Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters)
In many situations in everyday life, sunlight levels need to be reduced. Optical filters with asymmetric transmittance dependent on the incident angle would be useful for sunglasses and vehicle or architectural windows, among others. Herein, we realized the production of optical filters, called “lou...
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| Format: | Article |
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MDPI AG
2023-08-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/16/16/5584 |
| _version_ | 1797584067556802560 |
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| author | Kohki Takatoh Mika Kobayashi Masahiro Ito |
| author_facet | Kohki Takatoh Mika Kobayashi Masahiro Ito |
| author_sort | Kohki Takatoh |
| collection | DOAJ |
| description | In many situations in everyday life, sunlight levels need to be reduced. Optical filters with asymmetric transmittance dependent on the incident angle would be useful for sunglasses and vehicle or architectural windows, among others. Herein, we realized the production of optical filters, called “louver filters”, comprising HAN-type LC film produced using liquid crystalline ink with dichroic dyes. For the formation of the HAN-type LC film, the liquid crystalline ink was aligned on a rubbed polyimide layer and polymerized by UV irradiation. Two kinds of filters are proposed: one is a filter composed of HAN-type LC film and a polarizer, and the other is composed of two HAN-LC films with a half-wave plate between them. The dependence of the asymmetric transmittance on the incident angle was confirmed for these filters. The dependence changed depending on the pretilt angle of the alignment layers. Photographs taken with the optical filters displayed their effectiveness. |
| first_indexed | 2024-03-10T23:47:01Z |
| format | Article |
| id | doaj.art-efc2473eeab54ebe9d971d324e7da14f |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T23:47:01Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-efc2473eeab54ebe9d971d324e7da14f2023-11-19T01:59:44ZengMDPI AGMaterials1996-19442023-08-011616558410.3390/ma16165584Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters)Kohki Takatoh0Mika Kobayashi1Masahiro Ito2Department of Electrical Engineering, Faculty of Engineering, Sanyo-Onoda City University, 1-1-1 Daigaku-dori, Sanyo-Onoda 756-0884, JapanDepartment of Electrical Engineering, Faculty of Engineering, Sanyo-Onoda City University, 1-1-1 Daigaku-dori, Sanyo-Onoda 756-0884, JapanMedical Engineering Course, Department of Medical Course, Faculty of Health and Medical Science, Teikyo Heisei University, 2-51-4 Higashi-ikebukuro, Toshima-ku, Tokyo 170-8445, JapanIn many situations in everyday life, sunlight levels need to be reduced. Optical filters with asymmetric transmittance dependent on the incident angle would be useful for sunglasses and vehicle or architectural windows, among others. Herein, we realized the production of optical filters, called “louver filters”, comprising HAN-type LC film produced using liquid crystalline ink with dichroic dyes. For the formation of the HAN-type LC film, the liquid crystalline ink was aligned on a rubbed polyimide layer and polymerized by UV irradiation. Two kinds of filters are proposed: one is a filter composed of HAN-type LC film and a polarizer, and the other is composed of two HAN-LC films with a half-wave plate between them. The dependence of the asymmetric transmittance on the incident angle was confirmed for these filters. The dependence changed depending on the pretilt angle of the alignment layers. Photographs taken with the optical filters displayed their effectiveness.https://www.mdpi.com/1996-1944/16/16/5584liquid crystalliquid crystalline inklouver filterHAN-type LCasymmetric transmittance dependencepretilt angle |
| spellingShingle | Kohki Takatoh Mika Kobayashi Masahiro Ito Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters) Materials liquid crystal liquid crystalline ink louver filter HAN-type LC asymmetric transmittance dependence pretilt angle |
| title | Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters) |
| title_full | Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters) |
| title_fullStr | Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters) |
| title_full_unstemmed | Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters) |
| title_short | Optical Filters with Asymmetric Transmittance Depending on the Incident Angle, Produced Using Liquid Crystalline Ink (Louver LC Filters) |
| title_sort | optical filters with asymmetric transmittance depending on the incident angle produced using liquid crystalline ink louver lc filters |
| topic | liquid crystal liquid crystalline ink louver filter HAN-type LC asymmetric transmittance dependence pretilt angle |
| url | https://www.mdpi.com/1996-1944/16/16/5584 |
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