Under the Hood: FinePix F460 camera undergoes postmortem - Embedded.com

Under the Hood: FinePix F460 camera undergoes postmortem

Fuji's FinePix F460 camera was a midtier, circa 2006 5-megapixel camera with 3x optical zoom and the requisite 2.5-inch LCD. Price at introduction was in the $300 range. I say “was” since the camera is both discontinued and, in this case, a dead product brought home recently by a son coming back from a trip to the beach. It seemed like a logical teardown candidate (and even potentially fixable).

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After removing the usual array of small screws from the enclosure, I could split the case halves. The camera body is implemented with stamped aluminum shells and molded plastics, each contributing to the structure and fascia of the cigarette-pack-size digicam. Inside, a plastic frame supports the prismatic Li-ion battery pack. A second metal frame forms the mount for the LCD module and system electronics.

Although my rescue mission focused on optics that wouldn't deploy, a look at the electronics seemed in order.

The circuit board reveals that the outward Fuji brand of the F460 is likely backed up by Sanyo as the camera's original design manufacturer (ODM). The most prominent chip package is a large Sanyo-branded device. (Although it has not had broad success as a vendor of self-branded digicams, Sanyo has created a significant business by serving the major brands in the larger camera market.)

Three circuit boards–one rigid, two flexes–constitute the electronic assemblies, with the rigid board supporting most of the digicam engine, and the imaging devices mounted by flex to the lens. The second flex is used only for user interface buttons on the camera back.

The architecture mirrors the fairly stable partitioning seen in many charge-coupled-device (CCD)-based camera designs of the last several years. Component integration seems to have plateaued. The breakdown in functional blocks here is typical of recent cameras we've analyzed.

An ICX505 5-Mpixel CCD from Sony initiates image capturing. The drive of the CCD to affect pixel transfer is left to a pair of CXD3440 discrete chips from Sony. An Analog Devices AD9948A processes output from the CCD and orchestrates timing of CCD readout. The device incorporates the variable-gain amplifier, correlated double sampling and analog-to-digital conversion to create appropriate digitized output from the CCD and for downstream image processing.

A Maxim MAX8611 chip integrates multiple dc/dc converters to generate an array of voltages. The CCD brings complex biasing into the equation as an overhead associated with this still-preferred imager (in our experience) for most mid- to high-tier cameras. Mobile phone imaging, low-end digicams and, for different reasons, the upper echelon of digital SLR cameras still migrate toward CMOS imagers for performance, cost and power factors.

The circuitry for controlling the motors for lens extension, zoom and focus is partitioned into a dedicated ASIC provided by Sanyo (LB8659).

Audio output and microphone input are a third major “island” of analog, with a Rohm BH6412 handling ADC and DAC operations to translate audio I/O between processors and transducers. Maxim's MAX8622 handles high-voltage charge control, joining with a Renesas IGBT for discharge to fire the Xenon lamp.

As for the digital pieces, a small NEC microcontroller (uPD78F0533) is tasked with input from the F460's few buttons along with general system control functions. Larger processing tasks are left to the image processor from Sanyo. This primary IC handles the maze of data processing needed to go from raw uncompressed digital image data through to JPEG/MPEG compression, image display to the LCD, and image storage to the internal NAND memory or memory card slot. Samsung mobile SDRAM (K4M283233) provides working memory for image processing.

With a look at the electronics completed, it was back to the task at hand: trying to fix a stubborn lens. Ultimately, sand that was lodged in the tightly toleranced lens barrel ramps led to zoom lens freeze-up. (I mentioned that a trip to the beach was in the mix.) The camera could possibly have been rebuilt, but intricate flexes for the shutter/iris broke during lens teardown (a missed de-soldering?), and any chance of recovery was lost by the time the glide ramps could be cleaned.

In the end, I was struck by the cause of failure here. A few grains of sand dealt a fatal blow to the camera, ironic given the level of reliability likely engineered into virtually all of the system electronics. As digital camera platforms stabilize, more- robust mechanical design and environmental resistance may be the most significant opportunities for differentiation. n

David Carey is president of Portelligent (www.teardown.com), a CMP company. The Austin, Texas, group produces teardown reports and related industry research on wireless, mobile and personal electronics.

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