TWM635579U - Multi-angle Privacy Screen and Polarizer - Google Patents

Abstract

A multi-angle anti-spying film for multi-angle anti-peeping on the surface of a display element, comprising a half-wave plate, a polarizer, and a high retardation film sandwiched between the half-wave plate and the polarizer, and The thickness retardation value (R _th ) of the high retardation film is between -500~-1800nm. In addition, the present invention also provides a polarizing plate with the multi-angle privacy protection sheet.

Description

Multi-angle Privacy Screen and Polarizer

The present invention relates to a privacy-preventing polarizer and a polarizer, in particular to a privacy-prevention polarizer capable of multi-angle privacy protection, and a polarizer with the privacy-prevention polarizer.

In order to avoid the use of 3C products in public places, such as laptops or mobile phones, from being peeped by people around when transmitting information, therefore, the viewing angle of these 3C products can be limited by adding anti-peeping components, so that users can only view them by The front view of the screen prevents people outside the viewing angle from watching the screen, achieving the purpose of anti-peeping and maintaining the privacy of users.

At present, common anti-peeping components use anti-peeping patches that are directly attached to the display surface of the display. This type of anti-peeping patch mainly uses the principle of blinds to limit the outgoing light of the display to a certain range of viewing angles. The light outside the viewing angle range cannot pass through, so as to produce an anti-peeping effect.

Although the above-mentioned anti-peeping elements can achieve the anti-peeping effect, generally they can only prevent peeping at the angle of a single direction. Angle of view, and can not have anti-peep effect at the same time.

Therefore, the purpose of the present invention is to provide a multi-angle anti-spy sheet for the surface of the display element, which can prevent multi-angle privacy.

Therefore, the multi-angle anti-spy film of the present invention includes a half-wave plate, a polarizer, and a high retardation film sandwiched between the half-wave plate and the polarizer.

Wherein, the thickness retardation value (R _th ) of the high retardation film at a wavelength of 550nm is between -500~-1800nm.

In addition, another object of the present invention is to provide a polarizing plate used for display elements and capable of multi-angle anti-peeping.

Therefore, the polarizer of the present invention includes an upper polarizer and a multi-angle anti-peep unit.

The multi-angle anti-peeping unit includes a half-wave plate, a polarizer, and a high retardation plate sandwiched between the half-wave plate and the polarizer.

Wherein, the half-wave plate is sandwiched between the upper polarizer and the high retardation film, and the thickness retardation value (R _th ) of the high retardation film at a wavelength of 550nm is between -500~-1800nm.

The effect of this new model is: by making the phase value R _th of the high retardation film between -500~-1800nm, and setting a half-wave plate and a polarizer on the opposite surfaces of the high retardation film respectively, the polarization can be utilized. The light turns to achieve the purpose of anti-peeping from multiple angles.

100: display components

101: display surface

102: LCD module

103: lower polarizer

104: Upper polarizer

2: Multi-angle anti-spy film

21: Polarizer

22: half wave plate

23: High retardation film

3: polarizer

X, A: light absorption axis

θ: included angle

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: FIG. 1 is a schematic diagram illustrating this embodiment of the present invention; FIGS. Describe the spectrum measurement results of these specific examples, comparative examples, and comparative examples respectively; Figures 5-6 are a viewing angle distribution measurement, respectively explaining the viewing angle distribution measurement results of this specific example 3 and comparative example 4 ; Fig. 7 is a spectrogram of a bright state white picture facing up to it, which respectively illustrate the measured results of the bright white picture spectrum of this specific example 3 and commercially available examples 1 and 2; The viewing angle distribution measurement results of Example 3 and Commercial Examples 1 and 2; and FIG. 9 is a schematic diagram illustrating a schematic structure of integrating this embodiment of the present invention with the upper polarizer into a polarizer.

The relevant technical content, features and functions of the present invention will be clearly presented in the following detailed description of the embodiments with reference to the drawings. In addition, it should be noted that the drawings of the present invention only represent the structure and/or relative positional relationship between components, and are not related to The actual size of the elements is not relevant.

Referring to FIG. 1 , the novel multi-angle anti-peeping sheet 2 can be applied to a display element 100 to achieve multi-angle anti-peeping effect. Wherein, the display element 100 can be a liquid crystal display, an organic light-emitting diode display (OLED), etc., and has a display surface 101 for display, and the multi-angle privacy protection sheet 2 can be combined with the The display surface 101 is used to make the display element 100 which originally has no anti-peep effect produce a multi-angle anti-peep effect. Since the relevant structure of the display element 100 is known in the technical field and is not the focus of this case, it will not be described in detail. In this embodiment, the display element 100 is a liquid crystal display, and only the display element is simply shown in FIG. 1 A liquid crystal module 102 of 100, a lower polarizer 103 (light absorption axis 90 degrees) and an upper polarizer 104 (light absorption axis 0 degrees) respectively located on opposite sides of the liquid crystal module 102, and the rest of the components are Omitted without explanation.

An embodiment of the multi-angle privacy protection sheet 2 includes a polarizer 21 , a half-wavelength sheet 22 , and a high retardation sheet 23 .

The polarizer 21 can be obtained by stretching polyvinyl alcohol (PVA) dyed with iodine or other dichroic dyes in the machine direction (MD) and then combining with two protective films, so as to integrate the display element 100 The polarized light emitted by the light source is converted into polarized light in a specific direction. The thickness of the polarizer 21 is 70-115 μm, and the angle θ between the light absorption axis A of the polarizer 21 and the light absorption axis X of the upper polarizer 104 is 45±2 degrees.

The optical axis angle of the half-wave plate 22 is 1/2 of the angle θ between the light absorption axis A of the polarizer 21 and the light absorption axis X of the upper polarizer 104 , so as to rotate the incident polarized light. In this embodiment, the in-plane retardation value (R ₀ ) of the half-wave plate 22 at a wavelength of 550 nm is between 216 nm and 296 nm.

In some embodiments, the half-wave plate 22 has a thickness retardation value (R _th ) of 96-175 nm at a wavelength of 550 nm.

The high retardation film 23 is sandwiched between the polarizer 21 and the half-wave film 22 , and the high retardation film 23 has a negative thickness retardation value (R _th ) at a wavelength of 550 nm. Preferably, the thickness retardation value (R _th ) of the high retardation film 23 at a wavelength of 550nm is between -500nm and -1800nm.

In addition, the high retardation film 23 can be produced by film stretching or liquid crystal coating, and can be obtained by stacking a single film layer or multiple film layers.

Preferably, the thickness retardation value (R _th ) of the high retardation film 23 is between -600nm~-900nm.

In some embodiments, the thickness retardation value (R _th ) of the high retardation film 23 is between -600nm~-750nm.

In some embodiments, the thickness retardation value (R _th ) of the high retardation film 23 is between −750 nm˜−900 nm.

In some embodiments, the high retardation film 23 is a uniaxial positive C-plate compensation film, and nz>nx=ny of the high retardation film 23, wherein, nx, ny, nz are the high retardation film 23 Refractive index in X, Y, Z axis direction at 550nm wavelength.

In some other embodiments, the refractive index ratio (NZ) of the high retardation film 23 at 550 nm is between -750~-1200.

，d：膜厚平面內相位差值(R₀)=(nx-ny)xd，d：膜厚折射率比(NZ)=(nx-nz)/(nx-ny) The aforementioned thickness retardation value (R _th ), the in-plane retardation value (R ₀ ) and the biaxiality level (NZ) can be obtained by the following formulas;

, d: film thickness in-plane retardation value (R ₀ )=(nx-ny)xd, d: film thickness refractive index ratio (NZ)=(nx-nz)/(nx-ny)

In order to describe this embodiment of the multi-angle privacy protection sheet 2 of the present invention more specifically, the following comparative examples, commercially available examples 1-2, specific examples 1-3 and comparative examples 1-4 are used for detailed description.

Wherein, the display element 100 is a liquid crystal display (the general structure is shown in Figure 1), and the light absorption axis X of the upper polarizer 104 is 0 degree, and the light absorption axis X of the lower polarizer 103 is 90 degrees as an example, but the actual Implementations are not limited to this. The comparative example is the display element 100 without any anti-peeping sheet on the surface, and the commercially available examples, specific examples and comparative examples are anti-peeping displays with different anti-peeping sheets attached to the surface of the display element 100 . In addition, in the specific examples and comparative examples, the half-wave plate 22 is bonded to the surface of the display element 100 .

Comparative example:

Display: upper polarizer 104 (light absorption axis X=0 degree)/liquid crystal module 102/lower polarizer 103 (light absorption axis=90 degrees).

Commercially available example 1:

Anti-spy film: brand/3M, model/3M PF12.5.

Display: Same as this control.

Commercially available example 2:

Anti-spy film: Brand/LG.

Display: Same as this control.

Specific example 1

Anti-spy film: polarizer 21 (light absorption axis A=45 degrees, that is, angle θ=45 degrees with the light absorption axis X of the upper polarizer 104)/high retardation film 23 (R _th )-600nm/half wave Sheet 22 (optical axis angle = 22.5 degrees).

Display: Same as this control.

Specific examples 2~3

The structures of specific examples 2 to 3 are the same as those of the specific example 1, except that the R _th of the high retardation film 23 of the specific examples 2 to 3 are respectively -750 nm and -900 nm.

Comparative example 1~3

The structures of the comparative examples 1-3 are the same as those of the specific examples 1-3 respectively, except that the light absorption axis A of the polarizer 21 of the privacy protection sheet of the comparative examples 1-3 is 0 degree.

Comparative example 4

The structure of the comparative example 4 is the same as that of the specific example 3, except that the optical axis angle of the half-wave plate 22 of the privacy protection sheet of the comparative example 4 is 0 degree.

The nx, ny, and nz of the high retardation films 23 with different thickness retardation values (R _th ) used in the above-mentioned specific examples and comparative examples are organized as shown in Table 1 below:

The relevant structures of the anti-peeping sheets of the aforementioned specific examples 1-3 and comparative examples 1-4 are sorted out in Table 2.

Then, the above-mentioned specific examples 1-3, comparative examples 1-4 were respectively compared with the control examples and commercially available examples 1-2, and the spectroradiometer (Spectroradiometer, model: CS-2000, KONICA-MINOLTA) was used to check the bright white screen. Spectrum measurement and viewing angle distribution measurement.

The measurement results are summarized in Figures 2~5 and Tables 3~5 below.

Among them, the brightness difference in Table 3 is by: (45,0) brightness/(0,0) brightness x100%, (60,0) brightness/(0,0) brightness x100%, (75,0) brightness/( 0,0) Brightness x 100%, calculated.

Among them, the brightness differences in Table 4 are: (45,0) brightness/(0,0) brightness x100%, (60,0) brightness/(0,0) brightness x100%, (75,0) brightness/( 0,0) Brightness x 100%, calculated.

Among them, the comparison difference in Table 5 is: (45,0) contrast/(0,0) contrast x100%, (60,0) contrast/(0,0) contrast x100%, (75,0) contrast/( 0,0) compared with x100%, calculated.

Referring to FIG. 2, it can be seen from FIG. 2 that when the light absorption axis A of the polarizer 21 is 0 degrees (comparative examples 1-3), the R _th adjustment of the high retardation film 23 does not have much influence on the bright state spectrum And the central luminance is lower than that of the comparative example; in addition, it can be clearly seen from the results in Table 3 that when the light absorption axis A of the polarizer 21 is 0 degrees, the luminances of different high retardation films 23 at different side viewing angles are also the same. All are lower than that of the control group. This result shows that although comparative examples 1-3 can have anti-peeping effect, the effect is not good.

Referring to Fig. 3, it can be known from Fig. 3 that when the light absorption axis A of the polarizer 21 is adjusted to 45 degrees (specific examples 1 to 3), the performance of its bright state spectrum can be equivalent to that of the control group; 3, it can be seen that the side-view luminance difference performance of these specific examples 1-3 is good, and as the phase difference of the high retardation film 23 is larger, the brightness difference performance is better, and the specific example 3 (R _th =-900nm) When the side viewing angle (θ) is 60 degrees and 75 degrees, the difference in brightness can reach 1.4% and 2.33%. That is to say, the brightness of Specific Example 3 when the side viewing angle (θ) is 60 degrees and 75 degrees is only 1.4% and 2.33% of the front viewing brightness, but it can have excellent brightness difference performance at different viewing angles.

Referring to FIGS. 4 to 6 again, it can be seen from the results of the bright state spectrum of the specific example 3 and the comparative example 4 in FIG. 4 that controlling the optical axis angle of the half-wave plate 22 can effectively improve the bright state performance of the front view. From Figures 5 and 6, and the distribution diagrams of the viewing angles of specific example 3 and comparative example 4, it can be seen that through the angle control of the R _th of the high retardation film 23 and the light absorption axis A of the polarizer 21, it is possible to preliminarily have multi-angle Anti-peeping effect, but if the optical axis angle control of the half-wave plate 22 is not matched at the same time, the performance of the front view bright state is not good (comparative example 4), so it will affect the use results of normal users; and through the high retardation film of this case 23 R _th setting, and at the same time control the light absorption axis A of the polarizer 21 and the optical axis angle of the half-wave plate (specific example 3), then the anti-speech film can have an excellent front-view bright state performance, and The contrast difference decreases with the increase of the viewing angle, and it can have the effect of multi-angle anti-peeping.

Referring to Fig. 7, further measure the bright state spectrum of the specific example 3 and the commercially available examples 1 and 2. It can be seen from the results that the bright state performance of the specific example 3 in this case is better than that of the commercially available examples 1 and 2; In addition, it can be known from the aforementioned Table 5 that the specific example 3 (orthogonal viewing angle (ψ)=0) is comparable to commercially available examples 1 and 2 when compared at different side viewing angles (θ). And referring to Fig. 8, Fig. 8 (a) (c) is the angle distribution figure of this commercially available example 1, 2, and Fig. 8 (b) is this specific example 3 of the present invention distribution of viewing angles. Further, it can be clearly seen from the viewing angle distribution diagrams of this specific example 3 and commercially available examples 1 and 2 that the contrast value of the maximum brightness and minimum brightness of the specific example 3 in this case can be greater than 1000, which is better than commercially available examples 1 and 2 The contrast value between the maximum brightness and the minimum brightness (about 500~600); in addition, it can be clearly seen from Figure 8 that, compared with commercially available examples 1 and 2, this new type of privacy protection sheet can be used on multiple different Both the side viewing angle (θ) and the front viewing angle (ψ) have the anti-peep effect, and can have a more comprehensive multi-angle anti-peep effect, so the purpose of the novelty can indeed be achieved.

Referring to FIG. 9 , the new multi-angle privacy protection sheet 2 can also be pre-integrated on the upper polarizer 104 of the display element 100 shown in FIG. 1 to form a polarizer 3 . Since the multi-angle privacy protection sheet 2 is directly bonded to the upper polarizer 104, the polarizer 3 can replace the upper polarizer 104 during production and be directly attached to the display surface 101 of the display element 100, namely A display with anti-peeping effects from multiple angles can be manufactured while maintaining the brightness and contrast of the front viewing angle.

But the above-mentioned person is only the embodiment of the present invention, and should not limit the scope of implementation of the present invention with this, and all simple equivalent changes and modifications made according to the patent scope of the present application and the content of the patent specification are still within the scope of the present invention. Within the scope covered by this patent.

100: display components

101: display surface

102: LCD module

103: lower polarizer

104: Upper polarizer

2: Multi-angle anti-spy film

21: Polarizer

22: half wave plate

23: High retardation film

X, A: light absorption axis

θ: included angle

Claims (10)

A multi-angle anti-spy film, suitable for a display element, comprising: a half-wave plate, a polarizer, and a high retardation film sandwiched between the half-wave plate and the polarizer, wherein the high retardation The thickness retardation value (R _th ) of the sheet at a wavelength of 550nm is between -500nm and -1800nm. The multi-angle privacy protection sheet as claimed in Claim 1, wherein the thickness retardation value (R _th ) of the high retardation film is between -600~-900nm. The multi-angle privacy protection sheet as claimed in claim 1, wherein the thickness retardation value (R _th ) of the high retardation film 23 is between -750nm~-900nm. The multi-angle privacy protection sheet as claimed in Claim 1, wherein the in-plane retardation value (R ₀ ) of the half-wave sheet is between 215nm and 300nm. The multi-angle privacy protection sheet as claimed in claim 2, wherein the high retardation sheet is a positive C-plate compensation film. The multi-angle anti-spy film according to claim 3, wherein nz>nx=ny of the high retardation film. The multi-angle privacy protection sheet as claimed in Claim 1, wherein the thickness phase difference (R _th ) of the half-wave sheet is between 95nm and 180nm. The multi-angle privacy protection sheet as described in Claim 1, wherein the multi-angle privacy protection sheet is combined with the display element, and in the bright state, the central brightness of the multi-angle privacy protection sheet is not less than 90% of the brightness of the display element . The multi-angle privacy protection sheet according to Claim 1, wherein the included angle between the light absorption axis of the polarizer of the multi-angle privacy protection sheet and the light absorption axis of the upper polarizer of the display element is 45°. A polarizer, comprising: an upper polarizer; and a multi-angle anti-peeping unit, including a half-wave plate, a polarizer, and a high retardation film sandwiched between the half-wave plate and the polarizer, wherein , the half-wave plate is sandwiched between the upper polarizer and the high retardation film, and the thickness retardation value (R _th ) of the high retardation film at a wavelength of 550nm is between -500~-1800nm.

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