Casio develops time to set wrist camera

Chester Gould's Dick Tracy Watch is on the horizon. The ever-shrinking world of electronics brings imaging to your wrist in the form of the Casio Wrist Camera. Introduced in 2000, and later implemented in color, the Casio WQV-2 leverages the latest in consumer-grade packaging to fit a modest-quality imager and high-resolution LCD screen in an oversized sports watch format. And, yes, it also keeps time.

With most quartz LCD timepieces, a mere handful of components is required. Open up a time-only watch and you will find a single IC, simple segment LCD and a sprinkling of oscillator-related discretes. The Casio WQV-2 steps up wristwatch sophistication a notch, with five ICs and an infrared transceiver shoehorned into a case that also houses the CR2032 lithium coin cell battery, graphics LCD, system optics and user interface. Overall weight comes in at 32 grams (1.1 ounces)-sans wrist straps-with about one-third of the weight coming from the case enclosure and mechanics. Electronics for the WQV-2 are spread across three assemblies-a main board, the LCD panel and the camera module.

On the main board, a custom chip from NEC provides system controller and basic timekeeping functions. Paired with the central processor is a 1-Mbyte flash memory from Fujitsu/AMD, storing both the maximum 100 user images and system firmware. One of the more subtle but interesting components of the assembly is a tilt/motion sensor, used to detect physical activity of the watch and conserve power during extended at-rest periods. Very clever.

Because of the relatively high pixel count of the LCD, a sizable 13 x 6-mm LCD driver chip is directly attached to the flex circuit that links the LCD assembly to the main board. The roughly 1-inch- diagonal 14,400-pixel gray-scale display demands a rather amazing level of interconnect to serve rows and columns. The polyimide flex circuit used for interconnecting driver and glass panel has trace widths and spaces of only 30 microns-some of the most dense flex-circuit technology seen on a production basis.

The built-in digital camera module, which weighs a mere 0.5 gram, combines a 28,000-pixel, 1/14-inch optical format, gray-scale CMOS image sensor with the needed image coprocessor chip. The WQV-2, sampling now, is estimated to have production costs under $40.

Along with increasing electronics integration, optomechatronics and electronics packaging enable the world of gadgets to become ever more personal-in this case strapped directly to your wrist.

David Carey is president of Portelligent (www.teardown.com)