A Simple Designed Lens for Human Centric Lighting Using LEDs

Abstract

Light is generally important for human beings. Visible light supports vision and can modify circadian rhythm, and together with invisible light at longer or shorter wavelength can also make either a direct or indirect impact on human biological and mental health. For medical applications, several studies have shown success in using light to fasten the skin regeneration in burns and to cure diseases such as newborn jaundice. In daily life, an appropriate amount and time exposure to certain types of light can result in rising of alertness and mood improvement, which leads to noticeable growth in one’s productivity. Therefore, human centric lighting can modify lighting factors to make the best of the natural characteristics of light. The seek an ideal indoor lighting system is widely carried out not only by scientists but also by architects. A qualified luminaire is considered by many factors, including luminous productivity, visual comfort and expenses; meanwhile, the idealization of illuminance is also constructed in many ways, such as widening the lamp’s surface area, changing of luminaire’s positions and applying different methods to illuminate a surface. Approaching these problems, our idea is to study the uplighting method and freeform optics using low-cost acrylic lenses. By changing lens shape and optimizing the factors which affect the illuminance such as the irradiation angle and the distance between the luminaire and the reflection surfaces, we find the most effective lens and its peaks due to each factors using the ray-tracing simulation to obtain results concerning high uniformity of illumination.

Role of Architectural Design in Creating Circadian-Effective Interior Settings

“…Adding desktop luminaire directed towards desk user's eyes resulted in great circadian stimulation [43]. ThiGiang et al ( 2020) compared the effect of using downlighting and uplighting on the provision of indirect light inside architectural spaces [88]. Downlighting and semi-direct lighting are common, but they have disadvantages, such as low illuminance uniformity inside spaces and the considerable contrast between luminaires and their surroundings.…”

An Alternative Approach for High Uniformity Distribution of Indoor Lighting LED

“…Based on the illumination distribution in Fig. 5(a) we can design an asymmetric lens along the side-wall using the method reported [29]. Fig.…”

“…A 3-D free-form lens for uniform rectangular illumination was proposed by Liou et al [28]. Recently, our research group has also presented a simply designed lens for human-centric lighting using LEDs [29]. However, these previous works have not provided a general approach to design a secondary optical lens for indoor illumination systems.…”

A Field Study of the Impact of Indoor Lighting on Visual Perception and Cognitive Performance in Classroom

“…Over recent decades, researchers, lighting designers, and architects have realized that lighting design should be required to consider both visual and non-visual aspects of lighting [31][32][33][34]. Based on such a scientific consensus, researchers have recently focused on the concept of human-centric lighting (HCL) [35][36][37][38][39], which aims to maximize the benefits of proper lighting and covers a broad set of technologies. Specifically, HCL provides evidence-based lighting solutions optimized for vision, performance, alertness, and general human health, in the way of balancing the visual, emotional, and biological benefits of lighting.…”

“…This HCL metric comprised widespread used measures of colour quality (e.g., CRI Ra), descriptors of brightness (e.g., CIE L mes [40]), as well as an indicator of the circadian effect (the so-called DIN melanopic factor [41]). Additionally, in the latest study by Duong et al [38] that concentrated on the up-lighting method and freeform optics, a design of freeform lenses for HCL was developed. It was proved to be beneficial in obtaining the maximum luminous uniformity over an indoor space, which might result in less chance of myopia and improvement in health and mental wellness.…”