What are the types of LED light sources?

There are three main types of light sources: cold cathode fluorescent lamp, RGB tricolor light emitting diode (LED), and a few scanners use halogen light source.

 

 

 

Backlight classification: At present, according to the type of light source, there are three types of backlight: EL, CCFL and LED. According to the location of the light source, backlight can be divided into side light type and straight-down type (bottom backlight type). Here is a brief introduction to them.

 

 

 

1. Edge light type. The backlight is made by setting the linear or point light source on the side of the specially designed light guide plate. According to the actual needs of use, it can also be made into bilateral or even trilateral. Edge light backlight can generally be made very thin, but the light utilization rate of light source is small, and the thinner the utilization rate is, the smaller the utilization rate is, the maximum is about 50%. Its technical core is the design and fabrication of light guide plate. The most commonly used side light type are LED lamp backlight and CCFL backlight. Weizhi LED side light backlight has WU, WH, WN class as unilateral, WL, WJ, WK, WB class as bilateral. With the development of LCD modules towards brighter, lighter and thinner, side-light CCFL backlight has become the mainstream of backlight development. WQ products are Weizhi CCFL side light backlight. Ultraviolet LED

 

 

 

 

1) LED backlight. LED lamp is also called light emitting diode. Compared with other light sources, the power consumption of single LED lamp is the smallest. From blue to red, LED lights have many colors, such as Table 1 and Table 2. Another special color is white. Table 3 gives the range of colors commonly used. In various colors, it can be roughly divided into two types: high and low brightness: basically, "Table 1" belongs to low brightness (although amber, orange and red also have a slightly higher brightness), "Table 2" and "Table 3" belong to high brightness. Because white is a mixed color, there is no identifiable wavelength value, so it is expressed by its coordinate value on the chromaticity map. Customized as "cold white" and "warm white" two kinds. In all kinds of colors, there is a problem of color deviation, blue and white performance is more obvious, especially white, now LED suppliers can not effectively control it.

 

 

 

2) CCFL backlight. The biggest advantage of this kind of backlight is its high brightness, so it is basically used in large black-and-white negative phase, blue-mode negative phase and color liquid crystal display devices. In theory, it can make all kinds of colors according to the color matching principle of three primary colors. Its disadvantage is that it consumes a lot of power and needs to be driven by an inverting circuit, and the working temperature is narrower, ranging from 0 to 60 degrees, while other backlights such as LED can reach - 20 to 70 degrees.

 

 

 

2. Backlight type. It can be a continuous and uniform surface light source, such as EL or flat-panel fluorescent lamp, or it can be composed of more point light sources, such as lattice LED or incandescent lamp backlight. LED lattice and EL backlight are commonly used. UVled Light Source

 

 

 

1) EL backlight. Electroluminescence (EL) is a cold light source that emits light by the intrinsic luminescence of phosphors excited by alternating electric fields. Its greatest advantage is that it is thin and can achieve a thickness of 0.2-0.6 mm. The disadvantage is low brightness, short life (generally 3000-5000 hours), need to be driven by inverters, but also by circuit interference and flicker, noise and other bad. EL is driven by inverter and Driver IC. Because the current frequency and load output voltage of DriverIC can not reach the typical conditions of EL (400Hz, AC100V), the brightness of DriverIC is lower than that of inverter driver. Recently, white light (panchromatic) EL and LCD backlight came out one after another. But because of the darker brightness, it is basically used for small size liquid crystal display under 4 inches. For example: mobile phones, PDA, game consoles, etc. Whole color (white light), large size brightness backlight, now the mainstream is still using CCFL as the light source. Weizhi has not developed EL backlight at present.

 

 

 

2) LED backlight. The advantages are good brightness and uniformity. The disadvantage is that the thickness is larger (more than 4.0mm), the number of LED used is more, and the fever phenomenon is obvious. Generally, low-bright colors are used for design, while high-bright colors are not considered because of their high cost. WA products are Weizhidi backlight. UV oven