Search

The article presents a study which discusses the solid-state light sources model of phosphor-based light-emitting diode (LED). The study uses the ray tracing procedure along with the suitable LED emission apodization pattern checked through the signal-to-noise ratio examination on the illuminating plane and color coordinates determined by energy ratios. The study revealed that the illumination and color patterns can be restored, however, several factor influence the color distribution of LED.

A conference paper about the uniformity improvement of the light emitting diode (LED) illumination system is presented. It compares the three different types of lens such as the hemispheroid, unoptimized and the lens after optimization. It discusses the non-spherical lens design approach used to optimize and improve the extraction energy and the spatial uniformity of the LED illumination system. It reveals that the new developed lens can improve uniformity from 28.4% to 64%.

In Taiwan, issues in technology education (TE), such as indeterminate core mission and unclear role, could be addressed through an objective knowledge map of research to discern directions of development and prospects. This study explores sub-fields, genres, characteristics, and trends in TE research in Chinese and English over 24 years through bibliometric co-citation analysis using two databases: Web of Science and Airiti Library. As per the findings: (1) TE research has been progressing slowly in Taiwan, while it is developing rapidly elsewhere; Disciplines integrated with TE include education and educational research, engineering, computer science, social sciences, and medicine; (2) Research topics have evolved from industrial arts, technical and vocational education, technological literacy education, and curriculum development, to pedagogical skills of teachers of technology; Other countries focus on "professional development of technology teachers," while Taiwan emphasizes "curriculum and teaching materials;" (3) Clusters from different periods are complementary, and research topics and fronts reflect continuity. (4) "Assessment," as a research dimension, has received insufficient attention. Insights into the evolution of research topics and research fronts are offered for technology educators. [ABSTRACT FROM AUTHOR]

Although apodization patterns have been adopted for the analysis of sputtering sources, the analytical solutions for the film thickness equations are yet limited to only simple conditions. Empirical formulations for thin film sputtering lacking the flexibility in dealing with multi-substrate conditions, a suitable cost-effective procedure is required to estimate the film thickness distribution. This study reports a cross-discipline simulation program, which is based on discrete particle Monte-Carlo methods and has been successfully applied to a non-imaging design to solve problems associated with sputtering uniformity. Robustness of the present method is first proved by comparing it with a typical analytical solution. Further, this report also investigates the overall all effects cause by the sizes of the deposited substrate, such that the determination of the distance between the target surface and the apodization index can be complete. This verifies the capability of the proposed method for solving the sputtering film thickness problems. The benefit is that an optical thin film engineer can, using the same optical software, design a specific optical component and consider the possible coating qualities with thickness tolerance, during the design stage. [ABSTRACT FROM AUTHOR]

Fresnel-like prism arrays are designed using geometric ray optics and fabricated on a curved surface according to specific focal length requirements. In this study, the tolerance of Fresnel-like prism structures on arbitrary surfaces was investigated. Compact equations (iterative and non-iterative) based on analytical formulation can be helpful in exploring the sensitivity associated with the fabrication of Fresnel-like structures. The curved surface in this study revealed a linear relationship between maximum angular tolerance and the angle of incident rays. An understanding of such linearity is a key issue in the fabrication of lenses as well as in the sensitivity formulae used for optical structures in the development of next-generation optics. [ABSTRACT FROM AUTHOR]