What are main differences?
When you are starting to search for projector, you notice that there are several technologies on what projectors are built. In general there are two: LCD and DLP. The question is, should you know what the differences are? And, is it important to pay attention to this technological separation?
The general answer is – people who know more, often pay less and get things they need. Of course both technologies have some strengths and weaknesses, however there are things that can be useful in best model choice.
We’ll briefly describe how both technologies work.
LCD (Liquid Crystal Display) technology
On basis of LCD technology is light projection onto mirrors witch causes light split n 3 main colors: red, green and blue. Then light passes through 3 separate prisms and later projected through LCD panels. At this stage individual pixels are opened or closed, such a way letting concrete color light pass through or not. Then after passed through separate colors again are converged with the help of another prism and projected on screen forming an image what is viewed by projector users. Common LCD projection technique manufacturers are: Sanyo
DLP (Digital Light Processing) technology
DLP system works in different way. Most projectors built on this technology have one chip instead of glass panels. Current chip has surface that consists of thousands of tiny mirrors and every one of them correspond to one pixel. When light falls on the chip, these pixels can move back and forth to reflect light towards or the lens or away from it. DLP projectors have color wheel what allows to allow to obtain necessary colors for projected image. This wheel consists of main color filters (red, green and blue). This wheel is placed between the light source and DLP chip. Wheel is spinning and such a way colored light hits the chip. Mirrors located on the chip in order reflect necessary amount of color that is needed for concrete pixel and tilt it into the lens path. Well known DLP manufacturers are: Benq
As you see there are two different technologies used and each one of course is better for some and less good for other applications.
Pros choosing LCD projectors:
Colors are more accurate than using DLP technology
Sharper image at equal resolutions
LCD projectors are more light efficient. That means with same power light source in projector one can obtain brighter image with LCD projector.
Cons choosing LCD projectors:
Contrast parameters are worse than for DLP. Main disadvantage is that LCD cannot produce completely black color. There are several methods used for latest models to solve this issue. Apertures and filters are used, but in general contrast for LCD projector will be worse than one built on DLP technology.
Portability (weigh and size)
In general LCD projectors are larger and bigger in size than DLP same level devices. It must be remembered if you are searching for light portable technique.
Larger TCO because of air filters.
Air filters must be cleaned or changed periodically what raises costs of maintenance.
After long working time LCD panels can experience image degradation. That means that color balance can shifts and contrast become worse. Worse thing in this scenario is that LCD panels are enough expensive and one often must make decision between repair works and purchase of new projector.
As for LCD monitors, TVs, same problem can occur for LCD projector as well. One or more pixels after some time of usage can turn permanently on or off. If this is one pixel, no large problem (hardly at all) often is observable. However if there is cluster with such pixels, it can become a problem.
DLP projector advantages
DLP projectors are technology favorite mainly for people who want light portable devices and/or like to enjoy saturated colors, watching movies using home theatre.
In general DLP projectors weight less and are smaller.
Full black is often an argument why many home theatre enthusiasts choose this technology.
Less noticeable pixilation
Current issue is more actual if less expensive devices are compared.
DLP technique in genera fails less because of fewer parts. There should be noted that in most cases repair works for DLPs will be less expensive as well.
DLP technology disadvantages
The Rainbow effect
Actually DLP projectors have one main disadvantage described below.
As DLP has color wheel that rotates, sometime (mostly observed for older models) one can notice color stripes, often called as “rainbow”. It especially can be noticed on lighter parts of image. However ability to see these rainbows are far for all people and latest models has more light segments located on color wheel that makes this effect even less observable.
We hope this technical overview will help you to choose witch technology projector to choose. However in many situations TCO (total cost of ownership) will be main issue to consider, especially if you are projecting to buy good quality device for home theatre use or one for serious everyday workload for business needs. As main component (at least for first 3-5 lamp cycles) is projector lamp, it would be good to know lamps life parameters (hours) and price. Such a way you’ll be sure that bought technique will be beneficial purchase also from long time perspective.