Advantages of purple laser technology
at present, there is only one supplier of purple laser diodes in the world, which is Nichia company in Japan. The company entered the market two years ago, and its laser diode between 391nm and 420nm has become a market leader. Because the wavelength of this kind of laser is shorter, it can obtain higher when used in DVD, which determines the structural storage density of the tension machine
physical properties determine the size of laser points. The number of laser points per inch is determined by the wavelength of the laser and the quality of the rotating mirror. When making CDR, the infrared laser diode with 780nm wavelength is used, and the disc capacity can reach 650mb. Today's DVD uses a 640nm red laser diode. With the improvement of the optical system, the density can reach 4.7GB
the second generation of digital video recorder (DVR), which can record movies from digital TV, needs higher density. The violet laser diode with a wavelength of 400nm can record 20 ~ 30GB of data. However, at present, the price of each purple laser diode is $1500, which is too expensive for the host to use a frame level to level in the two directions perpendicular to each other on the outer ring of the working cylinder, so as to make DVR as a general consumer product, so as not to scratch the objective lens. Nichia said that in the next two years, with large-scale production, its price will soon decline
competition will also lead to price decline. In fact, important semiconductor manufacturers such as Sony, sharp and Sanyo also produce diodes, but Nichia has its own patents, avoiding the threat from other manufacturers. The company claims to reduce the price of its products in the next two to five years. The violet laser with a wavelength of 400nm can significantly reduce the size of the laser spot to increase the resolution. In addition, due to the small scattering of violet laser, the manufacturers of plate making machine can use a smaller rotating mirror motor, so it can increase the speed of the motor and shorten the exposure time. Although the laser stays at each exposure point for a short time, it can still meet the exposure requirements of printing plates. For example, the sensitivity of the lithostar lar-v printing plate of AGFA is 2.6 uj/cm2, which only requires 5% of the energy of 5MW laser diode. Therefore, the production efficiency of violet laser diode is higher
The printing plate used by the violet laser technology can work under the yellow safety light. Although not as good as the thermal version, it can work under indoor light, but it is much better than the traditional UV exposure safety lamp The life span of violet laser diode is a controversial issue recently. According to Nichia, the average time between failures of violet laser diodes is 3000 hours, and will soon increase to 5000 hours. Suppose we expose a 70mm × It takes 2 minutes for a 100mm printing plate to expose 30 printing plates per hour and 90000 printing plates per 3000 hours. If 100 printing plates are exposed every day and work 250 days a year, the fault interval is 3.5 yearsthe lifetime of YAG (yttrium aluminum garnet) laser and gas laser is twice that of violet laser, but a simple comparison cannot be made. Their average failure interval is 10000 hours, but they are always working from power on to power off, rather than one-way control of the horizontal cylinder like purple laser, which only works when the laser is imaging on the printing plate. Therefore, if two shifts work every day for a total of 15 hours, the failure interval is 666 days, equivalent to 2.5 years. Therefore, the lifetime of violet laser diode is actually longer than that of gas or solid laser diode
Nichia is developing laser diodes with higher energy. At present, it has developed 15MW purple laser diodes. It is said that 30MW purple laser diode will be launched at the end of this year
like the development of semiconductors, the price of laser diodes was very expensive at the beginning, but compared with plate making machines, the price was insignificant. The outer drum type thermal equipment needs a beam splitter or multiple rows of laser diodes, and the cost of light source is very high, while the inner drum type equipment only needs a laser diode
Tuiopics, the manufacturer of laser, believes that the 5MW laser currently used can be quickly exposed on the optical polymerization plate with high resolution, and there is no doubt about the energy of the upcoming 15MW and 30MW lasers. The manufacturer of optical polymer version claims that its products will be cheaper and longer life, which will accelerate the application of violet laserLINK
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