Moving object identifying system

• US 3,987,278 A
• Filed: 10/18/1972
• Issued: 10/19/1976
• Est. Priority Date: 10/18/1972
• Status: Expired due to Term

• Current Assignee: Gleason Works (Gleason)
• Original Assignee: Gleason Works (Gleason)
• Inventors: James, Hugh F., Van Elzakker, Peter J.
• Primary Examiner(s): Sloyan, Thomas J.
• Application Number:
  US05/298,685
• Time in Patent Office: 1,462 Days
• Field of Search: 235/61.11 R, 235/61.11 E, 235/61.11 D, 235/92 R, 235/92 DP, 235/92 EC, 235/92 EV, 235/92 SH, 250/219 D, 340/146.3 K
• US Class Current: 235/436
• CPC Class Codes: G06K 7/016 Synchronisation of sensing process
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48

Abstract

A device for reading digital information coded on relatively moving labels independently of the magnitude of the relative velocity, yet without a separate clock track. The device also has the capability of correctly reading such coded information independently of the direction of the relative velocity. Clock pulses are counted between two initial timing marks whereafter a similar number of clock pulses are cyclically re-counted to produce successive strobe pulses corresponding to the expected possible occurrences of information marks or bits on the label. The strobe pulses are effectively used to clock a shift register so that the label data is read without need for a separate timing track. A third direction mark or bit is used to set a reversible shift register to shift in a direction corresponding to the existing direction of relative motion thus making the final shift register data contents independent of the actual direction of relative motion.

Claims

1. A device for processing binary information marks coded as a series of binary valued marks each mark being represented by the presence of a sensible characteristic of one of two possible values on definite potential data locations which are of equal logitudinal extent on a relatively moving label independently of the then existing relative velocity therebetween said device comprising:

a mark sensor for sensing the presence and binary value of said marks when passing thereby and for providing corresponding binary valued electrical mark pulses in response thereto,

strobe timing means for detecting the transit time between at least two marks and for thereafter producing successive repetitive electrical strobe mark pulses which are timed to correspond to the expected subsequent occurrences of each potential information mark, and

data register means connected to said mark sensor and to said strobe timing means for accumulating successive binary data values corresponding to the binary value of said mark pulses in time with the occurrence of said strobe mark pulses thereby registering the coded format of said information marks on the moving label.

2. A device as in claim 1 further comprising:

decoding means connected to said mark sensor and to said strobe timing means for detecting at least one predetermined information mark as a code representing the direction of said relative velocity and for producing a direction signal in response thereto, and wherein

said data register means comprises a reversible shift register connected to said decoding means for controlling the register shifting direction in dependence upon said direction signal whereby the final data register contents is the same regardless of the direction of said relative velocity.

3. A device as in claim 1, wherein said mark sensor comprises:

a bifurcated optical light pipe having first and second separate apertures at one end thereof and a third common aperture at the other end thereof,

said third aperture being adapted for mounting in proximity to said relatively moving label,

a light source disposed at said first aperture for providing incident illumination through said third aperture onto said relatively moving label, and

a photodetector means disposed at said second aperture for receiving reflected illumination from said third aperture.

4. A device as in claim 1, wherein said mark sensor comprises:

optical means for optically sensing said information marks and for providing an electrical mark pulse in response thereto.

5. A device as in claim 1, wherein said strobe timing means comprises:

a clock for providing regular recurrent clock pulses,

a velocity register means for counting the number of said clock pulses which occur between at least two of said mark pulses, and

means for cyclically recounting substantially the same said number of clock pulses thereafter and for producing a strobe mark pulse at the conclusion of each such recounting thereby simulating the time occurrence of successive potentially present mark pulses by timing the strobe mark pulses to occur at intervals corresponding to the timing interval measured between said at least two mark pulses.

6. A device as in claim 5, wherein said means for cyclically recounting comprises:

a down counting counter connected for decrementing by said clock pulses,

means for loading said down counting counter with said number from said velocity register after each cyclic decrementing thereof to a predetermined counter contents, and

means for producing said strobe mark pulse after said predetermined counter contents is reached.

7. A device as in claim 1, wherein said strobe timing means further comprises:

shift register clock generating means connected to receive both said mark pulses and said strobe mark pulses and for producing a shift register clock pulse in response to either.

8. A device as in claim 7, wherein said data register means comprises:

a shift register with a data input connected to receive said mark pulses and a shift input connected to receive said shift register clock pulses whereby a first binary digit value is shifted into said register when both a mark pulse and a corresponding strobe mark pulse occur and a second binary digit value is shifted into said register when only a strobe mark pulse occurs.

9. A device as in claim 8, further comprising:

digital data decoding and display means connected to at least some stages of said shift register for displaying the processed information in a desired format.

10. A device as in claim 9, further comprising:

error detection means connected to at least some stages of said shift register for detecting a predetermined code and for enabling said display means only if said predetermined code is detected and for otherwise resetting said device to automatically restart another processing cycle for said information marks.