Optical Encoders Improve Zoom Accuracy

Photographers understand the need for zoom lenses on their cameras as do operators of cameras in commercial applications. Consider the camera phone with its digital or optical zoom – or in some cases, both. What are the differences in the zooms? An optical zoom changes the effective focal length of the camera lens using either a CCD or a CMOS sensor. A digital zoom uses a software algorithm rather than moving hardware to zoom in on a subject. With digital zoom, a smaller portion of the larger image is captured and enhanced.Optical Zoom

Optical zooming is considered important to determining the “true” zoom power of a camera phone, especially when you’re looking for a way to capture images without losing data integrity. Accurate lens positioning is important to the optical zoom to ensure quality of the enlarged image.  With optical zoom mechanisms it is the code strip that moves to capture the image. The encoder, within the code strip offers feedback to the camera sensors to capture the highest quality image.

The surface of the code strip has to be reflective and mirror-like in order to capture the image pattern and send it to the photo-diodes. The materials used for the surface strip are typically reflective film or metal.
End users seeking technologies with zoom capabilities need to be certain that the reflective surfaces were tested separately from a non-reflective surface. Tests should be performed on patterned as well as non-patterned surfaces as well in order to determine an average reflection pattern.

New encoder technology is being developed that integrates an index channel to the digital output channels. This index channel eliminates the photo-interrupter requirement in many devices. To determine the ideal type of lens and zoom mechanism for inclusion in either camera phones or in a commercial camera setting, the final desired outcome must first be determined before choosing a solution to meet the image capture needs you’re seeking.

Universe Kogaku designs and manufactures optical lenses for optical zoom, industrial, medical, high tech and electronic applications. We also offer standard and custom lens assemblies for scanners, CCTV, CCD/CMOS, medical imaging, surveillance systems, machine vision and night vision systems.

Posted in CCD/CMOS Lens.