Spin-off Products --- Bar Code Scanning

If we go to supermarkets, we will encounter a space technology, i.e. bar code. We can see that there are black and white bars printed on the items, that's bar code. The bar code store the information about the item, including key (a number used for identifying) of the item.
A barcode reader will read the bar code, send the information to a computer, the computer then check the name and the price of the item, and send these information to the screen. At the same time, the bill is calculated.
It largely reduce the mistakes that are caused by hand-input.

Straightening the Teeth Ski Goggles Bar Code Scanning