1. Show & Tell Digital Projectors By Alex Righolt, 18/03/2008 A&A Computers Ltd.

2. Names Other names used for the digital projector:  LCD projector  Data projector  Beamer

3. Technology  DLP technology is based on an optical semiconductor called a DMD chip (Digital Micromirror Device). A DMD chip is made up of millions of tiny mirrors, that can rotate at a 10 degrees angle. These mirrors switch on and off thousands of times per second and are used to direct light.  The length of time a pixel is on/off determines the level of gray seen in the pixel. Completely on is lightest (white) and off is darkest (black), although neither are ever pure white or black. The current DMD chips can produce 1024 shades of grey.  However, colour is still to be added.

4. Technology On a DMD chip, colour is added using a colour wheel. This wheel spins round about 200 x per second. Most of the cheaper models will be made up of a 4 segment colour wheel. This will be Red/Green/Blue and usually a clear segment. As light is passed through a point on the spinning colour wheel the mirrors switch in accordance to the light.

5. The lamp Approximate price: USD 400.-  Life span: 2,000 – 3,000 hours. Can be displayed in a menu option.  Lamp care: (1) Don’t move the projector while it is on. (2) Allow the unit to cool down after switching it off. (3) Allow the lamp assembly to cool down for 45 minutes before removing it.

6. The connections and controls

7. Distances, sizes for the BenQ MB610

8. Applications  Presentations – advertizing, training  Advertizing  TV & Video display

9. Important specifications  Resolution:Native SVGA (800 x 600)  Resolution:640 x 350 to 1280 x 1024  Brightness: 2000 ANSI Lumen  Lamp: 200W, 2000/3000 hours (Normal / Economic mode)  Contrast:2000:1  Image size:31" to 300"

10. Shutting down the projector  After you switch off the projector, it is to cool the lamp for another 2-3 minutes.  Advise clients to use a UPS – a 500 VA capacity is sufficient (eg our BenQ consumes 285 max.)

11. Show & Tell: the digital projector The end.