Lockout Timer Operation in an Optical Scanner
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
This article describes a technique for controlling a lockout time in a supermarket scanner to prevent erroneous "double selling" of the same item when an operator pauses while the item is still in the scanner window. Briefly, the lockout time period is not initiated until a sensor indicates the item has cleared the window. An available optical scanner has a scanning laser beam which exits the scanner window continuously. A lockout time is used to prevent the double-selling (or duplicated scanning) of a single item which is being passed slowly over the scanner window or is actually stationery above the scanner window. If the scanner reads the same UPC symbol twice within the lockout time, the second reading is assumed to be from the previously detected item rather than a second identical item.