Tomorrow marks the 35th anniversary of the first time a laser scanner was used to "read" a bar code, according to Motorola Inc.

The company has a few of the pertinent facts from that day, including that the first scan occurred at 8:06 a.m., June 26, 1974, at a Marsh supermarket in Troy, Ohio. The bar code was imprinted on a 10-pack of Wrigley's Juicy Fruit gum.

There were bar code patent applications going back to the early 1950s, but a bar code alone couldn't do much. Jerome Swartz, an electrical engineer, invented the laser scanner used for reading bar codes. He also co-founded Symbol Technologies, which is now part of Motorola Enterprise Mobility Solutions, said Bob Sanders, vice president of the group.

The technology has grown to the point that bar codes are ubiquitous, Sanders said. Motorola estimates that a specific type of bar code called the Universal Product Code is used more than 10 billion times a day in applications that service 25 industries, including packaged goods, food services and medicine.

Bar codes are used everywhere, including to identify babies in delivery rooms and to track medicines used by critical care patients. They can be transmitted to cell phones to be read by a scanner directly from the phone for admittance to a baseball game. It won't be long before air travelers will check in for a flight with a handheld device displaying a bar code on its screen, instead of printing out the bar code, Sanders said.

One of its most clever applications is the use of a bar code on a packet of coffee that is read by a coffee maker to give specific instructions on the amount of pressure and heat needed for a specific kind of drink, Sanders said. Motorola provides the scanning technology in such machines, he said.

Bar codes have evolved to the point where two-dimensional bar codes can be read by cameras, instead of lasers. A related tracking technology is RFID, which uses a radio signal emitted from a chip to track a device. The RFID chip can include specific information about a product, such as a dress or a shirt, while a UPC has an optical pattern that is translated into 12 characters that provides more general information.

Only 10 of the 12 characters are used to identify the product, the first five describing the manufacturer and the second five the specific product. By itself, that information is meaningless, but when it is transmitted to a server with a database from a cash register with a scanner, a price can be determined.

Sanders said there are efforts underway to add more fields to the bar code, which could make it helpful in tracking certain products. A tainted food, for example, could be tracked down to a single item, such as a bag of peanuts.

"I don't see the bar code going away any time soon," Sanders said.

For at least a decade, inventors have talked about using bar codes as hyperlinks to find specific items on the Internet. A customer in a store, for example, could use a cell-phone camera to read a product's bar code and learn about competitor's products through a quick browser search. "Some groups are dabbling with that technology and its day will come, it's not far off," Sanders said.

Some smartphones, such as the T-Mobile G1, already have an application that turns the phone's camera into a price tag scanner.

When bar codes and scanning were paired in the 1970s, the technology set off a national tremor among privacy advocates. "That worry has gone away, and people see the bar code as a productivity tool now. They see there's no secret society tracking them," Sanders said. "People were worried about bar codes on frequent shopper cards, until they discovered they might be used to save 50 cents on a purchase."