1968 HP company will produce a red LED light wavelength (660 nm), and then appeared in succession can be used to display the green wavelength (570 nm), blue (wavelength 470 nm) and pure green wavelength (525 nm), but at the moment because of high brightness blue, pure green semiconductor chip manufacturing technology is mainly in Japan, the United States a few companies, such as causing prices more expensive. Applied to the display screen LED luminescent material has the following form:
(1) LED lamp (or single lamp)
Generally consists of a single LED chip, reflective bowl, metal anode, metal cathode, outsourcing has pervious to light condensing capacity of epoxy resin shell. Available for one or more (different color) single lamp form a basic pixels, due to their high brightness, more for outdoor display.
(2) the LED dot matrix module
Consist of a chip number luminous matrix, wrap in a plastic case with epoxy resin. Suitable for scanning drive, easy to form high density of the display screen, used for indoor displays.
(3) the patch type LED lamp (or SMD LED)
Is LED lamp post welding forms of packaging, can be used in indoor full color display screen, which can realize the single point of maintenance, effectively overcome the Mosaic phenomenon