Japan's Kyocera Corporation has combined a piezoelectric actuator with a special resin film to produce a proprietary, piezo film speaker that is considerably thinner and lighter than conventional electromagnetic speakers, while boasting similar audio levels. The Smart Sonic Sound already provides the audio for LG's 55-inch curved-screen OLED TV and the company hopes it will give designers of future TVs, computers and tablets more scope to place speakers on the front face of products, enabling an overall size reduction and expanding design options.
Smart Sonic Sound comes in three different sizes. The large speaker measures 70 x 110 x 1.5 mm, weighs 23g, and has a frequency range of 200 Hz to 20 kHz. The medium version measures 35 x 65 x 1.0 mm, weighs 7g, and has a frequency range of 500 Hz to 20 kHz. The smallest speaker measures a diminutive 19.6 x 27.5 x 0.7 mm, weighs just 1g, and outputs a frequency of 600 Hz to 20 kHz.
According to Kyocera, the directional projection of sound waves is more balanced than a traditional speaker as the piezo actuator and laminated film create sound through vibrations. The resultant sound quality and volume are delivered at almost equal levels within a 180 degree range creating a more precise audio representation. Kyocera says the Smart Sonic Sound is capable of reproducing “delicate and minute sounds such as raindrops and background effects, with greater clarity,” enhancing audio playback for a more true-to-life listening experience.
LG Electronics’s recently launched 55-inch curved-screen OLED TV is the first TV to use the Smart Sonic Sound piezo film speakers under license from Kyocera. The TV has an extremely thin edge thickness of 4.3 mm making it the ideal candidate with which to launch the new technology to the audio visual market.
Smart Sonic Sound is in fact the second piezoelectric actuator product brought to the digital arena by Kyocera. The Smart Sonic Receiver was introduced by the company in 2012 for smartphones sold in Japan and North America. It uses a ceramic actuator to send vibrations “via tissue conduction and traditional air conduction through display screens without the need for a traditional earpiece or loudspeaker.” The latest Smart Sonic Sound uses the same core technology but with “a different implementation that amplifies air conduction.”
In addition to the Smart Sonic Receiver and Smart Sonic Sound, Kyocera has developed a number of other piezo actuator products using the company’s fine ceramic and lamination technologies. Notable examples include actuators for diesel-engine vehicles and actuators used in the “world’s fastest” inkjet print head. Kyocera has big plans to further develop the use of its actuator technology in the automotive and digital device markets, particularly where size and weight restrictions are limiting design factors.