Automatic laser bar code symbol reading system and method of reading bar code symbols using same

Claims

We claim:

1. An automatic bar code symbol reading system, comprising:

a hand-supportable housing having a light transmission aperture through which visible light can exit and enter into said hand-supportable housing;

object detection means in said hand-supportable housing, for detecting an object located in a scan field defined external to said hand-supportable housing, and automatically generating an activation signal in response to the detection of said object located in said scan field;

activatable scan data producing means in said hand-supportable housing, for producing scan data from a detected object located in said scan field, said scan data producing means including,

laser beam generating means for generating a visible laser beam,

means for directing said visible laser beam through said light transmission aperture and into said scan field,

laser beam scanning means for repeatedly scanning said visible laser beam across said scan field and a bar code symbol on said detected object,

laser light detecting means for detecting the intensity of laser light reflected off said bar code symbol and passing through said light transmission aperture as said visible laser beam is repeatedly scanned across said scan field and said bar code symbol on said detected object, and

means for automatically producing scan data indicative of said detected intensity;

activatable scan data processing means for processing produced scan data so as to detect and decode said bar code symbol on said detected object, and automatically producing symbol character data representative of said decoded bar code symbol; and

control means for controlling the operation of said automatic bar code symbol reading system, said control means including

means for automatically activating said activatable scan data producing means and said activatable scan data processing means for up to a predetermined time period in response to the generation of said activation signal, and

means for automatically deactivating said activatable scan data producing means and said activatable scan data processing means in response to the failure of said scan data processing means to detect and decode said bar code symbol on said detected object within said predetermined time period.

2. The automatic bar code symbol reading system of claim 1, wherein said laser beam generating means comprises a laser diode.

3. The automatic bar code symbol reading system of claim 1, wherein said bar code symbol has first and second envelope borders, and wherein said scan data processing means comprises means for detecting the first and second envelope borders of said bar code symbol, and means for decoding said detected bar code symbol.

4. The automatic bar code symbol reading system, of claim 1, wherein said object detection means comprises means for receiving energy reflected from an object within an object detection field defined external to said housing and having an essentially volumetric extent, and

wherein said scan field is characterized by at least one scanning plane having an essentially planar extent, and

wherein said object detection field spatially encompasses at least a portion of said scan field.

5. The automatic bar code symbol readi