Chinese smartphone manufacturer Oppo might be lesser known on Western shores than some of its competitors, but in the past it has launched several smartphone models with novel camera features and concepts; for example, the N-series with its swiveling camera modules. Now Oppo has launched the first sensor-based stabilization system for smartphones at the Mobile World Congress in Barcelona. All previous systems on smartphones have been based on a floating optical element in the lens, which requires less space than a moving sensor.
Oppo has used a MEMS (micro-electro-mechanical system) design: the mechanism for moving the sensor is part of the chip itself. The design uses what are known as comb drives - two opposing rows of tiny fins fabricated into the silicon that can attract and repel one another, when a current is passed through them.
Oppo says that the new system brings with it a key advantage: unlike most current systems that only correct efficiently for motion on two axes – pitch and yaw – the Oppo stabilization also corrects for roll. It also takes up less space than lens shake designs, which require a comparatively bulky voice coil motor to hold and control the lens movement.
The comb drive chip, which Oppo calls SmartSensor, can correct for camera shake in only 15 milliseconds. At the same time, using only 10 milliwatts, it uses 50 times less power than lens-based systems, reducing the generation of heat in the camera module, especially during longer photo sessions and making less of a dent in battery life. Oppo also claims Smartsensor is also more precise than competing systems. The company says its stabilization is precise to a vibration of just 0.3μm while most lens-based systems have a precision of between 3 and 5μm.
Oppo has some experience of working with comb drives, having developed a system to replace voice coil motors for autofocus.
The SmartSensor stabilization has not been implemented in any production models yet but a prototype used in a demo against the LG G4 at the Oppo MWC booth worked impressively well. The Oppo engineers also told us that the stabilization system is combined with additional digital stabilization and that the system can be adapted for use with different sensor sizes by adjusting a range of internal parameters. We are hoping to be able to use and test the system in a production unit soon.