Comb Filter

You may regularly see the term Comb Filter referred to when looking at LCD monitor specifications. Put simply the Comb Filter is there to help colour correction and enhance any picture loss or degradation when the image is transferred to the monitor. When a composite picture is sent to a monitor, the information is all sent together, during the signal processing, the Comb Filters job is to separate this jumbled signal and make sense of it and then enhance it and to display the best picture possible. The filter does this by overlaying a delayed version (sometimes several) of the signal onto itself. This delayed signal is known as feedfoward or feedback, dependant on the technology used, this refers to the direction of the delayed signal before it is added to the original input. The reason for it being called a Comb Filter is because when viewed on an Oscilloscope, the trace is seen as a series of regular spikes, giving the resemblance of a Comb. In essence the better the Comb Filter the better the resulting image quality.