Antireflection film and its use on a substrate
This disclosure relates to an antireflection film, as well as its use on a substrate ( 3 ) to decrease a fracture of light striking the substrate ( 3 ) reflected by said substrate ( 3 ), wherein said coating is formed of a transparent first layer ( 1 ) applied on the substrate ( 3 ) and a transparent second layer ( 2 ) on said first layer ( 1 ). The essence of the solutions according to this disclosure is that thickness (d 1 ) of the first layer ( 1 ) ranges from 10 to 70 nm and refractive index (n 1 ) of said first layer ( 1 ) satisfies the relation 1.05<n 1 <1.35 within the wavelength range of 375 to 1000 nm, and wherein thickness (d 2 ) of the second layer ( 2 ) ranges from 30 to 100 nm and refractive index (n 2 ) of said second layer ( 2 ) satisfies the relation 1.25<n 2 <1.5 within the wavelength range of 375 to 1000 nm, and wherein n 1 <n 2 also holds.
1. An antireflection coating comprising:
a transparent first layer ( 1 ) applied on a substrate ( 3 ) of low refractive index (n substrate ); and
a transparent second layer ( 2 ) over the first layer ( 1 ),
wherein thickness (d 1 ) of the first layer ( 1 ) ranges from 10 to 70 nm and refractive index (n 1 ) of said first layer ( 1 ) satisfies 1.05<n 1 <1.35 within an entire wavelength range of 375 to 1000 nm, and
wherein thickness (d 2 ) of the second layer ( 2 ) ranges from 30 to 100 nm and refractive index (n 2 ) of said second layer ( 2 ) satisfies 1.25<n 2 <1.5 within the entire wavelength range of 375 to 1000 nm, and
wherein n 1 <n 2 .
2. The antireflection coating according to claim 1 , wherein the substrate ( 3 ) for the antireflection coating is transparent within the wavelength range of 375 to 1000 nm.
3. The antireflection coating according to claim 2 , wherein the antireflection coating is formed on both side surfaces of the substrate ( 3 ).
4. The antireflection coating according to claim 2 , wherein the substrate ( 3 ) forms an envelope or at least a part of an envelope of a light emitting device.
5. The antireflection coating according to claim 2 , wherein the substrate ( 3 ) is an optical lens.
6. The antireflection coating according to claim 1 , wherein the low refractive index (n substrate ) of said substrate ( 3 ) satisfies n substrate <2.5.
7. The antireflection coating according to claim 1 , wherein said substrate ( 3 ) is made of at least one substance chosen from the group consisting of glass, quartz glass and polycarbonate.
8. A method comprising using an antireflection coating on a substrate ( 3 ) to decrease a fraction of light striking the substrate ( 3 ) reflected by said substrate ( 3 ), wherein refractive index (n substrate ) of the substrate ( 3 ) satisfies n substrate <2.5, and wherein said antireflection coating applied on said substrate ( 3 ) is formed of a first layer ( 1 ) and a second layer ( 2 ) over the first layer ( 1 ), wherein thickness (d 1 ) of the first layer ( 1 ) ranges from 10 to 70 nm and refractive index (n 1 ) of said first layer ( 1 ) satisfies 1.05<n 1 <1.35 within a wavelength range of 375 to 1000 nm, and wherein thickness (d 2 ) of the second layer ( 2 ) ranges from 30 to 100 nm and refractive index (n 2 ) of said second layer ( 2 ) satisfies 1.25<n 2 <1.5 within the wavelength range of 375 to 1000 nm, and wherein n 1 <n 2 .
9. The method according to claim 8 , further comprising the antireflection coating decreasing the fraction of light striking the substrate reflected by said substrate ( 3 ) in a broad range of wavelengths.
10. The method according to claim 9 , wherein said broad range of wavelengths ranges from about 400 nm to about 900 nm.
11. The method according to claim 8 , further comprising the antireflection coating decreasing the fraction of light striking the substrate reflected by said substrate ( 3 ) in a broad range of angles of incidence.
12. The method according to claim 11 , wherein said broad range of angles of incidence ranges from about 0° to about 70°.
13. The method of claim 8 , wherein said substrate ( 3 ) is made of at least one substance chosen from the group consisting of glass, quartz glass and polycarbonate.