TWI792243B - Touch element and display device containing the same - Google Patents

Abstract

A touch element includes a polymer-type retardation layer, and a touch sensing structure. The polymer-type retardation layer receives the linearly polarized incident light and then producing a phase difference. The touch sensing structure is disposed on the polymer-type retardation layer.

Description

Touch element and display device including the touch element

The present invention relates to a touch element, in particular to a bendable and high temperature resistant ultra-thin touch element.

At present, the circular polarizer (CPOL) is mainly a circular polarizer combined with a phase retardation layer (Retarder) and a linear polarizer. It is often used as an anti-reflection film in the display field to solve The reflected light generated by the incident light reduces the display troubles, wherein the phase retardation layer used may be a quarter wave plate (QWP). FIG. 1 is a schematic diagram illustrating that an anti-reflection sheet 100a receives incident light from an external environment. As shown in FIG. 1, when the incident light L from outside passes through the outermost linear polarizing layer 10a, the linear polarizing layer 10a converts the incident light L into linearly polarized incident light _L1 , and the polarization direction of the linearly polarized incident light _L1 is Vertical direction, then, linearly polarized incident light L ₁ enters the 1/4 wave plate as phase retardation layer 20a, makes this linearly polarized incident light L ₁ produce phase retardation, and converts linearly polarized incident light L ₁ into left-handed polarized light L _cl ; Next, when the light is reflected by the display panel 200, it will form a reverse right-handed polarized light L _cr , and then pass through the 1/4 wave plate as the phase retardation layer 20a, finally making the polarization direction of the linearly polarized incident light L ₂ It is perpendicular to the polarization direction of the linearly polarized incident light L ₁ , so that the incident light from the external environment cannot pass through the linear polarizing layer 10 a and is blocked in the circular polarizer 100 a.

In addition, the anti-reflection sheet 100a may be assembled with the touch sensing structure 30a to form an integrated product. FIG. 2 is a schematic diagram of the structure of the integrated anti-reflection sheet 100a and the touch sensing structure 30a in the prior art; as shown in FIG. phase retardation layer), the problem is that the anisotropic liquid crystal must use the substrate 20c as the basic material to provide structural strength during the manufacturing process, which will result in a thicker anti-reflection film, and the circular polarizer of the prior art must be provided with another layer The transparent adhesive layer 20b is bonded and assembled with the touch sensing structure 30a, resulting in the thickness of the final anti-reflective sheet product reaching 64um, which does not conform to the current trend of increasingly thinner and thinner displays, so it is necessary to thin it.

In addition, as disclosed in KR102146739 (KR'739), touch sensors with various structures, such as GFF, GF2, G1F, etc., can be attached to the phase retardation layer, but the present invention considers that the phase retardation layer is an optical element, and the touch sensor The sensor is an electrical component. The direct combination of two components with different functions must consider whether the respective characteristics will be affected by the other component and fail. That is to say, KR'739 only generally proposes a phase delay layer and touch control The possibility of combination of sensing modules, KR'739 did not prove that the touch sensing module will not cause the shift of the characteristics of the phase delay layer (such as the phase delay value).

Furthermore, returning to the material point of view of the phase retardation layer 20a, KR'739 discloses that the material of the phase retardation layer 20a can be an anisotropic liquid crystal or a thin-film phase retardation layer made of a polymer, but the present invention proposes to use an isotropic The reliability of the tropic liquid crystal as the phase retardation layer 20a has its doubts. Please refer to Figure 3, which is the result of the weather resistance simulation experiment under high temperature environment. Figure 3 shows that the liquid crystal phase retardation layer has passed the high temperature test under the visible light The difference of the final phase retardation value is greater than 7nm. For example, under the condition of wavelength 575nm, the difference of phase retardation value (absolute value of change) is 7.2. This experimental result represents the optical performance of the antireflection sheet product using the liquid crystal phase retardation layer Functions (such as the anti-reflection function mentioned above) will be reduced or lost due to environmental conditions, usage status, etc., which may also affect the display effect of the terminal product. That is to say, KR'739 only proposed the possibility of a combination of a phase retardation layer and a touch sensing module, and KR'739 did not recognize the problem that the reliability of the liquid crystal phase retardation layer could not meet the demand.

Therefore, the inventors of the present application came up with the present invention after observing the above-mentioned deficiency.

The purpose of the present invention is to provide a touch element, wherein the touch element is formed by integrating an electrical signal processing element (touch sensing structure) and an optical element (polymer phase retardation layer), and the touch sensing structure is formed by nano Composed of rice silver wires, two components with different characteristics/functions will not damage their respective characteristics when matched, which meets the needs of integration.

The purpose of the present invention is to provide a touch element, wherein the touch element can still maintain a very low difference in phase retardation value after a period of time at high temperature, and the polymer phase retardation layer of the touch element in the visible light range The difference in phase retardation values can be less than 7.0nm or less than 2.0nm, or can be between 0nm to 2.0nm, 0.1nm to 2.0nm, 0.2nm to 2.0nm, 0.3nm to 2.0nm, 0.2nm to 1.0nm, 0.3 The range from nm to 0.7nm, or from 0.7nm to 2.0nm, thereby realizing high-reliability touch elements and products thereof.

Another object of the present invention is to provide a touch device, wherein the polymer phase retardation layer of the touch device can be directly used as a substrate without additional substrates. The thickness of the polymer phase retardation layer according to the present invention is less than 53 μm, whereby a bendable and ultra-thin touch element and its products can be realized.

In order to achieve the above object, the present invention provides a touch control element, comprising: a polymer phase retardation layer; and a touch sensing structure disposed and contacting the polymer phase delay layer, wherein the touch sensing structure is nanometer A composite layer of silver wire and polymer; wherein the phase delay value R ₀ of the polymer phase retardation layer before and after setting the touch sensing structure is less than 1% in the visible light range.

Preferably, according to the touch element of the present invention, the thickness of the touch element is less than 64 μm.

Preferably, according to the touch device of the present invention, the thickness of the polymer phase retardation layer is less than 53 μm.

其中，R ₀表示該觸控元件在約25°C下在575nm所量測的第一相位延遲值， R ₀'表示該觸控元件在85°C下持續240小時再回復到約25°C下在575nm所量測的第二相位延遲值，ΔR ₀表示該第一相位延遲值與該第二相位延遲值差值的絕對值，該ΔR ₀小於7.0nm。 Preferably, according to the touch element of the present invention, the phase delay difference ΔR ₀ of the touch element is expressed by the following formula:

Wherein, R ₀ represents the first phase delay value of the touch element measured at 575nm at about 25°C, and R ₀ ' means that the touch element lasts for 240 hours at 85°C and then returns to about 25°C Next, the second phase retardation value measured at 575nm, ΔR ₀ represents the absolute value of the difference between the first phase retardation value and the second phase retardation value, and the ΔR ₀ is less than 7.0nm.

Preferably, according to the touch element of the present invention, wherein the ΔR ₀ is between 0 nm to 2.0 nm, 0.1 nm to 2.0 nm, 0.2 nm to 2.0 nm, 0.3 nm to 2.0 nm, 0.2 nm to 1.0 nm, 0.3 nm to 0.7nm or the range from 0.7nm to 2.0nm.

其中，R ₀表示該觸控元件在約25°C下在575nm所量測的第一相位延遲值，R ₀'表示該觸控元件在85°C下持續240小時再回復到約25°C下在575nm所量測的第二相位延遲值，ΔR ₀表示該第一相位延遲值與該第二相位延遲值差值的絕對值，該ΔR ₀介於0 nm至1.0nm、0.1nm至1.0nm、0.2nm至1.0nm或0.7nm。 Preferably, according to the touch element of the present invention, wherein the thickness of the polymer phase retardation layer is about 13 μm, the phase retardation difference ΔR ₀ of the touch element is expressed by the following formula:

Wherein, R ₀ represents the first phase delay value measured at 575nm of the touch element at about 25°C, and R ₀ ' means that the touch element lasts for 240 hours at 85°C and then returns to about 25°C Under the second phase delay value measured at 575nm, ΔR ₀ represents the absolute value of the difference between the first phase delay value and the second phase delay value, and the ΔR ₀ is between 0 nm to 1.0nm, 0.1nm to 1.0 nm, 0.2nm to 1.0nm or 0.7nm.

其中，R ₀表示該觸控元件在約25°C下在575nm所量測的第一相位延遲值， R ₀'表示該觸控元件在85°C下持續240小時再回復到約25°C下在575nm所量測的第二相位延遲值，ΔR ₀表示該第一相位延遲值與該第二相位延遲值差值的絕對值，該ΔR ₀介於0 nm至2.0nm、0.1nm至2.0nm、0.2nm至2.0nm、0.3nm至2.0nm或0.3nm。 Preferably, according to the touch element of the present invention, wherein the thickness of the polymer phase retardation layer is about 25 μm, the phase retardation difference ΔR ₀ of the touch element is expressed by the following formula

Wherein, R ₀ represents the first phase delay value of the touch element measured at 575nm at about 25°C, and R ₀ ' means that the touch element lasts for 240 hours at 85°C and then returns to about 25°C Under the second phase delay value measured at 575nm, ΔR ₀ represents the absolute value of the difference between the first phase delay value and the second phase delay value, and the ΔR ₀ is between 0 nm to 2.0nm, 0.1nm to 2.0 nm, 0.2nm to 2.0nm, 0.3nm to 2.0nm or 0.3nm.

Preferably, according to the touch element of the present invention, the touch element is assembled on a linear polarizing layer.

Moreover, in order to achieve the above object, the present invention further provides a display device based on the above touch element, comprising: a display panel having a display area; and the above touch element disposed on the display panel, wherein the The touch sensing structure of the touch element overlaps with the display area correspondingly.

Preferably, according to the display device of the present invention, wherein, the display panel is a liquid crystal display panel, an organic electroluminescent display panel, an organic light emitting diode display panel, or a micro light emitting diode display panel, however, the present invention does not limited to this.

In order to enable those who are familiar with the technical field to understand the purpose, features and effects of the present invention, the present invention will be described in detail below with the help of the following specific embodiments and accompanying drawings.

Hereinafter, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings, and the advantages, features and methods for achieving the present invention will be apparent. It should be noted, however, that the present invention is not limited to the following exemplary embodiments but may be implemented in various forms.

The terminology used herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the terms "a" and "the" in the singular also include the plural unless the context clearly dictates otherwise. Unless the context clearly indicates otherwise, the terms "weather resistance" and "reliability" used herein should be understood as the same concept.

In addition, it will be understood that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may be present. In addition, the thickness value referred to herein is not absolute, and those skilled in the art can understand that the thickness referred to may include manufacturing tolerances, measurement errors, etc., preferably, the thicknesses listed herein may have 10%, 20% scope.

It should also be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish various elements. Thus, a first element in some embodiments could be termed a second element in other embodiments without departing from the teachings of the present invention. In this specification, the same reference numerals denote the same elements.

Please refer to FIG. 4. FIG. 4 is a schematic diagram of the touch element of the present invention. The touch element 40 according to the present invention includes: a polymer phase retardation layer 20, and a touch sensor set and in contact with the polymer phase retardation layer 20. Measuring structure 30. The combination of the touch element 40 and the linear polarizing layer 10 can constitute the anti-reflection optical element of the embodiment of the present invention, such as a circular polarizer; Function and optical function of the multifunctional module, and the touch sensing structure 30 will not affect the optical properties of the polymer phase retardation layer 20 .

Specifically, please refer to FIG. 4 and refer to the foregoing description for FIG. 2 , the linear polarizing layer 10 receives an incident light L from the external environment, and converts the incident light L into a linearly polarized incident light L ₁ . In a preferred embodiment, the linearly polarized incident light L ₁ has a vertical polarization direction. However, the present invention is not limited thereto.

The polymer phase retardation layer 20 in Fig. 4 can also be referred to as a film-type phase retardation layer or a stretched phase retardation layer, which is arranged under the linear polarizing layer 10, and the polymer phase retardation layer 20 receives the linear polarization incident light L _l , and make the linearly polarized incident light produce a phase delay. In a preferred embodiment of the present invention, the phase delay makes the linearly polarized incident light L ₁ convert into left-handed polarized light L _cl , and the left-handed polarized light L _cl has a polarization direction of left-handed circular polarization; then, when the light is reflected by the display panel 200, it will form a reverse right-handed polarized light L _cr , and then pass through the polymer phase retardation layer 20, finally making the linearly polarized incident light L ₂ The polarization direction is perpendicular to the polarization direction of the linearly polarized incident light L ₁ , so that the incident light from the external environment cannot pass through the linear polarizing layer 10 and is blocked in the touch element 40 . However, the present invention is not limited thereto.

Specifically, please refer to FIG. 4 , the touch sensing structure 30 is disposed on and contacts the polymer phase retardation layer 20 . For example, the touch sensing structure 30 can form a single-layer electrode structure. In some embodiments, the touch sensing structure 30 includes a single-layer touch electrode layer, and the single-layer touch electrode layer can be set Above the polymer phase retardation layer 20 , that is, the single-layer touch electrode layer 3 is between the polymer phase retardation layer 20 and the linear polarizing layer 10 . In addition, in some embodiments, the single-layer touch electrode layer can be disposed under the polymer phase retardation layer 20, please refer to FIG. Between the linear polarizing layers 10. In addition, the touch sensing structure 30 can form a double-layer electrode structure. In some embodiments, the touch sensing structure 30 includes a first touch electrode layer 32 and a second touch electrode layer 33. The first touch The control electrode layer 32 is disposed between the linear polarizing layer 10 and the polymer phase retardation layer 20 , and the second touch electrode layer 33 is disposed below the polymer phase retardation layer 20 (refer to FIG. 8 ). Please refer to FIG. 4 . FIG. 4 is a schematic structural diagram of a touch element according to a first embodiment of the present invention. As shown in FIG. 4 , the touch device 40 according to the present invention includes: a polymer phase retardation layer 20 and a touch sensing structure 30 disposed and in contact with the polymer phase retardation layer 20 . Similar to the foregoing, the linear polarizing layer 10 of this embodiment is disposed on the touch-sensing structure 30 to constitute the anti-reflection optical element of the embodiment of the present invention.

Specifically, please refer to FIG. 4, the polymer phase retardation layer 20 is disposed under the linear polarizing layer 10, the polymer phase retardation layer 20 receives the linearly polarized incident light L _l , and causes the linearly polarized incident light to produce a phase delay, In this embodiment, the polymer phase retardation layer 20 is made of colorless polyimide (colorless polyimide, CPI), wherein polyimide has excellent mechanical properties, heat resistance, chemical resistance, and Electrical insulating properties. However, the present invention is not limited thereto. It should be further explained that the colorless polyimide according to the present invention is prepared by condensation reaction of diamine monomer and dianhydride monomer, wherein the ratio of diamine monomer to dianhydride monomer is in the range of 0.95- 0.05: 0.05 - 0.95. However, the present invention is not limited thereto.

It is worth mentioning that, in the embodiment of the present invention, the above-mentioned touch sensing structure 30 is made of metal nanowires (such as silver nanowires), and the method used may be to mix the dispersion solution containing silver nanowires Coating on the polymer phase retardation layer 20, for example, mixing silver nanowires into a solvent, such as: water, alcohol, ketone, ether, hydrocarbon or aromatic solvent (benzene, toluene, xylene, etc.) to form a coating/slurry; The above coatings/slurries may also contain additives, surfactants or binders, for example: carboxymethyl cellulose (CMC), 2-hydroxyethyl cellulose (HEC), hydroxypropyl methylcellulose Cellulose (hydroxypropyl methylcellulose, HPMC), sulfonate, sulfate, disulfonate, sulfosuccinate, phosphate or fluorine-containing surfactant, etc. After the coating is completed, a silver nanowire layer is formed through a curing step, and the silver nanowire layer can be patterned to form the touch sensing structure 30 by a patterning method known to those skilled in the art, and make the touch sensing structure 30 is disposed on the polymer phase retardation layer 20 and is in contact with the polymer phase retardation layer 20 .

Preferably, the nano-silver wires will be fixed on the surface of the polymer phase retardation layer 20 without falling off to form the nano-silver wire layer, and the nano-silver wires can contact each other to provide a continuous current path, Further, a conductive network is formed, in other words, the silver nanowires are in contact with each other at the crossing positions to form a path for electron transmission. That is to say, one silver nanowire layer and another silver nanowire layer will form a direct contact state at the intersection position, thus forming a low-resistance electron transfer path. In one embodiment, when a region or a structure has a sheet resistance higher than 10 ⁸ ohms/square (ohm/square), it can be identified as electrically insulating, preferably higher than 10 ⁴ ohms/square (ohm/square ), 3000 ohms/square (ohm/square), 1000 ohms/square (ohm/square), 350 ohms/square (ohm/square), or 100 ohms/square (ohm/square). In one embodiment, the sheet resistance of the silver nanowire layer formed by the silver nanowires is less than 100 ohm/square.

In one embodiment, a polymer layer can be further provided so that the polymer layer covers the silver nanowires. In a specific embodiment, an appropriate polymer/polymer is coated on the silver nanowires, and the polymer with a flow state/property can penetrate between the silver nanowires to form a filler, and the silver nanowires will be embedded in the polymer In polymers, a composite structure is formed after the polymer is cured. That is to say, in this step, the polymer layer is coated on the silver nano wire, and the silver nano wire will be embedded in the polymer layer to form a composite structure. In some embodiments of the present invention, the polymer layer is formed of an insulating material. For example, the material of the polymer layer can be non-conductive resin or other organic materials, such as polyacrylate, epoxy resin, polyurethane, polysilane, polysiloxane, poly(silicon-acrylic acid), poly Ethylene (polyethylene; PE), polypropylene (Polypropylene; PP), polyvinyl butyral (Polyvinyl butyral; PVB), polycarbonate (polycarbonate; PC), acrylonitrile-butadiene-styrene copolymer (Acrylonitrile butadiene styrene; ABS), poly(3,4-ethylenedioxythiophene) (PEDOT), poly(styrenesulfonic acid) (PSS) or ceramic materials and so on. In some embodiments of the present invention, the polymer layer can be formed by spin coating, spray coating, printing and the like. In some embodiments, the thickness of the polymer layer is about 20 nm to 10 microns, or 50 nm to 200 nm, or 30 to 100 nm. For example, the thickness of the polymer layer may be about 90 nm or 100 nm. For simplicity of illustration, the present invention does not draw the polymer layer.

Since the present invention relates to the phase retardation value of the phase retardation material, the measurement method will be described below first. The embodiments of the present invention measure the phase retardation value measured on a plane perpendicular to the thickness direction of the object to be measured, that is, the in-plane retardation value (in plane retardance/retardation (R ₀ )). The embodiment of the present invention uses a commercial device model: AxoScan (manufacturer Axometrics, Inc) to measure the in-plane phase retardation value of the object under test in the visible light wavelength range, and for the sake of data brevity, this paper only records the in-plane phase of a specific wavelength such as 550nm or 575nm delay value.

Specifically, the difference ΔR of the phase retardation value after the reliability test of the polymer phase retardation layer 20 according to the present invention is expressed by the following formula, wherein, _R0 represents the initial state of the polymer phase retardation layer 20 at the first temperature The first phase retardation value under , R ₀ ' represents the second phase retardation value measured after the polymer phase retardation layer 20 is kept at the second temperature for a period of time, and then returned to the first temperature, ΔR ₀ represents the absolute value of the difference between the first phase delay R ₀ and the second phase delay value R ₀ ′, that is, the polymer phase according to the present invention is judged by the change of the difference ΔR ₀ of the phase delay value Whether the phase delay of the retardation layer 20 will be affected by the temperature, that is, it can be deduced by using the ΔR ₀ after the test for a period of time (such as 100, 240, 360, 500 hours or more) at a high temperature (such as 80~100°C) The weather resistance of the polymer phase retardation layer 20 and products including the polymer phase retardation layer 20 of the embodiment of the present invention (such as touch elements, anti-reflection elements, displays, etc.) was evaluated. The ΔR ₀ of the polymer phase retardation layer 20 according to the present invention is in the range of 0.1nm to 2.0nm, therefore, it can be judged that the polymer phase retardation layer 20/touch element/anti-reflection element/end product according to the present invention has different Technical efficacy affected by high temperature.

It needs to be further explained that the difference ΔR ₀ of the phase delay value is ideally zero (that is, the phase delay value is not affected by temperature), but the following embodiments of the present invention may be subject to the error of the measuring instrument. According to the present invention, The ΔR ₀ of the touch element 40 with the polymer phase retardation layer 20 measured by the measuring instrument is in the range of 0.1 nm to 2.0 nm. However, the user may choose a measuring instrument with a smaller error range to measure ΔR ₀ according to the requirement, and the measured value may be smaller. This is only for illustration, and the present invention is not limited thereto. In addition, the phase retardation value referred to in the present invention can be defined as measured under the visible light range (such as 400-700 nm), and the difference calculated by the preceding formula is the difference of the phase retardation value under the same wavelength; or, for For convenience of description, the phase retardation value referred to in the present invention can be defined as measured at a specific wavelength such as 550nm or 575nm, and the difference calculated by the preceding formula is the difference of the phase retardation value at 550nm or 575nm. Moreover, in order to avoid confusion, if the difference obtained by the aforementioned formula is a negative number, the mathematical operation of the absolute value is performed.

Specifically, the first temperature for the present invention to carry out the above-mentioned reliability test is room temperature (such as 25°C), and the second temperature is 85°C, and the test object is put into a constant temperature and humidity testing machine (model: GTH-408 -40-CP-AR, manufacturer: Jufu Instrument) continued for 240 hours, then took out the test object and left it at room temperature (about 5~10 minutes), and then carried out the aforementioned phase delay value. The description of the value is that in the present invention, the object to be tested is clamped and fixed by two pieces of glass on the upper and lower sides, and then put into the constant temperature and humidity testing machine, and there is a gap between the object to be tested and the upper and lower glasses, so as to facilitate the uniformity of the object to be tested. Receive the test environment/conditions in the constant temperature and humidity testing machine.

Please refer to Table 1. Table 1 is a description of the polymer phase retardation layer 20 according to the first embodiment of the present invention and the liquid crystal phase retardation layer of the prior art (the liquid crystal phase retardation layer is attached to the substrate by optical glue for phase retardation. value measurement) the phase retardation value R ₀ measured at each wavelength, the phase retardation value R ₀ of the two in the visible light range is similar; and the polymer phase retardation layer 20 of the first embodiment of the present invention The measured phase retardation value R ₀ at a wavelength of 550nm is 138.71nm, which is very close to the ideal phase retardation value R ₀ of 138.75nm. In this way, it can be determined that the polymer phase retardation layer 20 according to the first embodiment of the present invention has good optical properties, meets the requirements of practical applications, and can replace the aforementioned liquid crystal phase retardation layer.

Table 1 wavelength (nm) polymer phase retardation layer Liquid crystal phase retardation layer 400 171.2 160.7 425 161.7 157.0 450 155.0 154.3 475 150.7 150.0 500 145.0 144.9 525 141.7 144.5 550 138.7 137.9 575 136.7 137.1 600 134.2 138.3 625 132.5 135.2 650 132.6 131.2 675 128.5 130.5 700 130.6 132.2 725 129.0 130.8 750 128.9 127.0 775 127.6 127.7 800 122.7 125.8

It should be further explained that, in general, the touch sensing structure 30 may include indium tin oxide (ITO), metal grid (metal mesh), nano silver wire (silver nanowire, SNW), carbon nanotube ( Carbon nanotube, CNT), graphene (graphene) and other materials, but the present invention proposes a combination of a silver nanowire/polymer layer composite touch sensing structure 30 and a polymer phase retardation layer 20, and in In the case of using a composite touch sensing structure 30, the phase retardation value _R0 measured in the visible light range is different from that of a separate polymer phase retardation layer 20 (that is, without using a composite touch sensing structure). 30) The measured phase delay values are quite close, for example, the difference between the two phase delay values R ₀ is less than 1%. It can be seen from Table 2 that under the test at a wavelength of 575nm, the data calculation of the first phase delay value _R0 of the touch sensing structure 30 using the composite type and the touch sensing structure 30 without using the composite type is 0.3%; It can be seen that, according to the aforementioned experiments, the touch element 40 composed of the composite touch sensing structure 30 composed of silver nanowires/polymer layers and the polymer phase retardation layer 20 of the present invention has high stability and is in line with reality. application requirements, etc. As mentioned above, KR'739 only generally proposed the possibility of combining a phase delay layer with a touch sensing module. KR'739 did not prove that the touch sensing element will not cause the phase delay layer to change in optical characteristics (such as phase delay value) That is to say, compared with KR'739, the present invention proposes a feasible integration scheme of the nano silver wire/polymer layer touch sensing structure and the polymer phase retardation layer, and under this framework, the nano The composite touch sensing structure 30 composed of silver wire/polymer layer and the polymer phase retardation layer 20 can be matched with each other without affecting the characteristics of each other.

However, the present invention considers that materials such as indium tin oxide (ITO), metal mesh (metal mesh), carbon nanotube (carbon nanotube, CNT), and graphene (graphene) are used in combination with the polymer phase retardation layer 20, then it is possible The characteristics (such as phase retardation value, etc.) of the polymer phase retardation layer 20 are caused to vary. That is to say, as verified by the embodiment of the present invention, the composite conductive layer composed of silver nanowires/polymer layer will not have an optical impact on the polymer phase retardation layer 20 .

Table 2 wavelength (nm) R ₀ without silver nanowires R ₀ using silver nanowires 575 148.1 147.7

Specifically, in the first embodiment of the present invention, a composite conductive layer composed of silver nanowires/polymer layer is placed on a polymer phase retardation layer 20 with a thickness of 13 μm according to the aforementioned method, and the reliability test is carried out (ie After heating up to 85°C and continuing for 240 hours), the phase delay value was measured. Please refer to FIG. 5 and Table 3. FIG. 5 is a graph illustrating the difference between the phase delay value and the wavelength of the prior art and the reliability test according to the first embodiment of the present invention. Table 3 is an excerpt of the prior art and the present invention. The difference ΔR ₀ of the phase retardation measured at a wavelength of 575 nm in the first embodiment of the invention. According to Table 3, the difference ΔR ₀ of the phase retardation measured at a wavelength of 575 nm in the first embodiment of the present invention is 0.7, while the difference ΔR ₀ of the phase retardation measured at a wavelength of 575 nm in the prior art is 7.2 ; Fig. 5 shows that the phase retardation value difference ΔR ₀ of the first embodiment of the present invention is in the range of 0.2nm to 1.0nm in the visible light range, and the phase retardation value measured in the visible light range by the prior art The difference ΔR ₀ is greater than 7.0nm. The optical properties of the liquid crystal phase retardation layer used in the conventional technology will decline significantly after passing through a high-temperature environment, which will reduce the anti-reflection effect and cause the quality of the display product to decline. The difference in phase retardation value after the reliability test (ie heating up to 85°C for 240 hours) must be less than 7.0nm in order to maintain good product quality under high temperature environment.

The difference ΔR ₀ of the phase retardation value of the polymer phase retardation layer 20 according to the present invention is obviously lower than the difference ΔR ₀ of the phase retardation value of the touch element of the prior art, therefore, the polymer phase retardation layer 20 has better weather resistance properties. It is worth noting that although the difference ΔR ₀ of the phase retardation value measured at 575nm in this embodiment is 0.7, the lower limit of ΔR ₀ may It is reasonably expected to be zero to 0.1 nm, so ΔR ₀ is between 0 nm to 1.0 nm, 0.1 nm to 1.0 nm, 0.2 nm to 1.0 nm, or 0.7 nm.

table 3 Liquid crystal phase retardation layer polymer phase retardation layer wavelength R ₀ R ₀ ' ΔR ₀ wavelength R ₀ R ₀ ' ΔR ₀ 575 116.6 109.5 7.2 575 142.0 141.3 0.7

In addition, the thickness of the polymer phase retardation layer 20 used according to the first embodiment of the present invention is only about 13 μm, and the thickness of the overall touch element 40 is 25 μm, compared with the total thickness of the touch element in the prior art of about 64 μm , the thickness of the embodiment of the present invention is greatly reduced, and in the case of thickness reduction, it is more beneficial to realize a bendable ultra-thin touch element. Therefore, compared with the conventional technology, the touch element and its products of the embodiments of the present invention have thinner thickness and higher weather resistance.

It is worth mentioning that, in other embodiments of the present invention, the material of the polymer phase retardation layer 20 of the touch element 40 according to the present invention can use other materials besides colorless polyimide (CPI). For example: cyclo-olefin polymer (cyclo-olefin polymer, COP), triacetyl cellulose (triacetyl cellulose, TAC) or polycarbonate (PC, Polycarbonate) and other film materials.

Table 4 shows the phase retardation difference ΔR ₀ between the second embodiment of the present invention and the comparative example using film materials with different thicknesses. It can be understood that the touch element 40 of the present invention can consider the cost and thickness according to the requirements, and select a suitable material as the material of the polymer phase retardation layer 20. According to Table 4, the second embodiment uses a polymer with a thickness of 25 μm For the phase retardation layer 20, the difference ΔR ₀ of the phase retardation value after the weather resistance test measured at 575nm is 0.3 nm, which shows that the optical properties have a smaller variation compared with the prior art, so it has better performance. Reliability; In addition, according to the second embodiment of the present invention, the thickness of the polymer phase retardation layer 20 used is only 25 μm, and the thickness of the overall touch element 40 is 37um, compared with the total thickness of the touch element in the prior art ( 64 μm), the thickness of the embodiment of the present invention is greatly reduced, and in the case of thickness reduction, it is more beneficial to realize a bendable ultra-thin touch element.

It is worth noting that the comparative example in Table 4 uses a polymer phase retardation layer 20 of 53 μm, and the thickness of the overall touch element 40 is 65 μm, which exceeds the total thickness of the touch element in the prior art (64 μm). Therefore, it is greater than The polymer phase retardation layer with this thickness is not the polymer phase retardation layer used in the present invention. In this comparative example, the difference ΔR ₀ of the phase retardation value after the weather resistance test measured at 575nm is 2.0nm. Therefore, the polymer phase retardation layer 20 to be used in the present invention is divided by the thickness (53 μm). Then the measured phase retardation value difference under this thickness is converted into the phase retardation value difference range claimed by the embodiment of the present invention, that is to say, ΔR ₀ is 2.0nm, which can be defined as the polymer phase retardation layer of the present invention 20 The upper limit of the change in the phase delay value difference after the weather resistance test.

Table 4 Polymer Phase Retardation Layer ( Second Embodiment ) Polymer phase retardation layer ( comparative example ) thickness 25μm 53 μm wavelength ΔR ₀ ΔR ₀ 575 0.3 2.0

Considering the second embodiment of the present invention and the comparative example comprehensively, the phase retardation difference ΔR ₀ of the touch element 40 of the present invention can be between 0 nm to 2.0 nm, 0.1 nm to 2.0 nm, 0.2 nm to 2.0 nm, 0.3 nm to 2.0nm or 0.3nm.

Other examples of touch elements are provided below, so that those skilled in the art to which the present invention pertains can understand possible variations more clearly. Components denoted by the same reference numerals as in the above embodiment are substantially the same as those described above with reference to FIG. 4 . The same elements, features, and advantages as those of the touch element 40 will not be repeated.

Please refer to FIG. 6 , which illustrates another embodiment according to the present invention. The main structural difference compared with FIG. 4 is that the touch sensing structure 30 of the touch element 40 of this embodiment is disposed under the polymer phase retardation layer 20 . Relevant descriptions of this embodiment may refer to the foregoing, and details are not repeated here.

Please refer to FIG. 7 , which illustrates another embodiment according to the present invention. The main structural difference compared with FIG. 4 is that the touch sensing structure 30 of the touch element 40 of this embodiment includes a first touch electrode layer 32 and a second touch electrode layer 33, the first touch The sensing structure 30 is disposed between the linear polarizing layer 10 and the polymer phase retardation layer 20 , and the second touch electrode layer 33 is disposed below the polymer phase delay layer 20 . Relevant descriptions of this embodiment may refer to the foregoing, and details are not repeated here.

Considering the first and second embodiments of the present invention and the comparative example comprehensively, the phase delay difference ΔR ₀ of the touch element 40 of the present invention may be less than 7.0 nm, or may be between 0 nm to 2.0 nm, 0.1 nm to 2.0 nm, or 0.2 nm to 2.0nm, 0.3nm to 2.0nm, 0.2nm to 1.0nm, 0.3nm to 0.7nm, or 0.7nm to 2.0nm, it can be understood that the setting position of the touch sensing structure 30 will not affect The phase delay value difference ΔR ₀ , and those skilled in the art to which the present invention pertains can make various changes and adjustments based on the above examples, which will not be listed here.

An embodiment in which the touch element according to the present invention is applied to a display device will be described below.

Please refer to FIG. 8 , which is a schematic structural diagram of a display device according to a preferred embodiment of the present invention. The display device 300 includes a display panel 200 and a touch element 40 . The display panel 200 has a display area. The touch element 40 is disposed on the display panel 200 . The touch sensing structure 30 of the touch element 40 overlaps with the display area correspondingly. Specifically, the display panel 200 may be, but not limited to, a liquid crystal display panel (LCD), an organic electroluminescence display panel, an organic light emitting diode display panel, or a micro light emitting diode display panel (μLED display). In another embodiment, the touch element 40 can form an anti-reflection element with the linear polarizing layer 10 , and then be assembled with the display panel 200 to form a terminal product.

Finally, the technical characteristics of the present invention and the technical effects that can be achieved are summarized as follows at least:

1. The touch element 40 according to the present invention can still maintain a very low difference in phase delay value after being kept at a high temperature of 85° C. for 240 hours, whereby a touch element with high temperature resistance and good reliability can be realized and its product.

2. The polymer phase retardation layer 20 of the touch element 40 according to the present invention can be directly used as a substrate without additional substrates, and the thickness of the polymer phase retardation layer 20 of the present invention can be selected below 53 μm to achieve a flexible Foldable and ultra-thin touch element. Furthermore, the polymer phase retardation layer 20 of the present invention and the composite structure touch sensing structure 30 made of silver nanowires have good characteristic matching.

The implementation of the present invention is described above through specific specific examples. Those skilled in the art can easily understand the technical features, advantages, and effects of the present invention from the content disclosed in this specification.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. All other equivalent changes or modifications that do not deviate from the spirit disclosed in the present invention shall be included in the scope of the following patent applications.

100a: circular polarizer 10: linear polarizing layer 10a: linear polarizing layer 20: polymer phase retardation layer 20a: phase retardation layer 20b: transparent adhesive layer 20c: substrate 30: touch sensing structure 30a: touch sensing structure 32 : first touch electrode layer 33: second touch electrode layer 40: touch element 200: display panel 300: display device L: incident light L ₁ : linearly polarized incident light L ₂ : linearly polarized incident light L _cl : left-handed Polarized light L _cr : right-handed polarized light R ₀ : first phase retardation value R ₀ ': second phase retardation value ΔR ₀ : difference of phase retardation value

Figure 1 is a schematic diagram of a circular polarizer receiving incident light from the external environment, illustrating the principle of anti-reflection; FIG. 2 is a structural schematic diagram of conventional technology integrating an anti-reflective sheet and a touch sensing structure; 3 is a graph illustrating the difference in phase retardation versus wavelength of a liquid crystal phase retardation layer in the prior art after a reliability test; 4 is a schematic structural view of a touch element according to the present invention; 5 is a graph illustrating the difference between the phase delay value of the conventional technology and the touch element according to the first embodiment of the present invention; 6 is a schematic structural diagram of a touch element according to other embodiments of the present invention; 7 is a schematic structural diagram of a touch element according to other embodiments of the present invention; and FIG. 8 is a schematic structural diagram of a display device according to an embodiment of the present invention.

10: Linear polarizing layer

20: Polymer phase retardation layer

30: Touch sensing structure

40: Touch element

Claims (9)

A touch element, comprising: a polymer phase retardation layer; and a touch sensing structure disposed and in contact with the polymer phase delay layer, wherein the touch sensing structure is a composite layer of silver nanowires and polymers ; Wherein the phase retardation value R ₀ difference of the polymer phase retardation layer before and after setting the touch sensing structure is less than 1% in the visible light range. The touch element according to claim 1, wherein the thickness of the touch element is less than 64 μm. The touch device according to claim 1, wherein the thickness of the polymer phase retardation layer is less than 53 μm. The touch element as described in claim 3, wherein the phase delay difference ΔR ₀ of the touch element is expressed by the following formula:

Wherein, R ₀ represents the first phase delay value of the touch element measured at 575nm at about 25°C, and R ₀ ' means that the touch element lasts for 240 hours at 85°C and then returns to about 25°C Next, the second phase retardation value measured at 575nm, ΔR ₀ represents the absolute value of the difference between the first phase retardation value and the second phase retardation value, and the ΔR ₀ is less than 7.0nm. The touch element as described in claim 4, wherein the ΔR ₀ is between 0 nm to 2.0 nm, 0.1 nm to 2.0 nm, 0.2 nm to 2.0 nm, 0.3 nm to 2.0 nm, 0.2 nm to 1.0 nm, 0.3 nm to 0.7nm or the range from 0.7nm to 2.0nm. Such as the touch element of claim 1, wherein the thickness of the polymer phase retardation layer is about 13 μm, and the phase retardation difference ΔR ₀ of the touch element is expressed by the following formula:

Wherein, R ₀ represents the first phase delay value of the touch element measured at 575nm at about 25°C, and R ₀ ' means that the touch element lasts for 240 hours at 85°C and then returns to about 25°C Under the second phase delay value measured at 575nm, ΔR ₀ represents the absolute value of the difference between the first phase delay value and the second phase delay value, and the ΔR ₀ is between 0 nm to 1.0nm, 0.1nm to 1.0 nm, 0.2nm to 1.0nm or 0.7nm. The touch element as described in claim 1, wherein the thickness of the polymer phase retardation layer is about 25 μm, and the phase retardation difference ΔR ₀ of the touch element is expressed by the following formula:

Wherein, R ₀ represents the first phase delay value of the touch element measured at 575nm at about 25°C, and R ₀ ' means that the touch element lasts for 240 hours at 85°C and then returns to about 25°C Under the second phase delay value measured at 575nm, ΔR ₀ represents the absolute value of the difference between the first phase delay value and the second phase delay value, and the ΔR ₀ is between 0 nm to 2.0nm, 0.1nm to 2.0 nm, 0.2nm to 2.0nm, 0.3nm to 2.0nm or 0.3nm. The touch element according to claim 1, wherein the touch element is assembled on a linear polarizing layer. A display device comprising: a display panel having a display area; and The touch element according to any one of claims 1 to 8 is disposed on the display panel, wherein the touch sensing structure of the touch element overlaps with the display area correspondingly.

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