Displays with direct-lit backlight units

• Main Authors: Xu, Daming, Yin, Victor H, Sun, Yu P, Son, Mookyung, Keresztes, Janos C, Gorkhali, Suraj P, Qi, Jun, Hong, Ziruo, Zhu, Xinyu, You, Chenhua, Lv, Wei, Kang, Edward H, Liu, Rong, Zhu, Wenyong, Lin, Hung Sheng, So, Pee Khiam, He, Juan, Suh, Heesang, Spechler, Joshua A, Han, Ling, Luo, Zhenyue
• Format: Patent
• Language: English
• Published: 26.01.2021
• Subjects: BASIC ELECTRIC ELEMENTS; BLASTING; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FREQUENCY-CHANGING; HEATING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21Sand F21V, RELATING TO THEFORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THELIGHT EMITTED; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATINGELEMENTS; LIGHTING; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; MECHANICAL ENGINEERING; NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; PRINTED CIRCUITS; SEMICONDUCTOR DEVICES; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; WEAPONS

A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a backlight unit. The backlight unit may include a printed circuit board, a plurality of light-emitting diodes mounted on the printed circuit board, at least one light spreading layer formed over the printed circuit board that spreads light received from the plurality of light-emitting diodes, a partially reflective layer formed over the at least one light spreading layer, a color conversion layer formed over the partially reflective layer, a collimating layer formed over the color conversion layer, a brightness enhancement film formed over the collimating layer, and a diffuser formed over the brightness enhancement film. The at least one light spreading layer may include two light spreading layers with elongated protrusions that are rotated relative to each other.