The largest difference between two types of laser pointer

The largest difference between two types of laser pointer will be demonstrated.
Magnetic materials. Generally speaking, the permanent magnet materials is toward the high magnetic energy product, high coercivity, high remanence direction of NdFeB permanent magnet alloy the maximum energy product has reached 52MGOe; soft magnetic materials is toward high saturation flux density, high permeability rate, low magnetic loss, low coercivity, high cutoff frequency direction is the development of nanocrystalline soft magnetic alloy magnetic permeability up to 100, 000H / m, the saturation magnetic flux density of up to 1.3T. High-density magnetic recording devices, low noise, small size requirements of the magnetic powder particle size from micron to submicron and nano-direction, and particle size distribution to be as narrow as possible. Still holds the absolute superiority of magnetic recording devices and media in the field of computer storage hard drive 1998 sales of 145 million units, according to reports, the annual sales income of 30.08 billion U.S. dollars, increased to 253 million units in 2002, sales revenue reached 50.32 billion U.S. dollars.The modern use of semiconductor lasers, typically a laser diode, its principle is very similar to the ordinary diode.
Scanning high dot matrix characters, a complete character is divided into multiple scan is complete. Graphic information of the lattice formation and character dot-matrix form are similar. The drum is the core component of the laser printer. It is a photosensitive device, run out of guide material. The basic working principle is the photoelectric conversion process. In the laser printer as the use of consumable materials, and its price is also more expensive. Photosensitive semiconductor semiconductors in common, such as thermal excitation, change the conductivity after doping. In addition, it also has other semiconductor does not have "light conductive features. Photosensitive semiconductor by light irradiation, the conductivity can be increased by several orders of magnitude. The output power of laser pointer should not more than 5mW.When the incident laser beam shines on the MN side of point A, if the angle of incidence is θ  i, then the reflected beam reflected reflection angle θ  d, θ  i = θ  d, when MN turned to an angle φ The incident beam direction unchanged, the reflected beam turned 2φ, which is the reflected beam is twice the angular rotation to the MN. If P is the reflected light in one end of the drum, while the P1 is the reflected light points at the other end of the drum to complete the horizontal scanning of the photosensitive drum, of course, the rotation speed of the scanner is extremely fast, so P ~ P  1 between the formation of the reflected laser beam point.