Digital camera pixel counts continue to climb, and market demands for higher image quality are on the rise. An optical low pass filter is often provided on digital cameras to combat moiré patterns*1. Conventional OLPFs employ a construction containing thr ee quartz plates. The three-quartz plate system, however, does not provide uniform light separation characteristics at certain wavelengths, and thus not all moiré patterns are eliminated. Epson Toyocom's latest OLPF employs a new structure wherein a wide- band phase retardation film is sandwiched between a pair of quartz plates (Fig. 1). This design provides uniform light separation at all wavelengths of visible light (Fig. 2) and is thus able to eliminate moiré patterns across the visible spectrum. The ne w OLPF is also thinner and lighter than the conventional structure because it requires only two quartz plates.
As a result, this new OLPF will further boost the image quality of digital cameras and enable them to be made thinner. The lighter weight of the new design also makes this OLPF ideal for CCD-shift camera-shake correction mechanisms and for functions desig ned to physically vibrate dust off the filter.
The new OLPF and other crystal devices will be on display at the Epson Toyocom booth (No. 6E116) at CEATEC JAPAN 2007, to be held at Makuhari Messe from October 2-6.-Epson
Posted September 8th, 2007 by harminka
