TWI625661B - Touch display device - Google Patents

Abstract

A touch display device includes a display module with a display area, a cover plate on the top side of the display module, a touch-sensitive structure provided on the display module and having a distribution position corresponding to the display area, And an optical bonding layer. The cover plate includes a contact surface with a pair of viewing areas corresponding to the display area and a pair of non-viewing areas corresponding to positions outside the display area. The optical bonding layer joins the cover plate and the touch-sensing structure, and has a low-dielectric portion with a distribution position corresponding to the visible area and at least one high-dielectric portion with a dielectric constant greater than the low-dielectric portion. The distribution position of the high-dielectric part corresponds to at least one of the viewable area and the non-viewing area. In this way, the sensing capacitance generated by the touch-sensing module due to sensing the conductor contacting the non-viewing area is not too small.

Description

Touch display device

The invention relates to a touch display device, in particular to a capacitive touch display device.

As shown in FIG. 1, the existing capacitive touch display device has a cover plate 90 (such as glass), a display module 902 under the cover plate 90 and having a display area a, and a cover plate for bonding the cover plate 90 and the optical adhesive 903 (OCA, Optically Clear Adhesive) of the display module 902, and most of the sensing electrodes 904 and 905 located in the display area a. In order to meet the assembly requirements such as wiring, the edge of the display area a shrinks by a distance d compared to the edge of the cover glass 90. Therefore, a contact surface 901 of the cover glass 90 can be divided into a viewable area 9011 covering the display area a and the sensing electrodes 904, 905, and an uncovered display area a and the sensing electrodes 904, The non-viewing area 9012 of 905 is generally located at the outer edge of the viewing area 9011 as shown in the figure.

When the finger 101 and the finger 102 of the user touch the visible area 9011 and the non-viewing area 9012 respectively, the sensing capacitances detected from the sensing electrode 904 and the sensing electrode 905 are the capacitance value C _n and the capacitance value C _{f respectively} . Since the distance between the finger 102 and the sensing electrode 905 is relatively greater than the distance between the finger 101 and the sensing electrode 904, the capacitance value C _{f is} relatively smaller than the capacitance value C _n .

However, the difference between the capacitance values C _n and C _f will cause the corresponding processing circuit to process and calculate the difference to increase the complexity of the processing circuit. In addition, when the capacitance value C _{f is} too small, it may be difficult to be effectively detected Defects, as a result, when the user touches the non-viewing area 9012 of the contact surface 901, the problem of insensitive touch or invalid touch is likely to occur.

Therefore, the object of the present invention is to provide a touch display screen that can overcome at least one of the above-mentioned shortcomings of the prior art.

Therefore, the touch display device of the present invention includes a display module, a cover plate, a touch sensing structure, and an optical bonding layer. The display module has a display area for presenting image frames. The cover plate is located on the top side of the display module and includes a contact surface having a pair of visible areas corresponding to the display area and a pair of non-viewing areas corresponding to positions outside the display area. The touch-sensing structure is disposed on the display module and the distribution position corresponds to the display area and is used to sense a conductor approaching or contacting the contact surface of the cover plate. The optical bonding layer is disposed between the cover plate and the touch-sensing structure to bond the cover plate and the touch-sensing structure, and has a low dielectric portion and at least one high dielectric constant higher than the low dielectric portion The dielectric part, the distribution position of the high dielectric part corresponds to at least one of the visible region and the non-viewing region, and the distribution position of the low dielectric part corresponds to The viewable area.

In some embodiments, the touch-sensing structure includes a plurality of sensing electrodes. Among the sensing electrodes, the sensing electrodes closest to the non-viewing area of the contact mask of the cover plate serve as the plurality of first sensing electrodes, and Among the sensing electrodes, those different from the first sensing electrode each serve as a second sensing electrode, and the optical bonding layer has a plurality of the high-dielectric parts, and the high-dielectric parts are distributed on the contact surface Between the non-viewing area and the first sensing electrodes, the distribution position of the low dielectric portion corresponds to the second sensing electrodes.

In some embodiments, the number of the high-dielectric parts is the same as the number of the first sensing electrodes.

In some embodiments, the non-viewing area of the contact surface of the cover plate surrounds the viewing area.

In some embodiments, the high-dielectric parts surround the viewing area at intervals.

In some embodiments, the first sensing electrodes are respectively adjacent to the edge of the display area and surround the second sensing electrodes.

In some embodiments, the inwardly extending range of each high dielectric portion covers but does not exceed the inwardly extending range of the first sensing electrodes.

In some embodiments, the distribution position of each high-dielectric portion of the optical bonding layer corresponds to the non-viewing area of the contact surface of the cover plate.

In some embodiments, the high dielectric portion is an optical glue with metal ions.

In some embodiments, the material of the high-dielectric part is conductive silver paste.

In some embodiments, the dielectric constant of the low dielectric portion of the optical bonding layer falls within the range of 3.5 to 4.5, and the dielectric constant of the high dielectric portion of the optical bonding layer falls within the range of 4 to 8. Inside.

The effect of the present invention is that: by the configuration of the high-dielectric part and the low-dielectric part of the optical bonding layer, the touch-sensing module is generated by sensing the conductor of the non-viewing area contacting the contact surface The capacitance value of the sensing capacitor is not too small, and can be effectively detected. In addition, it is between the capacitance value of the sensing capacitor generated by the touch-sensing module and the conductor of the viewable area contacting the contact surface due to sensing The difference can be effectively reduced, and the complexity of the corresponding processing circuit can be reduced.

100‧‧‧Touch display device

200‧‧‧Touch display device

1‧‧‧Display module

2‧‧‧cover

21‧‧‧Contact surface

211‧‧‧Viewable area

212‧‧‧Non-viewing area

3‧‧‧Touch sensing structure

31‧‧‧The first induction electrode

32‧‧‧Second induction electrode

4‧‧‧Optical bonding layer

41‧‧‧Low dielectric part

42‧‧‧High dielectric part

90‧‧‧cover

901‧‧‧Contact surface

9011‧‧‧viewable area

9012‧‧‧Non-viewing area

902‧‧‧Display module

903‧‧‧Optical glue

904‧‧‧Induction electrode

905‧‧‧Induction electrode

101 ~ 104‧‧‧ finger

A‧‧‧Display area

B‧‧‧Border

Other features and functions of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: FIG. 1 is a schematic cross-sectional diagram illustrating the existing touch display device; FIG. 2 is a schematic cross-sectional diagram illustrating the present invention. A first embodiment of the touch display device of the invention; FIG. 3 is a schematic top view illustrating the first embodiment; and FIG. 4 is a schematic cross-sectional view illustrating a second implementation of the touch display device of the invention example.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same number.

Referring to FIG. 2, a first embodiment of the touch display device 100 of the present invention includes a display module 1, a cover plate 2, a touch sensing structure 3, and an optical bonding layer 4.

The display module 1 has a display area A for presenting image frames. In this embodiment, the display module 1 is, for example, a display structure with a liquid crystal layer.

The cover plate 2 is located on the top side of the display module 1 and includes a contact surface 21 having a pair of viewing areas 211 corresponding to the display area A and a pair of non-viewing areas 212 corresponding to positions outside the display area A .

Referring to FIG. 3, please refer to the dotted line in FIG. 3, which represents the range of the display area A, the non-viewing area 212 is a portion other than the dotted line, and the visible area 211 is a portion within the dotted line, in other words, in this embodiment The non-viewing area 212 surrounds the viewing area 211. The cover plate 2 is an insulating transparent plate material such as glass, acrylic, or sapphire glass.

Referring to FIG. 3, the touch-sensing structure 3 is provided in the display module 1 and the distribution position corresponds to the display area A, for sensing a conductor approaching or contacting the contact surface 21 of the cover plate 2. Fingers 103, 104 or stylus (not shown). The touch sensing structure 3 includes a plurality of first sensing electrodes 31 and a plurality of second sensing electrodes 32. The cross-hatched boxes and the uncross-hatched boxes in FIG. 3 represent the first sensing electrodes 31 and the second sensing electrodes 32, respectively. The overall cooperation of the first sensing electrodes 31 and the second sensing electrodes 32 can be used to touch in the X direction (horizontal direction in the figure) and the Y direction (vertical direction in the figure) of the touch display device 100 The implementation structure of touch-sensitive positioning detection is not limited to any type. Here, it is defined that the first sensing electrodes 31 are closer to the non-viewing area 212 of the contact surface 21 of the cover plate 2 than the second sensing electrodes 32. In this embodiment, the first sensing electrodes 31 are respectively adjacent to the edge of the display area A and surround the second sensing electrodes 32.

Referring to FIG. 2, the optical bonding layer 4 is disposed between the cover plate 2 and the touch-sensing structure 3 to join the cover plate 2 and the touch-sensing structure 3, and has a low dielectric portion 41 and a plurality of dielectrics The high-dielectric portion 42 having a higher electric constant than the low-dielectric portion 41. The distribution position of the low dielectric portion 41 corresponds to the visible area 211. In this embodiment, the distribution position of the low dielectric portion 41 corresponds to the second sensing electrodes 32. Specifically, the low dielectric portion 41 41 covers all the second sensing electrodes 32. The distribution positions of the high-dielectric portions 42 correspond to the non-viewing area 212. In this embodiment, the high-dielectric portions 42 are respectively distributed on the non-viewing area 212 of the contact surface 21 and the first sensing electrodes 31 between.

Referring to FIG. 3, preferably, the high-dielectric portions 42 surround the viewing area 211 at intervals, and the number of the high-dielectric portions 42 is the same as the number of the first sensing electrodes 31, not This is limited. The number and shape of these high dielectric parts 42 And the size ratio is not limited to what is disclosed in the drawings, and may vary according to actual needs. For example, in other implementations, the high-dielectric portions 42 may be implemented as a continuous whole surrounding the low-dielectric portion 41. It is worth noting that, in this embodiment, the high-dielectric portions 42 do not cover the display area A, so even if the transparency of the high-dielectric portions 42 is not high, it will not affect the display of the display area A image.

In this embodiment, the dielectric constant of the low dielectric portion 41 of the optical bonding layer 4 falls on the premise that the dielectric constant of the low dielectric portion 41 must be lower than that of the high dielectric portion 42 It is in the range of 3.5 to 4.5, and the dielectric constant of the high dielectric portion 42 of the optical bonding layer 4 may fall in the range of 4 to 8. In this embodiment, the high-dielectric portion 42 is, for example, an optical paste with metal ions. For example, the material of the high-dielectric portion 42 may be implemented as a conductive silver paste.

Referring to FIG. 2, when one of the first sensing electrodes 31 generates a sensing capacitance due to sensing the finger 104 touching the non-viewing area 212 of the contact surface 21, since the high dielectric portion 42 is interposed between the finger 104 and the first Between the sensing electrodes 31, the capacitance value C _F of the sensing capacitor generated by the first sensing electrode 31 is not too small and can be effectively detected. On the other hand, when one of the second sensing electrodes 32 senses the finger 103 touching the visible area 211 of the contact surface 21 to generate a sensing capacitance, since the low dielectric portion 41 is interposed between the finger 104 and the first Between the two sensing electrodes 32, so even if the distance between the finger 103 and the second sensing electrode 32 is relatively greater than the distance between the finger 103 and the first sensing electrode 31, the induction generated by the second sensing electrode 32 The capacitance value C _N of the capacitor will also be close to the capacitance value C _F.

It is added that the number and size of the first sensing electrodes 31 are not limited to the drawings, and should be changed according to actual needs. For example, without adjusting the number, shape, and size ratio of the high-dielectric parts 42, if the capacitance value C _{F is} smaller than the capacitance value _CN , it can be increased by providing a larger first sensing electrode 31 Large capacitance value C _F. Similarly, if the capacitance value of the capacitance C _F is greater than the value C _N, the smaller can be provided by way of a first sensing electrode 31 to reduce the capacitance value C _F, and so can be laid a greater number of the first sensing electrode 31 In order to improve the accuracy of touch-sensitive positioning detection.

Referring to FIG. 4, the only difference between the second embodiment of the touch display device 200 of the present invention and the first embodiment is the distribution state of each high-dielectric portion 42. In the second embodiment, the distribution position of the high-dielectric portion 42 not only corresponds to the non-viewing area 212, but also corresponds to a portion of the viewing area 211 connected to the non-viewing area 212. Specifically, each high The distribution position of the dielectric portion 42 extends from the non-viewing area 212 to the viewing area 211. It is worth noting that the inwardly extending range of each high-dielectric portion 42 covers but does not exceed the inwardly extending range of the first sensing electrodes 31, that is, the distribution position of each high-dielectric portion 42 The maximum can only be extended to the boundary B in FIG. 4, so that the capacitance values C _F and _CN can be prevented from increasing at the same time so that the difference between the capacitance values C _F and _CN cannot be reduced.

It is added that the distribution state of the high-dielectric part 42 is in addition to the aspects disclosed in the first and second embodiments, in other implementation aspects, the high-dielectric part The distribution position of the points 42 may only correspond to the portion of the viewing zone 211 connecting the non-viewing zone 212.

In summary, due to the configuration of the high-dielectric portion 42 and the low-dielectric portion 41 of the optical bonding layer 4, the first sensing electrodes 31 sense the non-viewing area 212 contacting the contact surface 21 The inductive capacitance generated by the conductors is not too small and can be effectively detected. In the implementation state where the non-viewing area 212 is located at the outer edge of the viewing area 211, the user can accurately and effectively touch the edge of the cover 12 The ground is detected, so that the performance of the touch display device 100 can be improved. In addition, the difference between the sensing capacitances generated by the first sensing electrodes 31 and the second sensing electrodes 32 due to sensing the conductor contacting the visible area 211 of the contact surface 21 can be effectively reduced, which is beneficial to Reduce the complexity of the corresponding processing circuit. Furthermore, by limiting the maximum range in which each high-dielectric portion 42 extends inwardly, the capacitance values C _F and _CN can be prevented from increasing at the same time, so that the difference between the capacitance values C _F and _CN cannot be reduced. Can achieve the purpose of cost invention.

However, the above are only examples of the present invention, and should not be used to limit the scope of implementation of the present invention, any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still considered as Within the scope of the invention patent.

Claims (11)

A touch display device includes: a display module having a display area for displaying an image screen; a cover plate located on the top side of the display module and including a contact surface, the contact surface having a pair of corresponding The visible area of the display area and a pair of non-viewing areas that should be located outside the display area; a touch-sensitive structure is provided on the display module and the distributed position corresponds to the display area and is used to sense the contact that approaches or contacts the cover A conductor on the surface; and an optical bonding layer disposed between the cover plate and the touch sensing structure to join the cover plate and the touch sensing structure, and having a low dielectric portion and at least one dielectric constant greater than In the high-dielectric part of the low-dielectric part, the distribution position of each high-dielectric part corresponds to at least the non-viewing area, and the distribution position of the low-dielectric part corresponds to the visible area. The touch display device according to claim 1, wherein the touch sensing structure includes a plurality of sensing electrodes. Among the sensing electrodes, a plurality of sensing electrodes closest to a non-viewing area of the contact mask of the cover plate serve as multiple A first sensing electrode, and each of the sensing electrodes different from the first sensing electrode serves as a second sensing electrode, and the optical bonding layer has a plurality of the high dielectric parts, and the high dielectric parts Distributed between the non-viewing area of the contact surface and the first sensing electrodes, the distribution position of the low dielectric portion corresponds to the second sensing electrodes. The touch display device according to claim 2, wherein the number of the high-dielectric parts is the same as the number of the first sensing electrodes. The touch display device according to claim 2, wherein the non-viewing area of the contact surface of the cover plate surrounds the visible area. The touch display device according to claim 4, wherein the high-dielectric parts surround the viewing area at intervals. The touch display device according to claim 4, wherein the first sensing electrodes are respectively adjacent to the edge of the display area and surround the second sensing electrodes. The touch display device according to claim 4, wherein the range in which each high-dielectric portion extends inwardly covers but does not exceed the range in which the first sensing electrodes extend inward. The touch display device according to any one of claims 1 to 6, wherein the distribution position of each high dielectric portion of the optical bonding layer corresponds to the non-viewing area of the contact surface of the cover plate. The touch display device according to claim 1, wherein the high-dielectric part is an optical glue having metal ions. The touch display device according to claim 1, wherein the material of the high-dielectric part is conductive silver paste. The touch display device according to claim 1, wherein the dielectric constant of the low dielectric portion of the optical bonding layer falls within the range of 3.5 to 4.5, and the dielectric constant of the high dielectric portion of the optical bonding layer Falls within the range of 4 to 8.