Electronics Outside the Box

From the show that brought you the VCR (1970), the compact disc player (1981) and high definition television (1998), comes the next generation of electronic devices for the home, car and office. Indeed, the products featured at this year’s Consumer’s Electronics Show, held in Las Vegas this January, encompass audio, video, computer hardware, home entertainment, telecommunications and a host of other technologies. In all of these products, plastic is playing a vital role in turning cutting-edge, advanced technology and concepts into tangible items people can touch, see, hear and use. Along the way, consumer electronic companies and their supplier partners are redefining design and manufacturing methods, with implications that may eventually affect processors across all market segments.

THIN IS IN

Boston Acoustics, Inc. picked up an innovation award for its BA7500 Multimedia Audio System with patent-pending Slim-line Speaker Technology (SST) flat panels. The system, which is used with a computer, consists of four satellite speakers, together with a floor-standing sub-woofer with a hide-away design. Each satellite speaker is about 1 1/8 in. deep, which permits them to be mounted virtually out of sight on a wall. According to Steve Feinstein, director product management, the speakers in the 7500 system are the first-ever speakers to be built with a one-inch depth using a conventional speaker design.

“There have been other speakers that have been built this thin, but the technology they used resulted in a sound quality that is not up to today’s standards,” notes Feinstein. “This system takes a conventional approach for speaker design and has extremely high fidelity and high-quality sound reproduction.”

The key component to the speaker is a high-temperature glass-filled nylon speaker basket. The basket is part of the driver containing a speaker cone and a motor structure which react with an electrical input signal to make sound. Temperatures within the basket can reach as high 250 F and, given the speaker’s thinness, it is critical that the material be heat stable.

“It wouldn’t be possible to create the SST driver if it weren’t for the plastic design and manufacturing technologies, which enable us to test, change and make complex designs in a short period of time,” notes Feinstein.

He says there is a great demand in the marketplace for thin-panel speaker technology and speakers that do not take up a lot of space. While the 7500 is the first application of SST, he envisions the same technology will eventually be used in speakers for televisions, home entertainment systems and automobiles.

“Design space in today’s automobiles is at a premium,” he says. “You can’t afford to have speakers taking up space in the trunk or door walls.”

PORTABLE KEYBOARD TARGETS WIRELESS USES

The plastics-rich Stowaway Portable Keyboard from California-based Think Outside, Inc. was one of the most honored products at the CES, picking up an Innovations award, a Best-of-Show award and a Workstyle award. The Stowaway is the first full-size keyboard that folds up to about the size of a hand-held organizer, the company says. It is aimed for use with hand-held computers and organizers, otherwise known as personal digital assistants (PDAs); especially for applications with these devices involving large amounts of data or typing in which stylus or touch inputting isn’t practical.

One of the most innovative plastics features of the Stowaway is two double hinges, a left and right side, with two pivot points per hinge. Each hinge consists of a 1 mm diameter hinge pin, which fits in a hole 1.1 to 1.2 mm in diameter, surrounded by a hinge wall of about 0.8 mm thick, according to John Tang, company vice-president of engineering. The hinge pin is made of DuPont’s Delrin acetal resin. Tang says Delrin was chosen because it has low friction properties and good wear resistance. The pin holes are molded in with a mold slide pin. One of the pin holes is 18 mm in length

Other plastic components on the Stowaway include key caps, which are made from ABS, and the key scissors mechanism below the caps, which is also made from Delrin. Parts of the keyboard’s outer panel enclosures are made from a 10 percent glass-filled polycarbonate; while inner panels consist of a PC/ABS blend.

The company is continuing to evolve the Stowaway’s design and is currently looking at ways to replace the aluminum outer skins with plastic, says Tang. He says doing so will be tricky, as it will require molding a thinwall section of plastic less than 1 mm in thickness, while maintaining high surface finish and appearance standards for the part.

Palm Computing is currently reselling the Stowaway keyboard under the Palm name as an accessory for its complete line of Palm connected computers; as well Targus Group International is distributing the keyboard with Handspring Visor family line of handheld computers.

Tang sees a bright future for the Stowaway: “The really big market for this will eventually be cell phones with Internet capabilities.”

THE INCREDIBLE SHRINKING PC

IBM calls its wearable PC a direct response to the following challenge: How small and mobile can you make a PC without giving up any functionality? Quite small, it turns out. The central processing unit (CPU) of this fully functional PC, which clips onto a person’s belt, is about the size of a paperback book and weighs less than a pound. Its monitor, about the size of a pencap, rests about an inch from the eye and is held in place with a head band. The configuration gives the user the illusion of reading a 14-in. screen at normal viewing distances. The wearable PC comes with an eraser-size mouse; as well, the user can command the PC via an interactive voice/speaker system.

The wearable PC is still in the prototype stage, although about 100 of them have been produced using soft tooling. Enclosures and other plastic parts for the prototypes have been mainly made from polycarbonate. The computers are being used on a trial basis by customers in targeted fields, such as health/medicine, construction, aircraft maintenance and others in which it is often necessary to have access to large amounts of information instantly.

According to Bob Steinbugler, manager of strategic design at IBM, the company is expecting feedback on the wearable PC from customers no later than March. He says one of the biggest challenges of the project is how to comfortably and effectively put the technology on a human body.

“There is a tremendous amount of exploration in materials going on in the respect of how to best attach this to a person,” says Steinbugler. “We’re looking at a host of materials, everything from foam to rubber-like plastics.”

The importance of the role of internal components in shrinking the size of laptop computers is demonstrated in the design of power supplies made by Linfinity Microelectronics, Inc. The power supplies consist of several electrical and electronic components on a circuit board. The transformer has a low-profile coil form and a wire bridge insulator molded from DuPont Zenite liquid crystal polymer (LCP).

“Zenite LCP gives us a competitive advantage by helping to minimize the transformer’s size to save space in our customer’s computers,” says Brayton Holt, a magnetics design engineer for Linfinity.

Zenite fills the parts’ thin sections consistently during molding; as well, provides heat resistance and dimensional stability during manufacturing and service. The transformers are rated for operation from -40 to 100 C.

As one speaker at the CES show noted, the need for innovation in electronics has become more important than ever, as consumer demands and expectations continue to raise the bar for product quality and uniqueness. As you can see from these examples, plastics is playing a key role in helping designers meet those demands.