Touch display panel

A touch display panel includes an array substrate and an opposite substrate disposed opposite to the array substrate. The opposite substrate includes a first base substrate and a high-resistance film material layer which is disposed on the first base substrate, and a square resistance of the high-resistance film material layer is larger than or equal to 107 Ω/□ and is less than or equal to 1012 Ω/□.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Application No. 201510375783.6, filed Jun. 30, 2015, which is herein incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of liquid crystal display technologies and, in particular, to a touch display panel.

BACKGROUND

FIG. 1is a schematic diagram showing the structure of a display panel in the related art within the field of liquid crystal display technologies. As shown inFIG. 1, an existing display panel includes an upper substrate and a lower substrate, i.e., an array substrate11and a color filter substrate12. Additionally, in order to prevent an external electric field from influencing the displaying of the display panel, a shielding film, for example an Indium-Tin-Oxide (ITO) film13with a thickness of about 200 Å, can be deposited on the outside of the color filter substrate12.

Additionally, after the display panel is assembled, the ITO film13is electrically connected with a grounding piece15on the array substrate via conductive silver paste14, so that the ITO film13is grounded during the displaying of the display panel, to shield the displaying of the display panel from the external influence.

With the application of touch technologies, touch elements are generally integrated into the display panel at present and, more particularly, onto the color filter substrate or the array substrate, to form a touch display panel. The square resistance of the typical ITO film used in the related art is about 300Ω/□, thus the ITO film will shield off not only the influence of the environment on the displaying of the display panel, but also a touch signal from the environment, thereby influencing the touch sensing performance of the touch display panel.

SUMMARY

The present disclosure provides a touch display panel to avoid the influence of a shielding film on the touch sensing performance of the touch display panel.

The disclosure provides a touch display panel, which includes an array substrate and an opposite substrate disposed opposite to the array substrate, where the opposite substrate includes a first base substrate and a high-resistance film material layer which is disposed on the first base substrate, and the square resistance of the high-resistance film material layer is larger than or equal to 107Ω/□ and is less than or equal to 1012Ω/□.

In the touch display panel, according to embodiments of the disclosure, the opposite substrate includes the first base substrate, on which the high-resistance film material layer with a square resistance larger than or equal to 107Ω/□ and less than or equal to 1012Ω/□ is disposed. By using such high-resistance film material layer, the generated static electricity such as charges generated due to a high voltage (for example, at or above the level of kilovolt (KV)) may be discharged via the high-resistance film material layer for the purpose of releasing the static electricity. However, during touch detection, the high-resistance film material layer will not release charges accumulated due to a touch by a finger and the like, that is, the high-resistance film material layer has a weak shielding effect on the charge signal generated due to the touch by the finger and the like, without influencing the touch sensing performance of the touch display panel.

While multiple embodiments are disclosed, still other embodiments of the disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

DETAILED DESCRIPTION

In order to make the objects, technical solutions and advantages of the disclosure more clear, the technical solution of the disclosure will be clearly and fully described by the embodiments in conjunction with the accompanying drawings for the embodiments of the disclosure. The embodiments described are merely a part of rather than all of the possible embodiments of the disclosure. Other embodiments based on the described embodiments of the disclosure pertain to the protection scope of the disclosure.

FIG. 2Ais a schematic diagram showing the structure of a touch display panel, according to embodiments of the disclosure. The touch display panel includes an array substrate22and an opposite substrate21disposed opposite to the array substrate22. The opposite substrate21includes a first base substrate23and a high-resistance film material layer24, which is disposed on the first base substrate23and has a square resistance larger than or equal to 107Ω/□ and less than or equal to 1012Ω/□.

As such, in the touch display panel, according to embodiments of the disclosure, the high-resistance film material layer is disposed on the first base substrate of the opposite substrate, and the square resistance of the high-resistance film material layer is larger than or equal to 107Ω/□ and is less than or equal to 1012Ω/□. By using such high-resistance film material layer, the generated static electricity such as charges generated due to a high voltage (for example, at or above the level of kilovolt) may be discharged via the high-resistance film material layer for the purpose of releasing the static electricity. However, during touch detection, the high-resistance film material layer will not release charges accumulated due to a touch by a finger and the like, that is, the high-resistance film material layer has a weak shielding effect on the charge signal generated due to the touch by the finger and the like, without influencing the touch sensing performance of the touch display panel.

FIG. 2Bis a schematic sectional view showing the structure of the touch display panel, according to embodiments of the disclosure. The array substrate includes a second base substrate25, and a common electrode layer26and a grounding piece27that are disposed on the second base substrate25. The high-resistance film material layer24on the first base substrate21is electrically connected with the common electrode layer26, or is grounded (that is, the high-resistance film material layer24is electrically connected with the grounding piece27). The employment of the above technical solutions allows that: the generated static electricity such as charges generated due to a high voltage (for example, at or above the level of kilovolt) can be discharged via the high-resistance film material layer for the purpose of releasing the static electricity.

Further, in the embodiments of the disclosure, a first conductive line28is provided between the first base substrate23and the second base substrate25, so that the high-resistance film material layer24is electrically connected with the common electrode layer26or is grounded via the first conductive line28.

The first conductive line28in the above embodiments may be implemented in two manners. According to one of the two manners, referring again toFIG. 2A, a perimeter sealant31is disposed between the opposite substrate21and the array substrate22in the touch display panel, and at least a region of the perimeter sealant31is conductive to form the first conductive line28. For example, conductive metal balls are doped in the perimeter sealant to form the conductive region in the perimeter sealant.

FIG. 3Ais a schematic top view of the touch display panel, according to embodiments of the disclosure. The perimeter sealant31has a frame-shaped structure, and at least one side edge and/or at least one corner region of the perimeter sealant31is configured as conductive. As shown inFIG. 3A, conductive metal balls281, for example conductive copper balls, are doped at three side edges of the perimeter sealant31to form the first conductive line28in the perimeter sealant31. Alternatively, as shown inFIG. 3B, conductive metal balls281, for example conductive copper balls, are doped in two corner regions of the perimeter sealant31, so that the perimeter sealant becomes conductive to form the first conductive line28therein.

As shown in bothFIG. 3AandFIG. 3B, a single perimeter sealant31is disposed, and conductive metal balls are doped in the perimeter sealant31to form the first conductive line. Alternatively, as shown inFIG. 3CandFIG. 3D, a nonconductive first perimeter sealant311without conductive metal balls is disposed between the opposite substrate and the array substrate, and a second perimeter sealant312containing conductive metal balls281is disposed at the outside of the first perimeter sealant311, that is, beside at least one side edge and/or at least one corner region of the first perimeter sealant311.FIG. 3Cshows a second perimeter sealant312disposed beside one side edge of the first perimeter sealant311, andFIG. 3Dshows a second perimeter sealant312disposed beside two corner regions of the first perimeter sealant311.

Unlike the above embodiments in which conductive metal balls are doped in the perimeter sealant to form the first conductive line, embodiments of the disclosure further provide the other of the two manners of implementing the first conductive line. Referring toFIG. 4A, a perimeter sealant31is disposed between the opposite substrate21and the array substrate22, and conductive silver paste32is disposed as the first conductive line28on the outside of the perimeter sealant31. Moreover, in embodiments, the conductive silver paste32, rather than the perimeter sealant31, is configured for an electrical connection, thus the perimeter sealant31may be formed of a nonconductive material.

Additionally, in the case of the other of the two manners, the perimeter sealant31may also have a frame-shaped structure, and the conductive silver paste32is disposed on the outside of at least one side edge and/or at least one corner region of the perimeter sealant31. For example, as shown inFIG. 4B, the conductive silver paste32is disposed beside one side edge of the perimeter sealant31; and as shown inFIG. 4C, the conductive silver paste32is disposed beside two corner regions of the perimeter sealant31.

In the above embodiments of the disclosure, the first conductive line28may be formed in various manners, and may be disposed at different locations. In some embodiments, the particular location of the first conductive line is selected according to the specific structure of the array substrate. For example, as shown inFIG. 5which is a schematic top view of an array substrate, according to embodiments of the disclosure, the second base substrate25includes a display region41and a non-display region42around the display region41, where drive signal circuits43are disposed in the non-display region42of the second base substrate25, data lines44and scan lines45are disposed in the display region41of the second base substrate25, and the data lines44and/or the scan lines45are electrically connected with the drive signal circuits43via bridge structures (i.e. bypass structures)46located in the non-display region42. Depending on manufacturing processes, the bridge structures46may be exposed as the uppermost layer of the array substrate, or an insulating layer may be further disposed above the bridge structure46along a light transmission direction of the display panel.

When the bridge structures46are exposed as the uppermost layer of the array substrate, the first conductive line is required to bypass the bridge structures46, that is, a projection of the first conductive line onto the second base substrate25is required not to overlap projections of the drive signal circuits43onto the second base substrate25, so that the first conductive line is insulated from the bridge structures. When the first conductive line28is implemented in the above-described two manners, according to embodiments of the disclosure, i.e. when the conductive metal balls are doped in the perimeter sealant31at at least one side edge and/or at least one corner region of the perimeter sealant31to form the first conductive line28, or the conductive silver paste32is disposed as the first conductive line28on the outside of at least one side edge and/or at least one corner region of the perimeter sealant31, the first conductive line can bypass the bridge structures effectively.

The array substrate is manufactured by six masking processes. As shown inFIG. 6Awhich is a schematic sectional view of an array substrate, according to embodiments of the disclosure, the array substrate includes a first base substrate25, a first metal layer251and a second metal layer252. The drive signal circuit43is located in the first metal layer251, while the data lines44or scan lines45are located in the second metal layer252and electrically connected with the drive signal circuit43via the bridge structures46, in this case, the bridge structures46are exposed as the uppermost layer of the array substrate. Referring to the above embodiments, if disposed on the opposite substrate or the array substrate, the perimeter sealant31or the conductive silver paste32tends to be in contact and electrically connected with the bridge structures46. In this case, the projection of the first conductive line28onto the second base substrate25shall not overlap the projection of the drive signal circuit43onto the second base substrate25, so that the first conductive line28is insulated from the bridge structures46. In embodiments, the bridge structures46may be located on the same layer as pixel electrodes on the array substrate, that is, the bridge structures46and the pixel electrodes may be formed in the same one manufacturing process. Herein, the bridge structures46may be formed of Indium-Tin-Oxide (ITO).

Or, in the case that an insulating layer47is disposed above the bridge structures46in the light transmission direction, referring to the above embodiments, the projections of the first conductive lines28onto the second base substrate25may at least partially overlap the projections of the drive signal circuits43onto the second base substrate25. For example, for an array substrate with an embedded touch sensing function manufactured by eight masking processes, as shown inFIG. 6Bwhich is a schematic sectional view of the array substrate, according to embodiments of the disclosure, the drive signal circuit43is located in the first metal layer251, while the data lines44or scan lines45are located in the second metal layer252and are electrically connected with the drive signal circuit43via the bridge structures46. Further, an insulating layer47is disposed above the bridge structures46. In this case, because the bridge structures46are covered by the insulating layer47thereon, the possible electrical connection between the first conductive line28and the bridge structures46is avoided no matter where the first conductive line28is disposed, either in the case that the first conductive line28is formed by the perimeter sealant31doped with conductive metal balls or by the conductive silver paste32, according to the above embodiments of the disclosure. In embodiments, the bridge structure46may be located on the same layer as the pixel electrodes on the array substrate, that is, the bridge structure46and the pixel electrodes may be formed in the same one manufacturing process. Herein, the bridge structure46may be formed of ITO.

In embodiments of the disclosure, the drive signal circuit43is connected with the data lines44, to supply image display signals to the respective pixel units via the data lines. Alternatively, the drive signal circuit43is connected with the scan lines45via shift registers, and the drive signal circuit43is configured to output one or more of a clock signal, a high level signal, a low level signal and a scan triggering signal to the shift registers, which in turn generate scan signals according to the signal inputted thereto and output the generated scan signals to the respective scan lines45.

In embodiments of the disclosure, in order to electrically connect the high-resistance film material layer on the opposite substrate with the common electrode layer and the grounding piece on the array substrate, a first conductive line28is disposed between the opposite substrate and the array substrate. Further, referring to theFIGS. 3A, 3B, 3C, 3D, 4B and 4C, a second conductive line29is disposed on the array substrate, and a first end of the second conductive line29is electrically connected with one end of the first conductive line28, while a second end thereof is electrically connected with the common electrode layer26or is grounded. Here, the other end of the first conductive line28is connected with the high-resistance film material layer on the opposite substrate. When grounded, the second end of the second conductive line29is electrically connected with the grounding piece27.

FIG. 6Cis a schematic sectional view of the array substrate, according to embodiments of the disclosure. In addition to the structure in the example shown inFIG. 6B, a common electrode layer26and a second conductive line29are further disposed above the insulating layer in embodiments, and if the second end of the second conductive line29is electrically connected with the common electrode layer26, the second conductive line29functions as a common voltage signal line. Further, in embodiments shown in the aboveFIG. 6B, the common electrode layer26is located on a side of the insulating layer47that is away from the second base substrate25, and is located on the same layer as the common voltage signal line.

In the array substrate with an embedded touch sensing function, according to embodiments of the disclosure, referring toFIG. 6C, the common electrode layer26may include a plurality of common electrode blocks261which can be reused as touch electrodes. The common electrode blocks261which are operable as touch electrodes can be used for both a display function and the touch sensing function, according to embodiments. During a display phase, a common voltage signal is applied to the common electrode blocks261, while during a touch phase, touch driving signals are applied to the common electrode blocks261operating as touch electrodes for touch detection. As such, the reuse of the common electrode blocks261as the touch electrodes eliminates the provision of an additional touch electrode layer, thus effectively reducing the thickness of the array substrate and the whole touch display panel.

In embodiments of the disclosure, in order to improve the connection between the high-resistance film material layer on the opposite substrate and the first conductive line as well as the connection between the first conductive line and the second conductive line, referring toFIG. 7which is a schematic view showing the structure of a touch display panel, according to embodiments of the disclosure, a first bonding pad51is further disposed on the first base substrate23, and/or a second bonding pad52is disposed on the second base substrate25. The high-resistance film material layer24on the first base substrate23is electrically connected with the first conductive line28via the first bonding pad51, and the first conductive line28is electrically connected with the second conductive line29via the second bonding pad52.

Further, referring toFIG. 2B, in embodiments of the disclosure, the touch display panel further includes a flexible circuit board53, and the high-resistance film material layer24and the common electrode layer26are both electrically connected with a common electrode signal terminal of the flexible circuit board53. As such, during the displaying of the touch display panel, a common voltage signal is applied to the common electrode layer26, and hence the high-resistance film material layer24is also applied with the common voltage signal simultaneously, thus shielding off the influence of an outer electric field on the displaying of the touch display panel, and improving the reliability of discharging the static electricity from the touch display panel, meanwhile, the influence of the high-resistance film material layer24on the touch detection signal during the touch phase is insignificant.

FIG. 8Ais a schematic diagram showing a structure of a black matrix, according to embodiments of the disclosure. In embodiments of the disclosure, the high-resistance film material layer is embodied as a black matrix241doped with carbon powder on the opposite substrate21, and the square resistance of the high-resistance film material layer is equal to the equivalent square resistance of the black matrix241. In embodiments of the disclosure, the black matrix has a grid structure, and the square resistance of the black matrix with the grid structure may be equivalently calculated as a square resistance of an equivalent layer without openings, i.e., the equivalent square resistance. In embodiments, by doping an amount of carbon powder in the black matrix241, the equivalent square resistance of the black matrix241is adjusted to be larger than or equal to 107Ω/□ and less than or equal to 1012Ω/□.

In embodiments of the disclosure, the high-resistance film material layer24is formed by the black matrix, so that the dedicated high-resistance film material layer on the opposite substrate is eliminated, so that the existing process for manufacturing the opposite substrate is applicable in the embodiment, thus saving costs.

In embodiments of the disclosure where the high-resistance film material layer is formed by a black matrix, the doping of the carbon powder into the black matrix changes not only the square resistance of the black matrix, but also the optical density of the black matrix which influence the shading effect of the black matrix, and the optical density of the black matrix is larger than or equal to 3 in the embodiment, to ensure a good shading effect of the black matrix. However, in embodiments of the disclosure, by controlling the content of the carbon powder in the black matrix and the thickness of the black matrix, the optical density of the black matrix is adjusted to be larger than or equal to 3, and the equivalent square resistance of the black matrix is larger than or equal to 107Ω/□ and less than or equal to 1012Ω/□.

The square resistance RΠand the optical densityof the black matrix may be derived as follows.

The optical densityof the black matrix is calculated as=I g(1/T), where T represents light transmissivity of the black matrix.

Generally, the square resistance RΠof the black matrix varies with the content of carbon powder, that is, when the content of carbon powder is increased, the resistivity ρ of the black matrix is lowered. If the thickness of the black matrix is 1 μm, the square resistance RΠof the black matrix is equal to the resistivity ρ of the black matrix, and the value of the optical densityof the black matrix is equal to an optical density s corresponding to a unit thickness of the black matrix.

For example, given a sample 1 of the black matrix and a sample 2 of the black matrix, where the content of carbon powder doped in the sample 2 is lower than the content of carbon powder doped in the sample 1, thus the sample 2 has a higher resistivity ρ than the sample 1, and the value of the optical density s of the sample 2 corresponding to the unit thickness is smaller than the sample 1. The related parameters of the samples 1 and 2 meet relationships below:

ρ2=mρ1, that is, the resistivity ρ2of the sample 2 is m times the resistivity ρ1of the sample 1;

S2=1n⁢S1,
that is, the value S1of the optical density of the sample 1 per unit thickness is N times the value S2of the optical density of the sample 2 per unit thickness;

d2=α*d1, that is, the thickness d2of the sample 2 is α times the thickness d1of the sample 1; and

RΠ2=β·RΠ1, that is, the square resistance RΠ2of the sample 2 is β times the square resistance RΠ1of the sample 1;

Additionally, it may be known from the Lambert Beer Law that, the optical densityof the black matrix is proportional to the optical density s of the black matrix per unit thickness, that is,=s*d where d represents the thickness of the black matrix.

The square resistance RΠ2of the sample 2 is given as

The value of the optical density OD2of the sample 2 is given as

According to a formula

{RΠ2=β*RΠ12>1,
it may further be obtained that

Thus it may be seen that, if the resistivity ρ2of the sample 2 is m times the resistivity ρ1of the sample 1, and the value S1of the optical density of the sample 1 per unit thickness is n times the value S2of the optical density of the sample 2 per unit thickness, then,

when the thickness d2of the sample 2 is α times the thickness d1of the sample 1, the square resistance RΠof the sample 2 is ml α times the square resistance RΠ, of the sample 1; and when α>n , it may be met that the optical density of the sample 2 is larger than the optical density of the sample 1.

For example, samples 1 and 2 that meet specifications below are given.

It may be known from the above parameters that,

If α>1. 2, then>; at the same time, the square resistance value of the sample 2 is obtained as 1015/α(Ω/□), so that the square resistance value can match the optical density value by adjusting the thickness of the sample; in some embodiments, the thickness of the black matrix is in a range from 0.5 μm to 3.5 μm.

Additionally, in embodiments, the high-resistance film material layer is formed by a black matrix doped with carbon powder. Due to the presence of openings in the black matrix which has a grid structure, a light transmission region is disposed in each pixel region. Referring toFIGS. 8A and 8B, taking one pixel region on the top left corner of the black matrix as an example, since each pixel region may be equivalent to one rectangular structure with an equivalent length L, an equivalent width w, an equivalent thickness d, and resistivity ρ, if the black matrix is formed as the whole layer free of openings, the equivalent resistance of the black matrix corresponding to the rectangular structure,

R=ρ⁢Ld*W=RΠ⁢⁢e⁢⁢1*LW,
where RΠe1denotes the equivalent square resistance thereof.

FIG. 8Bis a schematic diagram showing the structure of one pixel region in the black matrix, according to embodiments of the disclosure. A light transmission region is disposed in the pixel region, and is equivalent to a rectangular structure with an equivalent length Lh1and an equivalent width wh.

Additionally, the pixel region may be divided into four parts, including: a first part, the length, width, thickness and resistance of which are respectively Lv1,w, de2and Rv1; a second part, the length, width, thickness and resistance of which are respectively L2, w, de2and Rv2; a third part, the length, width, thickness and resistance of which are respectively Lh1, Wh1, de2and Rh1; and a fourth part, the length, width, thickness and resistance of which are respectively Lh2, wh2, de2and Rh2, where L1=Lh2

Thus, in the pixel region provided with the light transmission region, the actual square resistance of the black matrix is denoted by RΠe2, and the resistance of the black matrix is obtained as

where, the values of Rh1, , Rh2, Rv1and Rv2may be calculated according to the above formulae, and it may further obtained by calculation that:

If R=Rhesh, the actual square resistance and the equivalent square resistance of the black matrix meet the formula below:

If the content of carbon powder in the black matrix is constant and the resistivity is the same, the preceding formula may be further simplified as:

Therefore, by only adjusting the thickness of the black matrix, it may be obtained thatR=Rhesh.

In the touch display pane!, according to embodiments of the disclosure, the opposite substrate includes the first base substrate, on which the high-resistance film material layer with a square resistance larger than or equal to 107Ω/□ and less than or equal to 1012Ω/□ is disposed. By using such high-resistance film material layer, the generated static electricity such as charges generated due to a high voltage (for example, at or above the level of kilovolt) may be discharged via the high-resistance film material layer for the purpose of releasing the static electricity. However, during touch detection, the high-resistance film material layer will not release charges accumulated due to a touch by a finger and the like, that is, the high-resistance film material layer has a weak shielding effect on the charge signal generated due to the touch by the finger and the like, without influencing the touch sensing performance of the touch display panel. In some embodiments, the high-resistance film material layer may be formed by a black matrix on the opposite substrate, so that the technical solution of the disclosure may be realized without changing the manufacturing process of the opposite substrate.

In embodiments of the disclosure, the touch sensing performance of the touch display panel that employs the high-resistance film material layer is verified by experiments. As shown in Table 1 below, the strength of touch sensing signals generated due to pressing by a metal pole is measured in the absence of a high-resistance film material layer and in the presence of a high-resistance film material layer with a square resistance of 108Ω/□, where, the touch sensing signals include: a touch sensing signal 1 measured at one end of the touch signal line that is near to the control chip, and a touch sensing signal 2 measured at the other end of the touch signal line that is away from the control chip. Additionally, the strength of a noise signal without touching is further measured. The measurement result is shown in Table 1 below:

It may be seen from Table 1 that, the strength of the touch sensing signal in the presence of the high-resistance film material layer is higher than the strength of the touch sensing signal in the absence of a high-resistance film material layer. Further, if a touch does not occur, the strength of the noise signal in the presence of the high-resistance film material layer is slightly different from the strength of the noise signal in the absence of the high-resistance film material layer, thus the high-resistance film material layer will not influence the touch sensing performance of the touch display panel.

In embodiments of the disclosure, the static electricity discharge performance of the touch display panel that employs the high-resistance film material layer is verified by experiments. Table 2 shows the static electricity discharge performance of a touch display panel that employs a high-resistance film material layer with a square resistance of 109Ω/□:

Table 3 shows the static electricity discharge performance of a touch display panel that employs a high-resistance film material layer with a square resistance of 108Ω/□:

Table 4 shows the static electricity discharge performance of a touch display panel without a high-resistance film material layer:

It may be seen from the above Table 2, Table 3 and Table 4 that, when a high-resistance film material layer with a square resistance of 108Ω/□ or 109Ω/□ is used, the touch display panel does not suffer from color distortion even when the static electricity voltage reaches −12 KV, thus improving the static electricity discharge performance of the touch display panel. However, in the absence of the high-resistance film material layer, the touch display panel will suffer from color distortion when the static electricity voltage reaches 10 kv.

It should be noted that the above described are embodiments of the disclosure and the used technical principles. Those skilled in the art will appreciate that the disclosure is not limited to the specific embodiments described herein. The various obvious alterations, readjustments and alternations may be made out without departing from the protection scope of the disclosure. Therefore, the disclosure has been described in detail by the above embodiments, but the disclosure is not limited to the above embodiments and also includes more other embodiments without departing from the scope of the disclosure as determined by the scope of the appended claims.