Lens made thinner using transparent ceramic

Thanks to the high refractive index of a novel glass ceramic, it is possible to make digital cameras 20 per cent thinner

Using proprietary optical technology, Casio has developed the world's first lens using transparent ceramics. This breakthrough will make it possible to create zoom lenses for cameras with greatly reduced profiles. Ever since Casio's Exilim credit-card-sized digital camera went on sale, the digital camera market has undergone a huge change. Compact digital cameras offering mobility in a small package have become mainstream, while there has been a major push in technological development to find better methods of creating smaller, thinner cameras. Casio is continuing to take the lead in this field by creating the world's first transparent ceramic lens using Lumicera, a transparent ceramic developed by Murata Manufacturing Co., Ltd. Lumicera has the same light transmitting qualities as optical glass commonly used in today's conventional camera lenses, but it has two very important properties that caught Casio's attention. Not only is Lumicera's refractive index (n d = 2.08) much greater than that of optical glass (n d = 1.5 to 1.85 ), it also offers superior strength. Casio has been able to create a ceramic lens with extremely high levels of precision thanks to several factors. Under recommendations from Casio, the material itself has been refined for use in digital camera optical lenses by endowing it with improved transmission of short wavelength light and eliminating pores (air bubbles) that reduce transparency. Casio has also established a complete process involving the perfect combination of polishing material, time and pressure, and by treating the lens with a special coating compatible with a high refractive index. By incorporating this lens into the construction of the zoom lenses developed by Casio over many years, a reduction in profile of approximately 20% has been made possible. TS