EnergyStar specifications for TVs will get more stringent in 2013, a fact that could be discerned from displays at the recent Consumer Electronics Show in Las Vegas. One means of cutting TV power consumption that will soon become commonplace is the use of motion sensors analogous to those now used for shutting off room lighting. Stray too long making that snack in the kitchen and your TV will shut itself off.
TVs will also dim themselves to save power depending on the room lighting. In that regard, sensor maker ams showed at CES technology that lets a 42-in flat-panel TV to use less than 60 W of power. At CES the company put its Digital Ambient Light Sensors and smart LED drivers in an off-the-shelf TV. ams says the TV that used up to 50% percent less energy than standard 42-in. models – exceeding Energy Star 6.0 guidelines – while providing high picture quality, even in the low light conditions. Energy Star 6.0 calls for a 42-in. TV to consume just 62.9 W, and the maximum any TV can consume – regardless of size – is just 85 W.
Additionally, the measurement of power usage will cover four levels of ambient room light, as most consumers prefer to watch television in living rooms with low light levels. ams claims 2013 televisions that combine a Digital Ambient Light Sensor with local dimming and high-accuracy drivers will meet and exceed the Energy Star 6.0 ratings without waivers or unusable brightness settings, while delivering a higher quality viewing experience. The ams Digital Ambient Light Sensor does this by sensing the ambient light level of the room and adapting the backlight to a lower power level. An ams light sensor development kit.
The impact of this is threefold, says ams: 1) The TV has improved contrast ratio, which is noticeable and pleasing to the eye; 2) There is no blinding or discomfort to the consumer by the “excessively bright displays, and 3) There are substantial power savings because the backlight drive gets adjusted based on ambient light conditions.
Light sensors for TVs mimic those for adjusting room lights to reflect the amount of natural daylight present. For example, the TSL4531 ambient light sensor provides a direct lux output and a 16-bit digital interface. Filters automatically reject the 100/120Hz ripple typically produced by a building’s fluorescent lighting systems, enabling the sensed light levels to more accurately measure the daylight that is entering the building.
