The Quest To Eliminate LCD Blur

Motion blur has been an issue with LCD TV's since their inception into the marketplace. Over time though the problem has improved considerably as manufacturers have gradually developed a variety of solutions.

LCD TV's originally had a 60hz signal. In a nutshell, this means that they flipped through 60 still frames per second or one every 16.67 milliseconds. Because LCD's hold the frame for the full 16.67 milliseconds and have very little time to flip frames in between, your eye interprets this as blur, especially in fast moving scenes such as those you'd see in sports broadcasts or action-packed movies.

The first solution to this problem was introduced by Philips. Philips introduced a backlight technology that flashes off when the frame is flipped and then back on again for a split second, and then back off. By flashing the screen for only a moment and then having black in between frames, this fools your brain into interpreting the action as steady motion, thus solving the "sample-and-hold" problem described above. This is an oversimplistic explanation to be sure, but reasonable enough to illustrate the point. Philips' 42" ClearLCD models utilize this technology.

(Credit: Hitachi) Alternating Dark Frames

The next step on the part of manufacturers was to increase the refresh rate to 120hz or 120 frame-flips per second. The first method utilizing the 120hz refresh rate is to insert a black frame between every picture frame. This will reduce blurring in a similar fashion as the backlight as each frame is on the screen for less time.

(Credit: Sharp) Interpolated Frames

The next step was to outfit LCD models with processors that were able to interpolate a made-up frame between each 2 actual frames. This is a work-in-progress for most of the major manufacturers. Example of models using this method on the market right now are JVC's Clear Motion Drive series and Sharp's Fine Motion Advanced series.

JVC Compares 120hz And 180hz Refresh Rates

Now for the latest step. JVC introduced a 180hz LCD TV at the CEATEC conference in Japan. There hasn't been much in the way of information released about the model; just that it is a 768 line, 720p set and the "LCD panel predicts, produces and inserts 2 additional frames of images every second in a standard video stream at 60 fps".

We'll be watching for updates regarding this breakthrough for sure!

Via hometheatermag.com, Gizmodo, Tech-On!

October 9, 2007

The Quest To Eliminate LCD Blur