Thursday, May 05, 2011

Cambridge Mechatronics Developed AF and OIS for Camera Phones

EETimes: Cambridge Mechatronics (UK) has developed an actuator technology for optical image stabilization in small camera modules. The system is based on wires of nickel-titanium shape memory alloy (SMA) and an associated control and heating ASIC. The alloy has the property that it contracts and expands in a precise and reliable manner under heating and cooling at frequencies of 1 to 30-Hz in response to gyroscope measurements of handshake:


The prototype camera modules are said to provide more than 24dB (more than 4 optical stops) of hand shake suppression for 8.5-mm by 8.5-mm by 5.7-mm 8MP module. The motor is controlled by XC104 SMA Motor Processor IC developed in collaboration with Swindon Silicon Systems. The chip is based on 8051 core that controls integrated MOSFETs that deliver up to 30-mA to heat and control the SMA wire. The chip is being manufactured by IBM at Burlington in a 0.18um process.

The company's business model is to license lens and camera module integrators to use its SMA actuator patent portfolio and provide the control ASIC, its CEO Simon Calder Calder said. Cambridge Mechatronics is targeting mass production of 8- and 13-MP OIS-plus-AF cameras in Q2 2012.

4 comments:

  1. Doesn't tilting the lens introduce focus error from one corner to another? This seems like just trading off one kind of blur (motion or hand-shake) for another.

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  2. I am interested on how this technology will survive shock. Especially when the handset is dropped 4-5 or even 6 feet onto concrete. Such a drop test used to be a "standard" gating test of any technology.

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  3. It looks like the sensor moves with the lens. Seems to be this way due to the tilt of the sensor matching with the lens. Shouldn't introduce focus error then.

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  4. I'm pretty sure that the memory alloys have a reasonably large elastic regime so they should be pretty resistant to shock as long as there are appropriate bump stops designed into the carrier the maximum force on the actuators should be well defined. The more interesting question for me is how are they getting data off the chip and if those structures are susceptible to fatigue.
    I was looking into this company a few months ago for an idea about sensor based AF and it seems that they already have AF modules on the market. If you look at the diagram it looks like the signal for the AF is transmitted through the blue and red colors.

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