Scanning system for preferentially aligning a package in an optimal scanning plane for decoding a bar code label

摘要

An automated retail point of sale scanning system includes a means for preferentially aligning an item traveling on an item path and through a scanning region such that two or more surfaces to be scanned are stably maintained in a substantially coplanar alignment with a corresponding focal plane of a bar code scanner. Two orthogonally disposed belts define an item path. The belts are tilted at an angle from the horizontal so that an item placed on either belt will have at least two surfaces stably registered by gravity, one surface to each adjacent belt. Alternatively, a stationary platen is disposed orthogonally to a transport belt such that at least two surfaces of the item being scanned are stabilized in a focal plane coplanar with a bar code scanner, one surface of the item being stabilized against the platen and another surface being stabilized against the adjacent transport belt. Scanning is done through O-rings or slots in the belts or platen, or through a transparent plate over which the item moves when it is in the scanning region. A sensor selectively activates one of two or more laser beams having different depths of focus to thereby provide an ideal depth of focus for resolving a bar code label of objects of varying sizes and shapes. The scanned and decoded bar code information is applied to a microprocessor which in turn activates a pattern of pixel elements on a moving display. The system optimizes customer interpretation and recognition of the item while providing minimum reading error.