North America
Europe
Denmark
France
Germany
Italy
Netherlands
Poland
Spain
Sweden
Switzerland
U.K.
Latin America
Asia Pacific
Argentina
Brazil
Mexico
Australia
China
Hong Kong
India
Japan
Korea
New Zealand
Singapore
Taiwan
UL的第三屆年度全球研究比以往規模更大、更好,主題是根據各類產品的相關因素比較製造商和消費者的態度及重點。

更多資訊 >
讓 UL 引以為傲的是與世界分享New Science。透過在四大基礎領域內進行基本探索、測試方法、軟體以及標準,新科技帶來的創新成果向我們展示了讓世界變得更安全的重要方式。

更多資訊 >

標準

每年有數千種產品及其零部件按我們的嚴格要求接受測試。

儀錶板

UL儀錶板的各種工具比以往更靈巧、更有效、更快捷,可使企業滿足不斷變化的市場需要。

瞭解更多 >

LIBRARY

MARKS HUB

SERVICES

STANDARDS

Share

About LEDs

Definition

Light emitting diodes, or LEDs, are small light sources illuminated by the movement of electrons through a semiconductor material.

Energy Efficiency

LEDs produce more light per watt than incandescent bulbs, making them exceptionally energy efficient. In fact, many LEDs use up to 90 percent less energy than an incandescent bulb to produce the same amount of light.

Common Applications

LEDs are a directional light source that point light a specific way, unlike incandescent bulbs which emit light in all directions. Much of the light produced by incandescent bulbs can be lost within the light fixture or reabsorbed by the lamp. For many fixture types, including recessed downlights, fluorescent lighting units, and under-cabinet fixtures, it is common for 40-50 percent of the total light output of the lamp to be lost before it even exits the fixture.

Because LEDs are directional lighting, the lamps are especially useful for task lighting, such as under cabinets, in hallways and in recessed and downlight fixtures. They also perform well when subjected to frequent on-off cycling.

Color Quality

Most people still expect LEDs to cast a cool, bluish light, but technology is improving. When introduced to the market, LEDs produced a cold light because of high correlated color temperatures (CCTs), often above 5000 Kelvin (K). These days, warm white LEDs with CCTs ranging from 2600K to 3500K, have significantly improved.

Cost

LEDs are currently more expensive, per lumen, than more conventional lighting technologies. This is attributed mostly to production needs and process. However, because LEDs are designed to have a long life, reporting approximately 35,000 to 50,000 hours of useful life, LEDs far surpass incandescent or halogen sources in terms of cost over the course of its life.

End-of-Life

LEDs indicate end-of-life by dimming over time.

Issues to Resolve

LED manufacturers continue to work with lighting experts to fine tune the following:

  1. Efficacy
  2. Temperature
  3. Color
  4. Price
  5. Complexity
--Sources: The Department of Energy and the Environmental Protection Agency