Digital light processing TVs are projection TVs that use a lamp or a bulb to project an image onto the screen. Because of all the hardware that's required to make DLP TVs work, they're heavier than newer plasma or LCD TVs and generally range in size from 40 inches to just over 70 inches diagonally. There's a variety of issues that could result in a blurry screen on a DLP TV, including a bad lamp or incorrect aspect ratio settings.
Change the aspect ratio on the TV. Some aspect ratios, such zoom or full screen, stretch the picture in some parts, causing the picture to become slightly blurred in those areas. For most channels pulled in over the air, a standard, 4-to-3 or native aspect ratio displays the picture in its native aspect. High-definition content may be best displayed in a wide screen aspect ratio, such as 16-to-9. Try each of the aspect ratios to see which one gives you the best quality image.
Lamp or Bulb
The lamp or bulb in your projection TV may be dying and need to be replaced. The life of bulbs and lamps vary, depending on the quality of the lamp or bulb and how often the TV is used. Lamps and bulbs are often located behind a cover on the lower half of projection TVs. Before replacing the lamp or bulb, seat the existing one properly, as a poorly connected lamp or bulb can also lead to blurriness and other picture problems.
Check all of the connections on the projection TV if you're having problems viewing the display for an external device. Push all of the connectors firmly into the connecting jacks on both the TV and any external devices plugged into the TV. Connectors that aren't making a solid connection between the device and the TV can lead to blurriness, the picture cutting in and out, a rolling picture or a number of other problems.
Move the antenna so it's not pointed toward large buildings, a group of trees or being blocked by any other objects if you're having issues with blurry channels being pulled in over the air. It's important to look for objects that are close that could be blocking the signal but also objects that are far away. Also, firmly connect the antenna to the appropriate input on the TV.