JP2023013912A - touch display module - Google Patents

Abstract

To provide a touch display module having sufficiently low reflectance, configured to reduce reflected light from an external environment, and having no effect on display quality.SOLUTION: A touch display module 100 includes a touch device 110 and a polarization element 150. The polarization element includes a polarizer 160 and a retardation film assembly 170. The retardation film assembly has a polarization ellipticity value (e value). An absolute value of the e value is larger than 0.8. A reflectance of the polarization element is less than 6%. Total reflectance of the touch device and the polarization element is less than 7%.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to touch display modules.

Organic light-emitting diode displays have the advantages of low power consumption, high color vividness, high contrast, etc., and can provide people with better visual enjoyment, but one of the biggest challenges is the external environment. An object of the present invention is to effectively suppress reflected light caused by incident light and reduce display problems. One solution is to implement a circular polarizer as an antireflection film to reduce the amount of reflected light after ambient light enters the display. The theoretical principle of a circular polarizer using a quarter-wave plate (QWP) and a linear polarizer is to circularly polarize external ambient light incident on the display. Incident circularly polarized light (eg, left-handed rotating light) is flipped into another circularly polarized light of opposite polarization direction (eg, right-handed rotating light) after being reflected by the electrodes of the display. The opposite circularly polarized light passes through the QWP again and becomes linearly polarized orthogonal to the polarization direction of the linear polarizer. For this reason, linearly polarized light perpendicular to the polarization direction of the linear polarizer cannot pass through the linear polarizer, and external environmental light reflected by the electrodes is removed or reduced, thereby eliminating problems such as reflection interference and uneven brightness on the display screen. Avoided. Based on the above principle, the first step of the antireflection mechanism is to circularly polarize the external environment light by the antireflection film, which is one of the important factors of the antireflection effect. In general, the antireflection effect can be improved by increasing the conversion rate of circularly polarized light with the same material.

Taiwan Patent No. 580995

As disclosed in prior art Taiwan Patent No. 580995 (hereinafter TW'995), an ambient light anti-reflection coating is provided that includes a linear polarizing layer and a chiral liquid crystal layer. Examples 1-4 in Table II of TW'995 show a minimum light reflectivity of 7.62 when the conversion of circular polarization is about 1 (i.e., linear polarization is completely converted to circular polarization). %. However, the present disclosure addresses the increasingly sophisticated display requirements when the reflectance is around 8%, especially in today's high resolution and high quality video, such as 4K and 8K, which have been favored by users. Insist that you can't meet. On the other hand, the touch-sensing electrodes assembled in the display have become one of the important human-machine interfaces in today's society, and the touch-sensing electrodes also cause the reflection of ambient light. In summary, the reflectance of the ambient light anti-reflection film supplied by TW'995 is too high, so it cannot meet the high-end display requirements after the display is assembled with the touch sensing electrodes. In other words, how to obtain an antireflection sheet with low reflectance is actually a major problem for those skilled in the art.

On the other hand, the conversion of circularly polarized light from Examples 1-4 at TW'995 is about 1, which corresponds to the ideal value, assuming laboratory-grade liquid crystal materials, which are very expensive and disadvantageous in commercial applications. . In the commercial market, the material specifications of electronic products are not very close to ideal values when considering cost. That is, considering typical commercial specifications/costs, the circular conversion of Examples 1-4 of TW'995 should be reduced (e.g. circular conversion is reduced to 0.9). . As a result, the above-described light reflectance also increases, and it is considered that the requirement for low reflectance cannot be further satisfied.

Furthermore, the chiral liquid crystal layer used in TW'995 is a cholesteric liquid crystal, and its working principle is that multiple crystals with different axial directions are used to achieve circular polarization of light, as shown in FIG. 2 of TW'995. It is to laminate the liquid crystal. For this reason, the multi-layer liquid crystal structure of TW'995 cannot reduce the thickness of the ambient light anti-reflection film, which poses a problem that it is not possible to meet the user's demand for light and thin portable devices.

The touch display module of an embodiment in the present disclosure has a sufficiently low reflectivity, thereby reducing reflected light from the external environment and not affecting display quality.

The technical solutions adopted in the present disclosure are as follows.

One aspect of the present disclosure is to provide a touch display module. According to one or more embodiments of the present disclosure, a touch display module includes a touch device and a polarizing element. A polarizing element is disposed on the touch device. A polarizing element includes a linear polarizer and a retardation film assembly. When ambient light passes through a linear polarizer to produce linearly polarized light, the linearly polarized light passes through the retardation film and is converted to circularly polarized light. The ratio of linearly polarized light converted to circularly polarized light is defined as the polarization ellipticity of the retardation film assembly. The absolute value of the polarization ellipticity value is greater than 0.8 in the wavelength range from 450 nm to 650 nm. The reflectance of ambient light passing through the polarizer is less than 6% in the wavelength range of 450 nm to 650 nm.

According to one or more embodiments of the present disclosure, a touch device includes a touch sensor. The touch sensor includes at least one of silver nanowires or polymer films, and the touch sensor is disposed on the linear polarizer or retardation film assembly.

According to one or more embodiments of the present disclosure, the touch device and polarizing element combination has a total reflectance in the wavelength range of 450 nm to 650 nm, with a total reflectance of less than 7% or less than 6%. In the wavelength range of 450 nm to 650 nm, the reflectance change rate before and after combining the polarizing element and the touch device is 0% to 15%, 0% to 13%, 0% to 8%, or 0% to 2%. Range.

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

According to one or more embodiments of the present disclosure, the optic axis angle of the positive dispersion half-wave plate with respect to the linear polarizer is in the range of 10° to 15°, and the positive dispersion quarter-wave plate with respect to the linear polarizer The plates range from 65° to 75°.

According to one or more embodiments of the present disclosure, the retardation film assembly includes an inverse dispersion quarter wave plate.

According to one or more embodiments of the present disclosure, the optic axis angle of the inverse dispersive quarter-wave plate with respect to the linear polarizer is 45°.

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, the absolute value of the polarization ellipticity value is in the range of 0.8-0.95 in the wavelength range of 450 nm-650 nm. The reflectance of ambient light passing through the polarizer is less than 5.5% in the wavelength range of 450 nm to 650 nm.

One aspect of the present disclosure is to provide a touch display module. According to one or more embodiments of the present disclosure, a touch display module includes a touch device and a polarizing element. A polarizing element is disposed on the touch device. A polarizing element includes a linear polarizer and a retardation film assembly. When ambient light passes through the linear polarizer to produce linearly polarized light, the linearly polarized light passes through the retardation film assembly and is converted to circularly polarized light. The ratio of linearly polarized light converted to circularly polarized light is defined as the polarization ellipticity of the retardation film assembly. The absolute value of the polarization ellipticity value is greater than 0.9 at a wavelength of 550 nm, and the reflectance of ambient light passing through the polarizing element is less than 5% at a wavelength of 550 nm.

Thus, according to the embodiments of the present disclosure, the polarization ellipticity value of the polarizing element does not need to be close to the theoretical value, so the touch display module can reduce the reflection of incident light from the external environment, and the touch display module can It can improve the visual and operating experience of the display module without excessively increasing the product cost.

The above description is for explaining the problems to be solved, the technical methods for solving the problems, the effects thereof, etc. In the following embodiments and related drawings, the specific contents of the present disclosure are described. explain.

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

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

1 is an exploded schematic diagram of a polarizing element according to an embodiment of the present disclosure; FIG.

FIG. 4 is a schematic diagram of an included optical axis angle formed by a polarizing element according to an embodiment of the present disclosure;

FIG. 4 is a relationship diagram between a polarization ellipticity value and a reflectance of a polarizing element according to an embodiment of the present disclosure;

4 is a relational diagram between absolute values of polarization ellipticity and reflectance. FIG.

FIG. 4 is a relationship diagram of a touch display module corresponding to different incident wavelengths and related reflectances according to an embodiment of the present disclosure;

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

Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. It will be apparent to those skilled in the art that various modifications and variations can be made to the structures of the disclosure without departing from the scope or spirit of the disclosure, according to the embodiments.

For display devices, reflected light from the external environment affects the user's visual experience. For users of touch display modules, the reflection of external environment light will further affect the operating experience. Although the wavelength range of external ambient light is very wide, the present disclosure aims at anti-reflection optical tuning in the wavelength band to which the human eye is sensitive (ie, 450nm-650nm).

The present disclosure can reduce the reflection of external environment light, thereby reducing the interference of the reflection of external environment light to the visual and operation experience, and maintaining a thin thickness. Regarding. The present disclosure does not need to reach or approach the ideal polarization ellipticity (ie, the polarization ellipticity value is equal to 1) of the polarizing element of the touch display structure in order to obtain an antireflective element with low reflectance. Therefore, there is a balance between cost and quality.

Referring to FIG. 1, FIG. 1 is a cross-sectional schematic diagram of a touch display module 100 according to an embodiment of the present disclosure. As shown in FIG. 1 , in one embodiment of the present disclosure, the touch display module 100 includes at least a touch device 110 and a polarizer 150 .

In this embodiment, the touch device 110 can be assembled with the display unit 120 . For example, the touch device 110 and the display unit 120 are bonded with an optical adhesive (OCA).

In some embodiments, the display unit 120 may be an organic light emitting diode (OLED), miniature light emitting diode (mini LED) display, or the like. Organic light emitting diode displays have the advantages of low power consumption, high color vividness and high contrast. In some embodiments, one or more organic light emitting diodes of display unit 120 can form an active matrix organic light emitting diode (AMOLED) for displaying images and signals.

As shown in FIG. 1, in one embodiment of the present disclosure, the display unit 120 can emit light L in direction D1 to display the screen accordingly. That is, the user can receive the signal transmitted from the display unit 120 in the D1 direction.

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

In some embodiments of the present disclosure, the touch device 110 includes electrodes patterned by a transparent conductive layer or film with high transmittance. For example, the light transmission for visible light (eg, wavelengths between 400 nm and 700 nm) is about 88%, 90%, 91%, 92%, 93%, or more. In some implementations, one of the transparent conductive layer or film comprises an indium tin oxide (ITO) material, a silver nanowire (SNW) material, or the like.

Referring again to FIG. 1, the polarizing element 150 is disposed on the touch device 110 as shown in FIG. In some embodiments of the present disclosure, the polarizing element 150 can convert ambient light from the external environment (eg, light L1 in FIG. 2) into polarized light, thereby reducing reflected light from the ambient light. and emitted outward in the direction of D1 to affect the user when looking at the screen. See the discussion below for details.

As shown in FIG. 1, polarizing element 150 includes linear polarizer 160 and retardation film assembly 170 . In this embodiment, retardation film assembly 170 is positioned between the light emitting surface (eg, optical touch structure) of touch device 110 and linear polarizer 160 .

Linear polarizer 160 can be configured to convert light passing through it into linear polarization. In some embodiments of the disclosure, the degree of polarization (DOP) of linear polarizer 160 is greater than 98%, although the disclosure is not so limited.

In some embodiments, retardation film assembly 170 includes one or more retarders. In this embodiment, the retardation film assembly 170 consists of a positive dispersion half-wave plate (HWQ) 173 and a positive dispersion quarter-wave plate (QWP) 176 . In this embodiment, QWP 176 and HWQ 173 are each single-layer liquid crystal coating layers. For example, QWP176 and HWQ173 are commercial products made of reactive mesogenic (RM) liquid crystals (eg manufacturer: DNP, commercial products: DNP_HWP and DNP_QWP).

Thus, the retardation film assembly 170 can be regarded as a liquid crystal coated retardation element. Since the liquid crystal is only a few microns (μm) thick, the overall thickness can be reduced. Compared with the layer thickness of the multilayer cholesteric liquid crystal used in the prior art TW'995, the RM used in this embodiment has one It only needs to be covered with a layer.

Referring to FIG. 2, when external ambient light L1 is incident, the light is incident generally along a direction D2 opposite to direction D1 (i.e., the direction shown in the figure) and is linearly polarized by linear polarizer 160. converted to L2. Linearly polarized light L2 passes through HWQ 173 and QWP 176 and is converted to circularly polarized light L3 (eg counterclockwise rotating light). When the circularly polarized light L3 is reflected by the touch device 110 or the display unit 120, an inverse circularly polarized light L3' opposite to the circularly polarized light L3 (eg, clockwise rotating light) is formed. At this time, the inverse circularly polarized light L3' passes through the retardation film assembly 170 and forms linearly polarized light L2' perpendicular to the optical axis of the linear polarizer 160. FIG. Since the polarization angle is orthogonal to the optical axis of the linear polarizer 160, the linearly polarized light L2' cannot exit from the linear polarizer 160. That is, in an ideal state, no reflected light L1' is generated. Thus, the polarizing element 150 having optical properties is called a circular polarizer (CPOL), and can be used to eliminate or reduce reflected light in optical applications, so the polarizing element 150 is also called an antireflection element.

That is, the polarizing element 150 converts the external ambient light into circularly polarized light, and the circularly polarized light is reflected again. Due to this polarization angle, the reflected circularly polarized light is blocked by linear polarizer 160 . Accordingly, it is possible to prevent the reflection of the external environment light from affecting the visual effect of the touch display module 100 . Linearly polarized light can be converted into ideal perfect circularly polarized light or elliptically polarized light that is close to circularly polarized light through the polarizing element 150 . Accordingly, the polarization ellipticity value (e value) of the retardation film assembly 170 can be defined according to the ratio of the linearly polarized light L2 converted to circularly polarized light. The polarization ellipticity value (e value) is a positive or negative numerical value depending on left-handed or right-handed rotation. For convenience of explanation, the polarization ellipticity values (e values) of the present disclosure are expressed as absolute values.

For example, when the circularly polarized light L3 is right-handed circularly polarized light, the polarization ellipticity value (e-value) of the retardation film assembly 170 is +1 (ie, perfect conversion). When the circularly polarized light L3 is elliptical polarized light with clockwise rotation of elliptical polarized light, that is, a combination of a part of linearly polarized light and a part of circularly polarized light, the retardation film assembly 170 has a polarization ellipticity value (e value) of -1. greater than or equal to 0 or less. Generally, when linearly polarized light is completely converted into circularly polarized light, the absolute value of the polarization ellipticity value (e value) is 1.

In some embodiments, the absolute value of the polarization ellipticity value (e-value) of the retardation film assembly 170 is less than one. That is, an antireflection effect can be obtained, but the value does not need to be close to the ideal polarization ellipticity (for example, the ideal e value is 1). Specifically, in some embodiments, the absolute value of the polarization ellipticity value (e-value) of the retardation film assembly 170 is greater than 0.8 (not necessarily the ideal e-value) in the wavelength range of 450 nm to 650 nm. as long as it is not close), the overall reflectance of the touch display module 100 can be effectively reduced. For example, the reflectance is less than 6% or less than 5.5%.

Furthermore, if the absolute value of the polarization ellipticity value (e-value) of the retardation film assembly 170 is greater than 0.8, but need not be close to the perfect polarization ellipticity value (e-value), the overall It shows that the reflectance can be effectively reduced.

FIG. 3 is a schematic diagram of the included optical axis angles θ1, θ2 formed by the polarizer 150 according to one embodiment of the present disclosure. The optical axis a1 corresponds to the linear polarizer 160, as shown in FIG. The polarization element 150 has an optical axis a2 corresponding to the HWQ173 of the positive dispersion coating type liquid crystal, and an optical axis a3 corresponding to the QWP176 of the positive dispersion coating type liquid crystal. Since HWQ 173 and QWP 176 are liquid crystal materials, HWQ 173 and QWP 176 each have their own optical axis. In this embodiment, the optical axis a2 and the optical axis a3 mean the slow axis of the element.

As shown in FIG. 3, the angle between the optical axis a1 and the optical axis a2 of the linear polarizer 160 is an angle θ1. The angle between the optical axis a1 and the optical axis a3 of the linear polarizer 160 is the angle θ2. In some embodiments, the range of each of angles θ1, θ2 may be between 0° and 180°. In this embodiment, the angle θ1 is 15° and the angle θ2 is 75°, but they are not limited to these. In one embodiment, the angle θ1 ranges from 10° to 15° and the angle θ2 ranges from 65° to 75°, although the disclosure is not so limited.

Referring again to FIG. 2, FIG. 2 is a schematic diagram of the test apparatus. According to one embodiment of the present disclosure, incident light L1 enters polarizing element 150 and is reflected into polarizing element 150 by reflective surface 300 having a reflectance of approximately 50-60%. It passes through to form reflected light L1'. Reflective surface 300 is, for example, a semi-reflective mirror (manufacturer: 3DLens, for example). FIG. 4 is a diagram showing the relationship between the absolute value of the polarization ellipticity (e value) and the reflectance (%) of the polarizing element 150 measured in the above embodiment.

As shown in FIG. 4 and Table 1, the absolute values of the polarization ellipticity values (e values) of the polarizing element 150 of the present disclosure, corresponding to the incident light L1 having a wavelength of 450 nm to 650 nm, are all 0 as indicated by the dotted line. .8 or more. The reflectance (R%) is less than 6%, ie less than 5.5%, corresponding to the incident light L1' having a wavelength in the range of 450 nm to 650 nm.

As described above, the absolute values of the polarization ellipticity (e value) of the polarizing element 150 of the present embodiment are all 0.8 or more, corresponding to the incident light L1 in the wavelength range of 450 nm to 650 nm. The reflectance (R%) of the polarizing element 150 in the wavelength range of 450 nm to 650 nm to which the eye is sensitive is less than 6%, ie less than 5.5%. Specifically, the absolute value of the polarization ellipticity (e value) of the polarizing element 150 of the present embodiment is in the range of 0.82 to 0.92, corresponding to the incident light L1 in the wavelength range of 450 nm to 650 nm. However, it is not necessary to approach the theoretical value (i.e., the ideal e value = 1), and the reflectance (R%) in the wavelength range from 450 nm to 650 nm can be less than 6% or less than 5.5%. This is advantageous in terms of commercial/industrial production costs. In one embodiment, the absolute value of the polarization ellipticity value (e-value) of the polarizing element 150 may be in the range of 0.8 to 0.95, but not necessarily the theoretical value (i.e., e-value=1). It does not need to be close and the reflectance in the range 450 nm to 650 nm is less than 6% or less than 5.5%.

Specifically, when the incident wavelength of the incident light L1 is 550 nm, the absolute value of the polarization ellipticity (e value) of the polarizing element 150 of the present embodiment may be 0.9 or more, but the theoretical value ( That is, the e-value=1) need not be approached, and the reflectance (R %) in the 550 nm wavelength range can be less than 6%, less than 5.5%, or less than 5%. Specifically, the absolute value of the polarization ellipticity (e value) of the polarizing element 150 of the present embodiment may be 0.92 or more corresponding to the incident light L1 having a wavelength of 550 nm, but the theoretical value (that is, It is not necessary to approach the e-value=1), and the reflectance (R%) at a wavelength of 550 nm may be 4.9%. As a result, there is an advantage in commercial/industrial production costs. To summarize the above, the absolute value of the polarization ellipticity (e value) of the polarizing element 150 of the present embodiment may be 0.9 to 0.95 at a wavelength of 550 nm, which is a theoretical value (that is, e value = 1). , and the reflectance (R %) at a wavelength of 550 nm to which the human eye is sensitive can be set to 4.5 to 5.0%.

FIG. 5 is a diagram showing the relationship between the absolute value of the polarization ellipticity value (e value) and the reflectance. Under incident light in the range of 450 nm to 650 nm, the horizontal axis of FIG. are arranged to represent the different reflectances (R%) of the corresponding polarizing elements of the retardation film assembly. According to the relationship diagram, when the absolute value of the polarization ellipticity (e value) exceeds 0.8, the reflectance (R%) of the polarizing element is less than 6% if the incident light is in the range of 450 nm to 650 nm. can do. On the other hand, when the central angle between the slow axis of the HWQ 173 and the optical axis a1 of the linear polarizer 160 is greater than 15°, or when the central angle between the slow axis of the QWP 176 and the optical axis a1 of the linear polarizer 160 is 75° , the absolute value of the polarization ellipticity (e value) is less than 0.8, and the reflectance (R%) of the polarizing element in the wavelength range of 450 nm to 650 nm (data points a, b, c, d, see) becomes greater than 6% and fails to meet the requirements. All other data points in FIG. 5 have been satisfied by the previously described embodiment and will not be repeated here.

According to one embodiment of the present disclosure, after the touch device 110 is assembled with the polarizer 150, it is tested to measure the polarization ellipticity (e-value) and light reflectance in the wavelength range of 450 nm to 650 nm. In one embodiment, the combination of touch device 110 and polarizer 150 can be integrated as an optoelectronic device, ie, an integrated device that has both optical and electrical functions. Here, the electrical function refers to the touch sensing function, and the optoelectronic element has total reflectance. In addition, since the touch device 110 also reflects light, the total reflectance of the photoelectric element is slightly higher than the total reflectance of the polarizer 150, and the total reflectance of the product is adjusted to the extent that the display quality is not affected. should be reduced. For the test method of this embodiment, reference can be made to the above-mentioned related descriptions shown in FIG. 2, and the test method is not repeated here.

In one embodiment, touch device 110 includes at least touch electrodes comprising silver nanowires and/or polymer films. Its particular method may be referred to and introduced/incorporated by the general description of US20190227650, Chinese Patent No. 101292362, etc. As shown in FIG. 6, the total reflectance of the integrated elements of the touch device 110 and the polarizing element 150 is in the wavelength range from 450 nm to 650 nm to which the human eye is sensitive, as shown in Table 2 below. can be less than 7% in

As shown in the above table, the reflectance in the wavelength range of 450 nm to 650 nm of the optoelectronic device of the present embodiment is less than 7%, ie less than 6%, corresponding to the incident light L1 in the wavelength range of 450 nm to 650 nm. In general, the reflectance in the wavelength range of 450 nm to 650 nm of the optoelectronic device of this embodiment is in the range of 5% to 6%.

More specifically, the reflectance of the optoelectronic device of this embodiment at a wavelength of 550 nm is less than 6%, or less than 5.5%, corresponding to the incident light L1 having a wavelength of 550 nm. More specifically, the reflectance of the optoelectronic device of this embodiment at a wavelength of 550 nm is 5.3%, corresponding to the incident light L1 with a wavelength of 550 nm. In general, the reflectance of the optoelectronic device of this embodiment at a wavelength of 550 nm is in the range of 5.0% to 5.5%.

Furthermore, when two components with different functions are assembled together, the properties of the components are usually influenced by each other. It can be seen that, according to embodiments of the present disclosure, when touch electrodes made of silver nanowires and/or polymer films are assembled to the polarizer 150, the properties of the polarizer 150 are not excessively degraded. Specifically, in embodiments of the present disclosure, when comparing touch electrodes composed of silver nanowires and/or polymer films assembled with polarizing elements 150 and polarizing elements 150 not assembled with touch electrodes, the is less than 15% in the wavelength range of . In general, the reflectance change of optoelectronic devices of embodiments of the present disclosure in the wavelength range of 450 nm to 650 nm ranges from 0% to 15%, 0% to 13%, 0% to 8%, or 0% to 2%. is.

More specifically, the reflectance change rate is less than 10% when corresponding to a wavelength of 550 nm. Specifically, when corresponding to a wavelength of 550 nm, the reflectance change rate is less than 8%. In summary, when corresponding to a wavelength of 550 nm, the reflectance change rate of the photoelectric elements of the embodiments of the present disclosure in the wavelength range of 450 nm to 650 nm is 0% to 10%, 5% to 10%, or 5% to 8%. %.

In some embodiments, a transparent protective cover can also be provided over the polarizing element 150 .

FIG. 7 is a cross-sectional schematic diagram of a touch display module 200 according to one embodiment of the present disclosure.

In this embodiment, as shown in FIG. 7, the touch display module 200 includes an optical touch element 210 and a polarizing element 250, which includes a polarizer 260 and a liquid crystal coated retardation film assembly 270. include.

A difference from the above embodiments is that at least the retardation film assembly 270 may include a retardation plate. In this embodiment, the retardation film assembly 270 has an inverse dispersion quarter-wave plate (QWP) 276 . In this embodiment, QWP 276 is a single layer liquid crystal coating layer. For example, QWP276 (eg manufacturer: DNP, commercial product: DNP_QWP) is a commercial product of reactive mesogenic (RM) liquid crystals. In this embodiment, QWP 276 has a single optic axis, and an included optic axis angle is formed between the optic axis (eg, slow axis) of QWP 276 and the optic axis of polarizer 260 . In some embodiments, the aforementioned included optical axis angle ranges from 0° to 180°. In some embodiments, the aforementioned included optical axis angle is 45 degrees. In some embodiments, the aforementioned included optical axis angle has a range of 40° to 50°.

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

As in the previous embodiment, the absolute value of QWP276 in the incident wavelength range of 450 nm to 650 nm is less than 0.8, and the polarization ellipticity (e value) is 0.82 or more and 0.92 or less, but the theoretical value ( That is, it is not necessary to approach e value=1). This allows the reflectance (R%) of the polarizing element 250 to be less than 6% or less than 5.5%, and the total reflectance of the polarizing element 250 and the optical touch element 210 to be less than 7%. Alternatively, the optical characteristics of the QWP 276 described in this embodiment and the optical characteristics of the QWP 276 assembled with the optical touch element are similar to those of the previous embodiments and are omitted here.

In another embodiment of the present disclosure, the polarizing element 250 may comprise a polymer film type QWP or a combination of polymer film type QWP and polymer film type HWP. Polymer film materials include PC (polycarbonate), CPI (colorless polyimide), COP (cycloolefin polymer), and the like. In other words, the present disclosure can be implemented regardless of the material and laminate of the polarizing element 250 as long as it is the same as the above embodiment.

In summary, the present disclosure provides a touch display module that includes a polarizing element with a reflectance of less than 6% or less than 5.5%. The polarizing element is implemented with a liquid crystal coated retardation film assembly so that the overall thickness can be reduced. In addition, although the absolute value of the polarization ellipticity value (e value) of the liquid crystal coating type retardation film assembly is larger than 0.8, it is not necessary to approach the ideal value. By converting to near light, the reflected light of the touch display module can be reduced. Furthermore, the total reflectance of the polarizing element and the touch device can be less than a certain value in the wavelength range to which the human eye is sensitive, for example, the total reflectance is less than 7% or less than 6%, and the touch display Improve the visual and operational experience of the module.

Although the disclosure has been described in considerable detail with reference to specific embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structures of the disclosure without departing from the scope or spirit of the disclosure. In view of the above, it is intended that this disclosure cover the modifications and variations of this disclosure insofar as they come within the scope of the following claims and their equivalents.

Claims (8)

a touch device;
a polarizing element disposed on the touch device;
The polarizing element is
a linear polarizer;
A retardation film assembly through which the linearly polarized light is transmitted and converted to circularly polarized light when ambient light is transmitted through the linear polarizer to generate linearly polarized light, wherein the proportion of the linearly polarized light that is converted to the circularly polarized light is the polarization ellipticity of the retardation film assembly;
including
The absolute value of the polarization ellipticity is greater than 0.8 in the wavelength range of 450 nm to 650 nm,
The reflectance of the ambient light passing through the polarizing element is less than 6% in the wavelength range of 450 nm to 650 nm.
touch display module. The combination of the touch device and the polarizing element includes:
having a total reflectance in the wavelength range of 450 nm to 650 nm, wherein the total reflectance is less than 7% or less than 6%;
or
In the wavelength range of 450 nm to 650 nm, the reflectance change achieved before and after combining the polarizing element and the touch device is 0% to 15%, 0% to 13%, 0% to 8%, or 0. % to 2%,
The touch display module of claim 1. The absolute value of the polarization ellipticity is 0.8 to 0.95 in the wavelength range of 450 nm to 650 nm,
The reflectance of the ambient light passing through the polarizing element is less than 5.5% in the wavelength range of 450 nm to 650 nm.
The touch display module according to claim 1 or 2. a touch device;
a polarizing element disposed on the touch device;
The polarizing element is
a linear polarizer;
A retardation film assembly through which the linearly polarized light is transmitted and converted to circularly polarized light when ambient light is transmitted through the linear polarizer to generate linearly polarized light, wherein the proportion of the linearly polarized light that is converted to the circularly polarized light is the polarization ellipticity of the retardation film assembly;
including
The absolute value of the polarization ellipticity is greater than 0.9 at a wavelength of 550 nm,
The reflectance of the ambient light transmitted through the polarizing element is less than 5% at a wavelength of 550 nm.
touch display module. The combination of the touch device and the polarizing element includes:
has a total reflectance at a wavelength of 550 nm, and the total reflectance is less than 6% or less than 5.5%;
or
At a wavelength of 550 nm, the reflectance change rate before and after combining the polarizing element and the touch device is in the range of 0% to 10%, 5% to 10%, or 5% to 8%.
The touch display module of claim 4. The absolute value of the polarization ellipticity is in the range of 0.9 to 0.95 at a wavelength of 550 nm,
The reflectance of ambient light passing through the polarizing element is in the range of 4.5 to 5.0% at a wavelength of 550 nm.
The touch display module according to claim 4 or 5. the touch device includes a touch sensor comprising at least one of silver nanowires or a polymer film, the touch sensor disposed on the linear polarizer or the retardation film assembly;
The touch display module according to any one of claims 1-6. the retardation film assembly includes an inverse dispersion quarter-wave plate;
The inverse dispersion quarter-wave plate is a cycloolefin polymer (COP),
The touch display module according to any one of claims 1-7.

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