TWI587194B - Touch display panel - Google Patents

Description

Touch display device

The present invention relates to a touch display device, and more particularly to a touch display device having a pressure sensing function.

The existing touch display device integrates the touch function and the display function to provide a more intuitive and convenient control mode for the user. However, with the development of applications (Apps) and the emergence of wearable touch display devices, touch display devices having only display functions and sensing touch position functions have been unable to meet market demands. If the pressure track (ie, pressure sensing) during touch can be further distinguished from the touch position, the touch sensing function can be more diversified, thereby achieving more operation modes.

The current touch display device mainly attaches a pressure sensing structure to one side of the display panel to realize pressure sensing. Only this method is easy to greatly increase the overall thickness of the touch display device, and additional space for accommodating the pressure sensing structure is required.

The invention provides a touch display device, which can effectively reduce the overall thickness And to accommodate the interference of the pressure sensing structure to the overall space design.

A touch display device of the present invention includes a display panel, a backlight module, and a pressure sensing structure. The backlight module is disposed under the display panel, and the backlight module includes an optical plate and a light source disposed on one side of the optical plate. The pressure sensing structure includes at least one first electrode and at least one second electrode. The at least one first electrode is disposed on an optical plate. The at least one second electrode is disposed to overlap the at least one first electrode, and the at least one second electrode and the at least one first electrode have a variable spacing.

In an embodiment of the invention, the optical plate is a light guide plate, and the optical plate has a light incident surface, a light exit surface, and a bottom surface. The light entrance surface is connected to the light surface and the bottom surface, and the light exit surface is located between the bottom surface and the display panel. The light source is placed beside the entrance surface. The at least one first electrode is disposed on one of a light emitting surface and a bottom surface.

In an embodiment of the invention, the number of the at least one first electrode is plural, and the first electrode grid is arranged on one of the light emitting surface and the bottom surface.

In an embodiment of the invention, the at least one second electrode is a continuous transparent conductive film, and the second electrode is disposed on a surface of the display panel facing the backlight module.

In an embodiment of the invention, the at least one second electrode is a reflective sheet disposed under the optical plate.

In an embodiment of the invention, the first electrode compartments are arranged on the bottom surface, and the touch display device further comprises an intermediate layer. The intermediate layer is disposed on the bottom surface, and the first electrode is located between the intermediate layer and the bottom surface. The reflection sheet is located below the middle layer, and the first The two electrodes are structurally separated from the intermediate layer.

In an embodiment of the invention, the intermediate layer has a refractive index that is less than a refractive index of the optical plate.

In an embodiment of the invention, the first electrode compartments are arranged on the bottom surface, and the touch display device further comprises an intermediate layer. The intermediate layer is filled between the optical plate and the second electrode.

In an embodiment of the invention, the material of the intermediate layer is a dielectric material or a piezoresistive material, and the intermediate layer has a refractive index smaller than that of the optical plate.

In an embodiment of the invention, the at least one first electrode is a continuous metal film, and the first electrode is disposed on the bottom surface. The number of the at least one second electrode is plural, and the touch display device further includes a substrate. The substrate is located below the first electrode. The second electrode is arranged on the substrate.

In an embodiment of the invention, the touch display device further includes an intermediate layer. The intermediate layer is disposed on the substrate. The second electrode is located on a surface of the substrate facing the first electrode, and the second electrode is located between the intermediate layer and the substrate. The intermediate layer is structurally separated from the first electrode.

In an embodiment of the invention, the touch display device further includes an intermediate layer. The intermediate layer is filled between the first electrode and the substrate.

In an embodiment of the invention, the material of the intermediate layer is a dielectric material or a piezoresistive material.

Based on the above, since the touch sensing structure is formed in the touch display device, the overall thickness and tolerance of the touch display device of the embodiment of the present invention can be effectively reduced. The interference of the nano-pressure sensing structure to the overall space design.

The above described features and advantages of the invention will be apparent from the following description.

100, 200, 300, 400, 500, 600, 700‧‧‧ touch display devices

110‧‧‧ display panel

120, 620‧‧‧ backlight module

122‧‧‧Optical board

124‧‧‧Light source

126‧‧‧reflector

128‧‧‧Optical diaphragm

130‧‧‧ Pressure sensing structure

132, 632‧‧‧ first electrode

134, 634‧‧‧ second electrode

440, 540, 640, 740‧‧‧ middle layer

650‧‧‧Substrate

G‧‧‧Variable spacing

SB‧‧‧ bottom

SI‧‧‧Into the glossy surface

SO‧‧‧ shiny surface

1 to 7 are schematic cross-sectional views of a touch display device according to first to seventh embodiments of the present invention, respectively.

1 to 7 are schematic cross-sectional views of a touch display device according to first to seventh embodiments of the present invention, respectively. Referring to FIG. 1 , the touch display device 100 includes a display panel 110 , a backlight module 120 , and a pressure sensing structure 130 . The backlight module 120 is disposed under the display panel 110 , and the backlight module 120 includes an optical plate 122 and a light source 124 disposed on one side of the optical plate 122 . The pressure sensing structure 130 includes at least one first electrode 132 and at least one second electrode 134. The at least one first electrode 132 is disposed on the optical plate 122. The at least one second electrode 134 is disposed to overlap with the at least one first electrode 132, and the at least one second electrode 134 and the at least one first electrode 132 have a variable pitch G therebetween.

The display panel 110 can be any kind of display panel, such as a liquid crystal display panel, but is not limited thereto. The backlight module 120 is adapted to provide a surface light source required for display. The backlight module 120 can be a side-lit backlight module, and the optical plate 122 can be Light guide plate. The material of the light guide plate can be glass, plastic or other materials suitable for guiding light. Further, the optical plate 122 has a light incident surface SI, a light exit surface SO, and a bottom surface SB. The light incident surface SI is connected to the light emitting surface SO and the bottom surface SB, and the light emitting surface SO is located between the bottom surface SB and the display panel 110. The bottom surface SB may be parallel to the light exit surface SO. Alternatively, the bottom surface SB may be inclined with respect to the light exit surface SO (ie, a wedge-shaped light guide plate). In an embodiment, a convex microstructure, a groove or a dot, or the like may be formed on the bottom surface SB or the light-emitting surface SO. The light source 124 is disposed beside the light incident surface SI. The light beam emitted by the light source 124 enters the optical plate 122 via the light incident surface SI, and the light beam is transmitted to the optical plate 122 by total reflection.

The backlight module 120 may further include other components according to different design requirements. For example, the backlight module 120 may further include a reflective sheet 126. The reflection sheet 126 is disposed below the bottom surface SB to reflect the light beam emitted from the bottom surface SB back into the optical plate 122, thereby improving the utilization of light. The backlight module 120 may further include a frame (not shown) for accommodating the optical plate 122, the light source 124, and the reflective sheet 126, and an optical film 128. The frame has an opening through which the surface light source passes. The optical film 128 and the display panel 110 are disposed on the opening and above the light emitting surface SO. Optical film 128 can be a diffusion sheet, a crepe sheet, or a combination thereof.

In this embodiment, the number of the first electrodes 132 is plural, and the first electrodes 132 are arranged on the light-emitting surface SO. For example, the first electrode 132 can be formed on the light-emitting surface SO by printing, coating, or attaching. In order to reduce the proportion of the first electrode 132 shielding the surface light source, the first electrode 132 is a light transmissive electrode such as a light transmitting conductive electrode or a metal mesh electrode. The light-transmitting conductive electrode is, for example, an electrode made of a metal oxide or graphene, but is not limited thereto.

In addition, the second electrode 134 of the embodiment is, for example, a continuous transparent conductive film, and the second electrode 134 is disposed between the display panel 110 and the backlight module 120. Further, the second electrode 134 may be disposed on a surface of the display panel 110 facing the backlight module 120. For example, the second electrode 134 can be formed on the surface of the display panel 110 facing the backlight module 120 by printing, coating or attaching. In addition, the second electrode 134 can also be disposed on a substrate (not shown) between the display panel 110 and the optical plate 122 or the optical film 128, and then attached to the surface of the display panel 110 facing the backlight module 120. on.

When the user presses the touch display device 100 with a touch object (such as a finger or a stylus), the distance between the display panel 110 and the optical plate 122 can be changed, thereby causing a relationship between the second electrode 134 and the first electrode 132. The variable spacing G changes. The change in the variable pitch G causes a change in the capacitance value between the second electrode 134 and the first electrode 132 (capacitance value) 1/G), the touch display device 100 can determine the pressure (ie, pressure sensing) of the touch display device 100 by changing the capacitance value, thereby implementing the pressure sensing function.

Since the touch sensing structure 120 (including the first electrode 132 and the second electrode 134) is formed in the touch display device 100, the overall thickness of the touch display device 100 of the embodiment can be effectively reduced and the pressure sensing can be accommodated. The interference of structure 120 with the overall space design.

The touch display device 100 may further include other components according to different design requirements. For example, the touch display device 100 can further include a touch sensing structure (not shown) for determining the two-dimensional touch coordinates. Touch sensing structure can be formed in the display The light-emitting surface of the display panel 110 is embedded in the display panel 110, but is not limited thereto.

Other embodiments of the touch display device will be described below with reference to FIG. 2 to FIG. 7. The same components are denoted by the same reference numerals, and the materials, configuration relationships, and functions of the same components will not be described below. Referring to FIG. 2 , the main difference between the touch display device 200 and the touch display device 100 is that in the touch display device 200 , the first electrode 132 is disposed on the bottom surface SB of the optical plate 122 . Under this architecture, the first electrode 132 can be a light transmissive electrode or a light blocking electrode. The light-shielding electrode is, for example, an electrode made of a metal, an alloy, or a combination thereof, but is not limited thereto.

Referring to FIG. 3 , the main difference between the touch display device 300 and the touch display device 200 is that in the touch display device 300 , the second electrode 134 is a reflective sheet 126 disposed under the optical plate 122 . Specifically, in this embodiment, the reflective sheet 126 of the backlight module 120 is used as the second electrode 134 of the pressure sensing structure 130. In other words, the reflective sheet 126 can be used for pressure sensing in addition to reflecting the light beam emitted from the bottom surface SB back into the optical plate 122. When the user presses the touch display device 300 with a touch object (such as a finger or a stylus), the distance between the optical plate 122 and the second electrode 134 (ie, the reflective sheet 126) may be changed, thereby causing the second electrode 134. The variable pitch G with the first electrode 132 changes. The change in the variable pitch G causes a change in the capacitance value between the second electrode 134 and the first electrode 132 (capacitance value) 1/G), the touch display device 300 can determine the pressure (ie, pressure sensing) of the touch display device 300 by changing the capacitance value, thereby implementing the pressure sensing function.

Please refer to FIG. 4 , the main body of the touch display device 400 and the touch display device 300 The difference is that the touch display device 400 further includes an intermediate layer 440. The intermediate layer 440 is disposed on the bottom surface SB, and the first electrode 132 is located between the intermediate layer 440 and the bottom surface SB. The second electrode 134 is located below the intermediate layer 440, and the second electrode 134 is structurally separated from the intermediate layer 440. The material of the intermediate layer 440 may be a dielectric material, and the refractive index of the intermediate layer 440 is preferably smaller than the refractive index of the optical plate 122, so that the light beam is transmitted to the optical plate 122 in a total reflection manner.

When the user presses the touch display device 400 with a touch object (such as a finger or a stylus), the touch display device 400 can be between the second electrode 134 and the first electrode 132 by the change of the variable pitch G. The change in the capacitance value determines the pressure applied to the touch display device 400. In an embodiment, the second electrode 134 may serve as a reference electrode during pressure sensing, and the first electrode 132 may be divided into a plurality of driving electrodes and a plurality of sensing electrodes. The variation of the bias value or the variation of the current value caused by the variation of the capacitance value or the change of the capacitance value caused by the pressure of the driving electrode and the second electrode 134 can be outputted to the external control circuit by the sensing electrode (not shown) Therefore, the magnitude of the pressure applied by the touch object to the touch display device 400 is determined.

Referring to FIG. 5 , the main difference between the touch display device 500 and the touch display device 400 is that the intermediate layer 540 is filled between the optical plate 122 and the second electrode 134 . In this architecture, the material of the intermediate layer 540 may be a dielectric material or a piezoresistive material, and the second electrode 134 may serve as a reference electrode, and the first electrode 132 may be divided into a plurality of driving electrodes and a plurality of sensing electrodes. .

In the structure in which the material of the intermediate layer 540 is a dielectric material, the change in the pitch G causes a change in the capacitance value between the second electrode 134 and the driving electrode. The variation of the bias value or the variation of the current value caused by the change of the value or the change of the capacitance value can be output to the external control circuit (not shown) via the sensing electrode, so that the control circuit determines that the touch object is applied to the touch display device. The size of the pressure of 500. On the other hand, under the structure of the material of the intermediate layer 540 being a piezoresistive material, the change of the pitch G causes the resistance value of the intermediate layer 540 to change, so that the external control circuit (not shown) can be mutated or resisted according to the above resistance value. The value of the variability of the current value or the variation of the bias value caused by the value change determines the relative value of the pressure applied by the touch object to the touch display device 500. As described above, the touch display device 500 can determine the pressure received by the touch display device 500 according to the change of the capacitance value or the resistance value caused by the pressure of the intermediate layer 540, thereby implementing the pressure sensing function.

Referring to FIG. 6 , the main difference between the touch display device 600 and the touch display device 400 is that the first electrode 632 is a continuous metal film, and the first electrode 632 is disposed on the bottom surface SB and can be used to emit the bottom surface SB. The beam is reflected back into the optical plate 122. Therefore, the backlight module 620 can omit the reflective sheet 126. Further, the number of the second electrodes 634 is plural, and the second electrodes 634 may be light transmissive electrodes or shading electrodes. The touch display device 600 further includes a substrate 650. The substrate 650 is located below the first electrode 632, and the second electrode 634 is arranged on the substrate 650. Further, the second electrode 634 may be arranged on the surface of the substrate 650 facing away from or facing away from the first electrode 632. The second electrode 634 and the substrate 650 may be composed of a circuit board or a flexible circuit board.

In the embodiment, the touch display device 600 may further include an intermediate layer 640. The intermediate layer 640 is disposed on the substrate 650, and the second electrode 634 is located in the middle Between layer 640 and substrate 650. Further, the intermediate layer 640 is structurally separated from the first electrode 632. The material of the intermediate layer 440 may be a dielectric material. When the user presses the touch display device 600 with a touch object (such as a finger or a stylus), the touch display device 600 can be caused by the change of the variable pitch G between the second electrode 634 and the first electrode 632. The change in the capacitance value determines the pressure applied to the touch display device 600. In an embodiment, the first electrode 632 can serve as a reference electrode during pressure sensing, and the second electrode 634 can be divided into a plurality of driving electrodes and a plurality of sensing electrodes. The variation of the bias value or the variation of the current value caused by the variation of the capacitance value or the change of the capacitance value caused by the pressure of the driving electrode and the first electrode 632 can be outputted to the external control circuit by the sensing electrode (not shown) Therefore, the magnitude of the pressure applied by the touch object to the touch display device 600 is determined.

Referring to FIG. 7 , the main difference between the touch display device 700 and the touch display device 600 is that the intermediate layer 740 is filled between the first electrode 632 and the substrate 650 . In this architecture, the material of the intermediate layer 740 may be a dielectric material or a piezoresistive material, and the first electrode 632 may serve as a reference electrode, and the second electrode 634 may be divided into a plurality of driving electrodes and a plurality of sensing electrodes. .

In the structure in which the material of the intermediate layer 740 is a dielectric material, the change in the pitch G causes a change in the capacitance value between the first electrode 632 and the driving electrode, and the variation in the bias value caused by the change in the capacitance value or the change in the capacitance value or The measurable current value variation can be output to an external control circuit (not shown) via the sensing electrode, so that the control circuit determines the magnitude of the pressure applied by the touch object to the touch display device 700. On the other hand, in the case where the material of the intermediate layer 740 is a piezoresistive material, the change in the pitch G causes an intermediate The resistance value of the layer 740 is changed, so that an external control circuit (not shown) can determine that the touch object is applied to the touch display device 700 according to the variation of the current value caused by the resistance value variation or the resistance value change. The relative value of the pressure. As described above, the touch display device 700 can determine the pressure received by the touch display device 700 according to the change of the capacitance value or the resistance value caused by the pressure of the intermediate layer 740, thereby implementing the pressure sensing function.

In summary, since the touch sensing structure is formed in the touch display device, the overall thickness of the touch display device of the embodiment of the present invention and the interference of the pressure sensing structure with the overall space design can be effectively reduced.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Touch display device

110‧‧‧ display panel

120‧‧‧Backlight module

122‧‧‧Optical board

124‧‧‧Light source

126‧‧‧reflector

128‧‧‧Optical diaphragm

130‧‧‧ Pressure sensing structure

132‧‧‧First electrode

134‧‧‧second electrode

G‧‧‧Variable spacing

SB‧‧‧ bottom

SI‧‧‧Into the glossy surface

SO‧‧‧ shiny surface

Claims (12)

A touch display device includes: a display panel; a backlight module disposed under the display panel, and the backlight module includes an optical plate and a light source disposed on one side of the optical plate; and a pressure sense The at least one first electrode is disposed on the optical plate, the at least one second electrode is disposed opposite to the at least one first electrode, and the at least one The optical plate has a variable spacing between the second electrode and the at least one first electrode, wherein the optical plate has a light incident surface, a light exit surface and a bottom surface, and the number of the at least one first electrode is plural, and the plurality of electrodes The first electrode compartment is arranged on one of the light emitting surface and the bottom surface. The touch display device of claim 1, wherein the optical plate is a light guide plate, and the light incident surface is connected to the light emitting surface and the bottom surface, and the light emitting surface is located between the bottom surface and the display panel. The light source is disposed beside the light incident surface. The touch display device of claim 1, wherein the at least one second electrode is a continuous transparent conductive film, and the second electrode is disposed on a surface of the display panel facing the backlight module. The touch display device of claim 1, wherein the at least one second electrode is a reflective sheet disposed under the optical plate. The touch display device of claim 4, wherein the first electrode grids are arranged on the bottom surface, and the touch display device further comprises: An intermediate layer is disposed on the bottom surface, and the first electrodes are located between the intermediate layer and the bottom surface, the second electrode is located below the intermediate layer, and the second electrode is structurally separated from the intermediate layer. The touch display device of claim 5, wherein the intermediate layer has a refractive index smaller than a refractive index of the optical plate. The touch display device of claim 4, wherein the first electrode spaces are arranged on the bottom surface, and the touch display device further comprises: an intermediate layer filled in the optical plate and the second Between the electrodes. The touch display device of claim 7, wherein the material of the intermediate layer is a dielectric material or a piezoresistive material, and the intermediate layer has a refractive index smaller than a refractive index of the optical plate. A touch display device includes: a display panel; a backlight module disposed under the display panel, and the backlight module includes an optical plate and a light source disposed on one side of the optical plate; a pressure sensing The structure includes at least one first electrode and at least one second electrode, the at least one first electrode is disposed on the optical plate, the at least one second electrode is disposed to overlap with the at least one first electrode, and the at least one second a variable spacing between the electrode and the at least one first electrode; and a substrate under the first electrode, the second electrodes being arranged on the substrate The optical plate has a light-incident surface, a light-emitting surface, and a bottom surface. The at least one first electrode is a continuous metal film, and the first electrode is disposed on the bottom surface, and the number of the at least one second electrode is Multiple. The touch display device of claim 9, further comprising: an intermediate layer disposed on the substrate, the second electrodes being located on a surface of the substrate facing the first electrode, and the second An electrode is located between the intermediate layer and the substrate, and the intermediate layer is structurally separated from the first electrode. The touch display device of claim 9, further comprising: an intermediate layer filled between the first electrode and the substrate. The touch display device of claim 11, wherein the material of the intermediate layer is a dielectric material or a piezoresistive material.