SENSING APPARATUS

• US 3,777,165 A
• Filed: 03/31/1972
• Issued: 12/04/1973
• Est. Priority Date: 03/31/1972
• Status: Expired due to Term

• Current Assignee: Allen-Bradley Company (Rockwell Automation, Inc.)
• Original Assignee: Elihu Craig Thomson, Jack A. Bryant
• Inventors: Bryant, Jack A., Thomson, Elihu Craig
• Primary Examiner(s): Lawrence, James W.
• Assistant Examiner(s): Nelms, D. C.
• Application Number:
  US05/240,056
• Time in Patent Office: 613 Days
• Field of Search: 250/219D,219DR,219CR,219LG,220,221,222,223 235/61.11E 340/146.3
• US Class Current: 235/462.25
• CPC Class Codes: B65G 47/493 by use of light responsive means
• CPC Class Codes: G06K 7/10871 randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code

Abstract

Scanning apparatus includes a linear array of sensors so that there is effectively a series of independent sensor elements disposed in aligned relation generally perpendicular to a scanning axis. Each sensor is arranged to provide a data output in response to a sensed code mark and an output channel is coupled to each sensor. Logic responsive to detection of a first code mark by a sensor of the array enables at least one code sensitive group of output channels and disables other output channels so that only a limited group of channels are rendered responsive to subsequently detected code marks.

Claims

1. Scanning apparatus for use with an article that has a series of code marks comprising a linear array of sensors arranged so that there is effectively a series of independent sensor elements disposed in aligned relation generally perpendicular to a scanning axis, each said sensor element being arranged to provide a data output in response to a sensed code mark, an output channel coupled to each sensor, and means responsive to a sensor data output to enable its output channel as a primary channel and the channel immediately adjacent said primary channel as a secondary channel and to disable other output channels so that said primary and secondary channels are responsive to the next sensed code mark and said other output channels are not responsive to the next sensed code mark.

2. The apparatus as claimed in claim 1 wherein each said sensor is a solid state photosensor and further including a mask structure disposed between the photosensor array and the code to be sensed, said mask having a slit that defines a photosensor read pattern, the read patterns of said sensors being aligned end to end and being independent of one another.

3. The apparatus as claimed in claim 2 wherein the slit width of said mask is less than the sensed width of the code mark and the sensed height of he code mark is at least twice the length of said photosensor read pattern.

4. Scanning apparatus for use with an article that has a series of code marks comprising a linear array of sensors arranged so that there is effectively a series of independent sensor elements disposed in aligned relation generally perpendicular to a scanning axis, each said sensor element being arranged to provide a data output in response to a sensed code mark, an output channel coupled to each sensor, logic responsive to the article to be sensed for initially applying an enabling signal to all of said output channels, and means responsive to detection of a first code mark by a sensor of said array to enable a code sensitive group of output channels that includes a primary channel and two secondary channels and to disable other output channels more remote from said primary channel than said secondary channel so that said primary and secondary channels are responsive to a subsequent code marking and said other output channels are not responsive to said subsequent code marking.

5. The apparatus as claimed in claim 1 wherein each said output channel includes a threshold amplifier which provides a data output, delay logic responsive to the data output which provides a conditioning output, AND logic responsive to said conditioning output, and cross-coupling logic responsive to the output of said AND logic for providing a latching function to define at least two primary channels and an enabling function to define two secondary channels.

6. Scanning apparatus for use with an article that has a series of code marks comprising a linear array of sensors arranged so that there is effectively a series of independent sensor elements disposed in aligned relation generally perpendicular to a scanning axis, each said sensor element being arranged to provide a data output in response to a sensed code mark, an output channel coupled to each sensor, means responsive to the article to be sensed for initially applying an enabling signal to all of said output channels, and logic responsive to detection of a first code mark by a sensor of said array to enable at least one code sensitive group of output channels and to disable other output channels so that said one group of output channels is responsive to the next detected code mark and said other output channels are not responsive to said next detected code mark.

7. The apparatus as claimed in claim 6 wherein said logic includes means responsive to a first data output produced by an output channel in response to a sensed code mark for disabling all of said output channels, and coupling means responsive to each output channel for overriding said disabling means to maintain in enabled condition each said output channel producing said first data output.

8. The apparatus as claimed in claim 7 wherein said disabling means resets said initial enabling means.

9. The apparatus as claimed in claim 6 wherein said logic includes means responsive to a sensor data output to enable its output channel as a primary channel and an immediately adjacent output channel as a secondary channel.

10. The apparatus as claimed in claim 6 wherein each said output channel includes cross-coupling logic responsive to said data sensor output for providing a latching function to define a primary group that includes at least one output channel and an enabling function to define a secondary group that includes an output channel immediately adjacent an output channel of said primary group.

11. The apparatus as claimed in claim 10 wherein each said output channel cross-coupling logic includes AND logic responsive to the output of its sensor, and means coupling the output of said AND logic to the input of the AND logic of an immediately adjacent channel.

12. The apparatus as claimed in claim 11 wherein each said sensor is a photosensor and further including mask structure disposed in front of the photosensor array for defining a photosensor read pattern, the read patterns of said sensors being aligned end to end and being independent of one another.

13. The apparatus as claimed in claim 12 wherein the sensed height of the code mark is at least twice the length of said photosensor read pattern, and said crosS-coupling logic latches said output channels so that there are at least two output channels in said primary group.