High-efficiency backlight module with two guiding modes

Abstract

We propose a design for a high-efficiency backlight module that does not require a brightness enhancement film (BEF). With the high-efficiency backlight module it is possible to achieve almost the same half-luminance angle as a conventional edge-lit backlight module can achieve. The backlight system is comprised of a crisscross light guide plate (LGP) and one diffuser sheet. The crisscross LGP is composed of a LGP and optically patterned film (OPF). The backlight module allows light to be extracted through the direct guiding mode and top guiding mode, respectively. We controlled arrangement of the microstructures to increase the optical efficiency and the uniformity by two modes. Compared to the conventional edge-lit backlight module, there is a two-fold improvement in both the total optical efficiency and on-axis luminance with the high-efficiency backlight module.

Design and fabrication of submicron period grating as an imprinted light guide plate for a backlight unit

“…The function of the BLU is to transform the light flux from the point or line source into the areal illuminator towards the LCD panel. Light is usually extracted from the LGP by the micro-optical structures and/or printed dots on the surface of the LGP [1][2][3][4][5][6][7][8]. Instead of modifying the surface of the LGP, several contributors have proposed the use of the scattering polymer, where the optical transmission particles inside the LGP work to extract the light [9][10][11].…”

Design of a brightness-enhancement-film-adaptive freeform lens to enhance overall performance in direct-lit light-emitting diode backlighting

“…Some solutions have been proposed to improve the output efficiency of backlight systems, such as the optimization of angular placements of the LEDs with cone-shaped caps [8], the arrangement of the microstructures by two guiding modes [9], the use of dual-cone-shaped lens caps for improving brightness and uniformity [10]. However, there is little literature referring to the optimization of output light distribution from a light source which adapt to the optical properties of the BEF.…”

Efficiency balance of a light guide plate with microstructures for a see-through head-mounted display

“…For example, Hung et al [7] designed a see-through HMD based on a light guide plate with microstructures that took advantage of TIR to extract the virtual image rays. Although this design could decrease the loss of virtual image energy [8] , the loss of the real world image energy was not considered. There are two important features to be considered in see-through HMDs, the visibility of the virtual image, and the visibility of the real image.…”