Electronic Design

Microdisplay Module Brings Sharper, Brighter Images To Viewfinders

Backlit thin-film-transistor (TFT) direct-view displays are often employed in camera viewfinders. But they tend to be afflicted with pixelation, high power consumption, and low optical efficiency. The CMD3X2A QVGA microdisplay viewfinder module, though, addresses these issues. It's a small, full-color, full-motion, video viewfinder module intended for digital cameras and camcorders.

Built by Colorado MicroDisplay Inc., the CMD3X2A uses nematic liquid-crystal-on-silicon technology. The company says that the device's total of 76,800 color pixels is over three times the pixel count of common backlit TFTs. Also, the display is characterized by a 93% fill factor per pixel. Viewers consequently perceive smooth, nonpixelated images. The effective image size is large as well, equivalent to an 11.1- by 8.3-in. screen viewed at a 1-m distance.

Delivering refresh rates up to 120 Hz (360 color-fields/s), the module ensures rock-steady images and support for full-motion video. A large color depth, typically 24 bits, accommodates the full range of content including text, still images, and full-motion video.

Included in the viewfinder module is a state-of-the-art, high image-fidelity illumination system (see the figure). It features a light mixer, an LED assembly, and the CMD3XLB illumination controller. A light, compact, and rugged enclosure integrates the display, illumination, optics, and electronic components.

The CMD3X2A QVGA microdisplay operates on a power budget of under 15 mW (display only). The entire module consumes 75 mW, including the display, illumination, and drivers. Accordingly, its maker claims it delivers twice the battery life of a direct-view display.

Samples of the CMD3X2A QVGA microdisplay and CMD3XLB illumination controller are available now. Production volumes are scheduled to ship in the first quarter of 2001. The CMD3X2A and CMD3XLB chip set costs less than $25 in OEM volumes. To assist OEMs in their design-in process, the CMD3X2A QVGA chip-set evaluation kit has the necessary elements for performing qualitative and quantitative assessments. It costs $2500.

Colorado MicroDisplay Inc., 2477 55th St., Boulder, CO 80301; (303) 546-9700; fax (303) 546-9800; www.comicro.com.

TAGS: Components
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