After more than 20 years of development, the projector can be said to have encountered a lot of bottlenecks today, and the entire projector field has never had a technological revolution like today. Due to the traditional light source of the projector, no matter the brightness, color or power consumption, it has been unable to reach a higher height, so the revolution of solid-state light source has come. The emergence of laser projection technology has indeed left endless curiosity and speculation for many projection enthusiasts. What kind of mysterious thing is laser projection technology? Let us introduce the past and present of laser projection technology by analyzing the internal structure, technical advantages and products of laser projectors.
Solid-state light source is the trend and the direction of future development
The solid-state light source is a revolution in light source technology, a leap-forward development, and a future trend. Perhaps a general introduction to solid-state light sources is difficult for readers to understand, but it is more specific if you talk about the recent hot LED light source and the laser light source that is partnered with it. It should be said that the LED light source and the laser light source are two technologies of solid-state light source, each having its own advantages and application fields. The LED light source can make the projector volume smaller and more environmentally friendly. But LED products also have their limitations. For example, in terms of brightness output and luminous flux of the projector's most important technical indicators, the current LED light source products are generally not high, thus limiting its application range, and is only suitable for use in smaller scenes.
The laser is an abbreviation of the first letter of the word "LightAmplificationbyStimulatedEmissionofRadiation" in English. It is the abbreviation of "Enlarged by Excitation Radiation Light". It has the outstanding characteristics of small divergence, single wavelength, good coherence and high energy density. Due to the principle of the laser, the light emitted by the laser is unidirectional light, and the laser can emit nearly parallel light with almost no divergence, which allows the laser to converge a large amount of light energy in a very small area, that is, the energy density is extremely high. Just like using a convex lens to collect sunlight, it can burn things. Even if the laser produces a few kilometers, the spot diameter is only a few centimeters. This highly concentrated laser beam has high reliability.
Here we focus on the laser source technology, which uses a laser beam to transmit the image. Among them, the optical components of the laser projector are mainly composed of a red, green and blue light valve, a combined X prism, a projection lens and a driving light valve. There are red, green and blue lasers in the laser projector. After the laser is expanded in the machine through the corresponding optical components and processing chips, it is transmitted to the X prism to integrate the three lasers, and then the integrated laser is transmitted by the projection objective to the projection screen to complete the entire laser projector display process. . Laser technology as a projection light source is a future development trend, but it is also a fact that LEDs cannot be completely replaced in the short term. However, with the development of technology, laser light sources will be popularized in the projection world, which will inevitably lead to the revolution of display technology, and will completely subvert the traditional display field.
The emergence of laser light source
Simple lasers have long been used in the real world, but they are more focused on light and shadow. The large laser stage effect is very dazzling and can be performed in an open outdoor. There are also many wonderful application cases in China, especially the large-scale water curtain movies have lasers. However , the laser as the light source of the projector is only a big event in the past two years. Compared with traditional light sources, LED light sources and laser LED hybrid light sources, pure laser technology is more difficult and historical. At present, some brands such as Sony and BenQ are pioneers of pure laser light sources.
Conventional projectors use a light bulb as a light source, and the bulb is internally filled with high-temperature gas, which makes the projector with a conventional light source dangerous to blow up. The laser uses packaging technology, so the sealing performance and impact resistance are very good, not easy to damage. Use it in harsh environments for a long time, and don't worry about the damage of the light source. In addition, from a health point of view, the laser source does not contain harmful substances such as mercury and sodium, and there is no environmental pollution caused by the ultra-high pressure mercury bulb, which meets the requirements of environmental protection, effectively reduces environmental pollution, and creates a green and healthy projection environment. It cannot be said that even if a laser light source is used, this does not change the imaging principle and technology of the projector, and the projector product of DLP, LCD or SXRD technology can still use the laser light source.
Advantages of laser light source
As a new projection light source, the emergence of laser light sources has solved many problems that projectors have encountered in the past, such as service life, color, power consumption and so on. It is undeniable that all illuminators are hot, and heat is the deadly source of detrimental service life. At this stage, the laser light source can work for 10,000 hours in normal mode and 20,000 hours in energy-saving mode. According to the data provided by a brand of laser projection products, the laser light source began to have significant brightness decay after 5000 hours, and the brightness will be attenuated by 40% after 14,000 hours, but nearly 60% of the brightness can still be used normally. Compared with the traditional light source of 2000 lumens, the energy-saving mode has a limit life of 6000 hours, and the advantages of laser technology are very prominent. For example, ordinary projector bulbs generally have a life span of several hundred to thousands of hours. During the use, regular replacement of the bulb is required, and cracking or explosion may occur due to unstable structure of the bulb. The laser projector laser structure has high reliability. According to the existing experimental results, the life expectancy is up to 100,000 hours, which is 9-10 times of the service life of the ultra-high pressure mercury lamp. It reduces maintenance and operating costs compared to projectors that require lamp replacement. Moreover, the brightness attenuation is not obvious for a long time, and the vivid image quality can be maintained for a long time.
Conventional projectors produce brightness attenuation, color saturation, and contrast reduction during use, which results in a much lower image quality than new projectors. The projector using the laser light source maintains high brightness, color saturation and contrast for a long time due to the wide color gamut and low attenuation of the light source, so that the color of the picture is always bright and new.
When using a traditional light bulb projector, everyone will have this experience. After the traditional light bulb projector presses the power button, it takes about half a minute to display the projected image, and it takes about 10-15 minutes. The brightness will tend to be stable and uniform. The laser is a cold light source, which has the characteristics of being instant on and off, which fundamentally eliminates the phenomenon that the original ultra-high pressure mercury bulb needs to wait a few minutes to fully illuminate. It achieves the projection of the maximum brightness in a short time, greatly shortens the time for projecting the highlight picture, and maximizes the use of time.
High purity, large color gamut
he laser light source makes full use of the characteristics of laser wavelength selection and high spectral brightness. Therefore, the display image has a larger color gamut, and its color gamut coverage can reach more than twice that of the phosphor, which can achieve the color space recognized by the human eye. More than 90%; and the laser is a line spectrum with high color saturation, completely breaking through the deficiencies of the color spectrum of the previous 3 generations of display technology, achieving the most perfect color reproduction in human history, enabling people to see our most authentic through the display terminal. The most beautiful world. Laser source Thanks to the use of very high purity red, green and blue primary light sources, a color space that is much larger than the traditional NTSC or DCI minimum color range can be achieved, showing most of the colors that the human eye can recognize. Regardless of which white field chromaticity standard is adopted, laser light sources that can be accurately controlled for the three primary colors of red, green, and blue are easily realized. At present, the xenon lamp source used by most projectors needs to be controlled by a color filter, which not only reduces The light utilization efficiency of the light source is not easy to adjust and control the color. Laser projection still needs development
The light source of the laser projector, like other light sources, can cause certain harm to the human eye. For example, if the lens is directly viewed with the eyes, the laser light source is more likely to cause damage to the human eye. The laser projection technology uses red, green and blue visible light lasers. After special expansion and shaping equipment, the laser divergence angle is enlarged to have an energy density close to that of the xenon light source, instead of the energy density being higher than the light. Tens of thousands of times of laser light, the low-energy secret monochromatic light at this time has no danger of just coming out of the laser, that is, the light emitted from the laser projector lens and the projector lens projected from any ordinary light source. The light produced has the same safety performance indicators. For example, there are many close-range projection products that use laser light sources, which avoids the risk of direct viewing by the human eye.
Laser micro-injection products are very mature Every time Apple's iPhone is released, many people speculate whether it will be equipped with micro-projection technology. As early as 2011, there are many projection brands, and launched a miniature projection product, which promotes the laser micro-projection power, the current micro-projection device The terminal product design can be mainly divided into PocketProjector (pocket projector) and PicoProjector (micro projector), and the PicoProjector without fan feature is the focus of future mobile phone or tablet embedded design. However, under the safety regulations of today's smart mobile devices, whether it is DLP, LCoS or Laser, the highest level on the market is only about 20 lumens. Although the current PocketProjector has the advantages of high portability and up to 200 lumens, it still has to be able to rise rapidly in the market under specific market positioning and reasonable prices. The application of micro-projection technology of mobile devices is the focus of future market. In terms of mobile phone market, volume, power consumption, imaging definition and price are the key elements for micro-projection modules to smoothly enter their supply chain. Laser projection technology is here. Played a very good catalytic role. to sum up: Traditional bulb light sources have been subject to certain bottlenecks due to their limited life span and the user's late maintenance costs. Especially in the engineering projector market, which has gradually become hot in recent years, the new light source has become a sought-after object of many manufacturers , such as laser light source technology. Not only is it easy to increase brightness, but it is also very suitable for high-end engineering projectors, making it more cost-effective than traditional bulb sources. The projector with laser light source has the advantages of laser light source projector compared with other current projection light source products. We believe that with the mature laser display technology combined with the huge display market, the huge commercial value of laser display technology will bloom.