While LCD projectors have a sharper image and superior picture quality, DLP projectors are lighter, portable, and considered to be more reliable.
DLP (Digital Light Processing) technology uses micro-mirrors to project images from a monitor onto a large screen. DLP is seen in standalone projection units, in rear projection TVs, and in a majority of digital cinema projection. LCD (Liquid Crystal Display) video projectors send light from a metal-halide lamp through a prism to display video, images, or computer data on a screen or flat surface.
What to Look for when Choosing a Projector
The ideal choice for your projector depends upon several factors: whether you want it for a home theater or office presentations; whether it has a dedicated spot or will be used when traveling often; and, of course, budget. Other factors like sharpness, clarity, picture quality, etc. are constant, and non-negotiable. This video guides you on what factors to consider before you buy a projector:
Pros and Cons
Advantages of DLP over LCD projectors
DLP projectors offer road warriors and home theater enthusiasts many advantages:
- Portability: DLP projectors tend to be smaller and easier to transport given one chip versus LCD’s 3 panels. DLPs using LED or pico technology are even more portable and can connect to smart phones, tablets and other mobile devices.
- Higher Contrast: DLP projectors’ deep blacks achievable make them popular for home cinema applications.
- Reduced Pixelation: DLP projectors have a muted pixel structure when viewed from a normal viewing distance, which may not affect a PowerPoint presentation, but will affect smooth video presentations.
- Reliability: DLPs have fewer parts and are less expensive to repair - sealed optics are good for dusty environments.
Advantages of LCD projectors
LCD projectors claim three main advantages over DLP projectors:
- Better picture quality: The quality of pictures is much better in LCD projectors as compared to DLPs on account of
- More accurate colors: DLP projectors can have clear section in color wheel, reducing saturation. LCD projectors do not have a color wheel.
- Sharper image: LCD projectors have sharper image than DLP projectors at equal resolutions.
- More light-efficient: A same wattage lamp in an LCD and DLP would produce a brighter image in the LCD.
Disadvantages of DLP projectors
The few disadvantages of DLP projectors are:
- The Rainbow effect: Looking away from a projected image on older DLP or from one side of a screen may have “rainbow” effect, or moment of rainbow-colored stripes around brighter objects.
- Light leakage: Grey band outside of the image can cause stray light reflecting off the edges of the mirrors on DLP chip. This can be avoided by installing black borders around the older DLP projector screen.
Disadvantages of LCD projectors
LCD disadvantages are more relevant to video:
- Screen door effect: Sharper images can be disadvantage, since precise focusing makes pixilation more obvious.
- Contrast: LCD contrast cannot produce completely black images with older models.
- Bulky: More parts make LCD bulkier and less portable than DLPs.
- Image degradation: More parts can cause image degradation if color balance shifts and contrast reduced.
- Dead pixels: One or more pixels turn permanently on or off. Clusters of affected pixels interfere with the image quality and the experience.
How Projectors work
This video explains how DLP and LCD projectors work:
How DLP Projectors Work
DLP projectors rely primarily on a DLP chip, or digital micromirror device (DMD), which comprises up to two million tiny mirrors, each mirror one-fifth the width of a human hair. Each of these mirrors can independently move toward or away from a light source to create a dark or light pixel. The color is fed to the DMD by a beam of light from a light lamp source, which then passes through a spinning color wheel before it reaches the chip, and the image is fed through the lens and onto the projection screen.
A DLP projector with three-chip architecture can deliver up to 35 trillion colors. A three-chip DLP projector uses a prism to split light from the lamp, and each primary color of light is routed to its own DLP chip, then recombined and routed out through the lens. Three-chip systems are in higher-end home theater and large venue projectors, and DLP Cinema projection systems in digital movie theaters.
How does an LCD projector work?
LCD projectors use 3 LCD technology systems with the same LCD displays as those used to create images in watches and other electronic devices. This system combines three liquid crystal displays, where an image is created in a multi-step process. A light source provides a beam of white light, which is passed to three mirrors (or dichroic mirrors) specially shaped to reflect only a certain wavelength of light.
Here the mirrors reflect red, blue, and green wavelengths. Each colored light beam is fed to an LCD panel, which receives an electrical signal. The signal instructs the panel how to arrange the pixels in the display to create the image. The same image is created by the three LCD panels, but each with different hues due to the colored light through the panel. The images then combine in a prism, resulting in a single image with up to 16.7 million colors. Finally, the image is passed through the lens for projection onto a screen.
Technology and Light Source
DLP technology is 'reflective'. Instead of passing a light source through a LC material, light is reflected off the DMDs. In a single-chip DLP projector, light from the lamp enters a reverse-fisheye, passes through a spinning color wheel, crosses underneath the main lens, and reflects off a front-surfaced mirror, where it is spread onto the DMD. From there, light either enters the lens or is reflected off the top cover down into a light-sink to absorb unneeded light.
LCD projectors use transmissive LCD, which allows light to pass through the liquid crystal. In LCD projectors there are always three LCD panels, and they are always light transmissive devices rather than reflective or direct view displays
Being light-source agnostic, DLP technology can effectively use a variety of light sources. Typically, the main DLP light source is a replaceable high-pressure xenon arc lamp unit. Alternatively, ultra-small or pico DLP projectors use high-power LEDs or lasers. For LCD projectors, Metal-halide lamps are used given their outputting an ideal color temperature and a broad spectrum of color. Smaller metal-halide lamps make LCD projectors smaller, hence more portable than most other projection systems.
Depending on the quality and functionality, both DLP as well as LCD projectors can cost anywhere from $300 to well above $1000. Here are two helpful shopping links for projectors on Amazon.com: