Definition of Lighting, Development of Lighting, Basics of Lighting

Definition of Lighting

1. Definition of Lighting

 Lighting is the act of illuminating objects and their surroundings with light for the purpose of utilizing it in human life and activities. It also involves using light to influence people's emotions or moods and making the light source itself visible for conveying information through signs, indicators, billboards, and signals. Additionally, lighting aims to utilize radiation for human life and activities. This definition includes not only visible radiation but also the application of ultraviolet and infrared radiation.

 It is the use of light to ensure that what is being viewed is seen clearly or to create a specific atmosphere. More broadly, it includes the application of visual and light information, as well as the effects of radiation—including ultraviolet, visible light, and infrared—on various materials, living organisms, and biological systems.

 

In our daily lives and activities, the "information" we receive from our environment is extremely important. Stimuli perceived through sight, hearing, smell, taste, and touch are transmitted to the brain, which then processes them by interpreting the signals, making decisions, or selecting appropriate actions. The brain then sends commands to control subsequent behaviors. The signals and stimuli that are useful for judgment and command are referred to as information. Among the senses, the amount of information received through vision is exceptionally large and plays a significant role in our everyday activities.

 

 To accurately and rapidly process this large amount of visual information, high-quality artificial lighting is essential. Appropriate lighting can help overcome temporal and spatial constraints in daily activities. Since humans first began using fire, light-related technologies have contributed to the development of civilization and culture.

 

 In lighting technology, the design, construction, and operational planning of facilities must align with the intended use of the space. It is essential to fully understand the role of lighting to enhance the quality of the living environment.

 

Development of Lighting

2. Development of Lighting

 A significant characteristic that distinguishes humans from other animals in the history of mankind is the invention of tools and the use of fire. In particular, fire has supported human progress through its heat and light. The light produced by combustion in the early days extended human activity into nighttime, and later, as seen today, enabled the use of spaces such as underground areas and large-scale architecture.

 The realization of modern lighting has been made possible through research and development of light sources. The first lighting source was the light produced by burning wood. Although combustion-based lighting continued for a long time, efforts were made to improve combustion methods by exploring more efficient fuels. The transition from using animal and vegetable oils to petroleum-based fuels, followed by the introduction of coal gas lighting systems, led to the emergence of electric power supply in the late 19th century. With rapid technological advancements, large quantities of light became available at an economical cost.

 Light sources have evolved from natural light sources such as the sun and the moon to various combustion-based sources. The development of lighting systems integrated with energy supply, such as gas lamps and incandescent bulbs, as well as advancements in discharge lamps and, more recently, semiconductor light sources, has progressed alongside scientific and technological innovations. The primary goals of light source development are high efficiency and high color rendering. When achieving both efficiency and color rendering posed challenges, the development of phosphors led to the emergence of three-band fluorescent lamps. Additionally, miniaturization of discharge lamps was pursued to enhance light utilization efficiency when combined with lighting fixtures. Furthermore, the introduction of low-power lamps and semiconductor-based lamps enabled significant advancements in lighting systems and techniques, allowing for precise light distribution and control.

 With the advent of electric lighting, light became available at relatively low costs. As a result, the demand for increased indoor brightness grew, leading to reductions in electricity costs and improvements in lighting equipment, making higher levels of illumination more accessible.

 The approach to lighting also evolved from simply ensuring safety in the environment to providing higher illumination levels that facilitate visual tasks and enhance efficiency in daily activities. While higher illuminance levels were sought, issues such as glare and energy conservation were gradually addressed. Over the past several decades of the 20th century, the recommended illuminance for general lighting increased at nearly twice the rate every decade. However, recent research on visual information processing and energy-efficient lighting techniques suggests an optimal illuminance level of 500–750 lx. To compensate for individual differences in visual needs, localized lighting solutions have been implemented.

 When considering the economics of lighting installations, the majority of operational costs come from electricity consumption. A comprehensive evaluation is required to maximize lighting efficiency. Additionally, efficiency is not just a cost-related issue but is also linked to global environmental concerns. Since the 1970s, discussions have emerged regarding the anticipated increase in human population, improvements in living standards, the limitations of finite resources, the constraints on available energy, and the environmental pollution associated with energy resource consumption. These issues have been taken seriously in the field of lighting as well.

 Efforts to improve light source efficiency, research on visual system characteristics, and the reassessment of the relationship between illuminance and productivity are ongoing. The goal is to balance cost savings achieved through increased illuminance with environmentally harmonious lighting technologies. As a result, architectural design and lighting systems are becoming increasingly integrated from the planning stage to create more comfortable and efficient environments.