Secret history of the development of projection lamp life from 2,000 to 20,000 hours
Whether it is ancient shadow puppets or modern projectors and other products related to video playback, an important component is inseparable, that is, the light source part, the candle of the shadow puppet show, the backlight of the LCD TV, and the bulb of the projector. Modern projectors appeared in the 1950s, using CRT display technology, also called three-gun projectors. This type of projector has three lenses, each with three colors of RGB, but the volume is very large, and the brightness is only 300 lumens. In 1989, Japan’s Epson and Sony developed the world’s first LCD projector using their mastered LCD technology, and successfully digitized the projector. Soon Texas Instruments also launched a DLP projector product using DMD reflection technology. The two display technologies have been applied so far, but both the early CRT projectors and the current digital projectors have one thing in common, which is the projector bulb. ▲In ancient times, CRT projectors needed candles to illuminate shadow puppets, but a candle costs a few cents, while a projector bulb costs 1,000 yuan or as high as 10,000 yuan, but its life span is only a few thousand hours... to become a projector During the application process, the highest subsequent cost. Therefore, before choosing a projector, you should also understand the problem of the projector bulb, so as not to fall into the abyss of later application costs. 2000 hours Metal halide bulbs At present, projector bulbs on the market mainly include ultra-high pressure mercury bulbs and metal halide bulbs. Earlier used in the projector market are metal halide bulbs, which are named after the bulbs are filled with metal halides. ▲Metal halide bulbs Metal halide bulbs are thermal light sources. They produce warm light and require greater power to produce sufficient brightness. They have a short service life and a very fast brightness decay. Generally, after 1000 hours, the brightness is only about that of a new bulb. Half of it, and by about 2000 hours, the projector bulb is basically scrapped. ▲Single LCD DIY projector is not only that, it also has a lot of heat, which makes the temperature of the entire projector higher, and the requirements for the heat dissipation system of the projector are also higher, so it is not suitable for long-term projection use. At present, this kind of bulb Basically, it has been eliminated, but it can still be seen on copycat projectors and DIY projector products. Replacing the high-pressure mercury lamp every 6000 hours In order to solve the problems of too short lamp life, low brightness, and high heat generation, a high-pressure mercury-filled projector bulb, called a high-pressure mercury lamp, is also called a UHE bulb and UHP bulb. Compared with metal halide lamps, this kind of bulb has the characteristics of low temperature and long life. ▲High-pressure mercury lamp UHE bulbs are currently widely used light sources in mid-range projectors. It has the advantages of moderate price, rich variety, and long life. It can generally reach more than 4000 hours, and the brightness is almost not attenuated before 2000 hours of use, and The price of this bulb is also relatively low, the general market price is about 800-1200 yuan. UHP bulb is also a mainstream projector bulb type at present, and it is also a cold light source bulb. It has a longer use time than UHE. It can generally be used for 4000 hours to 6000 hours, and the brightness attenuation is very small, but it is patented The technology is monopolized by certain lighting companies, so the price is higher, and once this kind of light bulb reaches life insurance, it will be extinguished immediately. The starting point of the new light source at 20,000 hours and 6000 hours seems to be very long, but in actual use, it cannot fully meet the needs of current users, and the mercury contained in the bulb is also very polluting to the environment. With the development of technology, A new generation of projector light sources is gradually being developed. ▲LED light source Among these new light sources, the first to meet with us was the LED light source. The LED light source was used in micro projectors around 2000. This light source has the characteristics of small size, low temperature and long life of 2000 hours, but there is one The problem is that its brightness is too low. After years of development, the brightness is still around 500 lumens. Compared with the current mainstream business projectors of 3000 lumens, LED projectors are more suitable for home entertainment. ▲The other light source of the laser emitting group used by the BenQ laser projector is laser. This light source has the characteristics of ultra-high brightness and 20,000 hours of life. It can easily increase the brightness of the projector to more than 10,000 lumens, but the laser As a pure light, it is difficult to color it. ▲Mixed light source projector structure ▲The third light source of the Casio ultra-portable hybrid light source business projector is a mixed light source developed by Casio in 2009. This mixed light source uses LED and laser light sources, which are carried out inside the projector. Mixing makes up for the problems of low LED brightness and difficult laser coloring. Its brightness reaches 4000 lumens, and it is thought that these two light sources are cold light sources and are very small in size, so the mixed light source projector can be made very thin and smallest. The hybrid light source projector is only about the size of A4 paper, but the brightness can reach the brightness of 400 lumens of mainstream business projectors, and the life of the light source can reach more than 20,000 hours.