TWI571657B - Blu-ray filter elements - Google Patents

Description

Blue light filter element

The present invention relates to a filter element, particularly a filter element having an average reflectance of 20% ± 5% for harmful blue light.

Since many screens use LED backlight modules, they will emit strong blue light. If the eyes receive blue light for a long time, they will easily cause eye fatigue, degeneration of the macula, cataracts and other problems.

Therefore, related companies have developed a blue-light filter element. For example, there is a "selective blue-filtering optical device" of the Republic of China Patent Publication No. 201418821, which mainly includes an ophthalmic lens and a selective light wavelength filter, wherein The ophthalmic lens is selected from the group consisting of a spectacle lens, a contact lens, an intraocular lens, a corneal mosaic, a corneal covering, a corneal graft, and a corneal tissue; the selective light wavelength filter is blocked 5 - 50% of light having a wavelength in the range of 400 to 500 nm, and transmitting at least 80% of light across the visible spectrum, the selective wavelength filter comprising the dye or mixture of dyes.

However, the filter of the above case uses a dye or a mixture of dyes, so it is easy to affect the stereoscopic effect of the image, cause serious chromatic aberration problems, and gradually lose the filter effect over time, and the utility is insufficient.

Filter elements that are not dyed or dyed, such as Patent Publication No. M461811, "Blu-ray Optical Films and Screen Protectors", and Patent Publication No. M503319, "Filter Screens for LCD Screens", etc. .

However, the above case filters out more than 30% of the full-band blue light, and it is easy to cause the image tones to be yellowish, which affects the visual effect. Furthermore, the above-mentioned film-related pre-sales only have a single function of filtering blue light, and does not have the function of filtering out ultraviolet light, and it is difficult to fully protect the eyes.

Therefore, in order to improve the deficiencies of the general dyed lens for filtering blue light, the inventors propose a blue light filter element comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, the filter harmful blue light The average reflectance of the coating layer in the harmful blue light having a wavelength ranging from 415 nm to 455 nm is 20% ± 5%, and the average reflectance of the light in the remaining visible wavelength range is not more than 2%.

Further, the filtered harmful blue light coating layer has an average reflectance of more than 99% in ultraviolet light having a wavelength ranging from 320 nm to 400 nm.

Further, the filter harmful blue light coating layer is a periodic structure composed of a high refractive index coating and a low refractive index coating of a plurality of layers, and the high refractive index coating is selected from one of the following groups: Bismuth pentoxide (Ta ₂ O ₅ ), niobium pentoxide (Nb ₂ O ₅ ), hafnium oxide (HfO ₂ ), zirconium dioxide (ZrO ₂ ); the low refractive index coating is selected from the following groups One of them: sodium fluoroaluminate (Na ₃ AlF ₆ ), magnesium fluoride (MgF ₂ ), cerium oxide (SiO ₂ ).

Further, the filter harmful blue light coating layer is a periodic structure composed of a 13-layer alternating stack of a high refractive index coating and a low refractive index coating, wherein the high refractive index coating is tantalum pentoxide (Ta ₂ O ₅ ), The low refractive index coating is magnesium fluoride (MgF ₂ ), and the thickness of each layer of the periodic structure is from the end of the adjacent air, and is sequentially 22.40 nm, 72.49 nm, 48.07 nm, 61.14 nm, 38.01 nm, 63.91 nm, 39.75 nm, 60.06 nm, 34.56 nm, 65.66 nm, 40.81 nm, 50.83 nm, 34.97 nm, making the filter element in the wavelength range from 320 to 380 nm The average reflectance of ultraviolet light is higher than 99.27%, and the average reflectance of harmful blue light in the wavelength range from 415 nm to 455 nm is 21.98%, and the wavelength is in the range of 500 nm to 780 nm. The average reflectance is 1.88%.

Further, the substrate is selected from one of the following groups: glass, polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (Polycarbonate, PC). , Hydroxyethyl methacrylate (HEMA).

Further comprising an anti-reflective coating layer bonded to the other side of the substrate, the anti-reflective coating layer has a reflectance of less than 2.5% for light having a wavelength ranging from 320 nm to 780 nm.

Further comprising an anti-reflective coating layer bonded to the other side of the substrate, the anti-reflective coating layer comprising a widening layer that does not affect the reflectance of the reference wavelength to broaden the low-reflection region having a wavelength between 320 nm and 780 nm. Range, the anti-reflective coating layer is one of the admittance trajectories analyzed by the admittance trajectory method as shown in the third figure.

Further comprising an anti-reflective coating layer bonded to the other side of the substrate, the anti-reflective coating layer is a periodic structure composed of 8 layers of a high refractive index coating and a low refractive index coating, wherein the high refractive index The coating is tantalum pentoxide (Ta ₂ O ₅ ), and the low refractive index coating is sodium fluoroaluminate (Na ₃ AlF ₆ ), and the thickness of each layer of the periodic structure is calculated from one end of the adjacent air, in order 86.81 nm, 18.59 nm, 17.52 nm, 114.07 nm, 16.06 nm, 25.20 nm, 30.99 nm, 10.31 nm, making the anti-reflective coating layer wavelength range from 320 nm to 780 nm The reflectance of the light is less than 0.5%.

According to the above technical features, the following effects are obtained:

1. Due to the filter harmful blue light coating layer, it chooses to filter harmful blue light with wavelength range from 415 nm to 455 nm, and the average reflectance is 20%±5%, so as to reduce the harm of blue light to the eyes and avoid The color tone of the image produces the effect of chromatic aberration. On the other hand, since the harmful blue light coating layer is an optical coating layer, the clear effect of the image presentation can be avoided.

2. It has anti-UV function for the average reflectance of ultraviolet light with a wavelength range of 320 nm to 400 nm higher than 99%.

3. It may further comprise an anti-reflective coating layer bonded to the other side of the substrate, so as to prevent harmful light (such as UV light and harmful blue light) incident on the eyes from the rear, thereby further protecting the eyes.

4. The anti-reflective coating layer may comprise a widening layer that does not affect the reflectance of the reference wavelength to broaden the range of the low reflection region.

5. The invention is not limited to general lenses (such as ophthalmic optical elements such as spectacle lenses and contact lens lenses), and can also be applied to optical elements for general filtering.

(1) (10) ‧‧‧Substrate

(11) ‧ ‧ ‧ one side

(12) ‧ ‧ the other side

(2) (20) ‧ ‧ filter harmful blue coating layer

(3) ‧‧‧Anti-reflective coating

[First Figure] is a schematic cross-sectional view showing a first embodiment of the present invention.

[Second A] is a reflectance spectrum of the filter-defective blue light-coating layer of the first embodiment of the present invention.

[Second B] is a reflectance spectrum of the antireflection coating layer of the first embodiment of the present invention.

[Third image] is an admittance trace diagram of the antireflection coating layer of the first embodiment of the present invention.

[Fourth Diagram] is a reflectance spectrum diagram of a second embodiment of the present invention.

[Fifth Graph] is a reflectance spectrum diagram of a third embodiment of the present invention.

[Sixth Graph] is a reflectance spectrum diagram of a fourth embodiment of the present invention.

[Seventh Graph] is a reflectance spectrum diagram of a fifth embodiment of the present invention.

[Eighth Graph] is a reflectance spectrum diagram of a sixth embodiment of the present invention.

[9th] is a reflectance spectrum diagram of a seventh embodiment of the present invention.

[Tenth Graph] is a reflectance spectrum diagram of an eighth embodiment of the present invention.

[11th A] is a reflectance spectrum diagram of a ninth embodiment of the present invention.

[11th B] is an admittance trajectory diagram of a ninth embodiment of the present invention.

[Twelfth AA] is a reflectance spectrum diagram of a tenth embodiment of the present invention.

[Twelfth B] FIG. 4 is an admittance trajectory diagram of a tenth embodiment of the present invention.

[Thirteenth Figure] is a schematic cross-sectional view showing an eleventh embodiment of the present invention.

[Fourteenth] is a reflectance spectrum of the eleventh embodiment of the present invention.

[Fifteenth Figure] is a reflectance spectrum diagram of the twelfth embodiment of the present invention.

[16] Fig. 16 is a reflectance spectrum diagram of the thirteenth embodiment of the present invention.

[17th] is a reflectance spectrum diagram of the fourteenth embodiment of the present invention.

In summary of the above technical features, the main effects of the blue light filtering element of the present invention will be apparent from the following examples.

Please refer to the first figure, which discloses a blue light filter element according to a first embodiment of the present invention, comprising: a substrate (1), a filter harmful blue light coating layer (2) and an anti-reflection coating layer (3), wherein: The substrate (1) is made of glass in the embodiment, but is not limited thereto, and may be polymethylmethacrylate (PMMA) or polyethylene terephthalate (PET). ), polycarbonate (Polycarbonate, PC), hydroxyethyl methacrylate (HEMA), and the like.

The filter harmful blue light coating layer (2) is bonded to one side (11) of the substrate (1), and the filtered harmful blue light coating layer (2) has an average reflection of harmful blue light in a wavelength range of 415 nm to 455 nm. The rate is 20% ± 5%, and the average reflectance of the remaining visible light wavelength range is not higher than 2%. Specifically, the filter harmful blue light coating layer (2) is a periodic structure composed of a plurality of layers of a high-refractive-index coating and a low-refractive-index coating, and the high-refractive-index coating is pentoxide in this embodiment. Dioxane (Ta ₂ O ₅ ), but not limited thereto, may also be niobium pentoxide (Nb ₂ O ₅ ), hafnium oxide (HfO ₂ ), zirconium dioxide (ZrO ₂ ), etc.; In the present embodiment, sodium fluoroaluminate (Na ₃ AlF ₆ ) is used for the refractive index coating, but it is not limited thereto, and may be a material such as magnesium fluoride (MgF ₂ ) or cerium oxide (SiO ₂ ). Preferably, the high refractive index coating and the low refractive index coating material comprise light that can filter out ultraviolet light regions. Therefore, there are not many high and low refractive index materials applicable at the same time, and preferably in the wavelength range of 320. The average reflectance of ultraviolet light from nanometer to 400 nm is higher than 99%, and it has anti-ultraviolet function to provide users with better protection.

Continued, please refer to Table 1-1. In detail, the filter harmful blue light coating layer is a periodic structure composed of a 13-layer alternating stack of high refractive index coating and a low refractive index coating, and the periodic structure is composed of each layer. The thickness is calculated from one end of the adjacent air, and its layers are configured as shown in Table 1-1 below:

The reflectance spectrum of the filter-defective blue light-coating layer of the first embodiment is as shown in FIG. 2A, wherein the ultraviolet light band has an average reflectance of 99.27% from 320 nm to 380 nm, and the harmful blue light region has an average reflectance of 21.98% from 415 nm to 455 nm. The average reflectance of the region from 500 nm to 780 nm is 1.88%.

The anti-reflective coating layer (3) is bonded to the other side (12) of the substrate (1), and the anti-reflective coating layer (3) has a reflectance of less than 2.5 for light having a wavelength ranging from 320 nm to 780 nm. %.

Continuing to refer to Table 1-1, in detail, the anti-reflective coating layer is a periodic structure composed of one layer of a high-refractive-index coating and a low-refractive-index coating, and the thickness of each layer of the periodic structure. From the end of the adjacent air, the layers are configured as follows:

The reflectance spectrum of the antireflection coating layer of the first embodiment described above is as shown in FIG. 2B, wherein the average reflectance of the wavelength band 320 nm to 780 nm is 0.424%, and the total band reflectance is less than 0.5%.

Preferably, the anti-reflective coating layer comprises a widening layer that does not affect the reflectance of the reference wavelength to broaden a range of low-reflection regions having a wavelength between 320 nm and 780 nm, and the anti-reflective coating layer is guided by an admittance trajectory. One of the method analysis admittance trajectories is shown in the third figure.

Hereinafter, the second embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a 13-layer alternating stack of a high refractive index coating and a low refractive index coating, wherein the high refractive index coating is five. Bismuth oxide (Ta ₂ O ₅ ), the low refractive index coating is sodium fluoroaluminate (Na ₃ AlF ₆ ), and the thickness of each layer of the periodic structure is calculated from one end of the adjacent air, and the layers are arranged as shown in Table 2 below. -1:

The reflectance spectrum of the second embodiment is as shown in the fourth figure, wherein the ultraviolet light band has an average reflectance of 99.5% from 320 nm to 380 nm, the average reflectance of the harmful blue region from 415 nm to 455 nm is 22.07%, and the average reflectance of the visible light region is from 500 nm to 780 nm. 1.66%.

Hereinafter, a third embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a 13-layer alternating stack of a high refractive index coating and a low refractive index coating, and the substrate material is polymethyl. Polymethylmethacrylate (PMMA), the configuration of each layer is as follows Table 3-1:

The reflectance spectrum of the third embodiment described above is as shown in the fifth figure.

The fourth embodiment of the present invention will be further described. The filter-detrimental blue-light coating layer is a periodic structure composed of a 14-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the fourth embodiment is as shown in the sixth figure, wherein the average reflectance of the ultraviolet light band from 320 nm to 380 nm is 99.42%, the average reflectance of the harmful blue light region from 415 nm to 455 nm is 20.93%, and the average reflectance of the visible light region is from 500 nm to 780 nm. 1.21%.

The fifth embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a 15-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the fifth embodiment is as shown in the seventh figure, wherein the average reflectance of the ultraviolet light band from 320 nm to 380 nm is 99.54%, the average reflectance of the harmful blue light region from 415 nm to 455 nm is 22.39%, and the average reflectance of the visible light region is from 500 nm to 780 nm. 1.46%.

The sixth embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a high-refractive-index coating and a low-refractive-index coating of 17 layers of alternating layers, and the layers are arranged as follows:

The reflectance spectrum of the sixth embodiment described above is as shown in the eighth figure, wherein the average reflectance of the ultraviolet light band from 320 nm to 380 nm is 99.81%, the average reflectance of the harmful blue light region from 415 nm to 455 nm is 21.44%, and the average reflectance of the visible light region is from 500 nm to 780 nm. 1.79%.

A seventh embodiment of the present invention will be further described. The anti-reflective coating layer is a periodic structure composed of a two-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the seventh embodiment described above is as shown in the ninth figure, wherein the average reflectance of the band 320 nm to 780 nm is 1.32%, and the reflectance of the whole band (the whole band is 320 to 780 nm) is less than 2.1%.

The eighth embodiment of the present invention will be further described. The anti-reflective coating layer is a periodic structure composed of a 4-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the eighth embodiment described above is as shown in the tenth graph, wherein the average reflectance of the wavelength band 320 nm to 780 nm is 1.24%, and the total band reflectance is less than 1.5%.

The ninth embodiment of the present invention will be further described. The anti-reflective coating layer is a periodic structure composed of a 6-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the ninth embodiment described above is as shown in FIG. 11A, in which the average reflectance of the wavelength band 320 nm to 780 nm is 0.625%, and the total band reflectance is less than 1.25%. The admittance trajectory is as shown in FIG. 11B, in which the third layer near the substrate is a dummy layer with a full-band half-wave thickness.

The tenth embodiment of the present invention will be further described. The anti-reflective coating layer is a periodic structure composed of a 10-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the above-described tenth embodiment is as shown in Fig. 12A, in which the average reflectance of the wavelength band 320 nm to 780 nm is 0.374%, and the total band reflectance is less than 0.4%. The admittance trajectory is as shown in the twelfth B-picture, wherein the seventh layer near the substrate is a dummy layer.

Continuing to refer to a thirteenth embodiment, a cross-sectional view of a blue light filter element according to an eleventh embodiment of the present invention includes a substrate (10) and a filter harmful blue light coating layer (20), the main difference being that only for filtering The blue light design, so the material selection is not limited to the light that can filter out the ultraviolet region.

The filter harmful blue light coating layer (20) is a periodic structure composed of a high-refractive-index coating and a low-refractive-index coating in the fourth layer of the present embodiment, and the layers are arranged as follows:

As shown in the fourteenth embodiment, the reflectance spectrum of the eleventh embodiment shows that the number of coatings can be reduced to four layers if only designed for the blue light filtering.

Hereinafter, the twelfth embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a 6-layer alternating stack of a high refractive index coating and a low refractive index coating, and the layers are arranged as follows:

The reflectance spectrum of the above twelfth embodiment is as shown in Fig. 15.

The thirteenth embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a 10-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the above-described thirteenth embodiment is as shown in Fig. 16.

The fourteenth embodiment of the present invention will be further described. The filter harmful blue light coating layer is a periodic structure composed of a 12-layer alternating stack of a high refractive index coating and a low refractive index coating. The layers are arranged as follows:

The reflectance spectrum of the above-described fourteenth embodiment is as shown in Fig. 17.

In view of the foregoing description of the embodiments, the operation and the use of the present invention and the effects of the present invention are fully understood, but the above described embodiments are merely preferred embodiments of the present invention, and the invention may not be limited thereto. Included within the scope of the present invention are the scope of the present invention.

(1) ‧‧‧Substrate

(11) ‧ ‧ ‧ one side

(12) ‧ ‧ the other side

(2) ‧ ‧ ‧ harmful blue coating layer

(3) ‧‧‧Anti-reflective coating

Claims (10)

A blue light filter component comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, the filter harmful blue light coating layer is 13 layers of alternating high refractive index coating and a low refractive index a periodic structure formed by the coating, wherein the high refractive index coating is tantalum pentoxide (Ta ₂ O ₅ ), and the low refractive index coating is sodium fluoroaluminate (Na ₃ AlF ₆ ), and the periodic structure is each layer The thickness is from the end of the adjacent air, in order of 22.40 nm, 72.49 nm, 48.07 nm, 61.14 nm, 38.01 nm, 63.91 nm, 39.75 nm, 60.06 nm, 34.56 nm, 65.66 Meter, 40.81 nm, 50.83 nm, 34.97 nm, the average reflectance of the filter element in the wavelength range of 320 to 380 nm is higher than 99.27%, and the wavelength range is 415 nm to The average reflectance of the harmful blue light of 455 nm is 21.98%, and the average reflectance of light of the wavelength range of 500 nm to 780 nm is 1.88%. The blue light filter element of claim 1, wherein the substrate is selected from one of the group consisting of glass, polymethylmethacrylate (PMMA), and polyethylene terephthalate. Polyethylene terephthalate (PET), polycarbonate (Polycarbonate, PC), hydroxyethyl methacrylate (HEMA). The blue light filter component of claim 1, further comprising an anti-reflective coating layer bonded to the other side of the substrate, the anti-reflective coating layer having a wavelength range of from 320 nm to 780 nm. The reflectance of light is less than 2.5%. The blue light filter component of claim 1, further comprising an anti-reflective coating layer bonded to the other side of the substrate, the anti-reflective coating layer comprising a widening layer that does not affect the reflectance of the reference wavelength, Broaden the range of low reflection areas with wavelengths from 320 nm to 780 nm. The blue light filter component of claim 1, further comprising an anti-reflective coating layer bonded to the other side of the substrate, the anti-reflective coating layer is an 8-layer alternating stack of high refractive index coating and a a periodic structure composed of a low refractive index coating, wherein the high refractive index coating is tantalum pentoxide (Ta ₂ O ₅ ), and the low refractive index coating is sodium fluoroaluminate (Na ₃ AlF ₆ ), and the periodicity The thickness of each layer of the structure is calculated from the end of the adjacent air, which is 86.81 nm, 18.59 nm, 17.52 nm, 114.07 nm, 16.06 nm, 25.20 nm, 30.99 nm, 10.31 nm. The antireflective coating layer has a reflectance of less than 0.5% for light having a wavelength ranging from 320 nm to 780 nm. A blue light filter component comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, wherein the filter harmful blue light coating layer is a layer of 14 layers of alternating high refractive index coating and a low a periodic structure formed by a refractive index coating, wherein the high refractive index coating is tantalum pentoxide (Ta ₂ O ₅ ), and the low refractive index coating is magnesium fluoride (MgF ₂ ), and the periodic structure is each layer The thickness is from the end of the adjacent air, in order of 122.10 nm, 37.23 nm, 54.66 nm, 40.88 nm, 69.16 nm, 34.97 nm, 58.13 nm, 39.23 nm, 62.69 nm, 37.51 Nai Meter, 69.66 nm, 43.63 nm, 59.15 nm, 35.30 nm, the average reflectance of the filter element in the wavelength range of 320 to 380 nm is 99.42%, in the wavelength range of 415 The average reflectance of harmful blue light from nanometer to 455 nm is 20.93%, and the average reflectance of light in the wavelength range of 500 nm to 780 nm is 1.21%. A blue light filter component comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, wherein the filter harmful blue light coating layer is a layer of 15 layers of alternating high refractive index coating and a low a periodic structure formed by a refractive index coating, wherein the high refractive index coating is tantalum pentoxide (Ta ₂ O ₅ ), and the low refractive index coating is magnesium fluoride (MgF ₂ ), and the periodic structure is each layer The thickness is from the end of the adjacent air, in order of 14.56 nm, 80.15 nm, 45.53 nm, 59.44 nm, 38.71 nm, 77.29 nm, 37.29 nm, 60.29 nm, 37.46 nm, 61.19 Nai Meter, 37.16 nm, 56.67 nm, 47.45 nm, 51.35 nm, 31.07 nm, the average reflectance of the filter element in the wavelength range of 320 to 380 nm is 99.54%, at the wavelength The average reflectance of harmful blue light ranging from 415 nm to 455 nm is 22.39%, and the average reflectance of light having a wavelength range of 500 nm to 780 nm is 1.46%. A blue light filter component comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, wherein the filter harmful blue light coating layer is a layer of 17 layers of alternating high refractive index coating and a low a periodic structure formed by a refractive index coating, wherein the high refractive index coating is tantalum pentoxide (Ta ₂ O ₅ ), and the low refractive index coating is magnesium fluoride (MgF ₂ ), and the periodic structure is each layer The thickness is from the end of the adjacent air, in order of 13.43 nm, 75.74 nm, 42.62 nm, 52.74 nm, 41.00 nm, 67.59 nm, 40.92 nm, 56.80 nm, 38.89 nm, 63.00 Nai Meter, 36.68 nm, 62.97 nm, 43.46 nm, 59.25 nm, 46.04 nm, 57.63 nm, 34.52 nm, the average of the filter elements in the ultraviolet range of wavelengths between 320 and 380 nm The reflectance is 99.81%, the average reflectance of harmful blue light in the wavelength range from 415 nm to 455 nm is 21.44%, and the average reflectance of light in the wavelength range from 500 nm to 780 nm is 1.79%. A blue light filter element comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, wherein the filter harmful blue light coating layer is a layer of 4 layers of alternating high refractive index coating and a low a periodic structure formed by a refractive index coating, wherein the high refractive index coating is titanium dioxide (TiO ₂ ), the low refractive index coating is magnesium fluoride (MgF ₂ ), and the thickness of each layer of the periodic structure is from adjacent air. The end of the calculation is 110.74 nm, 102.02 nm, 16.60 nm, and 27.44 nm. A blue light filter component comprising: a substrate; and a filter harmful blue light coating layer bonded to one side of the substrate, wherein the filter harmful blue light coating layer is a high-refractive-index coating of 6 layers of alternating layers and a low a periodic structure formed by a refractive index coating, wherein the high refractive index coating is titanium dioxide (TiO ₂ ), the low refractive index coating is magnesium fluoride (MgF ₂ ), and the thickness of each layer of the periodic structure is from adjacent air. At the end of the calculation, the order is 73.21 nm, 6.64 nm, 37.35 nm, 101.15 nm, 19.74 nm, 26.57 nm.