TWI866584B - Uv-curable band pass filter - Google Patents

Abstract

A UV-curable band pass filter, which includes a band pass filter having a base plate, a first film layer group and a second film layer group, the base plate is disposed between the first and second film layer groups, the first film layer group contains a first high refractive index layer and a first low refractive index layer of 32 layers, the first high refractive index layer has a first film layer thickness, the first low refractive index layer has a second film layer thickness, within 28 layers, the first film layer thickness is less than the second film layer thickness; the second film layer group contains a second high refractive index layer and a second low refractive index layer of 34 layers, the second high refractive index layer has a third film layer thickness, the second low refractive index layer has a fourth film layer thickness, the third film layer thickness is less than the adjacent fourth film layer thickness.

Description

UV-curable narrow band filters

The present invention relates to a narrowband filter, in particular to a narrowband filter which can be cured by ultraviolet light.

Narrowband filter is an important optical tool, usually composed of multiple layers of thin film stacking. Each layer of thin film has specific optical properties to achieve precise wavelength selection. It is used to separate and selectively observe light of specific wavelengths. Narrowband filter can absorb or reflect unnecessary bands to maintain that only light of a specific wavelength range is allowed to pass. For example, a narrowband filter used for light with a wavelength of 940 nm can filter light bands other than 940 nm, making the light source passing through the narrowband filter monochromatic (single band 940 nm).

UV curing adhesive is a special adhesive whose curing process depends on UV light source. It cures quickly through UV light irradiation and is widely used in many different application fields. However, as the narrowband filter mentioned above can only pass a single band, it causes inconvenience and limits application in the process where UV curing adhesive must be used for bonding and fixing or when UV light penetration is also required (the UV light cannot penetrate the narrowband filter), so there is a need for improvement.

The present invention provides a narrow-band filter that can be cured by ultraviolet light, and its main purpose is to include a narrow-band filter that can pass infrared light bands and ultraviolet light bands.

In view of this, the present invention provides a UV-curable narrow-band filter, comprising:

A narrowband filter has a substrate, a first film layer group and a second film layer group, the substrate is between the first film layer group and the second film layer group, the first film layer group includes a first high refractive index layer and a first low refractive index layer stacked along an axis, the first high refractive index layer and the first low refractive index layer add up to 32 layers, the first high refractive index layer has a first film layer thickness, the first low refractive index layer has a second film layer thickness, and the first film layer has a first film layer thickness of 1000 nm. The thickness of the first film layer is less than that of the second film layer adjacent to each other within 28 layers of the group; the second film layer group includes a second high refractive index layer and a second low refractive index layer stacked alternately along an axis, the second high refractive index layer and the second low refractive index layer add up to 34 layers in total, the second high refractive index layer has a third film layer thickness, the second low refractive index layer has a fourth film layer thickness, and the third film layer thickness is less than that of the fourth film layer adjacent to each other.

More specifically, at the 29th layer in the first film layer group, the thickness of the first film layer is greater than the thickness of the adjacent second film layer; at the 30th layer in the first film layer group, the thickness of the second film layer is less than the thickness of the adjacent first film layer; at the 31st layer in the first film layer group, the thickness of the first film layer is between the thickness of the adjacent second film layers; and at the 32nd layer in the first film layer group, the thickness of the second film layer is greater than the thickness of the adjacent first film layer.

Preferably, the substrate has a first side surface and a second side surface, the first film layer group is located on the first side surface, and the second film layer group is located on the second side surface.

Preferably, in the first film layer set, one of the first high refractive index layers contacts the first side surface of the substrate.

Preferably, in the second film layer set, one of the second high refractive index layers contacts the second side surface of the substrate.

More specifically, the narrowband filter can pass light in the ultraviolet light band of 365nm~400nm and the infrared light band of 900~1000nm.

More specifically, the first high refractive index layer and the second high refractive index layer are selected from titanium dioxide, tantalum pentoxide, niobium pentoxide, tantalum dioxide, silicon monoxide, silicon nitride, tin dioxide or zinc sulfide.

More specifically, the first low refractive index layer and the second low refractive index layer are selected from silicon dioxide, magnesium fluoride, barium fluoride, aluminum fluoride or strontium fluoride.

More specifically, within 28 layers in the first film layer group, the thickness of the first film layer is greater than 0.1 times and less than 1 times the thickness of the adjacent second film layer.

More specifically, in the second film layer group, the thickness of the third film layer is greater than 0.1 times and less than 1 times the thickness of the adjacent fourth film layer.

In summary, the present invention forms the first film layer group by stacking the first high refractive index layer and the first low refractive index layer in total 32 layers, and forms the second film layer group by stacking the second high refractive index layer and the second low refractive index layer in total 34 layers, and the first film layer group is disposed on the first side of the substrate, and the second film layer group is disposed on the second side of the substrate, so that the opposite sides of the substrate are the first film layer group and the second film layer group, thereby forming the narrow-band filter that can pass through the ultraviolet light band of 365nm~400nm and the infrared light band of 900~1000nm.

The following is a description of the structure and configuration of the main components of the present invention, and with the help of the drawings and the embodiments of the present invention, further explains the technical means adopted by the present invention to achieve the predetermined invention purpose. The drawings have been simplified for the purpose of explanation only, and the structure or method invention of the present invention is explained by describing the relationship between the elements and assemblies of the present invention. Therefore, the elements shown in the drawings are not presented in actual quantity, actual shape, actual size and actual proportion. The size or size proportion has been enlarged or simplified to provide better explanation. The actual quantity, actual shape or actual size proportion has been selectively designed and configured, and the detailed element layout may be more complicated.

Referring to FIG. 1 , a narrowband filter 1 provided by the present invention according to an embodiment comprises a substrate 3, a first film layer group 10 and a second film layer group 20. The substrate 3 is glass. The substrate 3 has a first side surface 31 and a second side surface 32 located on the opposite side of the first side surface 31. The first film layer group 10 is located on the first side surface 31 of the substrate 3. The second film layer group 20 is located on the second side surface 32 of the substrate 3, so that the substrate 3 is located between the first film layer group 10 and the second film layer group 20.

The first film layer group 10 includes a first high refractive index layer 101 and a first low refractive index layer 102 stacked alternately along an axis, any one of the first low refractive index layers 102 contacts an adjacent first high refractive index layer 101, and the first film layer group 10 (i.e., the first high refractive index layer 101 and the first low refractive index layer 102 stacked mutually) has a total of 32 layers, one of the first high refractive index layers 101 contacts the first side surface 31 of the substrate 3 to form a first layer, and one of the first low refractive index layers 102 is stacked on the first high refractive index layer 101 to form a second layer, and so on. The second film layer group 20 includes a second high refractive index layer 201 and a second low refractive index layer 202 stacked alternately along an axis, and any one of the second low refractive index layers 202 contacts an adjacent second high refractive index layer 201. The second film layer group 20 (i.e., the second high refractive index layer 201 and the second low refractive index layer 202 stacked on each other) has a total of 34 layers, one of the second high refractive index layers 201 contacts the second side surface 32 of the substrate 3 to form the first layer, and one of the second low refractive index layers 202 is stacked on the second high refractive index layer 201 to form the second layer, and so on. It is worth noting that the stacking method of the first film layer group 10 and the second film layer group 20 can be a commonly used process technology of physical vapor deposition (PVD) or chemical vapor deposition (CVD), but is not limited thereto.

Please refer to Table 1 and FIG. 1. In one embodiment, the first film layer group 10 is composed of 32 layers of the first high refractive index layer 101 and the first low refractive index layer 102 stacked on each other. More specifically, the first high refractive index layer 101 is titanium dioxide, and the first low refractive index layer 102 is silicon dioxide. The first film layer group 10 formed by stacking has a thickness of about 1000 Å. 4,535.99 nm, the first high refractive index layer 101 has a first film layer thickness L1, the first low refractive index layer 102 has a second film layer thickness L2, more specifically, within 28 layers of the first film layer group 10, the first film layer thickness L1 is less than the adjacent second film layer thickness L2, more specifically, it is greater than 0.1 times and less than 1 times, for example For example, 0.24 times, 0.55 times, 0.47 times, and 0.86 times, etc., wherein the thickness L1 of the 29th layer in the first film layer group 10 is greater than the thickness L2 of the second film layer adjacent to each other, the thickness L2 of the 30th layer in the first film layer group 10 is less than the thickness L1 of the first film layer adjacent to each other, and the thickness L2 of the second film layer in the 31st layer in the first film layer group 10 is less than the thickness L1 of the first film layer adjacent to each other. The thickness L1 of the first film layer is between the thickness L2 of the adjacent second film layers. More specifically, the thickness L1 of the first film layer at the 31st layer is greater than the thickness L2 of the second film layer at the 30th layer and less than the thickness L2 of the second film layer at the 32nd layer. In the 32nd layer in the first film layer group 10, the thickness L2 of the second film layer is greater than the thickness L1 of the adjacent first film layer.

Please refer to Table 2 and FIG. 1 . The second film layer group 20 is formed by stacking the second high refractive index layer 201 and the second low refractive index layer 202 to form a total of 34 layers. More specifically, the second high refractive index layer 201 is titanium dioxide, and the second low refractive index layer 202 is silicon dioxide. The second film layer group 20 formed by stacking has a thickness of approximately 2,304.41 nm. The second high refractive index layer 201 has a third film layer thickness L3, and the second low refractive index layer 202 has a fourth film layer thickness L4. More specifically, the third film layer thickness L3 is less than the fourth film layer thickness L4 adjacent to each other, and more specifically is greater than 0.1 times and less than 1 times, such as 0.6 times, 0.71 times, and 0.39 times.

Table 1 Number of layers Film name Material Thickness of the first film layer group 10 (nm) 1 First high refractive index layer 101 _TiO2 80.77 2 First low refractive index layer 102 SiO ₂ 131.98 3 First high refractive index layer 101 _TiO2 49.14 4 First low refractive index layer 102 SiO ₂ 106.30 5 First high refractive index layer 101 _TiO2 79.62 6 First low refractive index layer 102 SiO ₂ 145.26 7 First high refractive index layer 101 _TiO2 95.77 8 First low refractive index layer 102 SiO ₂ 150.63 9 First high refractive index layer 101 _TiO2 83.60 10 First low refractive index layer 102 SiO ₂ 108.20 11 First high refractive index layer 101 _TiO2 52.35 12 First low refractive index layer 102 SiO ₂ 122.62 13 First high refractive index layer 101 _TiO2 91.98 14 First low refractive index layer 102 SiO ₂ 155.53 15 First high refractive index layer 101 _TiO2 94.86 16 First low refractive index layer 102 SiO ₂ 148.08 17 First high refractive index layer 101 _TiO2 83.08 18 First low refractive index layer 102 SiO ₂ 357.80 19 First high refractive index layer 101 _TiO2 87.25 20 First low refractive index layer 102 SiO ₂ 142.75 twenty one First high refractive index layer 101 _TiO2 96.07 twenty two First low refractive index layer 102 SiO ₂ 168.42 twenty three First high refractive index layer 101 _TiO2 145.15 twenty four First low refractive index layer 102 SiO ₂ 196.18 25 First high refractive index layer 101 _TiO2 142.16 26 First low refractive index layer 102 SiO ₂ 222.06 27 First high refractive index layer 101 _TiO2 77.29 28 First low refractive index layer 102 SiO ₂ 153.69 29 First high refractive index layer 101 _TiO2 171.22 30 First low refractive index layer 102 SiO ₂ 123.31 31 First high refractive index layer 101 _TiO2 186.94 32 First low refractive index layer 102 SiO ₂ 311.00

Table 2 Number of layers Film name Material Second film layer group 20 thickness (nm) 1 Second high refractive index layer 201 _TiO2 49.62 2 Second low refractive index layer 202 SiO ₂ 81.43 3 Second high refractive index layer 201 _TiO2 54.23 4 Second low refractive index layer 202 SiO ₂ 75.66 5 Second high refractive index layer 201 _TiO2 29.77 6 Second low refractive index layer 202 SiO ₂ 79.16 7 Second high refractive index layer 201 _TiO2 49.05 8 Second low refractive index layer 202 SiO ₂ 84.83 9 Second high refractive index layer 201 _TiO2 42.45 10 Second low refractive index layer 202 SiO ₂ 72.89 11 Second high refractive index layer 201 _TiO2 40.86 12 Second low refractive index layer 202 SiO ₂ 78.94 13 Second high refractive index layer 201 _TiO2 45.86 14 Second low refractive index layer 202 SiO ₂ 85.30 15 Second high refractive index layer 201 _TiO2 51.46 16 Second low refractive index layer 202 SiO ₂ 313.68 17 Second high refractive index layer 201 _TiO2 10.90 18 Second low refractive index layer 202 SiO ₂ 97.29 19 Second high refractive index layer 201 _TiO2 59.00 20 Second low refractive index layer 202 SiO ₂ 100.83 twenty one Second high refractive index layer 201 _TiO2 71.94 twenty two Second low refractive index layer 202 SiO ₂ 92.62 twenty three Second high refractive index layer 201 _TiO2 58.11 twenty four Second low refractive index layer 202 SiO ₂ 117.76 25 Second high refractive index layer 201 _TiO2 60.90 26 Second low refractive index layer 202 SiO ₂ 100.09 27 Second high refractive index layer 201 _TiO2 62.73 28 Second low refractive index layer 202 SiO ₂ 110.21 29 Second high refractive index layer 201 _TiO2 60.94 30 Second low refractive index layer 202 SiO ₂ 113.28 31 Second high refractive index layer 201 _TiO2 67.96 32 Second low refractive index layer 202 SiO ₂ 88.43 33 Second high refractive index layer 201 _TiO2 72.50 34 Second low refractive index layer 202 SiO ₂ 209.18

The first high refractive index layer 101 and the second high refractive index layer 201 are preferably titanium dioxide (TiO ₂ ), and can further be tantalum pentoxide (Ta ₂ O ₅ ), niobium pentoxide (Nb ₂ O ₅ ), hafnium dioxide (HfO ₂ ), silicon monoxide (SiO 2 ), silicon nitride (Si ₃ N ₄ ), tin dioxide (SnO ₂ ) and zinc sulfide (ZnS ); the first low refractive index layer 102 and the second low refractive index layer 202 are preferably silicon dioxide (SiO ₂ ), magnesium fluoride (MgF Fluoride (MgF ₂ ), barium fluoride (BaF ₂ ), aluminum fluoride (AlF ₃ ) or strontium fluoride (Strontium fluoride, SrF ₂ ).

Please refer to FIG. 2 . In one embodiment, there is an incident light. The incident light is irradiated from the first film layer group 10 to the narrowband filter 1. The transmittance of the narrowband filter 1 in the full wavelength range is tested as shown in FIG. 2 . The narrowband filter 1 has two central wavelengths, which are 365nm~400nm (ultraviolet light) and 900~1000nm (infrared light). The waveforms of the two wavelengths are steep and the transmittance is greater than 95%, indicating that the narrowband filter 1 has a dual-wavelength transmittance of 1. (365nm~400nm and 900~1000nm) has an effective working band, and the background interference signal of the other ineffective bands is greatly reduced, so it has an excellent signal-to-noise ratio, high sensitivity and precision, so that the narrowband filter 1 can be used in the process of ultraviolet light curing in addition to the process of infrared light.

1: Narrowband filter

10: First film layer group

101: first high refractive index layer

102: first low refractive index layer

20: Second film layer group

201: Second highest refractive index layer

202: Second low refractive index layer

3: Substrate

31: First side

32: Second side

L1: first film thickness

L2: Second film thickness

L3:Thickness of the third film layer

L4: Fourth film thickness

Figure 1 shows the structure of the narrowband filter of the present invention. Figure 2 shows the spectrum curve of a preferred embodiment of the present invention.

1: Narrowband filter

10: First film layer group

101: First high refractive index layer

102: First low refractive index layer

20: Second film layer group

201: The second highest refractive index layer

202: Second low refractive index layer

3: Substrate

31: First side

32: Second side

L1: Thickness of the first film layer

L2: Second film layer thickness

L3:Third film layer thickness

L4: Fourth film layer thickness

Claims (9)

A UV-curable narrowband filter comprises: a narrowband filter having a substrate, a first film layer group and a second film layer group, the substrate being between the first film layer group and the second film layer group, the first film layer group comprising a first high refractive index layer and a first low refractive index layer stacked alternately along an axis, the first high refractive index layer and the first low refractive index layer being mutually interlaced and mutually interlaced. The total number of refractive index layers is 32 layers, the first high refractive index layer has a first film layer thickness, the first low refractive index layer has a second film layer thickness, and within 28 layers in the first film layer group, the first film layer thickness is less than the thickness of the second film layer adjacent to each other; the second film layer group includes a second high refractive index layer and a second low refractive index layer stacked alternately along an axis, the second high refractive index layer and the second low refractive index layer total a total of 34 layers, the second high refractive index layer has a third film layer thickness, the second low refractive index layer has a fourth film layer thickness, and the third film layer thickness is less than the thickness of the fourth film layer adjacent to each other; in the 29th layer in the first film layer group, the first film layer thickness is greater than the thickness of the fourth film layer adjacent to each other. The thickness of the adjacent second film layer is less than the thickness of the adjacent first film layer at the 30th layer in the first film layer group; the thickness of the first film layer is between the thickness of the adjacent second film layer at the 31st layer in the first film layer group; the thickness of the second film layer is greater than the thickness of the adjacent first film layer at the 32nd layer in the first film layer group. A UV-curable narrowband filter, comprising: a narrowband filter having a substrate, a first film layer group and a second film layer group, the substrate being between the first film layer group and the second film layer group, the first film layer group comprising a first high refractive index layer and a first low refractive index layer stacked alternately along an axis, the first high refractive index layer and the first low refractive index layer having a total of 32 layers, the first high refractive index layer having a first film layer thickness, the first low refractive index layer having a second film layer thickness, within 28 layers of the first film layer group, the first film layer thickness is The thickness of the second film layer is less than that of the adjacent second film layer; the second film layer group includes a second high refractive index layer and a second low refractive index layer stacked alternately along an axis, the second high refractive index layer and the second low refractive index layer add up to 34 layers, the second high refractive index layer has a third film layer thickness, the second low refractive index layer has a fourth film layer thickness, the third film layer thickness is less than that of the adjacent fourth film layer; the narrowband filter can pass light in the ultraviolet light band of 365nm~400nm and the infrared light band of 900~1000nm. A UV-curable narrowband filter as described in claim 1 or 2, wherein the substrate has a first side and a second side, the first film layer group is located on the first side, and the second film layer group is located on the second side. The UV-curable narrowband filter as described in claim 3, wherein in the first film layer group, one of the first high refractive index layers contacts the first side of the substrate. The UV-curable narrowband filter as described in claim 3, wherein in the second film layer group, one of the second high refractive index layers contacts the second side of the substrate. The UV-curable narrowband filter as described in claim 1 or 2, wherein the first high refractive index layer and the second high refractive index layer are selected from titanium dioxide, tantalum pentoxide, niobium pentoxide, einsteinium dioxide, silicon monoxide, silicon nitride, tin dioxide or zinc sulfide. The UV-curable narrowband filter as described in claim 1 or 2, wherein the first low refractive index layer and the second low refractive index layer are selected from silicon dioxide, magnesium fluoride, barium fluoride, aluminum fluoride or strontium fluoride. A UV-curable narrowband filter as described in claim 1 or 2, wherein within the 28 layers in the first film layer group, the thickness of the first film layer is greater than 0.1 times and less than 1 times the thickness of the adjacent second film layer. A UV-curable narrowband filter as described in claim 1 or 2, wherein in the second film layer group, the thickness of the third film layer is greater than 0.1 times and less than 1 times the thickness of the adjacent fourth film layer.

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