The answer is simple - neither is better than the other. They all have advantages over others and have their own limitations. Both technologies have made great strides compared to the past. The purpose of this article is to discuss the differences between them today, so that you can judge for yourself whether the image technology itself is an insignificant factor in your choice of projector.
It is important to note that there is also a third important optical path engine technology called LCoS (liquid crystal on silicon). The technology was developed and promoted by several manufacturers, the most famous of which are Canon, JVC and Sony. Many excellent projectors are manufactured using LCoS technology, including several outstanding home theater projectors, which many observers believe will exceed the value demands offered by LCDs and DLPs. The discussion of LCoS technology is beyond the scope of this article and will be addressed separately in another article that will be released soon.
Is it 3LCD or LCD?
You may have seen the term 3LCD on websites, projector prints, and product launches. Several LCD projector manufacturers have adopted 3LCD as the brand name for marketing. It is used to distinguish the special implementation of LCD technology in digital projectors from the more general direct-view LCD display technology in many consumer electronics products. In LCD projectors, there are always three LCD panels, which are always light transmissive devices, not reflective or direct view display devices. In the projector industry, there is no technical difference between 3LCD and LCD, so these two terms can be mixed. Welcome to China Home Theater Network
Which technology is leading the market?
Well, the answer to this question depends on how you define the word "leading." At the time of this writing, DLP technology has significant advantages in terms of the number of models currently in production. On today, July 28, 2009, our database lists 704 different models based on DLP technology being produced, compared to 430 models for LCDs. Therefore, DLP has an absolute advantage in terms of the number and type of models being put into production.
However, this is not the whole story. Many popular projectors today are LCD models. For example, currently ProjectorCentral's top 10 most popular 1080p home theater projectors (based on the latest 300,000 visitors), six are LCD machines, two are DLP machines, and two are LCoS machines. In fact, aside from the obvious advantages of DLP in the number of models produced, according to a report by Pacific Media Associates, LCD projectors accounted for 51% of the market in 2008. Obviously, both technologies have huge markets, and there are no players who can become dominant. Welcome to China Home Theater Network
Technical difference between 3LCD and DLP
The LCD (liquid crystal display) projector contains three independent LCD glass panels, which are three components of red, green and blue of the video signal. Each LCD panel contains tens of thousands (or even millions) of liquid crystals that can be configured to open, close, or partially close to different locations to allow light to pass through. Each individual liquid crystal essentially functions like a shutter or blind, representing a single pixel ("pixel"). When the red, green and blue colors pass through different LCD panels, the liquid crystal is turned on and off in real time based on how much each color of the pixel needs to be at that moment. This behavior modulates the light to produce an image that is projected onto the screen.
DLP (Digital Light Processing) is a proprietary technology developed by Texas Instruments. Its working principle is very different from LCD. Unlike glass panels that let light pass through, a DLP chip is a reflective surface made up of tens of thousands (or even millions) of microlenses. Each microlens represents a single pixel.
In a DLP projector, light from the projector's bulb is directed to the surface of the DLP chip, and the lens changes its slope back and forth, either by reflecting light onto the lens path to turn it on, or by leaving the lens to close the pixel.
In the most expensive DLP projectors, there are three separate DLP chips, each corresponding to a red, green, and blue channel. However, in most DLP projectors within $10,000, there is only one chip. To define color, you need to use a (at least) color wheel that contains red, green, and blue filters. This color wheel rotates on the light path between the bulb and the DLP chip, causing the color of the light projected onto the chip to change continuously between red, green, and blue. The microlenses reflect light in real time or into the lens path based on how much each of the three colors of each pixel is needed at a given time. This behavior modulates the light to produce an image that is projected onto the screen.
(Note: Most color wheels contain other color segments in addition to the red, green, and blue filters. Commercial projectors often use a "white" or transparent filter to enhance brightness, while many color wheels Filters with colors other than the main color, such as dark green, cyan, magenta, or yellow.)
Advantages of DLP We will examine the advantages and limitations of DLP and LCD in turn. The most important advantages of DLP technology include the following:
Sealed imaging chip. Most DLP projectors have a sealed DLP chip that eliminates the possibility of dust particles falling on the imaging plane, which creates a dust point on the projected image. LCD projectors do not have a sealed panel, so there is a possibility of dust spots. This is especially true when the air filter is not cleaned regularly according to the manual.
No filters are required. DLP projectors with sealed DLP chips can operate without an air filter. Maintenance work is reduced because there is no need to periodically clean or replace the filter. Some manufacturers claim that their DLP products are maintenance-free except for occasional lamp replacement, cleaning of the casing and lens. Other manufacturers are not so radical, but instead recommend regularly vacuuming the ducts to reduce the amount of dust entering the machine. Most DLP projectors on the market do not have air filters, but some of the most expensive high-performance 3-chip DLP models have a small number of early DLP models that are still in use today.
Whether the filterless design is really an advantage for the user is inconclusive. Inside most DLP projectors, components other than the image chip are not sealed and can be adversely affected by dust accumulation. In particular, dust that falls on the color wheel can affect the quality of the color and image. When the dust comes into contact with the surface of the bulb, it burns or melts, accelerating the attenuation of the lumen output over the life of the bulb. For a filterless projector, the adverse effects of dust depend on the amount of dust in the projector's operating environment. Texas Instruments argues that the amount of dust in a normal room environment does not adversely affect the operation of a filterless projector. Those who advocate the use of filters argue that air filters can also prevent accelerated attenuation of the lumen output of the bulb, even under normal room conditions. Welcome to China Home Theater Network
After recognizing that dust is a potential problem, Mitsubishi has taken additional steps to eliminate dust pollution in its latest filterless DLP projectors, the XD3200 and WD3300. They seal the color wheel to prevent dust from coming into contact. They also improved the light and airflow channels to reduce the amount of dust that could reach the bulb. These changes are designed to help the bulb maintain its lumens throughout its life cycle.
Those who advocate the use of air filters on projectors believe that there is no benefit to dust in the projector, so users should be able to use filters with a design that essentially prevents dust from entering the projector. All LCD projectors and some higher-end three-piece DLP models from Runco and Digital Projection use air filters.
Those who support the filterless design point out that many users with filter projectors fail to clean or replace the air filter as recommended. If an air filter is gradually blocked by dust, it will block the flow of air and increase the operating temperature inside the machine, which will adversely affect the life of the LCD panel.
No convergence problem. All projectors that use a three-chip imaging device, whether LCD, DLP, or LCoS, must have all three devices perfectly aligned so that the red, green, and blue information for each pixel can be aggregated. These three-piece systems have all along been unaligned. From time to time, there will be a slight convergence error in a new machine that has just been shipped. Convergence errors can soften the image of the projector and produce color image errors that should not occur.
The single-chip DLP design has a unique advantage over other three-chip or three-chip systems: since there is only one imaging chip, there is no convergence problem. In short, the monolithic DLP has nothing to do with it.
Contrast advantage. Most commercial-grade DLP projectors (for portable presentations or conference rooms) have a much higher Full On/Off contrast than comparable price LCD models. In the projector industry, ANSI contrast is rarely published, but ProjectorCentral's tests show that DLP projectors often have advantages over LCD competing models in terms of ANSI contrast. However, with the introduction of inorganic LCD panels used in most LCD 1080p home theater products, DLP's traditional advantages in contrast in the home theater segment have largely disappeared.
No image persistence. If a still picture is played for a long time, an LCD projector using an inorganic LCD panel tends to retain a weak afterimage of an image, even after switching to another image. This phenomenon does not appear on DLP projectors and does not appear on LCD projectors that use inorganic panels.
Some descriptions of the nature of advertising over-emphasize the seriousness of this problem. Anti-LCD advertising claims that LCD projectors are easy to "burn-in". Strictly speaking, this is not true. Burn-in, generally refers to the permanent damage of phosphor-based video display devices such as CRT or plasma. Once a still image is etched onto a phosphor display device through a long time display, it cannot be eliminated. This is different from what we see on LCD projectors. On organic LCD displays, the generation of image persistence is temporary and can be erased by displaying a fixed white picture for a period of time.
In any case, the point is that image persistence does not occur on DLP projectors or inorganic panel LCD projectors. So on these products, there is never a need to take steps to erase a persistent image afterimage.
Image quality does not decay over time. In general, DLP projectors do not experience image quality degradation after prolonged use, except in the case of excessive internal dust accumulation. But in any case, the DLP chip itself will not decline. In contrast, LCD panels and polarizers can decay over time, resulting in color shifts, uneven illumination, and reduced contrast. The current decline in LCD panels of products is somewhat a mystery, because those who know the most about the situation (LCD projector manufacturers) will not talk about this issue publicly. This issue will be discussed further later.
A slightly smaller pixel structure (window window effect) on low resolution products. One historical advantage of DLP over LCDs is that DLP images have a lesser degree of pixel structure. Pixels tend to give sharper clarity to an LCD projector, but also produce a more pronounced pixel structure on the image. This is often referred to as the screen window effect because the low resolution projector's picture looks like it is separated by a layer of screens.
However, in this respect, the difference between LCD and DLP is no longer as obvious as before. For two reasons, first, LCD manufacturers have successfully narrowed the gap between pixels, making the screen window effect very insignificant. Second, the original resolution of projectors currently on sale has increased significantly compared to a few years ago. As the resolution increases, the pixels become smaller and the pixel structure of the entire picture becomes less noticeable. However, in low-resolution products such as SVGA and even standard XGA products, DLP projectors still have advantages over LCD projectors in presenting less noticeable pixel structures. (Note: There is a disadvantage of having fewer pixel structures, that is, the image sharpness is reduced. We will discuss this issue further later.) Welcome to China Home Theater Network
DLP leads the trend of miniaturization. The single-chip optical path engine offers the opportunity to be extremely miniaturized by LCDs. There are currently 15 DLP projectors on the market weighing within 3 pounds (note: about 1.4 kilograms), but can produce more than 1000 lumens of brightness. In contrast, the lightest 3LCD projector on the market also has 3.5 pounds, most of which are above 4 pounds (Note: 3.5 pounds is about 1.6 kilograms, 4 pounds is about 1.8 kilograms).
The weakness of the DLP and the limited color wheel produce a rainbow effect. The weakness of the DLP technology most often pointed out is that it has a tendency to produce a "rainbow effect." The rainbow effect (sometimes referred to as a color separation image error) is an instant flash of a strip of color that looks like a rainbow. It appears randomly and lasts only for a moment. But for people who are sensitive to the rainbow, it is very distracting. If you devote yourself to a movie or a TV show, the rainbow effect can completely ruin your appreciation experience.
The rainbow effect is a problem that only occurs on single-chip DLP products, and in most cases, it only appears on products that use slower color wheels. This problem is usually presented when watching a movie or TV. People often don't feel this problem when watching still images such as charts or photos of speech.
The rainbow is produced because of the continuous color update from the color wheel. When the color wheel is rotated, the image on the screen is either red, green, or blue at any given moment. This technique relies on your eye's inability to perceive a change from one color to another. However, when your eye moves quickly in response to some movement in the picture, you get three updates of red, green, and blue at three different points on the retina, creating an impression of the rainbow. Not everyone will perceive a rainbow in the same way. Many people's eyes are less sensitive, so they are completely incapable of detecting the rainbow. The rest of the people will easily see the rainbow. In addition to watching a DLP projector yourself, there is no other way to know if you are the kind of person you can see or can't see.
Since LCD projectors and three-chip DLP projectors always display red, green, and blue images at the same time, they do not produce a rainbow effect. The new DLP projectors based on LED lighting technology will not produce rainbow effects, as these models no longer use color wheels. (Note: The monolithic DLP projector with three-color LED light, the pulse frequency of the LED light is not subject to the physical limitation of the color wheel speed, so the color update speed can be very fast, thus minimizing the probability of the rainbow appearing).
On a DLP projector with a color wheel, the rainbow effect can be reduced by increasing the speed of the color wheel. The first generation of DLP projectors used a color wheel that rotated 60 times per second, or 3600 RPM (3600 rpm). With a red, a green, and a blue filter on the color wheel, each color update can occur 60 times in a second. This speed of the first generation is called "1x" speed. In the second generation of DLP projector products, the speed of the color wheel doubled, ie 7200 RPM. The doubling of the color refresh rate reduces the time between color updates, thereby reducing the visibility of the rainbow effect for more people. But 2x speed is still not fast enough for projectors used in home theater or video applications.
Today, some DLP projectors designed for the home theater market use a color wheel that includes two sets of red, green and blue filters. The color wheel still rotates at 7200 RPM, but since the red, green and blue colors are refreshed twice instead of once in each rotation, the industry calls this a 4x speed. Some projectors have a 5x or 6x color wheel by increasing the physical speed to over 7200RPM. For most users, the 5x and 6x color wheels in most current home theater models have reduced the rainbow effect in video displays to almost no concern.
However, most DLP projectors designed for business and presentation are still using the 2x speed color wheel for cost reasons. If the content of the presentation is a static chart, picture, photo or anything that does not cause rapid eye movements, then there is no problem at all. For users who value video display or are partially used in home theater, we do not recommend DLP projectors with 2x speed color wheel.
Color saturation / color brightness. Some DLP projectors have excellent color saturation, while others are very poor. This is more related to the implementation of the manufacturer than to the technology itself. Advocates of 3LCD technology have always been ignorant of the lack of color brightness in monolithic DLP products, especially for machines with white segments in the color wheel. This phenomenon is worth talking about. Welcome to China Home Theater Network
When the color wheel has a white (or transparent) segment, the projector's lumen output will increase significantly, and the ANSI lumen level will skyrocket. The color wheel of most business-grade DLP products uses white segments to boost critical lumen levels. In contrast, most DLP projectors designed for home theater do not have white segments because this threatens the overall balance of color saturation and video images. In addition, for home theater projector sales, the level of lumens is not a big driver.
When you use a luminance meter to measure the brightness of red, green, and blue on an LCD projector, the sum of the three values ​​is the brightness reading of the white you get. This makes sense, because for an LCD projector, white is created by turning all three channels of red, green and blue. But on a DLP projector, the situation is different. Due to the presence of white segments in the color wheel, the white brightness reading can be up to twice the sum of the red, green and blue three color readings. In other words, if the white test value of an LCD projector is 2000 lumens, you will be able to get 2000 lumens of color brightness. If the white test value of a DLP projector is 2000 lumens, you may only get 1000 lumens of true color brightness, and the rest are white light.
In view of this, supporters of 3LCD technology have been lobbying for the projector's specifications to add color brightness indicators in addition to the ANSI lumens indicator. This recommendation is being supported in the industry. In the war on data indicators, it is clear that this will be a figure that LCD has an absolute advantage over DLP. Not surprisingly, Epson and Sony have begun to emphasize color brightness indicators on their LCD projectors. Color performance specifications are often consistent with ANSI lumens nominal values, which are typically written, for example, "2600 lumens color brightness output. , 2600 lumens white brightness output".
In general, DLP projectors with a white segment in the color wheel do not look good when testing color brightness. Color readings are generally much lower than white readings, sometimes as low as 50% or less. This is especially true when the color wheel only includes the basic red, green and blue colors and a white filter. Many DLP projectors have complementary filters such as cyan, magenta, and yellow. In this case, the test of color brightness becomes more problematic. So we can understand why manufacturers of Texas Instruments and DLP projectors have no interest in publishing color brightness indicators.
From a practical point of view, our feelings about this issue are mixed. Clearly, the 3LCD camp's view that traditional ANSI lumens cannot fully describe machine performance is correct. However, the color brightness indicator is also not possible. To be sure, the color on some DLP projectors is sluggish compared to LCD models with the same lumens. The irony is that this phenomenon is particularly prominent when the "BrilliantColor" (domestic translation for "extreme color") function is enabled. Although BrilliantColor increases the brightness of the image, it significantly reduces color saturation during the process. It's amazing that in order to get the most abundant and saturated colors from many DLP projections, users need to turn off the BrilliantColor function. (This is not always true for all DLP projectors with BrilliantColor, because the behavior of the BrilliantColor system will vary considerably based on the manufacturer's implementation.)
Oddly enough, on some DLP models with white segments in some color wheels, even on models with different color brightness than white brightness, we can see that one can easily and at the same price. The same lumen level LCD projector is comparable to the rich and vivid colors. One reason is that the color filter configuration of the color wheel has a great effect on the end result. Another reason is that although DLP's color brightness is much lower than white brightness, DLP has some compensation for its inherent contrast advantage. This compensation cannot be measured by indicators. Even though the color brightness is quite low, sometimes the picture does not look much lighter than an LCD projector with the same white brightness output placed next to AB.
When the color sharpness of a DLP projector looks worse than an LCD projector with the same price and performance index, this is due to the difference in the design and product cost of the manufacturer, but not related to the DLP technology itself. . DLP can be very fascinating or completely bleak, depending on the design and manufacture of the product. With so many variable factors, even with the color brightness indicator, the performance indicators can not fully explain the problem. It would be interesting to announce the color brightness indicator, and of course it would also draw attention to a technical difference between LCD and DLP that deserves attention. However, it is not a decisive factor in helping a smart buyer figure out which model to buy.
The high frequency vibration moving image is wrong. At any time, the position of each microlens of the DLP chip is either fully open for maximum brightness or fully closed to appear black. DLP microlenses have no way to "partially open" like a liquid crystal of LCD to render gray. Therefore, the DLP chip is grayed out by flipping the microlenses very quickly, so that they can open the eye to "on" and "off" by averaging enough time to get the desired brightness. level. This method is called high frequency vibration. It works quite well for rendering grayscale, but it produces some visible instability in a continuous area, mostly in dark areas, a problem known as high frequency vibration image errors. It looks like digital noise, but it is an image error caused by the DLP technology itself rather than the signal.
High-frequency vibration image errors do not occur on LCD products because LCDs do not use high-frequency vibration to achieve different gray levels. The liquid crystal can be fully open, fully closed, or partially turned in the middle to achieve the desired level of brightness transmission - again, this concept is similar to the leaflet's loose leaf. Welcome to China Home Theater Network
Limited compatibility with zoom lens and lens shift. Due to the innate mechanism of the DLP optical path engine, it is difficult for manufacturers to match a long zoom lens or a wide range of lens shifting functions to a DLP projector. For portable speech projectors, these limitations do not matter because their primary design goal is a small physical size, so no such machine has a large zoom range or lens shift. However, for the home theater projector market, LCD manufacturers have already gained a large market share due to the LCD projector with twice the zoom lens and a wide range of lens shifting capabilities. This allows the consumer to easily install the projector in any desired location, typically a rear shelf in the room. Due to the lens limitations of DLP projectors, it is rare to have a DLP model mounted on a rear shelf.
3LCD advantages
Many of the advantages and limitations of 3LCD have been covered in the discussion of DLP. However, there are several LCD advantages that have not been discussed, and several of these arguments have made new progress. Next are the key advantages of LCD technology:
Home theater products have a better price/performance ratio. The key to the success of LCD products in the home theater market is its huge price advantage. Especially in the 1080p class, LCD products show excellent value for money. In addition, they often have additional features not found in DLP models of the same price (if these features are visible on other DLP models).
The price advantage of LCD over DLP is most pronounced in consumer electronics and home theater products. There are no similar price differences in commercial products designed for mobile presentations and conference room use. One reason is that DLP manufacturers are able to use the cheaper 2x speed color wheel on most commercial products, while on the products designed for home theater, the use of high speed color wheels and the faster electronics they work with is necessary.
Home theater products have higher contrast. Many LCD projectors designed for home theaters have achieved better overall contrast performance and deeper black levels than DLP models. In particular, LCD models using inorganic LCD panels and auto iris technology. Inorganic panels are more expensive to produce, so they are not used in less expensive commercial machines. Part of the reason for the higher contrast is that the default position of the liquid crystal is off (ie black) and needs to be turned on with voltage. This is in contrast to conventional organic LCD panels, where the liquid crystal in its default position is turned on (maximum brightness passthrough) and needs to be turned off with voltage. The inherent contrast advantages of inorganic panels make LCDs substantially more competitive in the home theater market. In particular, ANSI contrast has been significantly improved. In ProjectorCentral's tests, LCD projectors with organic panels are typically in the 250:1 ANSI contrast range, and models with inorganic panels are available in the 400:1 to 450:1 range.
3LCD manufacturers have been very active in developing high-efficiency auto-iris systems that help increase the contrast that people feel on the screen. As far as we know, there are no technical restrictions to prevent DLP manufacturers from doing the same thing. However, this will further increase the cost of the DLP projector, making the DLP in the home theater market more significant than the LCD's already significant price disadvantage. There is also a common consensus among manufacturers that the contrast of DLP, although not industry-leading, is sufficient, so the enhancement of auto-iris is not critical. As a result, most DLP manufacturers are slow to deploy an automatic aperture system for their home DLP projectors.
Fewer image errors / better image stability. As mentioned earlier, high-speed vibration image errors and rainbow effects exist only on single-chip DLP projectors. Given the absence of these image errors on LCD products, it is easy to feel that LCD projectors have more stable video images when compared to a DLP competitor with similar price and performance levels. The video image of the LCD will look clearer and less noisy.
The data shows a sharper image. Since the pixel structure of the LCD is more sharp than the pixel structure of the DLP, the LCD tends to present a sharper image. It is most noticeable on lower resolution commercial products (SVGA and XGA), especially when data is displayed. At this resolution, the screen window effect of the LCD is slightly more noticeable in the video image, but the benefit is that sharper pixel resolution produces a sharper data display. In contrast, the data image display of SVGA and XGA resolution DLP projectors may be a bit soft. (Note: The data display generally refers to a still picture such as playing a document through a PC or a laptop).
On higher resolution products, the difference in sharpness is small, and there is no problem with the video display of 1080p products. At 1080p, both technologies produce very sharp images, and any perceived sharpness difference is often only related to non-display technology factors such as lens quality and video processing.
Better installation flexibility for home theater products. LCD projectors designed for home theaters are often equipped with 2x zoom lenses and a wide range of vertical and horizontal lens shifts. This makes them easy to install almost anywhere. In contrast, DLP projectors typically have only a short zoom and little or no lens shift. For a given screen size and position, a fixed projection angle limits the geometry of the projection and often specifies where a DLP projector must be installed.
For DIY home theater enthusiasts with limited budgets, the lens flexibility of LCD models is very attractive. This is because most DLP projectors require lifting, and most LCD projectors do not require lifting. So choosing LCD models, they can save money on hoisting and long-distance video cables, without wall-opening and ceiling wiring, or endure the unsightly lines on the ceiling.
Better light efficiency and lower power. LCD technology inherently has higher light efficiency. Most LCD projectors use a lower wattage bulb to produce the same image brightness as a DLP projector (using a higher wattage bulb). This difference is most apparent when comparing LCD projectors to DLPs that do not use white color wheel. For example, comparing two currently popular 1080p home theater projectors - Panasonic's AE3000 LCD projector uses a 165 watt bulb to produce 1600 ANSI lumens. In contrast, the Sharp Z15000 DLP projector requires a 250 watt bulb to get the same 1600 lumens. This can make a significant difference in power consumption, and the heat generated by the projector's exhaust in the listening room can be different. Welcome to China Home Theater Network
LCD weaknesses and limitations
The life of the LCD panel is unknown. If exposed to high-intensity ultraviolet light and extremely high heat for a long time, the organic compounds used in LCD panels will gradually decline in long-term use. Panel degradation can cause image discoloration and reduced contrast. The only solution to this problem is to replace the damaged LCD panel, which is generally not economically viable, and it is better to buy a new projector.
The key question is how long the panel can last. There is no good data on this issue so far produced and published by independent laboratories and used for general consumer reference. LCD manufacturers generally do not admit that LCD panel degradation will occur, so they will not make any statements about life expectancy. In general, most LCD manufacturers admit to some extent that LCD panels may suffer a final decline, but when it happens, it will already exceed the actual life of the product. An industry-recognized source of experience with both LCD and DLP product development believes that LCD panels have a lifetime of 4,000 to 10,000 hours, depending on the brightness of the projector - the brightest LCD ultra-high-brightness models will maximize the panel The pressure that leads to a faster recession. Low-light models such as those designed for home theaters produce minimal stress and thus a longer life expectancy.
Texas Instruments has conducted several tests on LCD life in the past seven years. Based on these tests, they believe that the LCD panel's recession is faster than LCD manufacturers are willing to admit, of course, faster than the 4000 hours quoted above. The response of the 3LCD camp to TI's test is as follows: TI's test puts the LCD projector 24 hours a day, 7 days a week, for several months without interruption, according to the 3LCD Alliance and Epson, given the projection used in the TI lab's tests. The machine is not designed at all for the high-intensity duty cycle of continuous operation, so the test results are not representative of what the average user will actually experience.
The introduction of inorganic panels is a new and important development that is closely related to this issue. In theory, inorganic LCD panels are not subject to the same degradation mode as organic LCD panels because there are no organic compounds that would fail under high intensity heat and ultraviolet light in inorganic LCD panels. However, the LCD camp will not confirm or deny any prediction differences about panel life, because as a policy, they will not discuss this issue at all. Texas Instruments also did not comment on the life expectancy of inorganic LCD panels.
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在现实ä¸ï¼Œè¿™ä¸ªå·®å¼‚更多是市场推广上的劣势而ä¸æ˜¯æŠ€æœ¯ä¸Šçš„。在大多数商务和教室设置下，投影显示都是在房间ç¯å…‰æ‰“开时进行的。在ä¸ç‰çŽ¯å¢ƒå…‰çº¿ä¸‹--例如，足够让教室内的å¦ç”Ÿè®°ç¬”è®°--æ¤æ—¶æŠ•å½±æœºçš„å¯¹æ¯”åº¦æŒ‡æ ‡åœ¨å¾ˆå¤§ç¨‹åº¦ä¸Šæ— å…³ç´§è¦ã€‚ä¸è®ºæŠ•å½±æœºçš„ç†è®ºå¯¹æ¯”度潜力是多少，在ä¸ç‰çŽ¯å¢ƒå…‰çº¿ä¸‹çš„å±å¹•å®žé™…对比度一般在50:1的范围内。但对于那些ä¸äº†è§£çŽ¯å¢ƒå…‰çº¿å¯¹äºŽå¯¹æ¯”度比率的巨大影å“的买家æ¥è¯´ï¼ŒDLPåœ¨å¯¹æ¯”åº¦æŒ‡æ ‡ä¸Šè¶…è¿‡LCD的显著优势会比实际表现更为é‡è¦ã€‚
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当ç°å°˜è½åˆ°LCD的红色或者è“色通é“上时，很少会明显到令人分心。但当它å‘生在绿色通é“上时，就会å˜å¾—相当显眼。一些厂家已ç»æ供了一些方法，通过这些方法，用户能够除掉ç°å°˜ï¼Œè€Œä¸ç”¨æŠŠæœºå™¨å‘回清ç†ã€‚Sanyo的家åºå½±é™¢æœºåž‹éƒ½å¸¦æœ‰ä¸€ä¸ªæ°”å¹ï¼Œå¯ä»¥æŠŠç©ºæ°”喷射到é¢æ¿ä¸Šã€‚但是鉴于我们还从未看è§è¿‡Sanyo投影机上的ç°å°˜ç‚¹ï¼Œæˆ‘们从未有机会å°è¯•è¿™ä¸ªæ–¹æ³•ã€‚除了这ç§è§£å†³æ–¹æ¡ˆä¹‹å¤–，把投影机打包å‘回维修点进行清ç†æ˜¯è®©æŠ•å½±æœºé‡æ–°æ£å¸¸å·¥ä½œçš„最åŽä¸€æ‹›ã€‚
LCDåˆ¶é€ å•†å£°ç§°ä»Šå¤©çš„ç©ºæ°”è¿‡æ»¤ç³»ç»Ÿæ¯”èµ·è¿‡åŽ»è¿›æ¥äº†å¾ˆå¤šï¼Œå› æ¤å¦‚æžœæ ¹æ®ç»´æŠ¤æŒ‡å—定期清ç†å’Œæ›´æ¢è¿‡æ»¤å™¨çš„è¯ï¼Œç°å°˜çš„污染éžå¸¸ç½•è§ã€‚大多数LCD厂家都在质ä¿ä¸åŒ…括了ç°å°˜åŽ»é™¤è¿™ä¸€é¡¹ï¼Œè¿™å¯¹äºŽå¤Ÿä¹°LCD投影机的延长质ä¿æ¥è¯´æ˜¯ä¸€ä¸ªå¾ˆå¥½çš„ç†ç”±ã€‚
å½“æˆ‘ä»¬åœ¨è¯„æµ‹æŠ•å½±æœºæ—¶ï¼Œæˆ‘ä»¬æ— æ³•åœ¨ä»»ä½•æœºåž‹ä¸Šæ¨¡æ‹Ÿç”¨æˆ·é¢ä¸´çš„ç°å°˜æ±¡æŸ“的实际风险。我们å¯ä»¥è¿™æ ·è®²ï¼Œæˆ‘们很少会在用于评测的LCD投影机或者在用于å‚照目的而长期è¿è¡Œçš„机器上å‘现ç°å°˜ç‚¹ã€‚然而，对于用户æ¥è¯´ï¼Œå¾ˆå®¹æ˜“忘记清æ´è¿‡æ»¤å™¨ï¼Œå› 为厂家建议对于一般使用应该æ¯ä¸¤ä¸ªæœˆå·¦å³å°±æ¸…æ´ä¸€æ¬¡ã€‚ä¸€æ—¦è¿‡æ»¤å™¨æ²¡äººç…§ç®¡ï¼Œç”¨æˆ·å°±å¢žåŠ äº†ç°å°˜æœ€ç»ˆè¿›å…¥æŠ•å½±æœºå†…部的风险。
in conclusion
3LCDå’ŒDLP的市场份é¢ä¹‹äº‰å·²ç»è¿›è¡Œåˆ°äº†éžå¸¸æ¿€çƒˆçš„程度。看到两ç§æŠ€æœ¯çš„厂家ä¸æ–创新从而在竞争ä¸æŠ¢å¾—先机，是一件引人入胜的事情。在过去的这个å年，éšç€å¯¹æ¯”度ã€åˆ†è¾¨çŽ‡å’Œè‰²å½©æ€§èƒ½çš„显著æå‡ï¼Œæ•°å—投影机的画é¢è´¨é‡å…·æœ‰äº†æˆå‰§æ€§çš„æé«˜ã€‚ä»·æ ¼ç›´çº¿ä¸‹é™ï¼Œæ›¾ç»ä¸€åº¦åªæœ‰å¯Œæœ‰çš„消费者或者真æ£éœ€è¦æŠ•å½±æœºçš„å…¬å¸æ‰èƒ½è´Ÿæ‹…的高å“质投影系统，现在已ç»åœ¨å¤§å¤šæ•°æ¶ˆè´¹è€…çš„é¢„ç®—ä¹‹å†…äº†ã€‚å› æ¤æˆ‘们å¯ä»¥è¯´ï¼Œæ¶ˆè´¹è€…æ‰æ˜¯DLPå’Œ3LCD技术的激烈竞争的最终å—益者。
æ£å¦‚æˆ‘ä»¬æƒ³åœ¨è¿™ç¯‡æ–‡ç« ä¸é˜æ˜Žçš„é‚£æ ·ï¼ŒDLPå’Œ3LCD都拥有超越对手的关键优势。它们也都有买家需è¦äº†è§£çš„å±€é™ã€‚但最终，我们今天在LCDå’ŒDLP投影机上都看到了比过去更好的图åƒè´¨é‡å’Œæ€§èƒ½--形势一片大好，越æ¥è¶Šå¥½ã€‚ (
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