LedRise LED Lighting Blog

The NCSU434C is a high-performance UV-C SMD LED with a typical radiant power of 110mW and 280nm wavelength. Its small size, 3.5mm x 3.5mm, and high radiant flux make it an excellent choice for smaller and more dense designs, and its 120-degree viewing angle and dimensions make it ideal for disinfection and sterilization applications.

One of the significant advantages of Nichia's UV-C LED technology is its germicidal efficacy, capable of deactivating a wide range of pathogens in the UV-C band (100–280 nm), including the SARS-CoV-2 virus. This makes it an ideal choice for use in water, near-surface, and air disinfection systems. Nichia also prioritizes both radiant flux and lifetime in the development of its LEDs, ensuring effective germicidal dosage over time. The company guarantees a minimum 10,000-hour reliability at L70 and realistic high temperatures for its UV-C LEDs, ensuring long-lasting and dependable performance.

In addition to its exceptional performance levels, the NCSU434C is also an environmentally friendly option. Its innovative design, coupled with Nichia's commitment to sustainability, makes it an ideal choice for customers seeking to replace traditional mercury lamps with energy-efficient LED systems. Nichia promises to continue to develop not only deep-ultraviolet LEDs but also higher-power ultraviolet LEDs with improved performance to help solve various social issues and assist in achieving a mercury-free and carbon-free society through energy conservation.

The information below is extracted from the research paper: "Fluence (UV Dose) Required for up to 99% disinfection from Viruses, Bacteria, Protozoa and Algae"  that can be downloaded also on our website at the links below:

PDF: Fluence (UV Dose) Required to Achieve Incremental Log Inactivation of Bacteria, Protozoa, Viruses and Algae

Germicidal action of UV radiation

The effectiveness of sterilization or disinfection with UV light depends on the exposure, time, wavelength and irradiance.

• Exposure or fluence (sometimes called dose) is measured in mJ/cm² (where 1 mJ/cm² = 10 J/m²)
• Exposure time is measured in seconds (s), minutes (m) or hours (h)
• Irradiance is the flux of radiant energy per unit area, in other words how much of the UV radiation power (measured in W = 1000 “miliwatts” mW = 1.000.000,00 “microwatts” μW ) reaches the surface. Irradiance is measured in mW/cm² or W/m² (1 mW/cm² = 10 W/m²) and is dependent on the radiant power, distance and dispersion of the radiation emitted by the lamp source.

Many studies that show the effectiveness of UV light in disinfection or sterilization present in their findings the inactivation of virus or bacteria for a given Exposure in an amount of time, for a given UV wavelength. However, it is difficult to centralize or build a database with so many variables. The most common solution to this problem is to present the fluence required to achieve a log reduction from 1 to 5.

 Log reduction explained

"Log reduction" is a mathematical term (as is "log increase") used to show the relative number of live microbes eliminated from a surface by disinfecting.  For example, a "5-log reduction" means lowering the number of microorganisms by 100,000-fold, that is, if a surface has 100,000 pathogenic microbes on it, a 5-log reduction would reduce the number of microorganisms to one, equal to 99.999% kill rate.

Human Centric Lighting (HCL) is an illumination specially designed to have a positive physiological and/or psychological effect on humans. It consists of adjusting the colour and intensity of the light throughout the day using adjustable white LED lighting solutions.

HCL supports human health, well-being and performance by considering and properly planning the implementation of a lighting system according to the desired visual, emotional and above all biological effects of light. Human Centric Lighting focuses on the needs of people for their living, leisure and working environment. The study is based on the properties and effects of natural light, a dynamic source of changing tone and brightness that changes throughout the day and seasons. 

A combination of white LED light sources, usually warm white (2700K) and cold white (6500K), is used to provide adequate human-centred lighting. This solution is also called Tunable White lighting. By adjusting the intensity of each individual, bright or dull white light with a hue between 2700K and 6500K can be achieved. It is a new way of using and implementing artificial light, corresponding to the changes of natural light and research on the effects on humans.

The positive health effects of the uniform spectral power distribution of the SunLike LEDs from Seoul Semiconductor have been confirmed in two independent studies, by universities from Switzerland and South Korea.

The new SunLike technology brings a major improvement to the LED spectral power distribution (SPD) which now mimics the SPD of the sun within the bounds of the human visual range. The SunLike LEDs LEDs use a three-phosphor mix and a violet emitter to achieve the SPD. Seoul has said that the LEDs can be used in a variety of applications including in human-centric lighting or lighting for health and well-being where tunable lighting can be applied to improve human well-being.

A study published by the University of Basel in Switzerland titled “Effect of daylight LED on visual comfort, melatonin, mood, waking performance, and sleep” found that volunteers had better visual comfort, more alertness, and happier moods associated with exposure to SunLike LEDs  compared LEDs. 

The university published the research in the Journal of Lighting and Research Technology. Professor Christian Cajochen led the research team investigating what they referred to as LEDs with a daylight spectrum.

The innovative Optisolis LEDs from Nichia have a light spectrum that closely matches the spectrum of natural sunlight.

Luminous efficacy measures how effectively a light source produces visible light. With LEDs and other light sources, luminous efficacy is the ratio of luminous flux to electrical power, known as lumens per watt (lm/w). For example, the light output (luminous flux) of a 1 Watt LED can be very bright for high efficacy or barely visible for low.

The luminous efficacy is one of the defining factors of LED performance. Top performance LEDs, with the highest luminous efficacy, have 220 lumens per watt (lm/w), such as the Nichia 757G LEDs. High performance LEDs, like those from many other manufacturers, have 150-200 lm/w. At the far end, we have the low cost, poor performance LEDs with an efficiency of less than 99 lumens per watt.

Introducing Nichia Optisolis LEDs: Harnessing the Full Spectrum of Sunlight for Various Applications

The world market leader in LED development, Nichia, has unveiled its latest innovation: the Optisolis™ technology. Optisolis™ LED emitters provide a natural light source with a spectrum that achieves the industry's closest match to that of standard illuminants, sunlight, and incandescent artificial light, boasting a color rendering index (CRI) of over 98.

The Optisolis family of LEDs are classified as Ultra-High CRI light sources, as they have maximum scores for all 16 color samples used in the color rendering index metric. The 5000K Nichia NF2L757G-F1 Optisolis LED can even achieve a Ra of 99 out of 100. Similarly, the scores with the new IES TM-30-15 light quality tests are equally high, with Rf at 98 and Rg at 99.

Illuminated stretch ceilings are an innovative lighting design solution that has gained popularity in recent years. They offer a wide range of advantages over traditional lighting systems, including uniform illumination, a relaxing ambiance, and minimal glare. Additionally, they can be used for a variety of lighting purposes, such as ambient lighting, general lighting, and even workplace lighting.

However, designing and installing an illuminated stretch ceiling can be a challenging task, and it is essential to take various factors into consideration to ensure optimal results. One of the most important factors to consider is the choice of materials, as the translucency of the stretch ceiling material plays a crucial role in determining the light transmission rate and overall illumination quality. The choice of lighting source is also crucial, as it can affect both the brightness and the energy efficiency of the stretch ceiling.

Another essential aspect to consider is the optimum distance between the LEDs and the stretch ceiling. To ensure even illumination, the LEDs must be evenly distributed behind the translucent material. Therefore, the distance between the light sources and the stretch ceiling should be at least 30 cm to a maximum of around 50 cm, depending on the type of LED used.

The shape of the illuminated stretch ceiling is also an essential factor to consider. It can be personalized and feature translucent images, which can greatly influence the overall design of the space. Additionally, spotlights or lamps can be used to highlight specific areas or objects, complementing the uniform light of the illuminated stretch ceiling.

Introduction to the Color Rendering Index (CRI)

In 1974, the International Commission on Illumination (CIE) introduced the Color Rendering Index (CRI) to compare the color rendering of artificial light sources to a reference standard illuminant modeled after daylight. The CRI aimed to express the quality of white light produced by various types of gas lamps available in the market at that time.

Over the past 40 years, the CRI index has become deeply ingrained in the lighting industry and among professionals. However, it remained relatively unknown to most consumers since it wasn't particularly relevant to their decision-making when purchasing lighting. Manufacturers produced most lamps based on their CRI value for specific applications, ensuring that the choice of lamp could not be wrong. For instance, office or linear lighting typically used Tri-Phosphor linear fluorescent tubes with a CRI over 80. Homes relied on incandescent lamps and halogens with a CRI of 100, while retail spaces utilized metal halide lamps with a minimum CRI of 85.

The makeup of some fixture types for common applications, such as down-lighting, spot-lighting, office-lighting and street-lighting. All can use LEDs.

Seoul Semiconductor’s SunLike Series, equipped with TRI-R technology, represents a groundbreaking advancement in LED lighting. These true natural spectrum LEDs produce light that closely emulates the spectrum of natural sunlight, thanks to a novel LED architecture. By using a purple emitter combined with a red, green, and blue (RGB) phosphor mix, SunLike LEDs offer significant improvements over conventional white LEDs, which rely on a blue emitter and yellow phosphor.

This innovative approach to full-spectrum LED lighting results in accurate color rendering, heightened awareness of contrast and texture, and an overall superior visual experience. In this article, we will delve into the unique properties of SunLike LEDs and their applications in art and museum lighting, which are truly transformative.