Image sensor suits ultra-thin mobile devices

An OmniVision product story

Edited by the Electronicstalk editorial team Oct 2, 2008

Omnivision Technologies has introduced a 1/4in, 5 megapixel system-on-chip (SOC) image sensor based on its OmniBSI technology.

The OV5642 combines 1.4-micron OmniBSI pixel with Truefocus image signal processor (ISP).

OmniBSI technology delivers low light sensitivity (>500mV/Lux-sec) in a small footprint, making it suitable for ultra-thin camera module designs for mobile applications.

Backside illumination represents a new approach to traditional CMOS image sensor technology, essentially inverting the sensor to collect light from the backside.

This approach offers the most direct path for light to strike the pixel, resulting in an improved fill factor, higher quantum efficiency and significantly reduced cross-talk.

OmniBSI technology also reduces stack height, increasing the chief ray angle (CRA) to enable greater zoom tolerances and significantly thinner camera modules.

The embedded Truefocus ISP is a signal processing engine designed to increase image quality and camera performance, while delivering extended depth of field (EDoF) using traditional, standard lens technologies.

Truefocus employs a combination of advanced de-noise, gamma and colour-correction algorithms to reduce colour noise without removing details.

Image sharpening techniques minimise colour aliasing to deliver sharp and clear colour images.

The OV5642 also features an internal anti-shake engine and supports thumbnailing and Scalado tagging for faster image preview and zoom.

It has an embedded auto-focus controller, which can be programmed via the internal microcontroller.

The auto-focus mechanism can be controlled via the general purpose I/O.

The OV5642 can output video in full resolution at 15 frames per second (fps).

It also supports 720p high definition (HD) at 60fps and 1080p HD video at 30 fps.

The OV5642 also offers Bridging and Daisy Chain support, which allow secondary cameras to share the use of its ISP via the digital video port (DVP), while providing continued output through the dual-lane MIPI interface.

An integrated JPEG compression engine simplifies data transfer for bandwidth limited interfaces.

For identification and storage purposes, the OV5642 incorporates one-time programmable (OTP) memory.