LED flashlight is a new type of flashlight with LED (light emitting diode) as light source. Because LED has high brightness, low power consumption, long life, small size and other characteristics, it is ideal for portable lighting.
Atomic electrons have a lot of energy levels, and when electrons transitions from high energy levels to low energy levels, the energy of electrons is reduced, and the reduced energy is converted into photon emission. A lot of these photons are laser.
LED light principle is similar. But the difference is that the LED does not emit light through the electronic transitions inside the atom, but by adding a voltage to both ends of the PN junction of the LED, the PN junction itself forms an energy level (in fact, a series of energy Level), and then electrons jump on this level and produce photons to glow.
The new LED display parts have the advantages of low power consumption, high brightness, long life and small size. This paper starts with the development of LED display parts, discusses the LED, LED and LED for automotive applications. Development trend, for the development of display devices in Chinese engineers have a certain reference value. The world's first commercial light-emitting diode (LED) was made in 1965 with germanium material, the unit price of $ 45.
In 1968, LED research and development has made a breakthrough, the use of nitrogen doping process to GaAsP device efficiency reached a lumens / watt, and can send red, orange and yellow light. To 1971, the industry has introduced the same efficiency GaP green die LED. In 1972 began a small number of LED display for watches and calculators. The world's first LED watch was originally sold in expensive jewelry stores, the price was as high as 2,100 US dollars. Almost at the same time, HP and Texas Instruments also introduced a 7-segment red LED display with the calculator. To the 20th century, 70 years, due to LED devices in the home and office equipment in a large number of applications, LED prices plummeted. In fact, LED is the era of flagship and text display technology. However, in many commercial devices, LED display has also been subject to fierce competition from other display technologies, such as LCD, plasma and vacuum fluorescent tube display.
This competitive incentive LED manufacturers to further expand their product types, and actively seek LED has a clear competitive advantage in the application areas. Since then the LED began to be applied to the dot matrix display, the background pattern with the light grid and bar graph array. Digital display size and complexity are growing from 2 digits to 3 digits or even 4 bits, from 7 digits to 14 or 16 segments that can display complex text and pattern combinations. By 1980 the manufacturer began to provide intelligent dot matrix LED display. This technological advancement enables the LED to be used in outdoor sports information releases as well as automotive central high stop stop lamps (CHMSL) equipment. The invention of the bright blue LED makes it possible to realize the true color display display, which can display true color, full motion video images.
The presence of blue LEDs enables people to partially convert high-energy blue light into other colors using retroreflective phosphorescent materials. Only the LED light source can completely cover all the saturation colors in the CIE chromaticity curve, and the organic integration of the various colors of LEDs with phosphorus can produce almost unlimited
What color? In terms of reliability, the half-life of the LED (ie, the amount of light output to the original half of the time) is about 10,000 to 100,000 hours. In contrast, the half-life of a small indicator incandescent lamp (where the half-life refers to the half of the lamp's failure time) is typically 100,000 to several thousand hours, depending on the rated operating current of the lamp.