Dot-pattern design of a light guide in an edge-lit backlight using a regional partition approach

Abstract

This paper employs a regional partition approach to establish the optimal distribution of the diffuser dots in the light guide of an edge-lit backlight. The proposed approach commences by dividing the light guide into a number of partitions and assigning an equal radius to every dot. An iterative optimization procedure is then performed in which the illuminance in each partition is calculated and the dot radius in each partition progressively adjusted until uniform luminance is obtained over the entire light-guide surface. To simplify the geometry construction process and improve the efficiency of the optimization procedure, a simple optical model is proposed for the diffuser dots and the bare surface of the light guide, and an analytical procedure is implemented to take account of the diffuser-film and brightness-enhancement-film effects. The simulation results confirm the ability of the proposed approach to accurately reflect the fine regulation of the dot radius required to obtain uniform luminance for typical light-emitting diode configurations used in practical backlight modules.

Illuminance Distribution and Photosynthetic Photon Flux Density Characteristics of LED Lighting with Periodic Lattice Arrangements

“…With the advancement of high-speed computing and optical analysis software packages, LightTools version 7.0, the computer-aided optical analyses of LED, LCD light guide plates, optical film and optical lens can be accelerated, in order to save time, manpower and costs [4][5][6][7]. Five arrays were designed for a LED in order to study the radiation pattern, uniformity ratio of illuminance and PPFD without lens.…”

“…LEDs have high luminance and wide spans of dominant wavelengths within the entire visible spectrum. Because of the narrow spectral distribution, LEDs are being further evaluated as one of the possible standard light source [4][5][6][7]. LED arrays are everywhere.…”

Micromilled optical elements for edge-lit illumination panels

“…This has been achieved by varying the size of the micro-optical structures (MOSs), 1,4,5 changing the pitch between adjacent MOSs, 6 or simultaneously adjusting both size and pitch. The spatial distribution of the MOSs can also be varied across the LGP surface such that the element density increases with distance from the LED sources.…”

“…The light guides in the backlit modules are designed to frustrate total internal reflection (TIR) and uniformly redistribute the light rays emitted from multiple LEDs across the active surface area with minimal optical losses along the nonactive edges and faces. 1 The shape, density, and spatial distribution pattern of the microoptical elements imprinted on the surface of the flat lightguide panel (LGP) are often "optimized" to improve the overall brightness and luminance uniformity. Optical simulation tools, such as LightToolsTM and TracePro,™ are often used to determine the distribution of micro-optical elements for the desired brightness and uniformity properties.…”

Nonlinear optimization to generate non-overlapping random dot patterns

“…Chang and Lee (2007) and Chang, Fang, and Ju (2009) also proposed similar molecular-dynamics-simulation-based redistribution algorithms for the dots. Meanwhile, Chang and Fang (2007) proposed an approach to optimize the dot radii iteratively, where the dot positions are fixed, i.e., the dots are on predefined grid points. We propose a new approach to the random dot pattern generation task.…”