touch display of the present invention.

12‧‧‧ scan line

14‧‧‧Information line

16‧‧‧Subpixel Control Module

18‧‧‧Touch sensor module

182‧‧‧Touch data reading line

184‧‧‧ touch reading components

1842‧‧‧Sense layer

1844‧‧‧Connecting parts

19‧‧‧Touch judgment module

Claims (14)

A touch display includes: an upper substrate including a common electrode layer; and a lower substrate opposite to the upper substrate, the lower substrate comprising: a plurality of scan lines, a plurality of data lines insulated from the scan lines, and A touch sensing module includes: a plurality of touch data reading lines respectively disposed apart from the data lines; a plurality of touch reading elements disposed on the touch data reading line An intersection of the plurality of scanning lines is a double-ended component, the first end of which is electrically connected to one of the touch data reading lines, and the second end and one of the scanning lines Electrically connecting, the touch reading component changes its own equivalent resistance according to an electric field change between the touch electrode and the common electrode layer, so that the voltage or output current of the touch data reading line changes; and a touch The judging module is electrically connected to each of the touch data reading lines, and determines the touch position according to the position of the touch data reading line and the position of the scanned scan line which are changed according to the voltage or the output current. The touch display device of claim 1, wherein each of the touch sensing elements comprises a sensing layer, and the material of the sensing layer is amorphous. The touch display device of claim 2, wherein the touch reading component further comprises two connecting members, wherein the two ends of the touch sensing component are respectively read by the two connecting members and the touch data The line and the scan line are connected. The touch display module of claim 2, wherein the touch sensing module further comprises a light shielding layer on a lower side of the sensing layer, the light shielding layer for preventing light from being irradiated on a lower side of the sensing layer. The touch display of any one of the second aspect of the present invention, wherein the touch display comprises a plurality of display control transistors, and each display control transistor is disposed at an intersection of each scan line and each data line. Each The sensing layer is laid in an amorphous layer layout showing the standard process of controlling the transistor. The touch display of claim 4, wherein the light shielding layer is laid in a gate metal layer layout of the display control transistor standard process. The touch display device of claim 3, wherein the touch reading element further comprises an ohmic contact layer disposed between the connecting member and the sensing layer, wherein the ohmic contact layer is controlled by the display The doped amorphous germanium process of the standard process of the transistor. The touch display of claim 5, wherein the touch display comprises a black matrix, and each sensing layer corresponds to the black matrix position. A touch display comprising: an upper substrate comprising a common electrode layer; a substrate disposed opposite the upper substrate, comprising: a plurality of scan lines, a plurality of data lines insulated from the scan lines, and a touch The control sensor module includes: a plurality of touch data reading lines respectively disposed at intervals from the data lines; a plurality of touch switch transistors, each of the touch switch transistors including a gate, a source, and a The gate is electrically connected to the scan line, the source is electrically connected to the touch data read line, and the plurality of touch read elements are disposed on the touch data read At the intersection of the line and the plurality of scanning lines, each of the touch reading elements is a double-ended element, the first end of which is electrically connected to one of the scanning lines, and the second end of the line is opposite to the touch switch transistor. The electro-optic connection, the touch-reading element changes its own equivalent resistance according to the electric field change between the touch-reading element and the common electrode layer, so that the voltage or the output current of the touch data reading line changes; Control judgment module, and various touch funds Read line electrically connected And determining the touch position according to the position of the touch data read line and the position of the scanned scan line according to the voltage or the output current. The touch display device of claim 9, wherein the second end of each touch reading component is electrically connected to the scan line of the touch display, and the touch read component is connected by a corresponding one. The scan line provides the read voltage. The touch display of claim 9, wherein the second end of each touch sensing element is electrically connected to a voltage source, and the voltage source provides the read voltage. The touch display device of claim 10, wherein the touch sensing element comprises a sensing layer, and the material of the sensing layer is amorphous. The touch display device of claim 12, wherein the touch-reading device further comprises a light-shielding layer, wherein the light-shielding layer is a non-transmissive layer, corresponding to the sensing layer, disposed on the sensing layer and The touch display is between one of the backlight modules. The touch display of claim 12, wherein the touch display further comprises a black matrix, and each sensing layer corresponds to the black matrix position.