Display Power Optimizer (DPO)

Display Power Optimizer (DPO) - Dramatically Lowers Display Power Consumption in Mobile Devices

As consumers, we will soon start talking about mobile device battery life in terms of "YouTube minutes" rather than "Talk Time". This is due to the fact that today, the dominant use cases for Smartphones, Mobile Internet Devices (MID), Smartbooks and Netbooks require the displays to be on all of the time - YouTube, Hulu and mobile TV to name a few. How to conserve power during these use cases is a significant system design issue. And, the problem won't go away any time soon. As illustrated in Figure 1, an analysis from IMS Research shows that Smartphone battery requirements are outpacing battery capacity well into the future.

The Mobile Handset Power Gap: Heavy Smartphone User

Smartphone battery Capacity vs. Power Requirements for Heavy Users (Source:IMS Research Sep-09)

As displays typically consume 30-60% of the total system power, there has been a tremendous amount of research put into methods of reducing display power. A common method, such as Content Adaptive Backlight Control (CABC), reduces backlight or brightness levels to save power. However, CABC significantly diminishes the viewing experience of content details, particularly in darker content. Furthermore, CABC typically only saves a small fraction of display power - on the order of 10%.

QuickLogic's approach using DPO and VEE is a radical advancement from primitive CABC technology. CABC was a good start that used the overall statistics of the entire image to determine how to set the backlight level. QuickLogic takes the idea of being content aware two further steps by evaluating the value of each individual pixel and the statistics of the all the nearby pixels. VEE then uses that information to adjust the value of the individual pixels, while DPO uses that to adjust the backlight. The ability to provide a unique tone curve for each pixel, as well as have tight control over the display backlight, gives greater flexibility than the global adjustment performed by CABC, which results is greater power savings and the entirely new capability of adapting to a bright environment.

DPO also seamlessly integrates with QuickLogic's Visual Enhancement Engine (VEE), ensuring both longer battery life and an excellent visual experience by coupling the Pulse Width Modulation (PWM) driving the display backlight with the display content processing parameters of the VEE technology.

All members of the ArcticLink II solution platform family optionally support the DPO PSB.

The DPO PSB transforms the mobile multimedia experience by:

• Significantly reducing power consumption of the display to extend video playback time