Concept of spatial front sound and optically invisible antenna on display liquid crystal cellular devices

Abstract

Presently, Liquid Crystal Displays (LCDs) are the dominant technology over the display market. However, a long with the r apid development in OLED technology , the LCD industry is facing through challenges and requiring new applications based on its intrastructure This paper proposes a novel c oncept of an LCD panel combined with spatial front speakers and optically invisible anten na s While conventional cellular devices have a Bottom Facing S peaker , it adopts a dual channel front facing speaker. Existing front sound devices such as Crystal Sound OLED(CSO) utilize the panel as a flat diaphragm and it is because the OLED panel i s thinner and more durable than LCD s . Different from the earlier approaches , we suggest a different front sound technology , which chooses Touch Screen Panel(TSP) as a diaph ragm in front of the d isplay panel. Fig. 1.(a) depicts a direct driving front sound generation structure. The exciter at Au dio Layer(AL) produces a spatial sound by vibrating TS P and our two exciters delivers the vibration s to the top and bottom plates. Those d istributed sounds built in dual channel provides volumetric stereo sound. In th e case of an optically invisible antenna, a liquid crystal ( layer is used as a phase shifter. Fig. 1.(b) shows a single anten n a element unit . The i nserted microstrip antenna radiates an ele c tromagnetic wave to upward direction and birefringence properti es of LC modify the wave front . In order to avoid the effect that the electrode blocks the radiation of the EM wave, we ch ose the In Pla ne Switching(IPS) configuration whose pixel consists of 4 sub pixels , such as red, gree n, blue and antenna element. The aligned several pixels constitute a phased array antenna on the LCD panel. We are optimizing the sound and electromagnetic wave using Finite Element Method (FEM) simulation package, COMSOL MULTIPHYSICS. It enables us to estimate and compare the sound and antenna quality of the cellular device. Display specifications such as transmittance and color gamut are calculated by TECHWIZ LCD, three dimensional LCD simulation software. In conclusion, this paper presents a concept of a new type cellular device combined with the Sound on Display (SoD) and Antenna on Display (AoD) technologies. The proposed cellular device, with functions of display, speaker and antenna, can have excellent bezel-less properties, and various modules in the present cellular display can be also included.