Tuesday, January 31, 2006
There are two main types of systems: LCD and DLP. The least expensive type and oldest type is LCD (liquid crystal display) that uses three transparent panels, one for red, green, and blue, the three primary colors. The amount of light transmitted to each pixel or light panel/picture element depends on the data received from the imaging source ‚Äì a computer or video. Light is directed through the color LCD panels, transferred to digital imaging, and then projected through a lens onto a huge screen. A LCD projector has the ability to transmit high-definition television-quality images. Sometimes the pixels can be seen if the viewing area is large, and it will produce what is better known in imaging as the ‚Äòscreen door‚Äô effect. It functions much the same as a slide projector, and advantages of LCD include ease of adjustment in brightness and contrast, and a higher image resolution. Digital Light Processing is the newest and most expensive technology and is better known as DLP. A DLP display or chip uses tiny mirrors instead of transparent color panels, with each mirror representing a pixel. Rather than the light going through the panel, it is reflected from it while in constant movement to vary the amount of light being projected. Color is then added as the image is passed through a filtering wheel containing and rotating red, green, and blue colors. The speed of rotation results in a color image that the human eye sees as natural color with advantages being a lighter weight, high-contrast imaging, and a lack of pixilation.
Brightness and contrast are measured in terms of lumens, and most projectors have brightness ranges of between 700 to 2000 lumens with a 800 being an average. It should be noted that if you are watching movies in a brightly lit room, you will need more lumens. Projectors need to have a contrast ratio with a capability of 1500:1 because the lower the ratio, the more faded the imaging.
It should be noted, too, that many DVD players have built-in digital projectors to enable you to see movies wherever you desire. Regular television is good for day to day viewing with projector viewing for special events, sports events, and movies. Digital projectors use expensive light bulbs, averaging $200 to $500 with a life expectancy of between 1000 and 4000 hours, with replacement necessary every other year or so. Comparison shopping is a good way to learn of the types and prices of projectors. Improve your home viewing experience of special events and programming by seeing bigger and better with a digital projector.