Philips is attempting to patent a technique that would prevent viewers from skipping through ads embedded within recorded programmes or even channel surfing during broadcast ad breaks - or force viewers to cough up cash if they want to avoid the ads.

"A viewer may either watch the advertisements or pay a fee in order to be able to change channels or fast forward when the advertisements are being displayed," Philips' potential patent states.

Philips' application - spotted by New Scientist magazine - was originally filed in December 2003 but only recently made available online. The filing outlines how digital flags would be transmitted with the adverts - a TV, PVR, DVD recorder or other receiver would detect the flag and ensure the ads are shown no matter what.

The system uses the Multimedia Home Platform standard for embedding interactivity into digital video broadcasts.

Philips admits this might by "greatly resented by the viewers" and suggests broadcasters and device makers present suitable warnings when the flag is detected and used. It acknowledges that the "manufacturer of a video display device (such as a set top box) has no way to ensure that a program broadcaster will notify the viewers and explain why the viewers are no longer able to switch channels during advertisements".

That probably explains why an idea first mooted in 2003 still hasn't made it to market. Let's hope it never does. ®