KR20230081577A - Integrated touch module and touch display device having the same - Google Patents

Abstract

Provided are an integrated touch module and a touch display device. The integrated touch module has a touch detection structure formed on a polymer film. The polymer film, a liquid crystal phase delay layer, and a linearly polarizing layer are configured with a circularly polarizing element. An average reflection factor of the circularly polarizing element in a visible light range is less than 5 % and a standard deviation of the reflection factor is less than 0.2 %. The touch display device comprises the integrated touch module.

Description

Integrated touch module and touch display device having the same

The present disclosure relates to an integrated touch module and a touch display device including the same, and particularly to an ultra-thin integrated type touch control module that is bendable and has broadband optical performance, and an integrated touch It relates to a touch display device including a module.

Current circular polarizers (CPOLs) mainly have a retarder and a linear polarizer, which are often used as antireflection films in the display field to solve display problems caused by reflection of incident light from the external environment. It may be a quarter wave plate (QWP). 1 is a schematic diagram showing an antireflection sheet that receives incident light from an external environment. As shown in FIG. 1, theoretically, when incident light L from the outside passes through the outermost linear polarization layer 10a, the linear polarization layer 10a converts the incident light L into linear polarization incident light L1, After the polarization direction of the linearly polarized incident light L1 becomes perpendicular, the linearly polarized incident light L1 enters the 1/4 wave plate used as the retarder 20a, causing the linearly polarized incident light L1 to phase retard, and the linearly polarized incident light L1 to be phase delayed. (L1) is converted to left polarization (Lcl). Then, when this light is reflected by the display panel 200, it will form reverse right polarization (Lcr), and then it will pass through the 1/4 wave plate used as the retarder 20a, resulting in linearly polarized incident light. The polarization direction of (L2) and the polarization direction of the linearly polarized incident light L1 finally become orthogonal, so that the incident light from the external environment cannot pass through the linearly polarized layer 10a and is blocked by the circularly polarized plate. In the above principle, the antireflection sheet that circularly polarizes the external ambient light is the first step of the above-mentioned antireflection mechanism, so the circular polarization of the external ambient light is one of the important factors of the antireflection effect, but in practice the antireflection mechanism in the entire visible light range. this cannot happen Since all incident light inside is not circularly polarized, ambient light of a specific wavelength is still reflected by the display panel 200, causing interference when a user views the screen.

Taiwan Patent No. 1663460 (hereinafter referred to as Patent 1663460) discloses a broadband compensation laminate comprising a chiral-half-wave phase compensation coating film and a chiral quarter-wave phase compensation coating film. . The chiral quarter-wavelength phase compensation cutting film and the chiral half-wavelength phase compensation coating film are in direct contact with each other. The broadband compensation laminate disclosed in Patent I663460 is a technical solution proposed to solve the above-mentioned problem of reflected light. For example, it is stated in paragraph [0014] of patent I663460 that “the ability of a compensation film to convert circularly polarized light is a broadband compensation film”.

However, the reflectance of the broadband compensation film of patent I663460 in the visible light range is still too high to effectively eliminate the reflection of ambient light. For example, as shown in Table 3 of patent I663460, the reflectance of the compensation film of patent I663460 under wavelengths of 450 nm, 550 nm, and 650 nm is about 8%. Since the circular polarizer is mainly used for anti-reflection of ambient light, the higher the reflectivity, the worse the anti-reflection effect of ambient light, which affects the display effect of the terminal product and interferes with reading. Reflection under heavy external light. may occur. The applicant of patent I663460 believes that the reflectance (8%) of the broadband compensation film in the visible light range can meet increasingly sophisticated display requirements, especially the current high-resolution and high-quality videos, such as 4K and 8K video, which have been favored by users. I see you can't It is worth noting that Table 4 of patent I663460 discloses a broadband compensation film having a reflectivity of about 4% to 5%. However, compared to the example in Table 3, patent 1663460 does not clearly specify the factor causing the difference in reflectance, so that those skilled in the art do not know how to implement it.

On the other hand, the materials of the chiral half-wavelength phase compensation coating film and the chiral quarter-wavelength phase compensation coating film of Patent I663460 are all made of an anisotropic liquid crystal (also referred to as a liquid crystal phase retardation layer). As a current touch display screen, assembling touch sensing electrodes on a display is one of the important human-machine interfaces. To make the product thinner, touch-sensing electrodes will be integrated and fabricated on other components where possible, and patent I663460 uses an anisotropic liquid crystal that cannot be used directly as a substrate to support the touch-sensing structure during the fabrication process. In other words, the adhesive layer and/or the supporting substrate must be used as a carrier material to provide the strength of the mechanism. Therefore, the thickness of the integrally combined touch sensing electrode and antireflection film cannot be reduced, which does not follow the current trend of increasingly thinner and lighter displays.

In addition, in the optical film industry, a half-wavelength phase compensation layer (or half-wave plate (HWP)) and a quarter-wavelength phase compensation layer (or 1/4) are used to achieve production efficiency and consider material adaptability. The quarter-wave plate (QWP) is made of the same material type. For example, patent 166346 uses the same liquid crystal material to prepare a chiral half-wave phase compensation layer and a chiral quarter-wave phase compensation layer. Prior to this application, there was no document teaching or recommending the use of a combination of optical films using different materials from the viewpoint of solving the problem of how to integrate elements with optical effects and electrical signal functions and how to manufacture an integration of the two components. There was no

Accordingly, the present disclosure has been provided in view of the above problems.

An object of the present disclosure is to provide an integrated touch module, which is integrated by an electrical signal processing element (touch sensing structure) and an optical element (phase retardation layer/polarization layer). Two components with different characteristics/functions will not damage each characteristic when matched, and the two components can make the product thinner at the same time to meet the integration requirements, so that the bendable and ultra-thin integrated touch module can be realized.

Another object of the present disclosure is to provide an integrated touch module, wherein the average reflectance of the circular polarization element in the visible light range is less than 5% and the standard deviation of the reflectance is less than 0.2%, so the integrated touch module has a high and uniform broadband anti-reflection function. this can be realized. The broadband range refers to a range covering the visible light range (450 nm to 675 nm), that is, the integrated touch module of the present disclosure has uniform and consistent phase delay characteristics and low reflection characteristics over the entire visible light range.

Another object of the present disclosure is to provide an integrated touch module, wherein a polymer film of the integrated touch module can be directly used as a substrate for forming a touch sensing structure on the polymer film. There is no need to additionally provide a substrate, and the polymer film can maintain its original optical properties after the manufacturing process of the touch sensing structure.

The integrated touch module of the present disclosure includes a silver nanowire touch sensing structure formed on a polymer film, the polymer film having a phase retardation value between 100 nm and 160 nm for a wavelength of 550 nm, the polymer film, a liquid crystal retardation layer and a linear polarization layer. constitutes a circular polarization element, and the average reflectance of the circular polarization element in the visible light range is less than 5%, and the standard deviation of the reflectance is less than 0.2%.

Preferably, according to the integrated touch module of the present disclosure, 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%.

Preferably, according to the integrated touch module of the present disclosure, the average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm is less than 6%, and the average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm and the wavelength of 550 nm The reflectance difference between the reflectances for the range is less than 5%. Alternatively, the average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm is less than 6%, and the difference in reflectance between the average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm and the reflectance in the wavelength range of 550 nm is less than 4.5% or less than 3.5%.

Preferably, according to the integrated touch module of the present disclosure, the reflectance difference between the average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm and the average reflectance in the wavelength range of 525 nm to 675 nm is less than 10%. Alternatively, the reflectance difference between the average reflectance of the circularly polarizing element in the wavelength range of 450 nm to 500 nm and the average reflectance in the wavelength range of 525 nm to 675 nm is less than 7% or less than 5.5%.

Preferably, according to the integrated touch module of the present disclosure, the polymer film is configured to withstand the process temperature of the silver nanowire touch sensing structure.

Preferably, according to the integrated touch module of the present disclosure, the glass transition temperature of the polymer film is equal to or greater than the highest process temperature for fabricating the silver nanowire touch sensing structure on the polymer film.

Preferably, according to the integrated touch module of the present disclosure, the polymer film is a positive dispersion type retardation layer with a thickness of about 25 μm, and the liquid crystal retardation layer is a positive dispersion type retardation layer with a thickness of about 2 μm. , and the optical axis difference between the polymer film and the liquid crystal phase retardation layer is about 60 degrees.

Preferably, according to the integrated touch module of the present disclosure, the highest processing temperature of the silver nanowire touch sensing structure is 135 ° C to 140 ° C, and the main component of the polymer film is methyl acrylate (PMMA), cycloolefin polymer (COP), polycarbonate (PC), polyethylene terephthalate (PET), colorless polyimide (CPI) or derivatives thereof, and the glass transition temperature of the polymer film is 135°C to 140°C or more.

Preferably, according to the integrated touch module of the present disclosure, the silver nanowire touch sensing structure includes a silver nanowire electrode layer disposed directly over the polymer film.

Preferably, according to the integrated touch module of the present disclosure, the silver nanowire touch sensing structure includes two silver nanowire electrode layers, and the two silver nanowire electrode layers are respectively arranged on the upper and lower surfaces of the polymer film.

Preferably, according to the integrated touch module of the present disclosure, the linear polarization layer is disposed over the liquid crystal phase retardation layer.

In addition, the present disclosure provides a display panel having a display area; and the above-described integrated touch module disposed on the display panel, wherein the silver nanowire touch sensing structure of the integrated touch module correspondingly overlaps the display area.

Preferably, according to the touch display device of the present disclosure, 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 disclosure is not limited to this.

In order to enable those skilled in the art to understand the objects, features, and effects of the present disclosure, the present disclosure will be described in detail with the following specific embodiments in conjunction with the accompanying drawings.

1 is a schematic diagram of a circular polarizing plate receiving incident light from an external environment to explain the principle of antireflection.
2 shows a reflectance spectrum curve of the reflectance of Comparative Example 1 for all wavelengths.
3 is a schematic diagram of an integrated touch module according to a first embodiment of the present disclosure.
4 is a spectral curve diagram of reflectance and wavelength of the circular polarization element of the first embodiment of the present disclosure.
5 is a schematic diagram of a structure of a display device according to a preferred embodiment of the present disclosure.

Hereinafter, exemplary embodiments according to the present disclosure will be described in more detail with reference to the accompanying drawings, and advantages, features, and methods for achieving the present disclosure will become apparent. However, it should be noted that the present disclosure may be implemented in various forms without being limited to the following exemplary embodiments.

Terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. Unless the context clearly dictates otherwise, the singular forms of the terms “a” and “the” as used herein also include the plural forms.

Also, it should be understood that when an element is referred to as being “on” another element, that element may be directly on the other element, or intervening elements may be present. Also, the thickness values mentioned in this disclosure are not absolute. One skilled in the art can understand that the stated thicknesses may include manufacturing tolerances, measurement errors, and the like. Preferably, the thicknesses listed in this disclosure may range from 10% or 20%.

Although the terms "first", "second", etc. may be used herein to describe various elements, it should also be understood that such elements should not be limited to these terms. This term is only used to distinguish each element. Thus, a first element in some embodiments may be referred to as a second element in other embodiments without departing from the teachings of this disclosure. Like reference numerals designate like elements in this specification. Also, optical element will be used interchangeably with "plate", "layer", "film" or other similar terms in this text unless otherwise specified.

Since the present disclosure relates to a phase retardation value of a phase retardation material, a measurement method will be described first. In an embodiment of the present disclosure, a phase retardation value measured on a plane perpendicular to the thickness direction of the object, that is, an in-plane retardance/delay (R0) is measured. Embodiments of the present disclosure use AxoScan (manufacturer Axometrics, Inc.), a commercial device with a model that measures the in-plane phase retardation value of an object in the visible light wavelength range. For brevity of the data, a specific wavelength from 450 nm is recorded once for each 25 nm up to an in-plane phase retardation value of eg 675 nm. That is, the visible light wavelength range referred to in this specification is 450 nm to 675 nm, and the so-called broadband range in the present disclosure can also be understood as a wavelength range of 450 nm to 675 nm.

The present disclosure provides a first comparative example of an integrated touch module. An integrated touch module includes a polymer phase retardation layer and a touch sensing structure disposed on the polymer phase retardation layer. As described above, in order to integrate the electrical signal processing element (touch sensing structure) and the optical element (polymer phase retardation layer), the touch sensing structure is directly placed on the polymer phase retardation layer without the need for an additional substrate on which the touch sensing structure is mounted. formed above The combination of a polymer phase retardation layer and a linear polarization layer/polarization layer can constitute an antireflection optical element, which may be referred to as a circular polarizer (or circular polarization element). To achieve the above-mentioned purpose of integration and product thinning, the polymer phase retardation layer uses a 45 μm thick cycloolefin polymer (COP), which can be used as a quarter phase compensation layer. Compared to the commercially available polymer stretch type 1/4 phase compensation layer, the thickness of the cycloolefin polymer (COP) with a thickness of 45 μm was reduced by 50%.

Further, in one embodiment of the present disclosure, the linear polarization layer/polarization layer may be a generally commercially available polarizing plate having a degree of polarization (DOP) greater than 98%, but the present disclosure is not limited thereto. The linear polarization layer/polarization layer includes two protective films (eg, cellulose triacetate (TAC)) with polyvinyl alcohol (PVA) fixed in the middle (referred to as a type A polarization layer), or a single protective film (eg, TAC) and It may be a combination of polyvinyl alcohol (PVA) materials (abbreviated as polarization layer of type B polarization layer). The above two polarization layers or any other type of polarization layer may be applied to the present disclosure, and the present disclosure is not limited to this embodiment.

According to the experimental method of the present disclosure, the incident light used enters the object under the test (eg, the combination of the aforementioned polymer phase retardation layer, the touch sensing structure, and the linear polarization layer), and then has a reflectivity of, for example, about 55%. After passing through a reflective surface such as a partial mirror (manufacturer: 3D Lens) and then passing through this object to reflect light, the reflectance (R%) in the visible light range can be measured. In general, international standards related to optical measurements mainly include ASTM D1003, CIE 130 1998, and ISO 13468. This disclosure uses the structure of ASTM D1003 for measurements.

Table 1 and Figure 2 are referenced. FIG. 2 shows a reflectance spectrum curve of a combination of a B-type polarizing layer and a 45 μm-thick cycloolefin polymer (COP) used in Comparative Example 1 for all wavelengths (i.e., 450 nm to 675 nm). The reflectances in Table 1 are captured from the curves in FIG. 2 at specific wavelengths. As shown in Table 1, the average reflectance of Comparative Example 1 in the visible light wavelength range is between 5% and 6%. The standard deviation of reflectance is about 1.21%. It is clear that the reflectance of Comparative Example 1 in the visible light wavelength range greatly varies with the wavelength. From an observational point of view, the reflectivity of a particular wavelength will be particularly high, and it is easily observed that there is a color shift on the display screen. It can be seen from FIG. 2 that high reflectance often disappears in the short wavelength range of visible light in Comparative Example 1. For example, in the wavelength range of 450 nm to 500 nm, the average reflectance is close to 7% (calculated from the reflectances of 450 nm, 475 nm, and 500 nm in Table 1, the average percentage is about 6.9%. Unless otherwise specified in the present disclosure, The data below are calculated in a similar way), which means that Comparative Example 1 will reflect incident light having a wavelength of 450 nm to 500 nm for observation. According to the first comparative example, it can be seen that the thickness of the phase retardation layer of the same polymer material is smaller (comparing the cycloolefin polymer with a thickness of 45 μm selected in this example with other thicker commercial products). A high reflectance (eg >6%) problem occurs in the wavelength range. Further, if the 550 nm wavelength is regarded as the central region of the visible light range, the average reflectance of the short wavelength range can be compared with the reflectance of the 550 nm wavelength to understand if there is an abrupt change in the reflectance. According to the calculation, the average reflectance of the first comparison under the wavelength range of 450 nm to 500 nm is significantly different from the reflectance under the wavelength of 550 nm, and the difference is about 55% (calculation formula: (6.9-4.47)/4.47=54.4%). The reflectance in Comparative Example 1 in the short wavelength range (i.e., 450 nm to 500 nm) will suddenly change, and the human eye will suddenly feel a large amount of reflected light in the short wavelength range, which leads to poor viewing quality and non-uniformity. It is clear that this will result in poor display performance. In addition, if visible light is divided into two sections, that is, a short wavelength range and a mid-long wavelength range, the change in reflectance can also be analyzed from the average reflectance difference between the short wavelength range and the mid-long wavelength range. According to the calculation, the difference between the average reflectance of Comparative Example in the wavelength range of 450 nm to 500 nm (short wavelength range) and the average reflectance in the wavelength range of 525 nm to 675 nm (mid-long wavelength range) is about 33% (calculation formula: (6.9)-4.63 )/6.9=32.9%). It is evident that the reflectance of Comparative Example 1 has a large change in the two wavelength ranges of visible light.

Wavelength (nm) Reflectance ( % ) 450 8.20 475 6.83 500 5.69 525 4.90 550 4.47 575 4.31 600 4.35 625 4.53 650 4.78 675 5.1 average 5.31 Standard Deviation 1.21

Table 2 shows the reflectance of a silver nanowire touch sensing structure fabricated on a 45 μm cycloolefin polymer (COP) having a thickness of 45 μm and then combined with a B-type polarizing layer, which is consistent with the above-described test method/equipment under a specific visible light. It is measured according to and shows the average value and standard deviation of the reflectance. As shown in Table 2, the average reflectance in the visible light range is 5.91% and the standard deviation of the reflectance in the visible light range is 0.81%. In other words, after integrating an optical film (ie, a quarter-wavelength phase compensation layer of COP material) and a silver nanowire touch-sensing structure, the reflectivity varies greatly with wavelength. In particular, in the short wavelength range, since the average reflectance is close to 7%, a problem of non-uniform display quality (eg, color shift, etc.) occurs. That is, the problem of high reflectance in the short wavelength range found in the first comparative example needs to be solved regardless of the presence or absence of the integrated touch sensing structure.

Wavelength (nm) Reflectance ( % ) 450 7.75 475 6.65 500 5.99 525 5.38 550 4.89 575 5.00 600 5.35 625 5.73 650 6.13 675 6.22 average 5.91 Standard Deviation 0.81

Reference is made to FIG. 3 which is a schematic diagram of the integrated touch module 100 according to the first embodiment of the present disclosure. An integrated touch module 100 according to the present disclosure 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 polarization layer 10. . The polymer film 20 and the liquid crystal phase retardation layer 23 constitute a phase retardation element. The phase retardation value R ₀ (550) of the polymer film 20 at 550 nm may be between 100 nm and 160 nm, preferably at least 130 nm. The phase retardation value R ₀ (550) of the liquid crystal phase retardation layer 23 at 550 nm may be between 230 nm and 310 nm, preferably at least 250 nm. Specifically, the polymer film 20 is a polycarbonate (PC) material (supplier: LONGHUA) with a thickness of 25 μm, and the phase retardation value at 550 nm is 131 nm. The measured phase retardation value of the polymer film 20 measured when the incident light wavelength is 550 nm is very close to the ideal 1/4 wavelength retardation value (138.75 nm). As such, it can be determined that the polymer film 20 according to the first embodiment of the present disclosure can be used as a 1/4 phase retardation layer and can be used as a substrate supporting the touch sensing structure 30 . In one embodiment, the slow axis of the polymer film 20 is about 75 degrees. The liquid crystal phase retardation layer 23 is, for example, a single layer of liquid crystal coating made of RM (Reactive Mesogen) reactive liquid crystal, which is a commercially available product. The thickness is about 2 μm, the slow axis is about 15 degrees, and the phase retardation at 550 nm is 260 nm. When the incident light wavelength of the liquid crystal phase retardation layer 23 of the first embodiment of the present disclosure is 550 nm, the measured phase retardation value is very close to the ideal 1/2 retardation value (275 nm). Thus, it can be determined that the liquid crystal phase retardation layer 23 according to the first embodiment of the present disclosure can be used as an antiphase phase retardation layer. In this embodiment, the optical axes of the polymer film 20 and the liquid crystal phase retardation layer 23 (eg, the aforementioned slow axis) differ by about 60 degrees. The linear polarization layer 10 is the above-described B-type polarization layer, which is a commercial product SPN32-1805M (supplier: SAPO), and the liquid crystal phase retardation layer 23 is a linear polarization layer using polyvinyl alcohol (PVA) water glue ( 10) is attached.

In addition, both the polymer film 20 and the liquid crystal phase retardation layer 23 have positive dispersion characteristics. In this specification, positive dispersion means an in-plane retardation value of a material. As the wavelength increases, the retardation value of a material decreases. In addition, it may be said that the phase retardation value of the material on the plane of long wavelength (eg, 650 nm) is smaller than the phase retardation value of the material on the plane of short wavelength (eg, 400 nm). In other words, R ₀ (650)/R ₀ (400)<1. The combination of the polymer film 20 and the liquid crystal phase retardation layer 23 can obtain negative dispersion characteristics, and the optical effect exhibited by the negative dispersion characteristics will be closer to the theory. Here, negative dispersion means that the retardation value of a material increases as the wavelength increases. It is worth mentioning that the forward variance and backward variance in this example are not perfectly linear changes, but only approximate trends. The description of the linear polarization layer 10 described above will not be repeated here.

See Table 3 and Figure 4. 4 uses the method/equipment described above to measure a phase retardation element having a polymer film 20, a liquid crystal retardation layer 23 and a linear polarization layer 10 (excluding the touch sensing structure 30). The spectral curves of reflectance and wavelength of the first embodiment of the present disclosure, obtained by Table 3 is an average value and standard deviation calculated based on the reflectance of FIG. 4 under a specific visible light. As shown in Table 3, the reflectance of the first embodiment of the present disclosure when the incident light wavelength is 550 nm is 4.54%, the average reflectance in the visible light range is 4.51%, and the standard deviation of the reflectance in the visible light range is 0.17%. From the low average reflectance and low reflectance standard deviation, it is clear that the present disclosure can provide an antireflection sheet having a low and uniform reflectance. From the comparison between the spectra of FIG. 4 and the above-described first comparative example (i.e., FIG. 2), the first embodiment of the present disclosure has a low wavelength in the medium to low wavelength range of visible light, for example, in the wavelength range of 450 nm to 500 nm. reflectance, and it can be seen that the average reflectance is 4.7% (calculated from the data in Table 3), so that the first embodiment of the present disclosure has good optical properties and has broadband low reflectance performance to meet practical application requirements. can know that Compared with the comparative example described above, the difference between the average reflectance of the optical layer (excluding the touch sensing structure 30) in the wavelength range of 450 nm to 500 nm and the reflectance at the wavelength of 550 nm of this embodiment is very small (calculation formula: (4.7-4.54)/4.54=3.5%). Compared with Comparative Example 1, the calculated difference value is as much as 10 times. It is evident to the viewer that the reflectivity of this example is very uniform in the short wavelength range, which is very good. In other words, there will not be a sudden large amount of obvious reflected light. When the difference between the average reflectance of the 450 nm to 500 nm wavelength range (short wavelength range) and the average reflectance of the 525 nm to 675 nm wavelength range (mid-long wavelength range) in this embodiment is calculated, the calculation result is approximately 5.5% (calculation formula: (4.7- 4.44)/4.7=5.5%). Compared to Comparative Example 1, the difference between the two average reflectance values in the two defined ranges is greatly reduced, so that the display quality is also effectively improved.

Wavelength (nm) Reflectance ( % ) 450 4.83 475 4.74 500 4.49 525 4.37 550 4.54 575 4.31 600 4.38 625 4.47 650 4.37 675 4.66 average 4.51 Standard Deviation 0.17

Also, according to the first embodiment of the present disclosure, the polymer film 20 can be directly used as a substrate. As shown in FIG. 3 , the touch sensing structure 30 of the first embodiment of the present disclosure may include a single layer of touch electrode layers. Since a single-layered touch electrode layer can be disposed on the polymer film 20 without an additional substrate, the thickness of the integrated touch module 100 can be greatly reduced, so that a bendable and ultra-thin integrated touch module and product can be realized. Specifically, in this embodiment, after a slurry containing a silver nanowire (SNW) and/or an overcoat (OC) resin (supplier: Cambrios) is directly coated on the polymer film 20, baking , After curing and patterning (not shown), silver nanowire electrodes are formed, and specific methods may be introduced with reference to US20190227650A, CN101292362, etc., which are incorporated herein by reference. The silver nanowire electrode has a high transmittance, for example greater than about 88%, 90%, 91%, 92%, 93%, or higher percentage transmittance in the visible light range. The formed silver nanowire electrodes are mainly located in the visible region for sensing a touch, and the silver nanowire electrodes are located in the surrounding area to facilitate connection with an external circuit (eg, flexible printed circuit (FPC)) for signal transmission. It must be connected to the wiring of the area. This can be accomplished using general techniques not repeated here. The silver nanowire electrodes are mounted on the polymer film 20, which preferably has high strength since the wires in the peripheral area and the wires on the FPC are generally connected by a hot pressing process (i.e., a bonding process). have The polymer film 20 must provide a supporting force capable of transferring the pressure of hot pressing to the junction (ie, bonding area) so that the wires and wires on the FPC can be well fixed. In an embodiment, the strength of the polymer film 20 is described by an elastic modulus that is between approximately 2 GPA and 72 GPa.

In an embodiment, the polymer film 20 must be able to withstand the process temperature for forming the silver nanowire electrode described above, that is, the highest temperature in the process for forming the silver nanowire electrode described above. Specifically, in this embodiment, the highest temperature used in the step of manufacturing the silver nanowire electrode is about 135° C. to 140° C. (considering the variation of equipment, the influence of the surrounding environment, etc.), and the polymer film 20 has the optical properties of the material. It needs to be selected to withstand processing temperatures of 135° C. to 140° C. to maintain properties. More specifically, the glass transition temperature (Tg) of the polymer film 20 is a factor generally used to select an appropriate material. In an embodiment, the glass transition temperature of the polymer film 20 may be higher than the process temperature of 135° C. to 140° C. to maintain optical properties. The glass transition temperature of the polymer film 20 of the polycarbonate (PC) material used in this embodiment is 137°C to 140°C. The glass transition temperature of the polymer film 20 of this embodiment can be considered to be basically/substantially the same as the process temperature for manufacturing the silver nanowire electrode. It should be noted that the processing temperatures described above are used only as examples and are not intended to limit the present disclosure.

After the silver nanowire electrodes (ie, the touch-sensing structure 30) are fabricated on both sides of the polymer film 20 using the above-described method, the liquid crystal phase retardation layer 23 is coated with an optically transparent adhesive (not shown). It is formed using transparent adhesive (OCA). The linear polarization layer 10 is attached to the polymer film 20 to form the integrated touch module 100 as shown in FIG. 3 . Table 4 is a first embodiment of the present disclosure for fabricating the silver nanowire touch-sensing structure 30 on both sides of the polymer film 20, the liquid crystal phase retardation layer 23 and the linear polarization layer 10 as described above Combined with the test method/equipment to obtain the reflectance under a specific visible light and calculate the average value and standard deviation. As shown in Table 4, the reflectance of the first embodiment of the present disclosure when the incident light wavelength is 550 nm is 5.87%, 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 difference between the average reflectance of the integrated touch module 100 of the present embodiment in the wavelength range of 450 nm to 500 nm and the reflectance of the integrated touch module 100 in the wavelength range of 550 nm is quite small (about 2.2%). It is evident that the reflectance of this embodiment is fairly uniform in the short wavelength range. It can be seen that the present disclosure can provide an integrated touch module 100 having a low and uniform reflectance. Since the silver nanowire touch-sensing structure 30 will increase the reflectance, the average and standard deviation of the reflectance are both higher than without the silver nanowire touch-sensing structure 30 (i.e., Table 3), but the difference is not large. However, it should be noted that the requirements for the final product may still be achieved. As described above, the materials of the antiphase compensation coating film and the optical 1/4 phase compensation coating film disclosed in Patent I663460 are both liquid crystal materials, and liquid crystal cannot be directly used as a substrate for forming the touch sensing structure 30 during the manufacturing process. . Thus, compared to patent I663460, this disclosure proposes a feasible integrated solution of touch sensing structure 30 and polymer phase retardation layer, which has a better antireflection effect for ambient light. With this arrangement, the touch-sensing structure 30 and the polymer phase retardation layer can be matched to each other, and the processing conditions of the touch-sensing structure 30 will not affect the optical properties of the polymer phase retardation layer. In addition, the polymer phase retardation layer can also meet the strength requirements of the substrate and the hot pressing process.

Wavelength (nm) Reflectance ( % ) 450 5.46 475 5.65 500 6.10 525 6.12 550 5.87 575 5.58 600 6.27 625 6.22 650 5.96 675 5.23 average 5.85 Standard Deviation 0.39

Hereinafter, a second comparative example of the present disclosure is described below. The polymer film 20 is a material (supplier: LONGHUA) having a thickness of 15 μm. Since the composition, thickness, and stretching conditions of the film are different from those of the first example, the glass transition temperature of the polymer film 20 of the second comparative example is lower than the process temperature (135° C. to 140° C.) of the silver nanowire electrode described above. 128 ° C to 130 ° C, and other conditions are the same as in the above-described embodiment. After the measurement, since the polymer film 20 of this comparative example cannot withstand the process temperature of the silver nanowire electrode, the polymer film 20 of the second comparative example of the present disclosure was fabricated with the structure of FIG. 3 and had a reflectance of 21% have It can be seen that the polymer film 20 having a Tg of 128° C. to 130° C. has lost its original optical properties. When the optical retardation value is measured after the polymer film 20 of the second comparative example of the present disclosure is left at a temperature of 140 ° C. for 1 hour to simulate the manufacturing process of the silver nanowire electrode, the experimental result is that the optical retardation value is (550 nm at a wavelength of) 2.05. This also demonstrates that the polymer film 20 of the second comparative example of the present disclosure has no optical retardation effect after being subjected to high temperature (ie, the test temperature exceeds the glass transition temperature of the material).

It should be noted that Example 1 and Comparative Example 2 of the present disclosure use polymer films of the same main material, but have different glass transition temperatures. The description of the present disclosure is as follows: the raw material sources of the polymers used in the examples are different, and the membranes are from different suppliers and have different compositions. The main components of the mold materials of the first example and the second comparative example may be the same, but other subcomponents/additives will be different. In addition, stretching conditions will also cause differences in the properties of the polymer film.

In addition to the polycarbonate (PC) used in the first embodiment described above, the present disclosure can expect materials used for the polymer film 20 from the glass transition temperature of the polymer, for example, the main component of the polymer film 20 (i.e., the weight percentage is at least >50%) is: Tg>146°C, published in the paper "Optical Poly(methyl methacrylate) copolymers Material with High Thermal Resistance" (2017) and incorporated herein by reference. methyl methacrylate (PMMA); commercially available cyclo olefin polymer (COP) products with a Tg=165° C. from Konica Minolta; commercially available colorless polyimide (CPI) products with Tg>180°C; It may be a commercial polyethylene terephthalate diester (PET) product having a Tg between 150° C. and 155° C. or a derivative based on the aforementioned compounds, and having a phase retardation value measured at a wavelength of 550 nm between 100 nm and 200 nm, or at least 130 nm, or between 127 nm and 134 nm, between 135 nm and 145 nm, between 129 nm and 132 nm, and between 130 nm and 131 nm, and the optical axis of the polymer film 20 is between 0 degrees and 180 degrees, preferably 75 degrees. On the other hand, the phase retardation value of the liquid crystal phase retardation layer 23 according to the present application measured in the visible light range may be between 200 nm and 300 nm, between 200 nm and 288 nm, between 237 nm and 279 nm, and between 259 nm and 271 nm, The optical axis of tangible liquid crystal phase retardation layer 23 ranges from 0 degrees to 180 degrees, preferably 15 degrees. It is to be understood that the foregoing embodiments may be subject to instrument variation. Therefore, the phase delay value is only an integer. Depending on the requirements, a measuring instrument with a smaller error range can be selected to measure the phase delay value. The examples herein are illustrative only and are not intended to limit the present disclosure.

The thickness of the polymer film 20 used according to the first embodiment of the present disclosure is only about 25 μm, the thickness of the liquid crystal retardation layer 23 is only about 2 μm, and the total thickness of all phase retardation elements is 27 μm. am. There are two types of silver nanowire electrodes, in one type the driving/sensing electrodes are fabricated on both sides of the polymer film 20 and each driving/sensing electrode is 8.5 μm, in the other type the driving/sensing electrodes are fabricated on both sides of the polymer film 20. The electrode/sensing electrode is fabricated on the same side of the polymer film 20 . The thickness of this drive/sensing electrode is 10 μm. Under such a thickness, it is more advantageous to realize a bendable ultra-thin touch module. Therefore, the touch module and product of the embodiments of the present disclosure can be made thinner.

Next, an integrated touch module according to a second embodiment of the present disclosure will be described. The difference from the first embodiment is that the polymer film 20 has a temperature Tg of 151 ° C and a thickness of 28 μm (supplier: Osaka Gas ) is the material of

Compared with the above comparative example, the average reflectance of this example in the wavelength range of 450 nm to 500 nm (about 5.6% after calculation of experimental data) and the reflectance in the wavelength of 550 nm differ by only 4.5%, which is different in the short wavelength range. It is shown that the reflectivity of this embodiment is fairly uniform, and no large amount of disturbing reflected light will be observed. Further, the calculated difference between the average reflectance in the wavelength range between 450 nm and 500 nm (i.e., short wavelength range) and the average reflectance in the wavelength range of 525 nm to 675 nm (i.e., medium-long wavelength range) in this embodiment is about 7.0 %am. According to the average reflectance of this embodiment in the wavelength range of 450 nm to 500 nm, both the integrated touch modules of the second embodiment and the first embodiment have an average reflectance of the circular polarization element in the visible light range less than the 5% requirement, and the reflectance standard It is considered that it can satisfy the deviation less than 0.2% requirement, it can also satisfy 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%.

In addition, the integrated method of the touch sensing structure 30 and the liquid crystal phase retardation layer 23 of the present disclosure has a phase retardation value change rate of less than 5% and has a long-term (500 hours) exposure in a high temperature (85 ° C.) environment. , weather resistance is good.

The following further provides another example of a touch control module so that a person skilled in the art of this disclosure may more clearly understand possible variations. Components indicated by the same component symbols as those in the above embodiment are substantially the same as those described above with reference to FIGS. 3, 4, and 7, and the same components, features, and advantages as those of the integrated touch module 100 will not be repeatedly described. .

In the third embodiment of the present disclosure, the touch sensing structure 30 of the integrated touch module 100 of this embodiment includes a first touch electrode layer (eg, a driving layer) and a second touch electrode layer (eg, a sensing layer). It is different from FIG. 4 in that it can be The first touch electrode layer and the second touch electrode layer are disposed on the same surface of the polymer film 20, for example, on a surface far away from the display module, but the present disclosure is not limited thereto. The relevant description of this embodiment above will not be repeated here.

It can be appreciated that the position 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 a person skilled in the art may modify and adjust based on the above examples, which are listed herein. It won't be.

Hereinafter, an embodiment in which the touch module according to the present disclosure is applied to a display device will be described.

5, which is a structural diagram of a display device according to a preferred embodiment of the present disclosure, is referred to. The display device 300 includes a display panel 200 and an integrated touch module 100 . The display panel 200 has a visible 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 the corresponding visible area. Specifically, the display panel 200 may include a liquid crystal display panel (LCD), an organic electroluminescent display panel, an organic light emitting diode (OLED) display panel, or a micro light emitting diode display panel (μLED display). ), but is not limited thereto. In addition, the linear polarization layer 10 is also attached to the cover 400 by an optical adhesive (not shown). The previously discussed description of integrated touch module 100 will not be repeated here.

Finally, the technical features of the present disclosure and its attainable technical effects are summarized as follows:

1. According to the integrated touch module 100 of the present disclosure, since the average reflectance of the integrated touch module 100 in the visible light range is less than 6% and the standard deviation is less than 0.4%, uniform optical properties for practical requirements are achieved.

2. The polymer film 20 of the integrated touch module 100 according to the present disclosure can be directly used as a substrate without an additional substrate, and the thickness of the polymer film 20 of the present disclosure is preferably only 17 μm or less. That is, a bendable and ultra-thin integrated touch module can be realized. In addition, the polymer film 20 of the present disclosure combined with the liquid crystal retardation layer 23 has good optical properties, and has broadband domain retardation properties to meet practical requirements.

Embodiments of the present disclosure are described above along with specific examples. From the contents disclosed in this specification, those skilled in the art will be able to easily understand the technical features, advantages, and effects of the present disclosure.

The above description is only a preferred embodiment of the present disclosure, and is not intended to limit the scope of the present disclosure. All other equivalent variations or modifications made without departing from the spirit of this disclosure are to be included within the scope of the following patent application.

Claims (11)

In the integrated touch module,
A silver nanowire touch sensing structure formed on a polymer film, wherein the polymer film has a phase retardation value between 100 nm and 160 nm for a wavelength of 550 nm,
The polymer film, the liquid crystal phase retardation layer, and the linear polarization layer constitute a circular polarization element, and the average reflectance of the circular polarization element in the visible light range is less than 5% and the standard deviation of the reflectance is less than 0.2%. . According to claim 1,
wherein an average reflectance of the integrated touch module in the visible light range is less than 6%, and a standard deviation of the reflectance is less than 0.4%. According to claim 1,
The average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm is less than 6%, and the reflectance difference between the average reflectance of the circular polarization element in the wavelength range of 450 nm to 500 nm and the reflectance for the wavelength of 550 nm is less than 5%. That is, an integrated touch module. According to claim 1,
The integrated touch module, wherein the polymer film is configured to withstand a process temperature range of the silver nanowire touch sensing structure. According to claim 4,
The glass transition temperature of the polymer film is higher than the highest process temperature for manufacturing the silver nanowire touch sensing structure on the polymer film, the integrated touch module. According to claim 5,
The highest process temperature of the silver nanowire touch sensing structure is 135 ° C to 140 ° C, and the main components of the polymer film are methyl acrylate (PMMA), cycloolefin polymer (COP), polycarbonate (PC), polyethylene terephthalate (PET) ), colorless polyimide (CPI) or a derivative thereof, and the glass transition temperature of the polymer film is 135 ° C to 140 ° C or higher, the integrated touch module. According to claim 1,
The polymer film is a positive dispersion type phase retardation layer having a thickness of about 25 μm, and the liquid crystal phase retardation layer is a positive dispersion type phase retardation layer having a thickness of about 2 μm, and the polymer film and the liquid crystal phase retardation layer have a thickness of about 2 μm. and an optical axis difference between the layers is about 60 degrees. The method of claim 1, wherein the silver nanowire touch sensing structure,
And an integrated touch module comprising a silver nanowire electrode layer disposed directly on the polymer film. The method of claim 1, wherein the silver nanowire touch sensing structure,
An integrated touch module comprising two silver nanowire electrode layers, wherein the two silver nanowire electrode layers are respectively arranged on upper and lower surfaces of the polymer film. According to claim 1,
wherein a reflectance difference between an average reflectance of the circular polarization element in a wavelength range of 450 nm to 500 nm and an average reflectance in a wavelength range of 525 nm to 675 nm is less than 10%. In the touch display device,
a display panel having a display area; and
Disposed on the display panel, the integrated touch module of claim 1
wherein the silver nanowire touch sensing structure of the integrated touch module overlaps correspondingly with the display area.

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