Integrated touch module and touch display device including the integrated touch module

Abstract

This invention relates to an integrated touch module and a touch display device. The integrated touch module has a touch sensing structure formed on a polymer film. The polymer film, a liquid crystal phase retardation layer, and a linear polarizing layer constitute a circular polarizing element. The circular polarizing element has an average reflectance of less than 5% and a standard deviation of reflectance of less than 0.2% in the visible light range. The touch display device includes the integrated touch module.

Description

Technical Field

[0001] This invention relates to an integrated touch module and a touch display device including the integrated touch module, and more particularly to an ultra-thin integrated touch module having a bendable shape and a wide waveband and a touch display device including the integrated touch module. Background Technology

[0002] Currently, circular polarizers (CPOLs) are mainly composed of a phase retarder layer and a linear polarizer. They are often used in the display field as anti-reflective films to solve the problem of reflected light generated by incident light from the external environment and reduce display problems. The phase retarder layer used can be a quarter wave plate (QWP). Figure 1 This is a schematic diagram illustrating how an antireflective sheet receives incident light from the external environment. For example... Figure 1 As shown, theoretically, when the incident light L from the 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. The polarization direction of the linearly polarized incident light L1 is perpendicular. Then, the linearly polarized incident light L1 enters the quarter-wave plate, which serves as the phase delay layer 20a, causing the linearly polarized incident light L1 to be phase-delayed and converted into left-handed polarized light Lcl. Then, when the light is reflected by the display panel 200, it will form right-handed polarized light Lcr, which then passes through the quarter-wave plate, which serves as the phase delay layer 20a. Finally, the polarization direction of the linearly polarized incident light L2 is orthogonal to the polarization direction of the linearly polarized incident light L1, so that the incident light from the outside environment cannot pass through the linear polarizing layer 10a and is blocked in the circular polarizer. Based on the above principles, the first step of the anti-reflection mechanism is to circularly polarize the ambient light, which is one of the important factors in the anti-reflection effect. However, in reality, the phase delay layer cannot ideally circularly polarize all incident light in the visible light range, causing some wavelengths of ambient light to still be reflected by the display panel 200, resulting in interference when the user views the screen.

[0003] Taiwan Patent No. 1663460 (hereinafter referred to as Patent 1663460) discloses a wide-bandgap phase compensation laminate, comprising an optically active half-phase compensation coating and an optically active quarter-phase compensation coating. The optically active quarter-phase compensation coating and the optically active half-phase compensation coating are in direct contact with a contact surface. The wide-bandgap phase compensation laminate disclosed in Patent 1663460 is a technical solution proposed to solve the above-mentioned problems. For example, paragraph

[0014] of Patent 1663460 mentions that "the compensation film has the ability to convert circularly polarized light into a wide-bandgap compensation film."

[0004] However, the reflectivity of the compensation film in patent I663460 is still too high in the visible light range, failing to effectively eliminate the problem of ambient light reflection. For example, as shown in Table 3 of patent I663460, the reflectivity of the compensation film in patent I663460 is approximately 8% at wavelengths of 450nm, 550nm, and 650nm. Since circular polarizers are mainly used to resist ambient light reflection, a higher reflectivity indicates a worse effect on resisting ambient light reflection, which may affect the display effect of the end product, causing reflections under strong external light and leading to reading interference. This application argues that the reflectivity (8%) of the compensation film in patent I663460 in the visible light range cannot meet the increasingly sophisticated display requirements, especially since high-resolution, high-quality videos such as 4K and 8K are now favored by users. It is worth noting that Table 4 of Patent I663460 discloses a compensation film with a reflectivity of about 4-5%, but compared with the embodiments in Table 3, Patent I663460 does not clearly explain what factors cause the difference in reflectivity, so those skilled in the art do not know how to implement it.

[0005] On the other hand, both the half-phase compensation coating and the quarter-phase compensation coating of optical rotation in patent I663460 use anisotropic liquid crystal (also known as a liquid crystal phase delay layer). Currently, assembling touch-sensing electrodes on displays as touch screens is an important human-machine interface. In order to make products thinner, touch-sensing electrodes are integrated into other components as much as possible. However, the anisotropic liquid crystal used in patent I663460 cannot be directly used as a substrate to bond and assemble with the touch sensing structure during the manufacturing process. An adhesive layer and / or substrate must be used as a supporting material to provide structural strength. This makes it impossible to reduce the thickness of the integrated touch-sensing electrode and anti-reflective sheet, which does not conform to the current trend of increasingly thinner displays. Therefore, it is necessary to improve this.

[0006] Furthermore, in the optical film industry, to achieve production efficiency and material compatibility, a combination of half-wave plates (HWP) and quarter-wave plates (QWP) of the same material type is typically used. For example, patent I66346 uses the same liquid crystal material to fabricate both the half-wave and quarter-wave plates. Admittedly, some documents have disclosed, in a general sense, optical film combinations of polymer-stretched half-wave and quarter-wave plates. However, prior to this application, no literature truly taught or suggested using optical film combinations of different material types from the perspectives of problem-solving, integrating optical effects and electrical signal functions, and integrating the two components in the manufacturing process.

[0007] Therefore, in view of the above-mentioned deficiencies, the present invention was developed. Summary of the Invention

[0008] The purpose of this invention is to provide an integrated touch module, wherein the integrated touch module is composed of an electrical signal processing element (touch sensing structure) and an optical element (phase delay layer / polarizing layer). The two elements with different characteristics / functions can be combined without compromising their respective characteristics, while also making the product thinner and meeting the requirements of integration, thereby realizing a flexible and ultra-thin integrated touch module.

[0009] Another object of the present invention is to provide an integrated touch module in which the circularly polarizing element included in the integrated touch module has an average reflectivity of less than 5% and a standard deviation of reflectivity of less than 0.2% in the visible light range. This enables an integrated touch module with high and uniform anti-reflectivity across a wide wavelength range. The wide wavelength range refers to covering the visible light range (450nm-675nm), meaning that the integrated touch module of the present invention has uniform and consistent phase delay characteristics and low reflectivity throughout the entire visible light range.

[0010] Another object of the present invention is to provide an integrated touch module, wherein the polymer film of the integrated touch module can be used directly as a substrate to form a touch sensing structure thereon without the need for a separate substrate, and the polymer film can retain its original optical properties after the manufacturing process of the touch sensing structure.

[0011] The integrated touch module of the present invention includes: a nanometer silver wire touch sensing structure formed on a polymer film, wherein the polymer film has a phase retardation value between 100nm and 160nm at a wavelength of 550nm; wherein the polymer film, a liquid crystal phase retardation layer and a linear polarizing layer constitute a circular polarizing element, wherein the circular polarizing element has an average reflectivity of less than 5% and a standard deviation of reflectivity of less than 0.2% in the visible light range.

[0012] Preferably, in the integrated touch module according to the present invention, the integrated touch module has an average reflectivity of less than 6% and a standard deviation of reflectivity of less than 0.4% in the visible light range.

[0013] Preferably, in the integrated touch module according to the present invention, the average reflectivity of the circular polarizing element in the 450nm-500nm wavelength range is less than 6%, and the difference between the average reflectivity of the circular polarizing element in the 450nm-500nm wavelength range and the reflectivity at 550nm wavelength is less than 5%. Alternatively, the average reflectivity of the circular polarizing element in the 450nm-500nm wavelength range is less than 6%, and the difference between the average reflectivity of the circular polarizing element in the 450nm-500nm wavelength range and the reflectivity at 550nm wavelength is less than 4.5% or less than 3.5%.

[0014] Preferably, in the integrated touch module according to the present invention, the difference in reflectance between the average reflectance of the circular polarizer in the 450nm-500nm wavelength range and the average reflectance in the 525nm-675nm wavelength range is less than 10%. Alternatively, the difference in reflectance between the average reflectance of the circular polarizer in the 450nm-500nm wavelength range and the average reflectance in the 525nm-675nm wavelength range is less than 7% or less than 5.5%.

[0015] Preferably, in the integrated touch module according to the present invention, the polymer film can withstand the process temperature of the silver nanowire touch sensing structure.

[0016] Preferably, in the integrated touch module according to the present invention, the glass transition temperature of the polymer film is greater than or equal to the highest process temperature at which the nano-silver wire touch sensing structure is fabricated on the polymer film.

[0017] Preferably, in the integrated touch module according to the present invention, the polymer film is a positively dispersed phase retardation layer with a thickness of approximately 25 μm; the liquid crystal phase retardation layer is a positively dispersed phase retardation layer with a thickness of approximately 2 μm; the optical axis difference between the polymer film and the liquid crystal phase retardation layer is approximately 60 degrees; and the phase retardation value of the liquid crystal phase retardation layer at a wavelength of 550 nm is between 230 nm and 310 nm.

[0018] Preferably, in the integrated touch module according to the present invention, the maximum process temperature of the nano-silver wire touch sensing structure is 135-140°C, the main component of the polymer film is methyl methacrylate (PMMA), cyclic olefin polymer (COP), polycarbonate (PC), polyethylene terephthalate (PET), colorless polyimide (CPI) or derivatives of the above compounds, and its glass transition temperature is greater than or equal to 135-140°C.

[0019] Preferably, in the integrated touch module according to the present invention, the nano-silver wire touch sensing structure includes: a nano-silver wire electrode layer disposed between the polymer film and the liquid crystal phase delay layer.

[0020] Preferably, in the integrated touch module according to the present invention, the nano-silver wire touch sensing structure includes: two nano-silver wire electrode layers, wherein the nano-silver wire electrode layers are respectively disposed on the upper surface and the lower surface of the phase polymer positive dispersion phase retardation layer.

[0021] Preferably, the integrated touch module according to the present invention further includes: a linear polarizing layer disposed above the phase delay layer.

[0022] Furthermore, the present invention provides a touch display device, comprising: a display panel having a viewing area; and the aforementioned integrated touch module disposed on the display panel, wherein the touch sensing structure of the touch module overlaps with the viewing area.

[0023] Preferably, in the touch display device according to the present invention, the touch 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 is not limited thereto. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a circular polarizer receiving incident light from the external environment, illustrating the principle of anti-reflection.

[0025] Figure 2 Plot the reflectance spectrum of the first comparative example against the entire wavelength.

[0026] Figure 3 This is a schematic diagram of the integrated touch module according to the first embodiment of the present invention;

[0027] Figure 4 This is a spectral curve of the reflectance versus wavelength of the circularly polarized element according to the first embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram of the structure of a display device according to a preferred embodiment of the present invention. Detailed Implementation

[0029] The advantages, features, and methods of achieving the present invention will become apparent from the following description of exemplary embodiments of the invention with reference to the accompanying drawings. However, it should be noted that the present invention is not limited to the following exemplary embodiments, but can be implemented in various forms.

[0030] The terminology used herein is for illustrating specific embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms of the terms “a” and “described” as used herein also include the plural forms.

[0031] Furthermore, it should be understood that when one element is referred to as being "on" another element, the element may be directly on the other element, or there may be an intermediate element. Additionally, the thickness values ​​referred to herein are not absolute; those skilled in the art will understand that the thickness may include manufacturing tolerances, measurement errors, etc. Preferably, the thicknesses listed herein may have a range of 10% or 20%.

[0032] It should also be understood that although terms such as "first," "second," etc., may be used herein to describe various elements, these elements should not be limited to these terms. These terms are used only to distinguish individual elements. Therefore, a first element in some embodiments may be referred to as a second element in other embodiments without departing from the teachings of the invention. In this specification, the same reference numerals denote the same elements. Furthermore, optical elements will be used interchangeably herein with terms such as "plate," "layer," "film," or other similar terms, unless otherwise specified, and these are merely differences in name.

[0033] It is worth mentioning that, since this invention relates to the phase retardation value of phase retardation materials, the measurement method will be described first below. In this embodiment, the phase retardation value measured on a plane perpendicular to the thickness direction of the object under test is called the in-plane retardance / retardation (R0). This embodiment uses a commercially available device, AxoScan (manufacturer Axometrics, Inc.), to measure the in-plane phase retardation value of the object under test within the visible light wavelength range. For data simplicity, this document only records specific wavelengths, such as starting from 450 nm and recording every 25 nm up to 675 nm. That is, the visible light wavelength range referred to herein is 450 nm to 675 nm, and the wide-bandwidth term in this invention can also be understood as the wavelength range of 450 nm to 675 nm.

[0034] This invention provides a first comparative example of an integrated touch module, comprising: a polymeric phase retardation layer and a touch sensing structure disposed on the polymeric phase retardation layer. As mentioned earlier, in order to integrate the electrical signal processing element (touch sensing structure) and the optical element (polymeric phase retardation layer), that is, the touch sensing structure is directly formed on the polymeric phase retardation layer without the need for an additional substrate to support the touch sensing structure. The combination of the polymeric phase retardation layer and the linear polarizing layer / polarizing layer constitutes an anti-reflective optical element, which can be called a circular polarizer (or circular polarizing element). To achieve the aforementioned integration and product thinning objectives, a 45µm thick cyclic olefin polymer (COP) is selected as the polymeric phase retardation layer, which can serve as a quarter-phase compensation layer. Compared to currently commercially available polymeric stretched quarter-phase compensation layers, the 45µm thick cyclic olefin polymer (COP) reduces the thickness by 50%.

[0035] In addition, in some embodiments disclosed herein, the linear polarizing layer / polarizing layer may be a commercially available polarizing plate having a degree of polarization (DOP) greater than 98%, but is not limited thereto. The linear polarizing layer / polarizing layer may be two protective films (such as cellulose triacetate, TAC) fixing polyvinyl alcohol (PVA) material in the middle (referred to as Type A polarizing layer), or a combination of a single protective film (such as TAC) and polyvinyl alcohol (PVA) material (referred to as Type B polarizing layer). Both of these polarizing layers or any other form of polarizing layer are applicable to this invention and are not limited to the embodiments described.

[0036] According to the experimental method disclosed herein, incident light is incident on the test object (e.g., the combination of the aforementioned polymer phase retardation layer, touch sensing structure, and linear polarizing layer), then passes through a reflective surface, such as a semi-reflective mirror with approximately 55% reflectivity (manufacturer: 3D Lens), and then becomes reflected light after passing through the test object. The reflectivity (R%) in the visible light range can then be measured accordingly. Generally, international standards related to optical measurement mainly include ASTM D1003, CIE 130 1998, and ISO 13468. This paper adopts the framework of ASTM D1003 for measurement.

[0037] Please refer to Table 1 first. Figure 2 As shown, Figure 2 A spectrum of reflectance against the full wavelength (450 nm–675 nm) was plotted for the combination of the 45 μm thick cyclic olefin polymer (COP) used in the first comparative example and a type B polarizing layer. Table 1 extracts the reflectance spectrum. Figure 2The reflectance curve at a specific wavelength; as shown in Table 1, the average reflectance of the first comparative example in the visible light wavelength range is between 5% and 6%, while the standard deviation of the reflectance is as high as 1.21%. Clearly, the reflectance of the first comparative example in the visible light wavelength range varies significantly with wavelength. From the viewer's perspective, the reflectance at certain wavelengths will be particularly high, making it easy for the viewer to perceive a color shift in the display image. And from... Figure 2 Analysis reveals that the first comparative example exhibits high reflectivity in the short wavelength range of visible light. For instance, in the 450nm-500nm wavelength range, the average reflectivity is close to 7% (calculated by averaging the reflectivity at 450nm, 475nm, and 500nm in Table 1, approximately 6.9%. Unless otherwise specified, data in this article are calculated using a similar method). This means the first comparative example reflects incident light in the 450nm-500nm wavelength range, making it visible to the viewer. Based on the first comparative example, we found that with a thinner phase retardation layer of the same polymer material (comparing the 45µm thickness of the cyclic olefin polymer used in this example with other thicker commercially available products), high reflectivity (e.g., >6%) occurs in the short wavelength range. Furthermore, if we consider the 550nm wavelength as the central region of the visible light range, we can compare the average reflectance of the short wavelength range with the reflectance of the 550nm wavelength to understand whether there is a sudden change in reflectance. According to calculations, the average reflectance of the first comparative example in the 450nm-500nm wavelength range is quite different from that in the 550nm wavelength range, with a difference of about 55% (calculation formula: (6.9-4.47) / 4.47=54.4%). It is evident that the reflectance of the first comparative example changes suddenly in the short wavelength range. For the human eye, this would suddenly result in a large amount of reflected light appearing in the short wavelength range, thus causing poor and uneven viewing quality. Furthermore, if visible light is divided into two segments: the short wavelength range and the medium-long wavelength range, the change in reflectance can also be analyzed from the difference in average reflectance between the short wavelength range and the medium-long wavelength range. According to calculations, the average reflectance of the first comparative example in the 450nm-500nm wavelength range (i.e., the short wavelength range) is about 33% different from the average reflectance in the 525nm-675nm wavelength range (i.e., the medium-long wavelength range) (calculation formula: (6.9-4.63) / 6.9=32.9%), which shows that the reflectance of the first comparative example varies greatly in the two wavelength segments.

[0038] Table 1

[0039]

[0040] Table 2 shows the reflectance under specific visible light conditions obtained by fabricating a nano-silver wire touch sensing structure on a 45µm thick cyclic olefin polymer (COP) and combining it with a type B polarizing layer, using the test methods / equipment described above. The average and standard deviation of the reflectance in the visible light range are calculated accordingly. As shown in Table 2, the average reflectance in the visible light range is 5.91%, while the standard deviation is 0.81%. This means that even after integrating the optical film (i.e., the quarter-phase compensation layer of COP material) with the nano-silver wire touch sensing structure, the reflectance still varies significantly across wavelengths, especially in the short wavelength range where the average reflectance approaches 7%, causing uneven display quality (e.g., color shift). Therefore, regardless of whether a touch sensing structure is integrated, the problem of high reflectance in the short wavelength range observed in the first comparative example needs to be addressed.

[0041] Table 2

[0042]

[0043] Please see Figure 3 , Figure 3This is a schematic diagram of an integrated touch module according to a first embodiment of the present invention. The integrated touch module 100 according to the present invention includes: a polymer film 20, a touch sensing structure 30 disposed on the polymer film 20, a liquid crystal phase retardation layer 23, and a linear polarizing layer 10. The polymer film 20 and the liquid crystal phase retardation layer 23 constitute a phase retardation element. The phase retardation value R0(550) of the polymer film 20 at 550 nm can be between 100 nm and 160 nm, preferably at least 130 nm; the phase retardation value R0(550) of the liquid crystal phase retardation layer 23 at 550 nm can be between 230 nm and 310 nm, preferably at least 250 nm. Specifically, the polymer film 20 is a 25µm thick polycarbonate (PC) material (supplier: LONGHUA), with a phase retardation value of 131nm at 550nm. The phase retardation value measured by the polymer film 20 in the first embodiment of the present invention at an incident light wavelength of 550nm is extremely close to the ideal quarter-wavelength phase retardation value (138.75nm). Therefore, it can be determined that the polymer film 20 according to the first embodiment of the present invention can serve as a quarter-wavelength phase retardation layer and simultaneously as a substrate supporting the touch sensing structure 30. In one embodiment, the slow axis of the polymer film 20 is approximately 75 degrees. The liquid crystal phase retardation layer 23 is a single-layer liquid crystal coating, for example, made of commercially available Reactive Mesogen (RM) reactive liquid crystal, with a thickness of about 2 μm and a slow axis of about 15 degrees. Its phase retardation value at 550 nm is 260 nm. The phase retardation value measured by the liquid crystal phase retardation layer 23 of the first embodiment of the present invention at an incident light wavelength of 550 nm is very close to the ideal half-phase retardation value (275 nm). Therefore, it can be determined that the liquid crystal phase retardation layer 23 of the first embodiment of the present invention can be used as a half-phase retardation layer. In this embodiment, the optical axis (e.g., the aforementioned slow axis) difference between the polymer film 20 and the liquid crystal phase retardation layer 23 is about 60 degrees; the linear polarizing layer 10 is the aforementioned type B polarizing layer, which is a commercially available product SPN32-1805M (supplier: SAPO), and the liquid crystal phase retardation layer 23 is bonded to the linear polarizing layer 10 by polyvinyl alcohol (PVA) based water adhesive.

[0044] Furthermore, both the polymer film 20 and the liquid crystal phase retardation layer 23 exhibit positive dispersion. Positive dispersion here refers to the in-plane phase retardation value of the material decreasing with increasing wavelength. In other words, the material has a small in-plane phase retardation value at longer wavelengths (e.g., 650 nm) and a large in-plane phase retardation value at shorter wavelengths (e.g., 400 nm), meaning R0(650) / R0(400)>1. Combining the polymer film 20 and the liquid crystal phase retardation layer 23 results in negative dispersion, which produces an optical effect closer to the theoretical value. Negative dispersion here refers to the phase retardation value of the material increasing with increasing wavelength. It is worth noting that the positive and negative dispersion described in this embodiment are only approximate trends and not completely linear changes. The description of the linear polarizing layer 10 can be found above and will not be repeated here.

[0045] Please refer to Table 3 and Figure 4 As shown, Figure 4 Table 3 shows the spectral curves of reflectance versus wavelength obtained by the first embodiment of the present invention, consisting of a phase retardation element composed of a polymer film 20 and the aforementioned liquid crystal phase retardation layer 23, and a linear polarizing layer 10 (excluding the touch sensing structure 30), using the aforementioned testing method / equipment. Figure 4 The reflectance under specific visible light conditions, and the average value and standard deviation calculated accordingly; as shown in Table 3, the first embodiment of the present invention has a reflectance of 4.54% at an incident light wavelength of 550nm, an average reflectance of 4.51% in the visible light range, and a standard deviation of 0.17% in the visible light range. The low average reflectance and low standard deviation clearly demonstrate that the present invention can provide an anti-reflective sheet with low and uniform reflectance. Figure 4 The spectrum compared with the first comparative example mentioned above (i.e. Figure 2By comparison, it can be found that the first embodiment of the present invention has low reflectivity in the low-to-mid wavelength range of visible light. For example, in the wavelength range of 450nm-500nm, the average reflectivity is 4.7% (calculated from the data in Table 3). Therefore, it can be shown that the first embodiment of the present invention has good optical characteristics and a wide-range phase delay that meets the requirements of practical applications. Compared with the aforementioned comparative example, the average reflectivity of the optical layer (excluding the touch sensing structure 30) in this embodiment (without touch sensing structure 30) in the wavelength range of 450nm-500nm is quite small compared with the reflectivity in the wavelength range of 550nm (calculation formula: (4.7-4.54) / 4.54=3.5%). Compared with the first comparative example, the calculated difference is more than 10 times. It is evident that the reflectivity of this embodiment is quite uniform in the short wavelength range, and viewers will not suddenly perceive a large amount of obvious reflected light. If we calculate the difference between the average reflectance in the 450nm-500nm wavelength range (i.e., the short wavelength range) and the average reflectance in the 525nm-675nm wavelength range (i.e., the medium-long wavelength range) in this embodiment, the result is approximately 5.5% (calculation formula: (4.7-4.44) / 4.7=5.5%). Compared with the first comparative example, the difference between the two is significantly reduced, thus effectively improving the display quality.

[0046] Table 3

[0047]

[0048] Furthermore, according to the first embodiment of the present invention, the polymer film 20 can be used directly as a substrate, such as... Figure 3As shown, the touch sensing structure 30 of the first embodiment of the present invention may include a single-layer touch electrode layer. This single-layer touch electrode layer can be disposed on the polymer film 20, eliminating the need for a separate substrate and significantly reducing the thickness of the integrated touch module 100. This enables the realization of a flexible and ultra-thin integrated touch module and its products. Specifically, in this embodiment, a paste containing silver nanowires (SNW) (supplier: Cambrios) is coated onto the polymer film 20, and then, after baking, curing, and patterning steps, a silver nanowire electrode (not shown) is formed. Specific methods can be found in and fully incorporated in US20190227650A and CN101292362. The silver nanowire electrode has high transmittance, for example, a transmittance in the visible light range greater than approximately 88%, 90%, 91%, 92%, 93%, or higher. The formed silver nanowire electrodes are mainly located in the visible area for touch sensing. These electrodes must overlap with the wiring in the surrounding area to facilitate signal transmission with external circuits (such as an FPC). This can be achieved using general technology and will not be elaborated upon here. In addition to carrying the silver nanowire electrodes, the polymer film 20 preferably has high strength. This is because the wiring in the surrounding area and the wires on the FPC are typically connected using a hot-pressing process (bonding). The polymer film 20 must provide support to transfer the pressure from the hot-pressing die to the connection point (bonding area) to ensure a good bond between the wiring and the wires on the FPC. In one embodiment, the strength of the polymer film 20 is described by its elastic modulus, which is approximately between 2 and 72 GPa.

[0049] In one embodiment, the polymer film 20 must be able to withstand the process temperature for forming the aforementioned silver nanowire electrode, that is, the highest temperature during the process of forming the aforementioned silver nanowire electrode. Specifically, in this embodiment, the highest temperature used in the step of fabricating the silver nanowire electrode is approximately 135-140°C (considering equipment errors, environmental influences, etc.). The polymer film 20 must be selected from materials that can withstand a process temperature of 135-140°C to maintain its optical properties. More specifically, the material is usually selected based on the glass transition temperature of the polymer film 20. In one embodiment, the glass transition temperature of the polymer film 20 can be greater than or equal to a process temperature of 135-140°C to maintain its optical properties. The glass transition temperature of the polycarbonate (PC) polymer film 20 used in this embodiment is 137-140°C. It can be basically considered that the glass transition temperature of the polymer film 20 in this embodiment is equal to the process temperature for fabricating the silver nanowire electrode. It is worth noting that the above process temperatures are for illustrative purposes only and are not intended to limit the invention.

[0050] Nanowire electrodes (i.e., touch sensing structure 30) are fabricated on both sides of the polymer film 20 using the aforementioned method. Then, an optically transparent adhesive (OCA, not shown) is used to bond the liquid crystal phase retardation layer 23 and the linear polarizing layer 10 onto the polymer film 20, thus forming a structure as shown above. Figure 3 The integrated touch module 100 is shown. Table 4 shows the reflectance under specific visible light obtained by the test method / equipment described above in the first embodiment of the present invention, which fabricates a nano-silver wire touch sensing structure 30 on both sides of a polymer film 20, combined with a liquid crystal phase retardation layer 23 and a linear polarizing layer 10, and calculates the average value and standard deviation accordingly. As shown in Table 4, the reflectance of the first embodiment of the present invention is 5.87% when the incident light wavelength is 550nm, the average reflectance in the visible light range is 5.85%, and the standard deviation of the reflectance in the visible light range is 0.39%. The average reflectance of the integrated touch module 100 in this embodiment in the wavelength range of 450nm-500nm is quite small (about 2.2%) compared with the reflectance at 550nm wavelength. It is evident that the reflectance of this embodiment is quite uniform in the short wavelength range. Therefore, it is clear that the present invention can provide an integrated touch module 100 with low and uniform reflectance. It is worth noting that, because the nano-silver wire touch sensing structure 30 causes an increase in reflectivity, both the average and standard deviation of reflectivity are higher than those without the nano-silver wire touch sensing structure 30 (i.e., Table 3), but the increase is not significant and still meets the requirements of the final product. As mentioned earlier, the materials used in the half-phase compensation coating and the optically active quarter-phase compensation coating disclosed in Patent I663460 are liquid crystal materials. Liquid crystals cannot be directly used as substrates for molding the touch sensing structure 30 during the manufacturing process. Therefore, compared to Patent I663460, this invention proposes a feasible integration scheme of a touch sensing structure and a polymeric phase retardation layer, which has superior anti-ambient light reflection effects. Under this architecture, the touch sensing structure and the polymeric phase retardation layer can be combined with each other, and the process conditions of the touch sensing structure 30 will not affect the optical properties of the polymeric phase retardation layer. Furthermore, the polymeric phase retardation layer can also meet the requirements of the mounting substrate and provide strength in the hot-pressing process.

[0051] Table 4

[0052]

[0053] The following describes a second comparative example of the present invention, in which a polymer film 20 with a thickness of 15 μm (supplier: LONGHUA) is used. Because the film composition, thickness, and stretching conditions differ from the first embodiment, the glass transition temperature of the polymer film 20 in the second comparative example is 128-130°C, lower than the aforementioned process temperature of 135-140°C for fabricating the silver nanowire electrode. Other conditions are the same as in the aforementioned embodiment. After testing, it was found that the polymer film 20 in this comparative example cannot withstand the process temperature of the silver nanowire electrode. Therefore, the polymer film 20 in the second comparative example of the present invention... Figure 3 After the structure was completed, its reflectivity reached 21%, indicating that the polymer film 20 had lost its original optical properties. If the polymer film 20 of the second comparative example of the present invention was placed at 140°C for one hour to simulate the fabrication process of the silver nanowire electrode, and then its optical retardation value was measured, the experimental results showed that the optical retardation value was 2.05 (at a wavelength of 550 nm). This also proves that the polymer film 20 of the second comparative example of the present invention does not have an optical retardation effect after being subjected to high temperature (i.e., the test temperature exceeds its glass transition temperature).

[0054] It is worth noting that the first embodiment and the second comparative example of the present invention use polymer films made of the same main material, but have different glass transition temperatures. This application explains as follows: Since the polymer raw materials used in the first embodiment and the second comparative example come from different sources, and different suppliers will have different compositions, that is, the main components of the mold material in the first embodiment and the second comparative example are the same, but other components will be different, and the stretching conditions will also cause differences in the properties of the polymer film.

[0055] In addition to the polycarbonate (PC) used in the first embodiment described above, the present invention can be expected to use materials for the polymer membrane 20 based on the glass transition temperature of the polymer. For example, the main component of the polymer membrane 20 (i.e., at least >50% by weight) can be: methyl methacrylate (PMMA) with a Tg > 146°C, as published in the paper: Optical Poly(methylmethacrylate) copolymers Material with High Thermal Resistance (2017); or a commercially available cyclic olefin polymer (COP) product with a Tg = 165°C (supplier: Konica). The product is a commercially available colorless polyimide (CPI) product with a Tg > 180°C; a commercially available polyethylene terephthalate (PET) product with a Tg between 150-155°C or a derivative thereof as the main component, and the phase retardation value measured at a wavelength of 550 nm is between 100 nm and 200 nm, or at least 130 nm, or between 127 nm and 134 nm, 135 nm and 145 nm, 129 nm and 132 nm, or 130 nm and 131 nm, and the optical axis of the polymer film 20 is between 0 and 180 degrees, preferably 75 degrees. On the other hand, according to the present invention, the phase retardation value of the liquid crystal phase retardation layer 23 measured in the visible light range is between 200nm and 300nm, or may be between 200nm and 288nm, 237nm and 279nm, or 259nm and 271nm. The optical axis of the liquid crystal phase retardation layer 23 is between 0 and 180 degrees, preferably 15 degrees. It is understood that the above embodiments may be subject to the error of the measuring instrument, therefore the phase retardation value is only taken as an integer. Users can choose a measuring instrument with a smaller error range to measure the phase retardation value as needed. This is only an illustrative example, and the present invention is not limited thereto.

[0056] According to the first embodiment of the present invention, the thickness of the polymer film 20 is only about 25 μm, and the thickness of the liquid crystal phase retardation layer 23 is only about 2 μm, with a total thickness of 27 μm for the overall phase retardation element. The silver nanowire electrodes are of two types: one with driving / sensing electrodes fabricated on both sides of the polymer film 20, each driving / sensing electrode being 8.5 μm thick; and the other with driving / sensing electrodes fabricated on the same side of the polymer film 20, with a thickness of 10 μm. This thickness is advantageous for achieving a bendable, ultra-thin touch module. Therefore, the touch module and its product according to the embodiments of the present invention further have the advantage of being thinner.

[0057] The integrated touch module of the second embodiment of the present invention is described below. The difference between it and the first embodiment is that the polymer film 20 is a material with a thickness of 28 μm (supplier: Osaka Gas), the main component of which is polyethylene terephthalate (PET), the Tg is 151°C, and the phase delay value measured at a wavelength of 550 nm is 132 nm.

[0058] Compared to the aforementioned comparative example, the average reflectance of this embodiment in the 450nm-500nm wavelength range (approximately 5.6% after experimental data calculation) differs from the reflectance at 550nm wavelength by only 4.5%. This demonstrates that the reflectance of this embodiment is quite uniform in the short wavelength range, and viewers will not suddenly perceive a large amount of obvious reflected light. Furthermore, the difference between the average reflectance in the 450nm-500nm wavelength range (i.e., the short wavelength range) and the average reflectance in the 525nm-675nm wavelength range (i.e., the medium-long wavelength range) of this embodiment is approximately 7.0% according to the calculated result. Based on the average reflectance of this embodiment in the 450nm-500nm wavelength range, this application believes that both the integrated touch module of the second embodiment and the first embodiment can meet the requirement that the average reflectance of the circular polarizer in the visible light range is less than 5% and the standard deviation of the reflectance is less than 0.2%, and can also meet the requirement that the average reflectance of the integrated touch module in the visible light range is less than 6% and the standard deviation of the reflectance is less than 0.4%.

[0059] Furthermore, the integrated solution of the touch sensing structure and phase delay layer of the present invention exhibits a phase delay value change rate of less than 5% when subjected to a high temperature (85°C) environment for a long period (500 hours), demonstrating excellent weather resistance.

[0060] The following provides further examples of touch modules to enable those skilled in the art to more clearly understand possible variations. Elements represented by the same reference numerals as in the above embodiments are substantially the same as those referenced above. Figure 3 , Figure 4 The components, features, and advantages described in Figure 7 that are the same as those in the integrated touch module 100 will not be repeated hereafter.

[0061] The third embodiment of the present invention is compared to Figure 4 The difference lies in the fact that the touch sensing structure 30 of the integrated touch module 100 in this embodiment may include a first touch electrode layer (e.g., a driving layer) and a second touch electrode layer (e.g., a sensing layer). The first touch electrode layer and the second touch electrode layer are disposed on the same side of the polymer film 20, for example, on the side away from the display module, but are not limited thereto. The relevant descriptions of this embodiment can be found above and will not be repeated here.

[0062] It is understood that the placement of the touch sensing structure 30 will not significantly affect the average reflectivity of the integrated touch module 100 in the visible light range, and those skilled in the art to which this invention pertains can make various changes and adjustments based on the above examples, which will not be listed here.

[0063] The following describes an embodiment of the application of the touch module according to the present invention in a display device.

[0064] Please refer to Figure 5 , Figure 5 This is a schematic diagram of a display device according to a preferred embodiment of the present invention. The display device 300 includes a display panel 200 and an integrated touch module 100. The display panel 200 has a viewable area. The integrated touch module 100 is disposed on the display panel 200. The touch sensing structure 30 of the integrated touch module 100 substantially overlaps with the viewable area. Specifically, the display panel 200 may be, but is not limited to, a liquid crystal display (LCD), an organic electroluminescent display panel, an organic light-emitting diode display panel, or a micro-light-emitting diode display (μLED display); in addition, a cover plate 400 is attached to the linear polarizing layer 10 by means of optical adhesive (not shown). The integrated touch module 100 has been discussed above and will not be repeated here.

[0065] Finally, the technical features of the present invention and the technical effects it can achieve are summarized as follows:

[0066] I. According to the integrated touch module 100 of the present invention, the circular polarizing element has an average reflectivity of less than 6% and a standard deviation of less than 2 in the visible light range, thereby achieving good optical characteristics and providing an integrated touch module and its products that meet the needs of practical applications.

[0067] Second, the polymer film 20 of the integrated touch module 100 according to the present invention can be used directly as a substrate without the need for a separate substrate, thus realizing a flexible and ultra-thin integrated touch module. Furthermore, the polymer film 20 of the present invention, combined with the liquid crystal phase retardation layer 23, has excellent optical properties and a wide-bandgap phase retardation characteristic, meeting the requirements of practical applications.

[0068] The above description of specific embodiments illustrates the implementation of the present invention. 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.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes or modifications made without departing from the spirit of the invention should be included within the scope of the following claims.

Claims

1. An integrated touch module, characterized in that, include: A silver nanowire touch sensing structure is formed on a polymer film, wherein the polymer film has a phase retardation value between 100nm and 160nm at a wavelength of 550nm. The polymer film, a liquid crystal phase retardation layer, and a linear polarizing layer constitute a circular polarizing element. The phase retardation value of the liquid crystal phase retardation layer at a wavelength of 550nm is between 230nm and 310nm. The average reflectivity of the circular polarizing element in the wavelength range of 450nm-675nm is less than 5%, and the standard deviation of the reflectivity is less than 0.2%.

2. The integrated touch module according to claim 1, characterized in that, The integrated touch module has an average reflectivity of less than 6% in the visible light range and a standard deviation of less than 0.4% for the reflectivity.

3. The integrated touch module according to claim 1, wherein, The average reflectance of the circular polarizing element in the 450nm-500nm wavelength range differs from that in the 550nm wavelength range by less than 5%.

4. The integrated touch module according to claim 1, characterized in that, The polymer film can withstand the process temperature of the silver nanowire touch sensing structure.

5. The integrated touch module according to claim 4, characterized in that, The glass transition temperature of the polymer film is greater than or equal to the highest process temperature at which the nano-silver wire touch sensing structure is fabricated on the polymer film.

6. The integrated touch module according to claim 1, characterized in that, The maximum process temperature of the nano-silver wire touch sensing structure is 135-140℃. The main components of the polymer film are methyl methacrylate (PMMA), cyclic olefin polymer (COP), polycarbonate (PC), polyethylene terephthalate (PET), colorless polyimide (CPI), or derivatives of the above compounds, and its glass transition temperature is greater than or equal to 135-140℃.

7. The integrated touch module according to claim 1, characterized in that, The polymer film is a positively dispersed phase retardation layer with a thickness of 25 μm; the liquid crystal phase retardation layer is a positively dispersed phase retardation layer with a thickness of 2 μm, wherein the optical axis difference between the polymer film and the liquid crystal phase retardation layer is 60 degrees.

8. The integrated touch module according to claim 1, characterized in that, The silver nanowire touch sensing structure includes: A silver nanowire electrode layer is disposed between the polymer film and the liquid crystal phase delay layer; or the silver nanowire touch sensing structure includes two silver nanowire electrode layers, which are respectively disposed on the upper and lower surfaces of the polymer film.

9. The integrated touch module according to claim 1, characterized in that, The difference between the average reflectance of the circular polarizing element in the 450nm-500nm wavelength range and the average reflectance in the 525nm-675nm wavelength range is less than 10%.

10. A touch display device, characterized in that, include: A display panel having a viewing area; as well as The integrated touch module according to any one of claims 1 to 9 is disposed on the display panel, wherein the nano-silver wire touch sensing structure of the integrated touch module overlaps with the visible area.

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