Full metadata record
DC FieldValueLanguage
dc.contributor.authorQin, Zongen_US
dc.date.accessioned2018-08-21T05:52:56Z-
dc.date.available2018-08-21T05:52:56Z-
dc.date.issued2017-12-01en_US
dc.identifier.issn0141-9382en_US
dc.identifier.urihttp://dx.doi.org/10.1016/j.displa.2017.09.006en_US
dc.identifier.urihttp://hdl.handle.net/11536/144123-
dc.description.abstractIn a conventional backlight, suppression of light loss caused by the prism film(s) is desired to enhance the luminance without sacrificing the viewing angle. In this paper, in a direct-lit light-emitting diode (LED) backlight, where an LED array is placed under the display panel, the transmission efficiency against the prism film(s) is investigated for incident light with different zenith and azimuth incident angles. A strong angle-dependent characteristic is found, even when the reflective recycling effect is available. To address this angle-dependent characteristic in a direct-lit LED backlight, a freeform lens is designed to deflect the light emitted from an LED into the incident angle range with high transmission efficiency. Two design examples are implemented by adopting dual- and single-layer prism film(s). The simulation results show that the freeform lens can enhance the on-axis luminance by 26% and 35%, respectively, while the viewing angle remains nearly unchanged. Furthermore, using a single layer of prism film, a 19-in. direct-lit LED backlight module is constructed for experimental verification. By fabricating the freeform lenses and adding them to the backlight module, the on axis luminance is enhanced by 24%, and the viewing angle is decreased by no more than 2 degrees. Finally, the influence of the diffusers, which causes the experimental results to degrade slightly compared with the simulation results, is analyzed.en_US
dc.language.isoen_USen_US
dc.subjectLiquid crystal displayen_US
dc.subjectBacklighten_US
dc.subjectPrism filmen_US
dc.subjectFreeform opticsen_US
dc.titleLuminance enhancement without sacrificing the viewing angle in a direct-lit backlight by addressing the angle-dependent characteristic of the prism filmen_US
dc.typeArticleen_US
dc.identifier.doi10.1016/j.displa.2017.09.006en_US
dc.identifier.journalDISPLAYSen_US
dc.citation.volume50en_US
dc.citation.spage49en_US
dc.citation.epage56en_US
dc.contributor.department光電工程學系zh_TW
dc.contributor.department顯示科技研究所zh_TW
dc.contributor.departmentDepartment of Photonicsen_US
dc.contributor.departmentInstitute of Displayen_US
dc.identifier.wosnumberWOS:000416191100007en_US
Appears in Collections:Articles