Product Survey: Video Projectors

Multi-function projectors

There is newcomer to the projection world: the multi-function. These marvelous toys include a DVD player, LCD or DLP projection system, and speakers for a maximum of portability and ease of use.

So will this new type of projector surpass classic models (without speakers or integrated players) as multifunction printers did the standard inkjet?

Overall increase in resolution, the arrival of multi-function projectors, the advent of HD, and a rise in contrast ratios for LCDs and DLPs are contributing to home projection's gain in popularity. 

Video projectors have inspired a clash of clans worthy of Star Wars or the Lord of the Rings saga.  On one side we have products based on DLP technology, and on the other there is the LCD faction.  The two differ in their functions and rendering.  DLP fans prefer that technology's depth in black colors and the total absence of afterglow.  Those who favor LCD like the larger images (from the same distance), and are sensitive to the rainbow effect of DLPs (some users will see occasional flashes of red, green and blue).  From the inside of these devices, here are the differences:

DLP : Digital Light Processing. This system is based on three elements: a light source, color wheel, and DMD (Digital Micromirror Device) chip.  The color wheel is divided into three colors (red, green and blue) and, by spinning, it divides the white light of the lamp.  These color fragments are then reflected by mirrors on the DMD chip, whose position varies by +/- 10% towards the projection lens.  Your eye then reconstructs the colors of the final image by fusing all of the colors reflected by the mirrors.  For example, when these mirrors rapidly reflect red and green, you will see yellow.  The number of mirrors in the chip is equal to the resolution of the projector.  For example, a resolution of 1280 x 720 equals 921,600 mirrors.

LCD: Liquid Crystal Display. This system is composed of a lamp, two prisms and three LCD panels.  The first prism is in charge of separating the light the lamp emits into the three components of red, green and blue.  Thanks to a series of mirrors, light rays each hit an LCD panel which, depending on the position of its cells, may or may not let the light through.  A last prism placed between the panels recombines the three light beams and sends the image through a projection lens.

The lamp issue

Projectors have one consumable that needs to be replaced-- the lamp.  After an average of 2,000 hours, it has to be changed and this can cost between $250 and $800.  2,000 hours doesn’t seem like much, but if we calculate three (2 hour)  movies per week, this means replacement once every six years.  If you are a real gaming buff and want to connect your game console, daily use of two hours will result in changing a new lamp after three years.   After that, for the daily news or your favorite television series, having a normal TV on hand is a good idea.

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  • bboysil
    "...For example, when these mirrors rapidly reflect red and yellow, you will see green..."
    This mirrors reflect white light. The color wheel is the device which lets the right color component pass in synch with the DMD.
    For example: the DMD is reflecting the blue channel of the image but this is white light coming from the lamp, so the color wheel is letting only the blue part of the spectrum. The same with red and blue.

    There are also DLP projectors that use three dmd's with three colored light sources( red green and blue) so no need for a color wheel. A frame being displayed with all color information on the screen at once. This means you can obtain 3 times the frame rate at a broader color depth with no rainbow effect.
  • waffle911
    Quote:
    For example, when these mirrors rapidly reflect red and yellow, you will see green.

    Besides being technically wrong as pointed out by bboysil, don't you mean red and green will create yellow? Red and yellow (which isn't a primary color of additive light) makes orange!
  • jeraldjunkmail
    http:\\diyprojectorkits.com

    I am a member there, and am going to build my own 1080P projector this summer. 40 *THOUSAND* hours of life per bulb. Commercial projectors are for amateurs...
  • JonnyDough
    COMPARISON CHARTS PLEASE
  • abbadon_34
    Either use standard Or metric but don't mix them both. Inches and ounces in one place, meters in another. Seeing how this is tomsguide/us I would assume standard US measurements, but at least be consistant. Even better, translate the articles or make a simple conversion program.
  • abbadon_34
    Wow, this article is a mess. Seems like it was written by half a dozen people and connected in random order. No format consistancy between products. Some mention power consumpsion, some price, some show screen shots, size, weight, etc.

    JonnyDoughCOMPARISON CHARTS PLEASE


    I'm guessing that's why no charts, no product has the same info.
  • abbadon_34
    OK, I swear this is my last comment:

    I couldn't figure out why they were using a condom for size comparison. Turns out it is a Euro coin! How about using something recognizable by the majority it of people reading this article.
  • Why is this site generating such poor quality articles these days (look at the equally useless webcam article)? What is this Digital Versus? Some copy and paste bot?

    I read the Panasonic review then gave up. Doesn't anyone bother proof-reading:
    "The fans this shape can relax"
    "I ended up forcing the it manually"
    "The image below" - it's not below
    "When uscaling"
    And how useless is the zoom option to see the two(!) Star Ratings?
  • dark_lord69
    LOL!@! At first I thought that coin was a condom!!
  • Tattysnuc
    A very wordy review. This needs metrics to compare each model if this is going to prove of any use.

    Nic topic coverage. Bit weird as I have just persuaded the wife that our front room would make a great home entertainment room.

    First purchase required.... Projector. Think I'll pop down to my local Sony shop and see for myself just what they are like. The reviews here have done nothing more than give me a starting point. Nothing that allows me to proactively compare the products.
  • I have the same prob, Firmware update doesn't help me use AC charger while projecting..HELP PLS!!
  • now my aiptek pocket cinema is dead.i've upgraded the firmware, now it won't turn on...pls help...