Monday, February 12, 2007

Omnivision Truefocus Camera Module Launched?

Omnivision launched its first product incorporating waveform-coding based Truefocus. Well, sort of launched, as there is neither a part number nor a production schedule announced.

Yahoo: OmniVision is demonstrating the 3-megapixel TrueFocus camera this week at its booth at the 3GSM World Congress in Barcelona, Spain.

From a manufacturer and system designer's point of view, transitioning to TrueFocus cameras is simple and straightforward. TrueFocus modules are smaller than the AF modules that are currently available. In TrueFocus systems, the mechanics found in classical AF systems move to silicon and thus become subject to Moore's Law. Wavefront Coded lenses can be formed in plastic at a cost comparable to classical lenses, and will be offered through major lens manufacturers. Replacing mechanical parts with lenses that do not require focusing during assembly simplifies sourcing and manufacturing by combining high quality optical systems with relaxed manufacturing tolerances. With no moving parts, a TrueFocus module requires less power, and performs more reliably in extreme temperatures.

Wavefront Coding was invented by the founders of CDM Optics and is protected by numerous U.S. and foreign patents dating from 1995. A Wavefront Coded system differs from a classical digital imaging system in two fundamental ways. First, the light traveling through a Wavefront Coded lens system is not focused on a specific focal plane. Instead, the specially designed lens system defocuses the light from each point in the field of view, regardless of its distance from the camera, and creates an intermediate unfocussed image. Another way to describe this effect is to say that the special Wavefront Coded lens system changes the path of each light ray such that the light deviates from the path that it would take when passing through a classical lens. The modification of the direction of the light as it passes through the lens system is referred to as "encoding."

The second difference found in a Wavefront Coded system, referred to as "decoding," arises when the intermediate unfocussed image is restored by digital processing. The intermediate image from the sensor is processed to produce an image that is as sharp and clear as a conventional image, but has the important non-classical property that the depth of field (or depth of focus) is much greater than that produced by a conventional lens system using an equivalent aperture or 'f' stop number.

Simultaneously Omnivision announced a 5MP AF camera module, this time with part number and in mass production, but with no mention of Truefocus:

Yahoo: The OV5623 CameraChip sensor at the heart of the 5 megapixel module has an optical format of just 1/2.5 inches and a 2592 x 1944 image array with digital image stabilization capability. A 10-bit A/D converter enables the OV5623 to operate at 7.5 frames per second (fps) in full resolution or 60 fps at a 864 x 648 resolution for enhanced video viewing on a TV screen.

The OV5623 is built using OmniVision's proprietary OmniPixel2(TM) technology manufactured using 0.13-micron CMOS process technology. The OV5623 design incorporates OmniVision's zero-gap micro-lens structures, improving the overall sensitivity of the device. In addition, the sensor's improved quantum efficiency optimizes image performance by further increasing full well capacity.

2 comments:

  1. It is funny that Photobit trademarked "TrueBit", "TrueColor" and "TrueSNAP" -- which now belong to Micron.

    Omnivision apparently liked that sequence in coming up with "TrueFocus"! heh. Imitation is the best form of flattery!

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  2. Actually, "true" is quite a popular word among marketing guys. For example, Sigma has "True Image Processing Engine" in its cameras. Kodak has "True 2-phase CCD". There used to be an image sensor company named TrueSight.
    Talking about trademarks in image sensors, my favorite one was SeeMOS by Philips, inherited by DALSA. But DALSA does not seem to have any interest in it.

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