The problem:
Quality, speed and reliability are three of the most important things that photographers demand of their equipment – especially in the top league of photography, the D-SLR domain. This applies equally to pro photographers earning their living or ambitious amateurs capturing their personal, precious moments. Top manufacturers therefore strive to outdo themselves (and one another) when it comes to developing ever new technological refinements for their products to enhance quality. The final goal is to provide photographers with the perfect tools for their task, so they can shoot hassle-free under all kinds of conditions and be pleased with their results. This includes developing technologies that: get the subject in focus no matter how brief the moment; deliver sharp shots even in swirling action; keep images spotless however often lenses are changed; and ensure that the equipment keeps working day in, day out.
The solution:
The Olympus Supersonic Wave Drive (SWD) is the result of over a decade of research and development. It is based on a piezo electric actuator – which was originally invented for use in microscopes. Nowadays this technology has a diverse range of applications. The SWD is an integral part of the latest high-performance Olympus D-SLRs. It not only handles the Supersonic Wave Filter (SSWF) dust reduction system, it is also employed by built-in mechanical image stabilisation units to accurately shift the image sensor position within fractions of a second to counteract involuntary camera movement. Furthermore, it also significantly accelerates and refines the autofocus capabilities of the SWD range of ZUIKO DIGITAL lenses, especially in the Olympus D-SLR flagship model, E-3.
The SWD in action: When the power is switched “on”, the SWD’s piezoelectric material starts to wave due to an inverse piezoelectric effect. Projections (or “legs”) attached to the SWD follow its waving movement. When the projections touch the surface, they can “kick” it and thereby instantly move its position. |
How it works:
The piezoelectric technology employed is based on a discovery made by the Curie brothers in 1880. It ascertained that mechanical pressure (Greek “piezein” – to press, squeeze) applied on quartz crystals generates an electric potential (direct piezoelectric effect). They also proved that an electric field applied to these materials causes them to change shape (inverse piezoelectric effect). In the past 50 to 60 years, developments in this technology have made great advances. The piezo effect exhibited by some natural materials (such as quartz) is rather small, so new polycrystalline ferroelectric ceramic materials with improved properties were developed. The fields of application of piezo technologies have also widened and comprise such seemingly simple uses as in piezoelectric gas lighters, where pressure is applied to a piezo ceramic element to generate the spark. The same technology – the piezoelectric igniter – is also used in car engines. Piezoelectric actuators, such as the Supersonic Wave Drive, employ the inverse piezoelectric effect, where a voltage is applied to the ceramic material to generate movement. This technology is extremely well suited for high-precision and highspeed positioning tasks. It is non-magnetic, compact and needs no special maintenance.
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Applications of the Olympus Supersonic Wave Drive
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Autofocus with ZUIKO DIGITAL SWD lenses
Utilising an ultra-compact encoder measuring just 5.3 x 4.3mm, the SWD in the high-performance range of Olympus ZUIKO DIGITAL SWD lenses allows for smooth, ultra-fast and absolutely precise autofocusing. It differs from other types of ultra - sonic motors in that it gains full speed instant - aneously and can be stopped without any advance slow-down once the correct focus position has been reached. This enables the world’s fastest AF speeds to date to be attained*. A special inner focusing mechanism means the lens does not extend, retract or rotate while focusing to further ensure accuracy. In addition, manual focusing is available at all times. Please also refer to the separate whitepaper on the E-3 AF system which contains further detailed explanations.
Lens with Supersonic Wave Drive
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SWD element
Encoder
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Image Stabilisation
Olympus D-SLRs featuring a built-in image stabilisation unit operate on the basis of shifting the image sensor. First, a gyro sensor detects involuntary camera movement and the SWD shifts the image sensor to counteract the effect accordingly. The SWD allows the fastest speed and most accurate control of the sensor positioning. Please refer to the separate whitepaper on this subject which is available for a more detailed explanation.
Body-mounted Supersonic Wave Drive Image stabilisation unit Gyro sensor
image stabilisation
Supersonic Wave Filter – also ultilising Supersonic Wave Technology
In the Supersonic Wave Filter, Olympus’ revolutionary dust reduction system for digital SLRs, Supersonic Wave technology is employed to generate the supersonic vibrations used to shake off dust and other particles from the filter surface. Please refer to the separate whitepaper on this subject which is available for a more detailed explanation.
Test of Supersonic Wave Filter SSWF cross section
*As of January 2008, with an Olympus E-3 using the ZUIKO DIGITAL 12-60mm 1:2.8-4.0 SWD lens |
