Philips Brilliance 150P4

Philips' LightFrame technology is a familiar sight in its CRT monitor range, allowing the entire screen or portions to be boosted in intensity. This makes video look more 'TV-like' and web images more lifelike. LightFrame was a welcome addition, combating some of the inadequacies of CRT technology - failings not shared by TFTs. So it's curious that Philips' next step for LightFrame is to implement the technology into its TFTs, starting with the soon-to-be-released Brilliance 150P4. We were lucky enough to be granted a sneak preview of the LightFrame 3-equipped150P4, giving us an insight into what impact the new technology might make.

LightFrame 3 allows up to 16 areas or eight framed windows to be highlighted and also automatically detects and highlights images in Internet Explorer. It adds the ability to handle overlaps too - for example, a drop-down menu overlapping a highlighted window - without having to de-highlight the zone. Alternatively, you can manually highlight areas by dragging a selection area on the screen, or highlight the entire screen for watching DVD movies or playing games.

The LightFrame software on the PC communicates the co-ordinates of these highlighted zones to the monitor using the first scan line of the display, which is blanked from the users' perspective. This removes the requirement for a separate connection such as USB to transmit the data. A chip embedded in the monitor then processes the information based on user-defined settings for features such as brightness and sharpness and generates the correct signals to peak the light output for that specific area.

The basic system behind LightFrame 3 on TFT is similar to that on CRT, but its implementation is very different due to the way both technologies work. In CRTs, the extra brightness and sharpness are achieved by adjusting the characteristics of the electron gun. CRT images are also constructed by scanning the electron beam across the screen from top to bottom. TFTs, on the other hand, have a constant backlight and display the image by twisting individual molecules to modify the amount of light let through.

That said, the initial stage of the process is similar - co-ordinates of the highlighted zones are encoded in the first line of the display and then processed inside the monitor. However, in the TFT system, the highlighted areas are processed digitally by a custom-designed chip, again depending on user-selected options such as brightness, contrast and sharpness. The backlight is also boosted by about 15 per cent, giving noticeably enhanced impact, although pixels in areas that aren't highlighted are automatically reduced in level so that they don't appear to change. This is a much more elegant solution than the brute-force CRT method, which has other disadvantages such as severely distorting text. Plus, as CRT is an analog system, the advanced digital filters can't be applied either.

We tried out this new technology on a pre-production Philips Brilliance 150P4 15in TFT and were impressed, despite the early state of the hardware. DVD movies were given a pleasing boost with more vivid colours and the digital sharpness filter produced a noticeable amount of extra detail. Add these features to the heritage of Philips' Brilliance 150P3A, which has been on our A List for six months, and the 150P4 seems destined for greatness.

Author: Gareth Ogden