TW202305413A - Touch display module - Google Patents

Abstract

A touch display module includes a touch device and a polarizing element. The polarizing element includes a polarizer and a retardation film assembly. The retardation film assembly has a polarization ellipticity value (e-value), and the absolute value of the e-value is greater than 0.8. A reflection rate of the polarizing element is less than 6%, and a total reflection rate of the touch device and the polarizing element is less than 7%.

Description

Touch display module

This disclosure relates to a touch display module.

Organic light-emitting diode displays have the advantages of low power consumption, high color vividness and high contrast, which can give people better visual enjoyment, but the biggest challenge is how to effectively resist the reflected light generated by the incident light from the external environment. Reduce display annoyances. One of the solutions is to use a circular polarizer as an anti-reflective film to reduce the amount of light reflected from the display after the ambient light enters it. The theoretical principle of a circular polarizer combined with a quarter-wave plate (QWP for short) and a linear polarizer is: to circularly polarize the external ambient light incident on the display, and the incident circularly polarized light (ex. left-handed light) will pass through the display. After the electrode is reflected, it is reversed into circularly polarized light with the opposite rotation direction (ex. dextrorotational light), and the circularly polarized light with the opposite rotation direction (dextrorotational light) passes through the quarter-wave plate again and becomes positive to the polarization direction of the linear polarizer. Intersecting linearly polarized light, so that the linearly polarized light perpendicular to the polarization direction of the linear polarizer cannot be emitted by the linear polarizer, thereby eliminating or reducing the reflection caused by external ambient light, so as to avoid problems such as reflection interference or uneven brightness on the display screen. From the above principles, the circular polarization of external ambient light by the anti-reflection sheet is the first step of the above-mentioned anti-reflection mechanism, so it is one of the important factors of the anti-reflection effect. Generally speaking, under the same material, increasing the circular polarization conversion rate can lead to better anti-reflection effect.

For example, TWI580995B (TW'995) proposes an anti-environmental light reflection film, which includes: a linear polarizing layer and an optically active liquid crystal layer formed on the linear polarizing layer, and examples 1-4 from TW'995 Table 2 show that in circular polarization conversion When the ratio is close to 1 (that is, the linear polarized light is fully converted into circular polarized light), the lowest reflectance of light is 7.62%. However, the present invention believes that a reflectivity of about 8% cannot meet the increasingly sophisticated display requirements, especially at present, high-resolution, high-quality videos such as 4K and 8K grades have been favored by users. On the other hand, assembling touch sensing electrodes on a display to form a touch display screen is one of the important human-machine interfaces in modern society, and the touch sensing electrodes are also factors that cause ambient light reflection. To sum up, the reflectivity of the anti-environmental light reflection film proposed by TW'995 is too high, so it may not be able to meet the high-end display requirements after matching with the display and touch sensing electrodes. In other words, how to obtain an anti-reflection sheet with lower reflectivity is a major task for those skilled in the art.

On the other hand, the circular polarization conversion ratio of Examples 1-4 of TW’995 is close to 1, which is equivalent to an ideal value. It is speculated that it should be a laboratory-grade liquid crystal material, and the cost is very high, which is not conducive to commercial use. In fact, in the commercial market, due to cost considerations, the material specifications of electronic products are not so close to the ideal value. That is to say, if the general commercial specifications/costs are considered, the circular The polarization conversion rate is bound to be reduced (for example, the circular polarization conversion rate is reduced to 0.9), and it is conceivable that the above-mentioned light reflectance will be improved accordingly, which cannot meet the requirement of low reflectance.

Furthermore, the optically active liquid crystal layer used in TW'995 is a cholesteric liquid crystal, and its working principle is to stack multiple liquid crystal layers with different axes to achieve circular polarization of light, as shown in Figure 2 of TW'995 As shown, therefore. The multi-layer liquid crystal structure of TW'995 will cause the problem that the thickness of the anti-environmental light reflection film cannot be reduced, so it cannot meet the user's demand for light and thin portable devices.

The touch display module of the disclosed embodiment can have sufficiently low reflectivity, so as to reduce the reflection from the external environment light and avoid affecting the display quality.

The technical solution adopted in this disclosure is:

One aspect of the present disclosure relates to a touch display module. According to one or more embodiments of the present disclosure, a touch display module includes a touch element and a polarizer. The polarizing element is disposed on the touch element. The polarizing element includes a linear polarizer and a phase retardation film assembly. When ambient light passes through the linear polarizer, the linearly polarized light generated by the phase retardation film assembly is converted into circularly polarized light, and the ratio of the linearly polarized light to circularly polarized light is defined as the circular polarization conversion rate of the phase retardation film assembly. In the wavelength range between 450nm and 650nm, the absolute value of the circular deflection conversion rate is greater than 0.8. In the wavelength range between 450nm and 650nm, the reflectance of ambient light passing through the polarizing element is less than 6%.

According to one or more embodiments of the present disclosure, the touch element includes a touch sensor made of silver nanowires and/or polymer films. The touch sensor is located on the linear polarizer or on the phase retardation film assembly.

In some embodiments, the combination of the touch element and the polarizing element has a total reflectivity in the wavelength range between 450nm and 650nm, and the total reflectivity is less than 7% or less than 6%; or in the wavelength range of 450nm to 650nm , the refractive index change rate caused by the polarizing element before and after being combined with the touch element is in the range of 0% to 15%, between 0% and 13%, between 0% and 8%, or 0 % to 2% range.

According to one or more embodiments of the present disclosure, the phase retardation film assembly is composed of a positive dispersion half-wave plate and a positive dispersion quarter wave plate.

In some embodiments, the angle of the optical axis of the half-wave plate relative to the linear polarizer is in the range of 10 degrees to 15 degrees, and the angle of the optical axis of the quarter wave plate relative to the linear polarizer is 65 degrees to 75 degrees. between the ranges.

According to one or more embodiments of the present disclosure, the phase retardation film assembly is composed of a quarter-wave plate of reverse dispersion type.

In some embodiments, the angle of the optical axis of the quarter wave plate relative to the linear polarizer is 45 degrees.

According to one or more embodiments of the present disclosure, the retardation film assembly includes a liquid crystal type retardation film or a polymer film type retardation film.

According to one or more embodiments of the present disclosure, in the wavelength range between 450nm and 650nm, the absolute value of the circular deflection conversion ratio is in the range of 0.8 to 0.95, wherein the wavelength range between 450nm and 650nm Under this condition, the reflectivity of ambient light passing through the polarizing element is less than 5.5%.

One aspect of the disclosure relates to a touch display module. According to one or more embodiments of the present disclosure, a touch display module includes a touch element and a polarizer. The polarizing element is disposed on the touch element. The polarizing element includes a linear polarizer and a phase retardation film assembly. When ambient light passes through the linear polarizer, the linearly polarized light generated by the phase retardation film assembly is converted into circularly polarized light, and the ratio of the linearly polarized light to circularly polarized light is defined as the circular polarization conversion rate of the phase retardation film assembly. At a wavelength of 550nm, the absolute value of the circular deflection conversion rate is greater than 0.9. At a wavelength of 550nm, the reflectance of ambient light passing through the polarizing element is less than 5%.

In this way, through the embodiment of the present invention, the circular conversion rate of the polarizer does not need to be close to the theoretical value, so that the touch display module can reduce the reflection of incident light from the external environment, thereby improving the visual and operating experience of the touch display module. It will not increase the product cost excessively.

The above description is only used to illustrate the problems to be solved by the present disclosure, the technical means for solving the problems, and the effects thereof, etc. The specific details of the present disclosure will be introduced in detail in the following embodiments and related drawings.

A plurality of embodiments of the present disclosure will be disclosed in the following diagrams. For the sake of clarity, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present disclosure. That is to say, in the disclosed embodiments, these practical details are unnecessary. In addition, for the sake of simplifying the drawings, some well-known structures and components will be shown in a simple and schematic manner in the drawings.

For the display device, the reflection from external ambient light will affect the user's visual experience. For the users of the touch display module, the reflection of external ambient light will affect the operating experience even more. The wavelength range covered by the external ambient light is very wide, and the present disclosure is aimed at performing anti-reflection optical configuration for the wavelength bands that human eyes are more sensitive to (eg, 450nm-650nm).

The present disclosure is related to the touch display structure, which can reduce the reflection of external ambient light, so as to reduce the interference from the external ambient light reflection to the visual and operation experience, and can maintain the overall thickness of light and thin. In this disclosure, anti-reflection elements with low reflectivity can be obtained without reaching or approaching the ideal circular deflection conversion rate (ie, the circular deflection conversion rate is equal to 1) for the polarizing element in the touch display structure, so there is a difference in cost and product quality. Pretty good balance.

Please refer to Figure 1. FIG. 1 is a schematic cross-sectional view of a touch display module 100 according to an embodiment of the present disclosure.

As shown in FIG. 1 , in an embodiment of the present disclosure, a touch display module 100 includes at least a touch element 110 and a polarizer 150 .

In this embodiment, the touch element 110 can be assembled with the display unit 120 , for example, using optical adhesive (OCA) to attach and fix the two.

In some embodiments, the display unit 120 includes an organic light-emitting diode (Organic Light-Emitting Diode, OLED), a mini-LED display, and the like. OLED displays can have the advantages of low power consumption, high color vividness, and high contrast ratio. In some embodiments, one or more organic light-emitting diodes of the display unit 120 can form an active-matrix organic light-emitting diode (AMOLED) to display images and signals.

As shown in FIG. 1 , in one embodiment of the present disclosure, the display unit 120 can emit light L toward the direction D1 and display images accordingly, that is to say, the user can receive the light emitted by the display unit 120 along the direction D1. signal.

In some embodiments, the touch element 110 may include a touch sensor. The touch sensor can sense the user's touch and gesture, so as to realize the touch operation of the touch display module 100 .

In some embodiments of the present disclosure, the touch element 110 includes an electrode formed by patterning a transparent conductive layer or a transparent conductive film, which has a high transmittance, for example, in visible light (such as a wavelength between 400nm-700nm) The light transmittance (Transmission) is greater than about 88%, 90%, 91%, 92%, 93% or more. In some embodiments, the transparent conductive layer or transparent conductive film includes ITO material, silver nanowires (SNW) material and the like.

Please go back to Figure 1. As shown in FIG. 1 , the polarizing element 150 is disposed on the touch element 110 . In some implementations of the present disclosure, the polarizing element 150 can convert the ambient light (such as light L1) from the external environment into polarized light, so as to reduce the reflection of the ambient light and emit it along the direction D1 and affect the user's viewing of the screen. For details, please refer to See discussion below.

As shown in FIG. 1 , the polarizer 150 may include a linear polarizer 160 and a phase retardation film assembly 170 . In this embodiment, the phase retardation film assembly 170 is located between the light emitting surface of the optical touch element 110 and the polarizer 160 .

The linear polarizer 160 can be configured to convert passing light into linearly polarized light. In some embodiments of the present disclosure, the degree of polarization (DOP) of the linear polarizer 160 is greater than 98%, but not limited thereto.

In some embodiments, the retarder assembly 170 may include one or more retarders. In this embodiment, the phase retardation film assembly 170 is composed of a positive dispersion type half wave plate (Half Wave Plate, HWQ) 173 and a positive dispersion type quarter wave plate (Quarter Wave Plate, QWP) 176 composed of. In this embodiment, both the quarter-wave plate 176 and the half-wave plate 173 are a single-layer liquid crystal coating, for example, a quarter wave plate made of a commercially available product: Reactive Mesogen (RM) reactive liquid crystal. One-wave plate 176 and one-half wave plate 173 (such as manufacturer DNP; DNP_HWP and DNP_QWP).

In this way, the phase retardation film assembly 170 can be regarded as a liquid crystal coated phase retardation element. Since the thickness of the coated liquid crystal is only a few micrometers (um), the overall thickness can be reduced. Compared with the thickness of the multi-layered cholesteric liquid crystals used in TW'995, the RM reactive liquid crystals used in this example only need to be coated with one layer to achieve the phase effect of retarding light, so it can meet the needs of thinner products.

Please refer to FIG. 2 , when the external ambient light L1 is incident, the light is generally incident along the direction D2 opposite to the direction D1 (ie, the screen display direction), and the external ambient light is converted into linearly polarized light L2 by the linear polarizer 160 . The linearly polarized light L2 then passes through the half-wave plate 173 and the quarter-wave plate 176 to turn into circularly polarized light L3 (for example, left-handed light). When the circularly polarized light L3 is reflected by the touch element 110 or the display unit 120, a reversed circularly polarized light L3' (for example, right-handed light) will be formed. At this time, the reversed circularly polarized light L3' passes through the phase retardation film assembly 170 to form a linearly polarized light L2' perpendicular to the optical axis of the linear polarizer 160. Since the polarization angles are orthogonal, the polarized light L2' cannot pass through the linear polarized light. The polarizer 160 emits outward, that is, in an ideal state, no reflected light L1 ′ will be generated. In this way, the polarizing element 150 is optically called a circular polarizer (CPOL), which can eliminate or reduce reflected light in optical applications, so it is also called an anti-reflection element.

In short, through the configuration of the polarizing element 150 , the external ambient light is converted into circularly polarized light, and then the circularly polarized light is reflected again. Due to the relationship of the polarization angle, the reflected circularly polarized light will be blocked by the linear polarizer 160 . In this way, it is possible to prevent the reflection of external ambient light from affecting the visual effect of the touch display module 100 . It is worth noting that, through the polarizing element 150 , the linearly polarized light can be transformed into ideally completely circularly polarized light or elliptically polarized light close to circularly polarized light. In this way, the circular polarization conversion rate or the circular polarization conversion rate (polarization ellipticity value, e-value) of the phase retardation film assembly 170 can be defined according to the ratio of linearly polarized light L2 converted into circularly polarized light, and because The circularity conversion rate has a positive/negative value according to left-handedness or right-handedness. For the convenience of description, the circularity conversion rate of the present invention will be explained in terms of absolute value.

For example, when the polarized light L3 is right-handed circularly polarized light, the circular polarization conversion rate of the phase retardation film assembly 170 is +1 (that is, completely converted); when the polarized light L3 is right-handed elliptically polarized light, that is, a The combination of linearly polarized light and a part of circularly polarized light, the circular polarization conversion rate of the phase retardation film assembly 170 is between +1 and 0; similarly, when the polarized light L3 is left-handed circularly polarized light, the total phase retardation film The circularity conversion ratio of 170 is between -1 and 0. In general, when linearly polarized light is completely converted into circularly polarized light, the absolute value of the circular polarization conversion rate is equal to 1.

In some embodiments, the absolute value of the circular deflection conversion ratio of the phase retardation film assembly 170 is less than 1. In other words, the anti-reflection effect can still be provided without nearly complete circular deflection conversion. Specifically, in some embodiments, in the wavelength range of 450-650nm, as long as the absolute value of the circular deflection conversion rate of the phase retardation film assembly 170 is greater than 0.8 (not close to the ideal value), the touch display can still be effectively reduced. The overall reflectivity of the module 100 is, for example, less than 6% or less than 5.5%.

To further illustrate, when the absolute value of the circular deflection conversion rate of the phase retardation film assembly 170 is greater than 0.8 but not close to the ideal value, the effect of reducing the overall reflectivity of the touch display module 100 can still be obtained.

FIG. 3 shows a schematic diagram of the included angles θ1 and θ2 of optical axes formed by a polarizing element 150 according to an embodiment of the present disclosure. In FIG. 3 , the optical axis a1 corresponds to the linear polarizing plate 160 . For the polarizer 150 , the optical axis a2 corresponds to the half-wave plate 173 of the positive dispersion liquid crystal coating type, and the optical axis a3 corresponds to the quarter wave plate 176 of the positive dispersion liquid crystal coating type. Since the half-wave plate 173 of the positively dispersing liquid crystal coating type and the quarter-wave plate 176 of the positively dispersing liquid crystal coating type are liquid crystal coating types, they only have single optical axes a2 and a3 respectively. a2, a3 can be the slow axis.

Relative to the optical axis a1 of the linear polarizer 160 , the optical axis a2 has an included angle θ1 of the optical axis. Relative to the optical axis a1 of the linear polarizer 160 , the optical axis a3 has an included angle θ3 of the optical axis. In some embodiments, the included angles θ1 and θ2 of the optical axes may range from 0° to 180°. In this embodiment, the included angle θ1 of the optical axis is 15 degrees, and the included angle θ2 of the optical axis is 75 degrees, but not limited thereto. In one embodiment, the angle θ1 of the optical axis is between 10° and 15°, and the angle θ2 of the optical axis is between 65° and 75°, but not limited thereto.

Please return to FIG. 2 , according to an embodiment of the present disclosure, it shows that an incident light L1 enters a polarizing element 150 and then passes through a reflective surface 300 , such as a half mirror (manufacturer: 3D Lens) with a reflectivity of about 50-60%. Then passing through the polarizing element 150 is a schematic diagram of the reflected light L1'. FIG. 4 is a graph showing the relationship between the absolute value of the circular conversion rate (e value) and the reflectance (R%) of the polarizer 150 measured according to the above-mentioned embodiment.

As shown in FIG. 4 and Table 1 below, corresponding to the incident light L1 with an incident wavelength in the range of 450 nm to 650 nm, the absolute value of the circular deflection conversion rate (e value) of the polarizing element 150 of the present disclosure is above 0.8, as shown by the dotted line As shown; while the incident light L1' in the range of 450 nm to 650 nm, the reflectance (R%) is less than 6%, or less than 5.5%. Table 1 wavelength(nm) e value Reflectivity R% 450 0.85 5.2 475 0.91 5.2 500 0.92 5.0 525 0.92 4.6 550 0.9 4.9 575 0.89 4.9 600 0.87 5.2 625 0.85 5.4 650 0.82 5.5

In this way, when the incident light L1 corresponding to the incident wavelength ranges from 450 nm to 650 nm, the absolute value of the circular deflection conversion rate (e value) of the polarizer 150 of this embodiment is above 0.8, so that in the range of 450 nm to 650 nm, which is sensitive to the human eye, The reflectance in the 650 nm range is less than 6%, or less than 5.5%. More specifically, when the incident light L1 corresponding to the incident wavelength ranges from 450 nm to 650 nm, the absolute value of the circular conversion rate (e value) of the polarizing element 150 in this embodiment only needs to be between 0.82 ~ 0.92 and does not need to be Close to the theoretical value (e value=1), the reflectance in the range of 450 nm to 650 nm, which is sensitive to the human eye, can be less than 6%, or less than 5.5%, so it has an advantage in commercial/industrial production costs. In one embodiment, the absolute value of the circular deflection conversion rate (e value) of the polarizing element 150 only needs to be between 0.8~0.95 and does not need to be close to the theoretical value (e value=1), which can make the human eyes sensitive The reflectance in the range of 450 nm to 650 nm is less than 6%, or less than 5.5%.

More specifically, when the corresponding incident wavelength is the incident light L1 of 550 nm, the absolute value of the circular deflection conversion rate (e value) of the polarizing element 150 of this embodiment only needs to be 0.9 or above and does not need to be close to the theoretical value (e value) =1), it can make the reflectance at 550 nm, which is sensitive to the human eye, less than 6%, or less than 5.5%, or less than 5%. More specifically, when the corresponding incident wavelength is the incident light L1 of 550 nm, the absolute value of the circular deflection conversion rate (e value) of the polarizer 150 of the present embodiment only needs to be 0.9 or above and does not need to be close to the theoretical value (e value) value=1), the reflectance at 550 nm, which is sensitive to the human eye, is 4.9%, so it has an advantage in commercial/industrial production costs. To sum up, the absolute value of the circular deflection conversion rate (e value) of the polarizing element 150 of this embodiment only needs to be 0.9-0.95 and does not need to be close to the theoretical value (e value=1), so that the human eyes can be sensitive to The reflectance at 550 nm is between 4.5~5.0%.

FIG. 5 shows a graph showing the relationship between the absolute value of the circular deflection conversion rate (e value) and the reflectance. Under an incident light in the range of 450 nm to 650 nm, the horizontal axis is set to use the liquid crystal coating type phase retardation film assembly with different absolute values of the circular deflection ratio (e value), and the vertical axis is used Corresponding to the reflectance (R%) of the polarizing element of the phase retardation film assembly. It can be seen that once the absolute value of the circular deflection conversion rate (e value) is less than 0.8, it can ensure that when the wavelength of the incident light is in the range of 450 nm to 650 nm, the reflectance (R%) of the polarizing element is less than 6%; and When the angle between the slow axis of the half-wave plate 173 and the optical axis a1 of the linear polarizer 160 exceeds 15 degrees, or the angle between the slow axis of the quarter-wave plate 176 and the optical axis a1 of the linear polarizer 160 exceeds 75 degrees, It is possible to cause the absolute value of the circular deflection conversion rate (e value) to be less than 0.8, and lead to a comparative example with a reflectance (R%) greater than 6% in the wavelength range from 450 nm to 650 nm (such as data point a in Figure 5 , b, c, d). The other data points in Fig. 5 all satisfy the above-mentioned embodiments, and will not be repeated here.

According to an embodiment of the present disclosure, after assembling the touch element 110 into the aforementioned polarizing element 150 , a test is performed to measure the circular deflection conversion rate and the light reflectance in the wavelength range of 450 nm to 650 nm. In one embodiment, the combination of the touch element 110 and the polarizing element 150 can be regarded as a photoelectric element, that is, an integrated element with both optical and electrical functions. The electrical function here refers to the touch sensing function, and the aforementioned optoelectronic The element has an overall reflectivity. Because the touch element 110 also causes light reflection, the overall reflectivity of this photoelectric element will be slightly greater than that of the polarizing element 150, and the overall reflectivity must be small enough in the product without affecting the display quality. . For the test method of this embodiment, reference may be made to the method shown in FIG. 2 and the above-mentioned related descriptions, and details are not repeated here.

In one embodiment, the touch element 110 at least includes touch electrodes made of silver nanowires and/or polymer films. For specific methods, reference can be made to US20190227650A, CN101292362, etc. in full. As shown in FIG. 6 , in the range of 450 nm to 650 nm sensitive to human eyes, the overall reflectance of the optical touch element 110 and the polarizing element 150 can be less than 7%, as shown in Table 2 below. Table 2 wavelength(nm) Reflectivity R% Change rate of reflectance (%) 450 5.9 13 475 5.8 12 500 5.6 12 525 5.2 13 550 5.3 8 575 5.3 8 600 5.3 2 625 5.4 0 650 5.3 -4* *Note: Experimental figures may be caused by instrument errors

As shown in the above table, when the incident light L1 corresponds to the incident wavelength in the range of 450 nm to 650 nm, the reflectance of the photoelectric element of this embodiment in the range of 450 nm to 650 nm sensitive to human eyes is less than 7% or less than 6%. In summary, the reflectance of the photoelectric element of the embodiment of the present invention is between 5% and 6% in the range of 450 nm to 650 nm, which is sensitive to human eyes.

More specifically, when the incident light L1 corresponding to the incident wavelength is 550 nm, the reflectance of the optoelectronic element in this embodiment at 550 nm is less than 6%, or less than 5.5%. More specifically, when the corresponding incident wavelength is the incident light L1 of 550 nm, the reflectance of the photoelectric element of this embodiment at the wavelength of 550 nm is 5.3%. In summary, the reflectance of the photoelectric element of the embodiment of the present invention is between 5.0% and 5.5% at a wavelength of 550 nm.

In addition, it often occurs when two elements with different functions are combined that characteristics may affect each other. In the embodiment of the present invention, it can be found that combining the touch electrodes made of silver nano wires and/or polymer films with the aforementioned polarizing element 150 will not excessively degrade the characteristics of the polarizing element 150 . Specifically, in the embodiment of the present invention, when the touch electrode composed of nano-silver wire and/or polymer film is combined with the aforementioned polarizing element 150, compared with the aforementioned polarizing element 150, the wavelength is in the range of 450 nm to 650 nm. , the change rate of its reflectance is below 15%; in general, the photoelectric element of the embodiment of the present invention has a change rate of reflectance of 0%~15%, 0%~13%, 0%~13%, 0%~8% or 0%~2%.

More specifically, at the corresponding wavelength of 550 nm, the change rate of the reflectance is below 10%; more specifically, at the corresponding wavelength of 550 nm, the change rate of the reflectance is 8%. In general, the photoelectric element of the embodiment of the present invention has a change rate of reflectance of 0%-10%, 5%-10% or 5%-8% at a wavelength of 550 nm.

In some embodiments, a transparent protective cover can be further arranged on the polarizing element 150 .

FIG. 7 shows a schematic cross-sectional view of a touch display module 200 according to an embodiment of the present disclosure.

In this embodiment, as shown in FIG. 7, the touch display module 200 includes an optical touch element 210, a display unit 220, and a polarizing element 250, and the polarizing element 250 includes a polarizing plate 260 and a liquid crystal coating type retardation film. Total 270.

The difference from the foregoing embodiments is at least that: the phase retardation film assembly 270 may include a phase retardation film (Retarder). In this embodiment, the phase retardation film assembly 270 is only composed of a quarter-wave plate 276 of reverse dispersion type. In this embodiment, the quarter-wave plate 276 is a single-layer liquid crystal coating, for example, a quarter-wave plate 276 made of a commercially available product: Reactive Mesogen (RM) reactive liquid crystal (manufacturer DNP; DNP_QWP). In this embodiment, the quarter-wave plate 276 has a single optical axis, and the optical axis (eg slow axis) of the quarter-wave plate 276 has an included angle with respect to the optical axis of the polarizer 260 . In some implementations, the range of the aforementioned optical axis included angle is between 0° and 180°. In some implementation manners, the aforementioned angle between the optical axes is 45 degrees. In some embodiments, the above-mentioned included angle of the optical axis is 40 degrees to 50 degrees.

In this embodiment, in the incident wavelength range of 450 nm to 650 nm, the retardation wavelength of the quarter wave plate 276 is between 100 nm to 160 nm.

In addition, similar to the foregoing embodiments, the quarter-wave plate 276 has a circular conversion rate with an absolute value of less than 0.8, or between 0.82-0.92 in the incident wavelength range of 450 nm to 650 nm without being close to the theory value (e value=1). In this way, it is ensured that the reflectance of the polarizing element 250 is less than 6%, or less than 5.5%, and the overall reflectivity of the polarizing element 250 and the optical touch element 210 can be less than 7%. Alternatively, the optical characteristics of the quarter-wave plate 276 in this embodiment, and the optical characteristics after it is combined with the touch element are the same as those in the foregoing embodiments, and will not be repeated here.

In another embodiment of the present invention, the polarizing element 250 may also include a film-type quarter wave plate, or a film-type quarter wave plate Combination with polymer film type (film-type) half wave plate. Polymer membrane material can be: PC, CPI or COP etc. That is to say, regardless of the material or laminated layers of the polarizing element 250, as long as it is the same as the foregoing embodiments, the present invention can be implemented.

To sum up, the present disclosure provides a touch display module, including a polarizing element with reflectivity less than 6%, or less than 5.5%. The polarizing element uses a liquid crystal coating type phase retardation film assembly, and the overall thickness is reduced. In addition, the absolute value of the circular polarization conversion rate (e value) of the liquid crystal coating type phase retardation film assembly is greater than 0.8 and does not have to be close to the theoretical ideal value, so that the linearly polarized light passing through the polarizing element is converted into circularly polarized light or close to circularly polarized light , so as to reduce the reflected light; in addition, the overall reflectance of the polarizing element and the touch element can be less than a specific value in the wavelength range sensitive to the human eye, for example, the overall reflectance is less than 7%, or less than 6%, which improves the user's vision and operational experience.

The embodiments disclosed above are not intended to limit this disclosure. Anyone who is familiar with the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all of them can be protected in this disclosure. . Therefore, the scope of protection of this disclosure should be defined by the scope of the appended patent application.

100,200: touch display module 110,210: touch components 120,220: display unit 150,250: polarizer 160,260: Polarizer 170,270: Phase retardation film assembly 173: 1/2 wave plate 176,276: quarter wave plate 300: reflective surface a1, a2, a3: optical axis a,b,c,d: data points D1, D2: direction L: light L1, L2, L3, L1’, L2’, L3’: light/ray θ1, θ2: angle

In order to make the above and other purposes, features, advantages and embodiments of the present disclosure more comprehensible, the accompanying drawings are described as follows: FIG. 1 shows a schematic cross-sectional view of a touch display module according to an embodiment of the present disclosure; FIG. 2 shows an exploded schematic diagram of a polarizer according to an embodiment of the present disclosure; FIG. 3 shows a schematic diagram of an included angle of an optical axis composed of a polarizing element according to an embodiment of the present disclosure; FIG. 4 shows a relationship diagram between a circular conversion rate and a reflectance of a polarizer according to an embodiment of the present disclosure; Fig. 5 shows a relationship diagram between the absolute value of the circular deflection conversion rate and a reflectivity; FIG. 6 shows a relationship diagram of a touch display module corresponding to different incident wavelengths and corresponding reflectivity according to an embodiment of the present disclosure; and FIG. 7 shows a schematic cross-sectional view of a touch display module according to an embodiment of the present disclosure.

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

100:Touch display module

110:Optical touch element

120: display unit

150: polarizing element

160: Polarizer

170:Phase retardation film assembly

173: 1/2 wave plate

176: Quarter wave plate

D1, D2: direction

Claims (10)

A touch display module, comprising: a touch element; and A polarizing element is arranged on the touch element, and the polarizing element includes: a linear polarizer; and A phase retardation film assembly, wherein when an ambient light passes through the linear polarizer, the linearly polarized light is converted into a circularly polarized light through the phase retardation film assembly, wherein the ratio of the linearly polarized light to the circularly polarized light is defined as the phase retardation film Circular conversion ratio of the assembly, Wherein in the wavelength range between 450nm and 650nm, the absolute value of the circular conversion rate is greater than 0.8, Wherein in the wavelength range between 450nm and 650nm, the reflectance of the ambient light passing through the polarizing element is less than 6%. The touch display module as described in claim 1, wherein the touch element includes: A touch sensor made of silver nanometer wire and/or polymer film is arranged on the linear polarizer or on the phase retardation film assembly. The touch display module as described in claim 2, wherein the combination of the touch element and the polarizing element has a total reflectivity in the wavelength range between 450nm and 650nm, and the total reflectivity is less than 7% or less than 6 %; or in the wavelength range from 450 nm to 650 nm, the refractive index change rate caused by the polarizing element before and after being combined with the touch element is between 0% and 15%, and between 0% and 13%. between 0% and 8%, or between 0% and 2%. The touch display module as described in Claim 1, wherein the phase retardation film assembly is composed of a positive dispersion type one-half wave plate and a positive dispersion type one quarter wave plate. The touch display module as described in claim 4, wherein the angle of an optical axis of the half wave plate relative to the linear polarizer is in the range of 10 degrees to 15 degrees, and the quarter wave plate relative to the An optical axis angle of the linear polarizer is in the range of 65 degrees to 75 degrees. The touch display module according to Claim 1, wherein the phase retardation film assembly is composed of a reverse dispersion type quarter-wave plate. The touch display module according to Claim 6, wherein an angle of an optical axis of the quarter-wave plate relative to the linear polarizer is 45 degrees. The touch display module according to Claim 1, wherein the phase retardation film assembly includes a liquid crystal type phase retardation film or a polymer film type phase retardation film. The touch display module as described in claim 1, wherein the absolute value of the circular deflection conversion rate is in the range of 0.8 to 0.95 in the wavelength range of 450nm to 650nm, wherein between 450nm and 650nm In the wavelength range between, the reflectance of the ambient light passing through the polarizing element is less than 5.5%. A touch display module, comprising: a touch element; and A polarizing element is arranged on the touch element, and the polarizing element includes: a linear polarizer; and A phase retardation film assembly, wherein when an ambient light passes through the linear polarizer, the linearly polarized light is converted into a circularly polarized light through the phase retardation film assembly, wherein the ratio of the linearly polarized light to the circularly polarized light is defined as the phase retardation film Circular conversion ratio of the assembly, Wherein at a wavelength of 550nm, the absolute value of the circular conversion rate is greater than 0.9, Wherein at a wavelength of 550nm, the reflectance of the ambient light passing through the polarizing element is less than 5%.

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