Digital Light Processing (DLP) is a registered trademark of Texas Instruments, which is a technology used in some televisions and video projectors. It was originally developed in 1987 by Dr. Larry Hornbeck of Texas Instruments. DLP is used in front DLP projectors (small standalone projection units) and DLP rear projection TV. DLP, LCD and LCoS, are the technology behind the television screen during the back-projection, having supplanted CRT projectors rear. These rear-projection technologies compete against LCD and plasma on the market for HDTV.
The single-chip version of 3LCD and DLP are the two main technologies used in modern digital projector in color, with both technologies in use in over 95% of projectors sold in 2008. DLP is also one of the technologies used in digital cinema projection. In March 2008, TI announced the initial production of DPP1500 chipsets, which are micro-projectors for use in mobile devices. The availability of the final products show the market in 2009.
Color Source
There are two main methods for which DLP projection systems create a color image-used by a single DLP chip, and those used by three-chip projectors. A third method, the sequential illumination by three colored LEDs, develops, and is currently used in TVs produced by Samsung. Yet another method, color laser printers, is currently in use in their products by Mitsubishi.
Single-chip projectors
In a DLP projector with a single chip, colors are produced either by placing a color wheel between a white lamp and the DLP chip, or by using individual light sources to produce primary colors, LED or laser, for example. The color wheel is divided into several sectors: the primary colors: red, green and blue, and in many cases, including the secondary colors cyan, magenta, yellow and black. The use of secondary colors is part of the new delivery system called BrilliantColor color processing of the primary colors with secondary colors to create a wider range of possible combinations of colors on the screen.
The DLP chip is the rotation of the color wheel, so that the green component is displayed on the DMD when the green area of the color wheel is synchronized directly in front of the lamp. The same goes for red, blue and other sections. The colors are then successively at a rate high enough for the viewer of a composite "full color" image is displayed. In early models, it was a rotation image.
Multicolor LED-based, laser-based single-chip projectors are capable of removing the wheel and reduce the rainbow effect as the heartbeat LED and lasers are not limited by physical movement.
Three-chip projectors
A three-chip DLP uses a prism to separate the light from the lamp and each primary color of light will be the owner of the DLP chip, then went back together and passed through the lens. Three-chip systems are high-end home theater projectors, projectors and large events found that DLP Cinema projection systems found in digital cinemas.
The three projectors chips used in theaters and producing 35 billion colors. The human eye is proposed to be capable of more than 16 million colors, which theoretically detect single-chip solution is possible. This, however, the color precision is not that the chip DLP projectors to three can be seen in a position to distinguish the full range of colors (which is basically impossible at all times with all systems in the composition with the addition of three primary colors). Instead, the single chip DLP, which has the advantage that any number of basic colors in a color wheel filter fast enough, and therefore the possibility of a better color space is available.
Light Source
The light source most used in the DLP-based projection screen TV in the back, a removable high-pressure mercury arc lamp, metal halide lamp (quartz tube with a sheet, a reflector, electric hook- and sometimes a quartz-base / glass), while some of the new DLP LED or high power lasers are used as light sources.
Metal-halide lamps
For metal-halide lamps, during start-up, the lamp is ignited by a 5000 volt pulse from a current-regulating ballast to initiate an arc between two electrodes in the quartz tube. After warmup, the ballast's output voltage drops to approximately 60 volts while keeping the relative current high. As the lamp ages, the arc tube's electrodes wear out and light output declines somewhat while waste heating of the lamp increases. The mercury lamp's end of life is typically indicated via an LED on the unit or an onscreen text warning, necessitating replacement of the lamp unit.
Older projectors would simply give a warning that the lamp life had expired but would continue to operate. Newer projectors will not power up until the lamp is replaced and the lamp hours are reset. Most devices include a lamp hours reset function for when a new lamp is installed, but it is possible to reset a projector to continue to use an old lamp past its rated lifespan.
When a metal-halide lamp is operated past its rated lifespan, the efficiency declines significantly, the lightcast may become uneven, and the lamp starts to operate extremely hot, to the point that the power wires can melt off the lamp terminals. Eventually, the required startup voltage will also rise to the point where ignition can no longer occur. Secondary protections such as a temperature monitor may shut down the projector, but a thermally overstressed quartz arc tube can also crack and/or explode, releasing a cloud of hot mercury vapor inside and around the projector. However, practically all lamp housings contain heat-resistant barriers (in addition to those on the lamp unit itself) to prevent the red-hot quartz fragments from leaving the area.
LED-based DLPs
The first commercially available LED DLP HDTV Samsung HL-S5679W was in 2006, which also eliminates the use of the color wheel. In addition to eliminating the need for long-term replacement of the lamp and the elimination of the color wheel are the other benefits of LED flash on the operation and the improved color, with a wider range of saturation colors and improved by over 140% of NTSC color space. Samsung LED extends the range of the model 2007 is available with products in 50", 56" and 61" screen size. For spring 2008, the third generation of Samsung DLP LED products in 61" (HL61A750) and 67" screen sizes (HL67A750).
Laser-based DLPs
The laser-based commercially available for the first DLP HDTV Mitsubishi LaserVue L65-A90 is in 2008, which also eliminates the use of a color wheel. Three separate laser lighting device color digital camera micromirror (DMD) rear projection TVs in them, creating a palette of colors richer, brighter than other methods. Watch the video display products to the laser for more information.
Source: http://en.wikipedia.org/wiki/Digital_Light_Processing
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