CN104423748A - touch display device - Google Patents

Abstract

The invention discloses a touch display device, which comprises a touch panel, a display module and at least one pressure sensing unit, wherein the touch panel is provided with a sensing area and a peripheral area; the display module comprises a display panel and a frame body for accommodating the display panel; each pressure sensing unit comprises a first electrode arranged on the peripheral area of the touch panel; a second electrode disposed on the frame; and the elastic insulator is arranged between the touch panel and the display module and is correspondingly positioned between the first electrode and the second electrode. The touch display device determines the pressing force input to the touch panel by the user according to the variation of the capacitance value between the first electrode and the second electrode. The touch display device can detect the touch pressure by the variation of the capacitance value of the pressure sensing unit in the peripheral area and quantize the touch pressure without using an electromagnetic touch pen or other pressure sensors.

Description

touch display device

technical field

The present invention relates to a touch display device, in particular to a touch display device capable of detecting the magnitude of touch pressure.

Background technique

In recent years, with the rapid development and application of information technology, wireless mobile communications and information home appliances, many information products such as mobile phones, notebook computers, MP4 and various automatic The service terminal has changed from the traditional input device such as keyboard or mouse to the use of touch panel as the input device, among which the touch display panel is the most popular product nowadays. Existing touch panels can be roughly classified into capacitive, resistive, and photosensitive types, among which resistive and capacitive touch panels are the mainstream products. However, no matter what kind of touch panel, the accuracy of its finger sensing is the focus of design.

Please refer to FIG. 1 , which is a cross-sectional view of a circuit structure of a touch sensor of a touch panel in the prior art. A touch sensor (indium tin oxide bridge structure) 10 of an existing touch panel includes peripheral metal traces 1 formed on a substrate 6, an indium tin oxide bridging layer 2, an insulating layer 3, and a first indium tin oxide pad layer 4 , the second indium tin oxide liner layer 4' and the uppermost protective layer 5, the operation mode of the touch sensor 10 is that the control chip (Drive IC) transmits the drive signal to the first indium tin oxide liner along the metal line 1 The pad layer 4, and sense the touch position according to the change of the capacitance value of the touch sensor. However, at this stage, products with touch panels only have touch functions, but the force of the touch cannot be known. If you need to confirm the pressure of the touch, you need to use it with an electromagnetic stylus.

Moreover, if the pressed state of the touch point, such as the pressed size, cannot be detected, more functional features of the electronic product cannot be provided. Therefore, considering cost, efficiency and operation convenience, how to design better products to meet market demand is the focus of active research and development by various manufacturers.

Contents of the invention

Therefore, one of the objects of the present invention is to provide a touch display device, without using an electromagnetic stylus or other pressure sensors, by using the capacitance value of the pressure sensing unit in the peripheral area of the touch panel The change in touch pressure is detected and quantified.

To achieve the above object, the present invention provides a touch display device, which includes a touch panel, has a sensing area and a peripheral area located on the periphery of the sensing area; a display module, the display module includes a display A panel and a frame body, the frame body is used for accommodating the display panel; and at least one pressure sensing unit. Each pressure sensing unit includes a first electrode disposed on the peripheral area of the touch panel; a second electrode disposed on the frame; and an elastic insulator disposed between the touch panel and the display module between, and correspondingly located between the first electrode and the second electrode. Wherein, the touch display device determines the pressing force input by the user to the touch panel according to the variation of the capacitance value between the first electrode and the second electrode.

As an optional technical solution, the first electrode is formed of metal conductive material.

As an optional technical solution, the frame body is made of metal material, and the second electrode is the frame body.

As an optional technical solution, the frame body is composed of at least one frame part, and the frame part is arranged corresponding to the first electrode; or the frame body is an integral structure.

As an optional technical solution, the first electrode is electrically connected to the connection pad of the peripheral circuit layer of the touch panel.

As an optional technical solution, all the first electrodes of the at least one pressure-sensitive sensing unit form a continuous ring structure located in the peripheral area and surrounding the sensing area.

As an optional technical solution, all the first electrodes of the at least one pressure-sensitive sensing unit are not connected to each other and arranged in a discontinuous ring along the peripheral area and around the sensing area.

As an optional technical solution, the touch display device further includes a determining unit, configured to determine the pressing force according to a variation of the capacitance value sensed by the pressure-sensitive sensing unit.

As an optional technical solution, the elastic insulator is a sealant.

As an optional technical solution, the elastic insulator is arranged in a continuous ring structure along the periphery of the sensing area of the touch panel.

Compared with the prior art, in the touch display device provided by the present invention, a first electrode (metal conductive layer) is newly added in the peripheral area of the touch panel. When the touch panel body is subjected to touch pressure, the metal conductive layer will contact with There must be compression between the metal frame (or the frame provided with the second electrode) that accommodates the display panel, so that the space between the first electrode and the second electrode of the pressure-sensitive sensing unit corresponding to the touch panel in the opposite area The capacitance value of the touch panel is different before and after the touch panel is touched, so that the touch pressure can be detected by the change of the capacitance value even without using an electromagnetic stylus or other pressure sensors , and quantify it. Moreover, the display image provided by the display module will not be interfered by other components, which is conducive to improving the display effect of the overall product. Moreover, the manufacturing procedure of the touch display device is relatively simple.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

FIG. 1 is a cross-sectional view of a circuit structure of a touch sensor of a touch panel in the prior art.

FIG. 2 is a schematic diagram of a first embodiment of a touch display device according to the present invention;

Figure 3 is a schematic cross-sectional view along line AA in Figure 2;

FIG. 4 is a schematic diagram of the touch display device shown in FIG. 3 after being pressed by a user;

FIG. 5 is a schematic diagram of a second embodiment of a touch display device according to the present invention;

FIG. 6 is a schematic diagram of a third embodiment of a touch display device according to the present invention;

FIG. 7 is a schematic diagram of a fourth embodiment of a touch display device according to the present invention;

FIG. 8 is a schematic diagram of the touch display device shown in FIG. 7 after being pressed by a user.

Detailed ways

Please refer to FIG. 2 and FIG. 3 . FIG. 2 is a schematic diagram of a first embodiment of a touch display device according to the present invention; FIG. 3 is a schematic cross-sectional view along line AA in FIG. 2 . The present invention provides a touch display device 100. The touch display device 100 includes a touch panel 101, a display module 102, and at least one pressure sensing unit 103. The touch panel 101 has a sensing area 104 and is located in the sensing area. The peripheral area 105 outside the area 104, in addition, the touch panel 101 also includes a cover plate disposed on its upper part to protect the surface of the touch panel 101, and the cover plate can be a transparent glass substrate or film, for example. The display module 102 includes a display panel 106 and a frame body 107 , and the frame body 107 is used for accommodating the display panel 106 . The display module 102 is, for example, a liquid crystal display module. In addition, each pressure sensing unit 103 includes a first electrode 108 , a second electrode 109 and an elastic insulator 110 . Wherein, the first electrode 108 is arranged on the peripheral region 104 of the touch panel 101, that is, the wiring area of the touch panel 101; the second electrode 109 is arranged on the frame body 107; the elastic insulator 110 is arranged on the touch panel 101 and the display. between the modules 102 and correspondingly between the first electrode 108 and the second electrode 109 . Wherein, the touch display device 100 determines the pressing force F input by the user to the touch panel 101 according to the variation of the capacitance value between the first electrode 108 and the second electrode 109 .

Wherein, in this embodiment, the first electrode 108 is formed by metal conductive material as an example, but it is not limited thereto. For example, the first electrode can also be formed by patterning ITO (Indium Tin Oxide, Indium Tin Oxide). In addition, as in this embodiment, the peripheral area 105 of the touch panel 101 also includes lead wiring (not shown in the figure), and the lead wiring is used to connect the first electrode 108 with the peripheral circuit layer of the touch panel. The connection pads 112 are electrically connected. For example, one end of the lead wire is electrically connected to each first electrode 108, and the other end is collected on one side of the peripheral area 105 where the connection pad 112 is located, so that the change in capacitance value between the first electrode 108 and the second electrode 109 The signal is introduced into the circuit board (IC) for calculation. Among them, the lead wiring is formed by printing, for example, Ag (silver). Furthermore, the first electrode 108 may be formed at the same time as the lead-out wiring, and printed from Ag or the like.

Moreover, in this embodiment, the touch display device 100 has a plurality of pressure-sensitive sensing devices 103 as an example for illustration. The sensing regions 104 are arranged discontinuously in a ring, that is, in this embodiment, all the first electrodes 108 of all the pressure-sensitive sensing units 103 are arranged discontinuously. Correspondingly, an implementation mode: the second electrode 109 can be arranged as a continuous integral structure as required, so as to correspond to the first electrode 108 , so that all the pressure sensing units 103 can share the second electrode 109 . In another embodiment, the second electrodes 109 can also be arranged in a discontinuous structure, and each second electrode 109 is arranged corresponding to each first electrode 108 . In addition, the sensing region 104 of the touch panel 101 has a transparent electrode pattern for sensing, and the first electrode 108 may also be formed simultaneously with the transparent electrode pattern of the sensing region 104 of the touch panel 101, or may be formed separately in a subsequent field. It is formed in the peripheral region 105 of the touch panel 101 in one step. In addition, the second electrode 109 can be formed, for example, by printing conductive paste or conductive ink on the frame body 107 , specifically, the second electrode 109 can use silver paste, for example.

In addition, it is preferable to use, for example, a material with less residual strain and a high recovery rate (recovery speed) for the elastic insulator 110 . As such a material, for example, silicone resin and polyurethane resin can be used. The elastic insulator 110 mentioned above is, for example, a sealant, and the sealant can combine with the first electrode 108 and the second electrode 109 by utilizing its own viscosity. If the elastic insulator 110 itself is non-adhesive, an adhesive layer can also be arranged between the first electrode 108 and the second electrode 109 and the elastic insulator 110 to bond the first electrode 108 to the elastic insulator 110 and to bond the second electrode 109 to the elastic insulator. insulator.

The elastic insulator 110 can also be a frame-shaped elastic insulator, that is, the sensing area 104 of the touch panel 101 is arranged in a ring shape, that is, all the pressure sensing units 103 share one elastic insulator. In this way, the arrangement of the elastic insulator 110 can prevent dust from the outside from invading between the touch panel 101 and the frame body 107 or the display module 102, specifically the gap between the touch panel 101 and the display panel 106. 113 inside. In this way, the frame-shaped elastic insulator 110 can have a sealing function to prevent the intrusion of dust from the outside, so that the display characteristics will not be affected by the intrusion of dust from the outside. Of course, the arrangement of the elastic insulator 110 is not limited to the above, for example, the elastic insulator 110 can also be arranged only corresponding to the opposite position of the first electrode 108 and the second electrode 109, that is to say, if the first electrode 108 and the second electrode At least one of the 109 is a discontinuous structure, and the elastic insulator 110 can also be configured as a discontinuous structure.

Of course, in addition to the above, the elastic insulator 110 may also use insulated elastic elements such as springs, gaskets, or silica gel to provide support. In addition, it is worth mentioning that in this embodiment, since the sealant is an insulating material, it provides support, so the capacitive coupling between the first electrode 108 and the second electrode 109 will not be affected under the configuration of the sealant. effect. In other words, the user presses the touch panel 101 to compress the sealant to change the distance between the first electrode 108 and the second electrode 109 , thereby changing the capacitance value between the first electrode 108 and the second electrode 109 , wherein the variation of the capacitance value can be used as a touch sensing signal to achieve a touch sensing function.

Please refer to FIG. 4 in conjunction with FIG. 3 . FIG. 4 is a schematic view of the touch display device shown in FIG. 3 after being pressed by a user. The principle of operation of the pressure sensing unit in this embodiment will be described with reference to FIGS. 3 and 4 . In this embodiment, when the user applies a pressing force F on the touch panel 101, the elastic insulator 110 constituting the pressure-sensitive sensing unit 103 will be strained in such a way that its thickness decreases. As shown in FIG. In front of the panel, the distance between the first electrode 108 and the second electrode 109 is d1; as shown in FIG. The center of gravity is shifted, and the distance between the first electrode 108 and the second electrode 109 is changed to d2, thus d2 is smaller than d1. And generally speaking, the size of the capacitance (C) is proportional to the distance (d) between the two conductive objects forming the capacitance, and proportional to the overlapping area (A) of the two conductive objects, that is to say, it satisfies the following formula: C= ε·A/d, where ε is the dielectric constant. Therefore, when the overlapping area between the first electrode 108 and the second electrode 109 is fixed, the variation of the capacitance value between the first electrode 108 and the second electrode 109 will reflect that between the first electrode 108 and the second electrode 109 changes in spacing. For example, after the user applies a pressing force F to the touch panel 101 , the capacitance between the first electrode 108 and the second electrode 109 will decrease. In this way, the pressure-sensing function is realized by using the capacitance value change between the first electrode 108 and the second electrode 109 caused by the displacement of the elastic insulator 110 . And in response to the corresponding change of the capacitance value, the pressing force applied to the touch panel 101 can be pushed back by detecting the difference of the capacitance value. Generally speaking, the variation of the capacitance value has a linear characteristic approximately proportional to the pressing force F applied to the touch panel by the user. In this way, the force range in which the pressing force F is roughly located can be determined according to the variation of the capacitance value, so as to define or determine the pressing force.

In addition, the closer to the pressing point, the greater the pressing force received, so the closer to the pressing point, the distance between the first electrode 108 and the second electrode 109 will be shortened and the variation of the capacitance value will increase. In this way, the size distribution of the variation of the capacitance value can be used as a reference basis for the touch position. In addition, in order to make the variation of the capacitance exist, the distance between the first electrode and the second electrode can only be greater than 0. That is to say, the first electrode 108 in this embodiment will not contact the second electrode 109 to generate a coupling effect with the second electrode 109 .

In addition, in this embodiment, the signal obtained from the first electrode 108 is input to the calculation circuit provided on the circuit board (not shown) through the connection pad 112, so that the signal between the first electrode 108 and the second electrode 109 can be detected. The amount of change in capacitance value. Moreover, according to the amount of change in the capacitance value between the first electrode 108 and the second electrode 109 , it can also be determined that an input determination operation has been performed by pressing the touch panel 101 .

In this embodiment, the touch display device 100 further includes a determination unit for determining the pressing force according to the variation of the capacitance value detected by the pressure sensing unit 103 . The determination unit includes the arithmetic circuit and can be configured as a part of the control unit of the touch display device 100 . The determination unit determines the pressing force according to the variation of the capacitance value detected by each pressure sensing unit 103 disposed on the touch panel 101 . In addition, since there are a plurality of pressure sensing units 103 in this embodiment, the determination unit can also determine the pressing force according to the accumulated value of the variation of the capacitance value of each pressure sensing unit 103 . Thereby, it is possible to perform highly accurate detection of the pressing force independent of the pressing position on the touch panel 101 . In this case, the determination unit may determine the pressing force based on, for example, the accumulated value of the capacitance value change, or the average value obtained by dividing the accumulated value by the number of pressure-sensitive sensing units 103 .

However, in another embodiment, in order to avoid the capacitances between the pressure-sensitive sensing units from interfering with each other, the first electrodes 108 corresponding to each corner or position, for example, perform sensing one by one during touch sensing. In particular, when one of the first electrodes 108 is used for sensing, the rest can be connected to the ground potential or a fixed potential.

Wherein, specifically, for example, when the user's finger touches the touch panel, the sensing circuit in the sensing area of the touch panel detects the coordinates of the plane where the touch panel is located (for example, the XY axis forms a plane) (this point is the prior art, no further details for this). Moreover, the user's finger touches the touch panel, so that the pressure sensing unit detects the pressing force applied in a direction perpendicular to the plane where the touch panel is located (eg, the z-axis direction), and determines the input decision. Thereby, it is not judged to be determined only by touching the touch panel with a finger, and thus, erroneous input can be reduced. Furthermore, since the finger can be moved on the touch panel in a state of being in contact with the touch panel, operability is better. Moreover, according to the change process of the capacitance value between the first electrode 108 and the second electrode 109 of the pressure-sensitive sensing unit 103, a single touch can be distinguished from a decision, so that a decision can be determined. In addition, the determination method is not limited to this. For example, after the motion of the finger on the touch panel is stationary, it may be determined as determined if the capacitance value changes in an increasing manner based on the movement of the finger.

Please refer to FIG. 5 , which is a schematic diagram of a second embodiment of a touch display device according to the present invention. The structure of the touch display device 200 in this embodiment is similar to that of the touch display device 100 in the first embodiment. The difference is that in this embodiment, the number and positions of the first electrodes 208 are different. One electrode 208 is disposed at each of the four corners of the peripheral region 105 of the rectangular touch panel 101 , a total of four electrodes 208 are disposed, and the four first electrodes 208 are electrically independent.

Please refer to FIG. 6 , which is a schematic diagram of a third embodiment of a touch display device according to the present invention. The structure of the touch display device 300 in this embodiment is similar to that of the touch display device 100 in the first embodiment, the difference is that in this embodiment, all the first electrodes 308 of all pressure sensing units are formed at The peripheral area 105 is a continuous ring structure surrounding the sensing area 104 , that is to say, all the pressure sensing units share one electrode 308 . Correspondingly, the second electrode 109 can also be arranged as a continuous integral structure as required, so as to correspond to the first electrode 308 . In another embodiment, the second electrode may also be configured as a discontinuous structure.

Please refer to FIG. 7 and FIG. 8. FIG. 7 is a schematic diagram of a fourth embodiment of a touch display device according to the present invention, and FIG. 8 is a view of the touch display device shown in FIG. 7 after being pressed by a user schematic diagram. The touch display device 400 in this embodiment is similar to the touch display device 100 in the first embodiment, the difference is that in this embodiment, the frame body 207 itself is made of metal material, so the frame body 207 itself It can be used as the second electrode. Similarly, corresponding to the arrangement of the first electrode 108 , the frame body 207 may be an integral structure; or the frame body 207 may be composed of at least one frame part, and the frame part is arranged corresponding to the first electrode 108 . Specifically, for example, the first electrode 108 is arranged in a continuous ring shape, and the corresponding frame body 207 can be an integral structure, that is, a frame-shaped structure, or the frame body 207 can be composed of a plurality of frame parts, and these frame parts are not If the first electrode 108 is arranged in a discontinuous ring, the corresponding frame body 207 can also be an integral structure, that is, a frame-like structure, or the frame body 207 can be composed of a plurality of frame parts, and these frame parts They are not connected to each other, and each frame portion corresponds to each first electrode 108 .

Similarly, in this embodiment, when the user applies a pressing force F on the touch panel 101, the elastic insulator 110 constituting the pressure-sensitive sensing unit 103 will be strained in such a way that its thickness decreases. As shown in FIG. 7, the user Before the touch panel is pressed, the distance between the first electrode 108 and the frame body 207 is d3; as shown in FIG. 8, after the user applies a pressing force F to the touch panel 101, the touch panel 101 will slightly The center of gravity is shifted by tilting, and the distance between the first electrode 108 and the frame body 207 is changed to d4, thus d4 is smaller than d3. And generally speaking, the size of the capacitance (C) is proportional to the distance (d) between the two conductive objects forming the capacitance, and proportional to the overlapping area (A) of the two conductive objects, that is to say, it satisfies the following formula: C= ε·A/d, where ε is the dielectric constant. Therefore, when the overlapping area between the first electrode 108 and the frame body 207 is fixed, the variation of the capacitance value between the first electrode 108 and the frame body 207 will reflect the distance between the first electrode 108 and the frame body 207. Variety. For example, after the user applies the pressing force F to the touch panel 101 , the capacitance between the first electrode 108 and the frame body 207 will decrease. In this way, the pressure-sensing function is realized by using the capacitance value change between the first electrode 108 and the frame body 207 caused by the displacement of the elastic insulator 110 . And in response to the corresponding change of the capacitance value, the pressing force applied to the touch panel 101 can be pushed back by detecting the difference of the capacitance value. Generally speaking, the variation of the capacitance value has a linear characteristic approximately proportional to the pressing force F applied to the touch panel by the user. In this way, the force range in which the pressing force F is roughly located can be determined according to the variation of the capacitance value, so as to define or determine the pressing force.

To sum up, in the touch display device provided by the present invention, a first electrode (metal conductive layer) is added to the peripheral area of the touch panel. When the touch panel body is subjected to touch pressure, the metal conductive layer will contact with the contained There must be compression between the metal frame of the display panel (or the frame provided with the second electrode), so that the capacitance between the first electrode and the second electrode of the pressure-sensitive sensing unit corresponding to the touch panel in the opposite area There is a difference in the capacitance value before and after the touch panel is touched, so that even without using an electromagnetic stylus or other pressure sensors, the touch pressure can be detected by the change of the capacitance value, and Quantify it. Moreover, the display image provided by the display module will not be interfered by other components, which is conducive to improving the display effect of the overall product. Moreover, the manufacturing procedure of the touch display device is relatively simple.

Through the above detailed description of the preferred embodiments, it is hoped that the characteristics and spirit of the present invention can be described more clearly, and the protection scope of the present invention is not limited by the preferred embodiments disclosed above. On the contrary, the intention is to cover various changes and equivalent arrangements within the protection scope of the appended claims of the present invention. Therefore, the protection scope of the claims applied for in the present invention should be interpreted in the broadest way based on the above description, so as to cover all possible changes and equivalent arrangements.

Claims (10)

1. A touch display device, characterized in that the touch display device comprises The touch panel has a sensing area and a peripheral area located on the periphery of the sensing area; A display module, the display module includes a display panel and a frame, the frame is used to accommodate the display panel; and At least one pressure-sensitive sensing unit, each pressure-sensitive sensing unit includes a first electrode disposed on the peripheral area of the touch panel; the second electrode is arranged on the frame; and an elastic insulator disposed between the touch panel and the display module, and correspondingly located between the first electrode and the second electrode; Wherein, the touch display device determines the pressing force input by the user to the touch panel according to the variation of the capacitance value between the first electrode and the second electrode. 2 . The touch display device according to claim 1 , wherein the first electrode is formed of conductive metal material. 3 . 3. The touch display device according to claim 1, wherein the frame is made of metal, and the second electrode is the frame. 4 . The touch display device according to claim 3 , wherein the frame body is composed of at least one frame part, and the frame part is disposed corresponding to the first electrode; or the frame body is an integral structure. 5 . The touch display device as claimed in claim 1 , wherein the first electrode is electrically connected to the connection pad of the peripheral circuit layer of the touch panel. 6 . The touch display device as claimed in claim 1 , wherein all the first electrodes of the at least one pressure-sensitive sensing unit form a continuous ring structure located in the peripheral area and surrounding the sensing area. 7. The touch display device according to claim 1, characterized in that all the first electrodes of the at least one pressure-sensitive sensing unit are non-connected to each other and arranged in a discontinuous ring along the peripheral area and around the sensing area . 8. The touch display device according to claim 1, characterized in that the touch display device further comprises a determination unit, the determination unit is used to determine according to the variation of the capacitance value sensed by the pressure sensing unit The pressing force. 9. The touch display device as claimed in claim 1, wherein the elastic insulator is a sealant. 10 . The touch display device according to claim 1 , wherein the elastic insulator is disposed in a continuous ring structure along the periphery of the sensing region of the touch panel. 11 .