A blue light privacy protection device based on photon bandgap angular selectivity

Abstract

The application discloses a kind of blue light privacy protection device based on photon forbidden band angle selectivity, including layered stack photonic crystal structure and the upper layer substrate and lower layer substrate distributed in the layered stack photonic crystal structure two sides, the outer surface of the upper layer substrate and lower layer substrate is evenly arranged with AR anti-reflection moth-eye film structure, the layered stack photonic crystal structure is formed by the anti-reflection coating of two ends and the main structure in the middle, the anti-reflection coating and main structure are all included sequentially arranged bismuth silicate and liquid crystal E7, the application utilizes anti-reflection layer to inhibit reflectivity, improves the rectangular coefficient of angle selection characteristic, to improve the accuracy of measurement;The moth-eye structure used on the outer surface of the device has certain intensity, and is not easy to damage;Utilize the angle selection characteristic of photonic crystal to realize privacy protection, make the light emitted by screen more occur transmission, improve screen brightness.Simultaneously, this kind of device covers entire blue light wave band, with wide frequency band.

Description

Technical Field

[0001] The present invention relates to a blue light privacy protection device based on photon bandgap angle selectivity, belonging to the technical field of angle filtering. Background Art

[0002] Angular filtering technology, based on the principle of the photonic bandgap, has the ability to filter electromagnetic waves at specific incident angles. Ideally, an angularly selective material system should operate across a broadband spectrum. Such a system could play a crucial role in numerous applications, with great potential and promise in fields such as optics, communications, and biomedicine.

[0003] Due to the widespread application of angle-selective technology in mobile phone privacy films, ATM privacy protection, and many electronic devices with high privacy protection requirements, many countries and companies are developing structures with angle-selective characteristics. We use the angle-selective properties of photonic crystals to design privacy protection structures and are one of the first teams in the world to propose this concept.

[0004] A search revealed a Chinese patent with publication number CN202878841U, issued on October 10, 2012, that discloses a screen privacy film. This patent utilizes ultra-fine louver optical polarization technology to select light within a specific angle range, effectively addressing the risk of screen peeping when using electronic devices. This patent was published before mobile phones were widely used, demonstrating its foresight. Since then, ultra-fine louver optical polarization technology has become the primary principle behind the manufacture of privacy films.

[0005] It can be seen that most of the current anti-peeping devices rely on a shutter structure to block light outside a certain angle range. However, while achieving this function, the light is completely blocked by the shutter, reducing the screen brightness. In addition, the outermost layer of this structure is PET material, which is not as scratch-resistant as glass, which will affect the user experience. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of the prior art by providing a blue light privacy protection device based on photonic bandgap angle selectivity. This privacy protection device is designed based on the angular characteristics of the photonic bandgap. An anti-reflection layer suppresses reflectivity, increasing the rectangular coefficient of the angle selectivity and thus improving measurement accuracy. The moth-eye structure used on the device's outer surface provides a certain degree of strength and is not easily damaged. The angle selectivity of photonic crystals is utilized to achieve privacy protection, allowing more light emitted by the screen to be transmitted, thereby increasing screen brightness. Furthermore, this device covers the entire blue light band and has a wide bandwidth.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0008] In the first aspect, the present invention provides a blue light privacy protection device based on photon bandgap angle selectivity, comprising: a layered stacked photonic crystal structure and an upper substrate and a lower substrate distributed on both sides of the layered stacked photonic crystal structure, the outer surfaces of the upper substrate and the lower substrate are both provided with AR anti-reflective moth-eye film structures, the layered stacked photonic crystal structure is composed of anti-reflective coatings at both ends and a main structure in the middle, and the anti-reflective coating and the main structure both include bismuth silicate and liquid crystal E7 arranged in sequence.

[0009] Furthermore, the dielectric arrangement of the main structure is E7 (Bi 12 SiO 20 E7) 32 .

[0010] Furthermore, the order of arrangement of the medium of the anti-reflection coating is Bi 12 SiO 20 (E7Bi 12 SiO 20 ) 4 E7(Bi 12 SiO 20 E7) 32 (Bi 12 SiO 20 E7) 4 Bi 12 SiO 20 .

[0011] Furthermore, the liquid crystal E7 of the layered stacked photonic crystal structure is arranged vertically at 25 degrees Celsius.

[0012] Furthermore, within the frequency range of blue light, the refractive index of the liquid crystal E7 varies within the range of 1.7693-1.7771.

[0013] Furthermore, the thickness of the bismuth silicate in the anti-reflection layer is 84 nm, and the thickness of the bismuth silicate in the main structure is 168 nm.

[0014] Furthermore, the thickness of the liquid crystal E7 in the main structure is 72 nm, and the thickness of the liquid crystal E7 in the anti-reflection layer is 75 nm.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The present invention uses photonic bandgap to achieve angle selection, replacing the traditional ultra-fine blinds optical polarization principle technology. When realizing the privacy protection function, it adopts a layered stacking structure and uses photonic crystals to achieve angle selection, maintaining a high transmittance, thereby ensuring the brightness of the screen.

[0017] (2) When the present invention realizes the privacy protection function, the privacy protection area has almost zero transmission. Only when the TM mode is incident, a transmission peak appears at a point close to 90 degrees. The impact on the overall performance of the device is negligible, and good angle selection is achieved.

[0018] (3) The privacy protection achieved by the present invention has a wide frequency bandwidth and can cover the entire blue light band.

[0019] (4) The present invention does not need to rely on polarization form. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the overall system structure of a blue light privacy protection device based on photon bandgap angle selectivity according to an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the unit structure of a blue light privacy protection device based on photon bandgap angle selectivity according to an embodiment of the present invention;

[0022] Figure 3 is the transmittance corresponding to different wavelengths of blue light incident at different angles when the light is incident in TE mode according to an embodiment of the present invention;

[0023] Figure 4 is the transmittance corresponding to different wavelengths of blue light incident at different angles when the light is incident in TM mode according to an embodiment of the present invention;

[0024] In the figure: 1. AR anti-reflective moth-eye film structure; 2. Upper substrate; 3. Layered stacked photonic crystal structure; 4. Lower substrate. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0027] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] Example 1

[0029] like Figure 1 As shown, this embodiment introduces a blue light privacy protection device based on photon bandgap angle selectivity, including: a layered stacked photonic crystal structure 3 and an upper substrate 2 and a lower substrate 4 distributed on both sides of the layered stacked photonic crystal structure 3, and the outer surfaces of the upper substrate 2 and the lower substrate 4 are both provided with an AR anti-reflective moth-eye film structure 1. This is only an optical structure. The one we use in this patent is developed by Japan's GEOMATEC company. The layered stacked photonic crystal structure 3 is composed of anti-reflection coatings at both ends and a main structure in the middle, and both the anti-reflection coating and the main structure include bismuth silicate and liquid crystal E7 arranged in sequence.

[0030] When blue light enters this device from air, only light within a 50-degree angle to the normal can pass through. When the light is greater than this angle, the transmission is zero or too low to be considered. The refractive index of light in the two-layer substrate composed of the AR anti-reflective moth-eye film structure is extremely close to that in air. This structure, manufactured by Japan's GEOMATEC, has superb water and oil repellency and excellent anti-fouling properties. Its nano-sized surface micro-protrusions (moth-eye structure) can produce super-hydrophobicity similar to the surface of a lotus leaf, and its hardness can be wiped repeatedly, basically meeting the quality requirements of electronic displays.

[0031] Due to its selectivity for incident angles, when a display screen made with this device is observed from an angle of more than 50 degrees, only a dark picture is seen, while a clear picture can be seen when observed within 30 degrees.

[0032] In the present invention, the reflectivity is suppressed by coating an anti-reflection layer, and the rectangular coefficient of the angle-selective transmission window is increased, thereby increasing the transmittance of light and improving the brightness; the privacy protection function is achieved through the angle selection characteristics.

[0033] When the entire device is working, it acts as a protective film attached to the screen of an electronic device that requires privacy protection. When blue light is incident, the photonic crystal in the main structure exhibits angle-selective characteristics, so that all blue light that deviates from the normal by more than 50 degrees is reflected or absorbed, while the transmission of blue light that deviates from the normal by 30-50 degrees is unstable and cannot form a good visual effect. Blue light that deviates from the normal within 30 degrees can be well transmitted out of the device, and the observer can clearly observe the screen content within this 60-degree range.

[0034] Layered stacked photonic crystal structure 1, such as Figure 2 As shown, the overall medium arrangement order is Bi 12 SiO 20 (E7Bi 12 SiO 20 ) 4 E7(Bi 12 SiO 20 E7) 32 (Bi 12 SiO 20 E7) 4 Bi 12 SiO 20 , consisting of anti-reflection coatings at both ends and a main structure in the middle, N1 = 4, N2 = 32, N3 = 4 represents the number of periods. The dielectric arrangement of the main structure is (Bi 12 SiO 20 E7) 32 , the dielectric arrangement of the anti-reflection coating is Bi 12 SiO20 (E7Bi 12 SiO 20 ) 4 and(Bi 12 SiO 20 E7) 4 Bi 12 SiO 20 。Bi 12 SiO 20 The refractive index is 2.45, and the refractive index of E7 varies with the wavelength in the range of 1.7693 to 1.7771. The thickness of the anti-reflection layer is 12 SiO 20 Thickness 84nm, E7 liquid crystal thickness 75nm, Bi in the main structure 12 SiO 20 Thickness is 168nm, and E7 LCD thickness is 72nm.

[0035] like Figure 3 As shown in the figure, when light is incident in TE mode, several wavelengths in the blue light band are analyzed. It can be seen that the transmittance is higher than 0.86 within 27 degrees, and a clearly visible visible area is always presented. Beyond 44 degrees, the transmittance is always 0, which is a privacy protection area.

[0036] like Figure 4 As shown in the figure, when light is incident in TM mode, several wavelengths within the blue light band are analyzed. It can be seen that the transmittance is higher than 0.86 within 31 degrees, and a clearly visible visual area is always presented. Beyond 51 degrees, most of the transmittance is 0, which is the privacy protection area. A transmission peak appears at around 85 degrees. Because the angle range of its high transmission is too small and close to 90 degrees, it does not affect the overall privacy protection performance of the device.

[0037] After a specific design (using the photon bandgap principle and introducing an anti-reflection layer), the present invention can realize the function of angle selection of blue light. The present invention has good anti-fouling and hydrophobic properties, has a certain strength, and effectively ensures the brightness of the screen.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A blue light privacy protection device based on photon bandgap angle selectivity, characterized in that: include: A layered stacked photonic crystal structure and an upper substrate and a lower substrate distributed on both sides of the layered stacked photonic crystal structure, wherein the outer surfaces of the upper substrate and the lower substrate are each provided with an AR anti-reflective moth-eye film structure, and the layered stacked photonic crystal structure is composed of anti-reflective coatings at both ends and a main structure in the middle, wherein the anti-reflective coating and the main structure both include bismuth silicate and liquid crystal E7 arranged in sequence; The dielectric arrangement of the main structure is E7 (Bi 12 SiO 20 E7) 32 ; The order of arrangement of the medium of the anti-reflection coating is Bi 12 SiO 20 (E7Bi 12 SiO 20 ) 4 E7(Bi 12 SiO 20 E7) 32 (Bi 12 SiO 20 E7) 4 Bi 12 SiO 20 ; In the frequency range of blue light, the refractive index of the liquid crystal E7 varies within the range of 1.7693-1.7771; The thickness of bismuth silicate in the anti-reflective coating is 84 nm, and the thickness of bismuth silicate in the main structure is 168 nm; The thickness of the liquid crystal E7 in the main structure is 72 nm, and the thickness of the liquid crystal E7 in the anti-reflection coating is 75 nm.

2. The blue light privacy protection device based on photon bandgap angle selectivity according to claim 1, characterized in that: The liquid crystal E7 of the layered stacked photonic crystal structure is vertically aligned at 25 degrees Celsius.

Images