MARK SENSING SYSTEM

• US 3,553,438 A
• Filed: 07/18/1969
• Issued: 01/05/1971
• Est. Priority Date: 07/18/1969
• Status: Expired due to Term

• Current Assignee: George G. Pick, Melvin H. Blitz
• Original Assignee: George G. Pick, Melvin H. Blitz
• Inventors: Blitz, Melvin H., Pick, George G.
• Application Number:
  US04/846,644
• Time in Patent Office: 536 Days
• US Class Current: 235/454
• CPC Class Codes: B65G 47/493 by use of light responsive means
• CPC Class Codes: G06K 2019/06243 concentric-code
• CPC Class Codes: G06K 7/10871 randomly oriented data-fields, code-marks therefore, e.g. concentric circles-code

Abstract

Mark sensing systems for reading a light-reflecting label which includes a plurality of radial data code elements circularly arranged in a predetermined coded format around a bull'"'"''"'"'s eye acquisition target formed from a plurality of concentric ring code elements. In accordance with one embodiment of the invention, an image of the label is derived by a rotating mirror wheel and directed onto an image dissector, and the image is linearly scanned in the image dissector to determine the presence of the label by sensing the image of the acquisition target, and then circularly scanned to derive the data content of the label by sensing the images of the radial data code elements. In other embodiments of the invention, the image of the label is scanned simultaneously in a linear scan pattern and a circular scan pattern or, alternatively, in a cycloidal scan pattern. An allelectronic version of the invention, requiring no rotating mirror wheel, is also disclosed.

Claims

1. A mark sensing system comprising:

a label containing a plurality of discrete code elements arranged in a predetermined coded pattern, said coded pattern including therein a unique coded acquisition target spaced from the remainder of the coded pattern and differing from the remainder of the coded pattern;

first scanning means for scanning a predetermined area through which said label is arranged to pass and operative when the label is present in the predetermined area to scan the label and to derive an image thereof;

second scanning means for receiving the image of the label derived by the first scanning means, said second scanning means being operative to scan the image of the label in a first geometrical scan pattern when the image of the label is received and in response to scanning the image of the unique coded acquisition target portion of the label to produce first electrical signals indicative of the presence of the label in the predetermined area, and also operative in response to a control signal to scan the image of the label in a second geometrical scan pattern differing from the first geometrical scan pattern, said second geometrical scan pattern generally conforming to the physical arrangement of the discrete code element comprising the remainder of the coded pattern, and in response to scanning the image of the remainder of the coded pattern of the label to produce second electrical signals representative thereof;

control means operative in response to the first electrical signals to produce the control signal to cause the second scanning means to scan tHe image of the label in the second geometrical scan pattern and to produce the second electrical signals; and

processing means for decoding the second electrical signals.

2. A mark sensing system in accordance with claim l wherein:

the first scanning means includes a source of light for illuminating the label and a rotating mirror wheel for scanning the label and for receiving light reflected from the label, the reflected light from the label constituting an image of the label; and

the second scanning means includes an image dissector having a tube face for receiving an image of a label from the first scanning means and scan control circuitry for causing the image dissector to scan the image of the label in the first and second geometrical scan patterns.

3. A mark sensing system in accordance with claim 2 wherein:

the acquisition target portion of the coded pattern is a bullseye target, and the remainder of the coded pattern comprises discrete, radial, data-representing code elements arranged in a circular format; and

the scan control circuitry includes means operative to cause a spot to be located on the tube face of the image dissector whereby when an image of a label is swept past the spot by the rotating mirror wheel the image is scanned in a linear scan pattern, the image dissector producing the first electrical signals indicative of the presence of the label in the predetermined area in response to the image of the bullseye acquisition target being scanned, the scan control circuitry further including means operative in response to the control signal from the control means to cause the image dissector to scan the image of the label in a circular scan pattern, the image dissector producing the second electrical signals representative of the data encoded in the label in response to scanning the image of the radial data-representing code elements.

4. A mark sensing system in accordance with claim 2 wherein:

the acquisition target portion of the coded pattern is a bullseye target, and the remainder of the coded pattern comprises discrete, radial, data-representing code elements arranged in a circular format; and

the scan control circuitry includes means operative to cause a spot to be located on the tube face of the image dissector whereby when an image of a label is swept past the spot by the rotating mirror wheel the image is scanned in a linear scan pattern, the image dissector producing the first electrical signals indicative of the presence of the label in the predetermined area in response to the image of the bullseye acquisition target.

5. A mark sensing system in accordance with claim 4 wherein the scan control circuitry comprises:

a gated step generator;

a ramp generator;

said gated step generator and ramp generator being operative in response to the control signal from the control means to generate a gating signal and a ramp signal, respectively;

a source of a sine signal;

a source of a cosine signal;

means for combining the sine signal, the gating signal, and the ramp signal to provide a first deflection signal for the image dissector;

said cosine signal providing a second deflection signal for the image dissector; and

said image dissector being operative in response to the first and second deflection signals to scan the image of the label in the cycloidal scan pattern.

6. A mark sensing system comprising:

a label containing a plurality of discrete code elements arranged in a predetermined coded pattern, said pattern including therein a unique coded acquisition target portion spaced from the remainder of the coded pattern and differing from the remainder of the coded pattern;

scanning means for scanning a predetermined area through which said label is arranged to pass, said scanning means being operative when the label is present in the predetermined area to scan the label in a first geometrical scan pattern and in response to scanning the unique coDed acquisition target portion of the label to produce first electrical signals indicative of the presence of the label in the predetermined area, and also operative in response to a control signal to scan the label in a second geometrical scan pattern differing from the first geometrical scan pattern, said second geometrical scan pattern generally conforming to the physical arrangement of the discrete code elements comprising the remainder of the coded pattern, and in response to scanning the remainder of the coded pattern of the label to produce second electrical signals representative thereof;

control means operative in response to the first electrical signals to produce the control signal to cause the scanning means to scan the label in the second geometrical scan pattern and to produce the second electrical signals; and

processing means for decoding the second electrical signals.

7. A mark sensing system in accordance with claim 6 wherein:

the scanning means includes a source of light for illuminating the label, an image dissector having a tube face for receiving light reflected from the label, the reflected light constituting an image of the label, and scan control circuitry operative to cause the image dissector to scan the image of the label in the first and second geometrical scan patterns.

8. A mark sensing system in accordance with claim 7 wherein:

the remainder of the coded pattern comprises discrete, radial, data-representing code elements arranged in a circular format; and

the scan control circuitry includes means operative when an image of a label is received by the image dissector to cause the image dissector to scan the image in a linear scan pattern, the image dissector producing the first electrical signals indicative of the presence of the label in the predetermined area in response to scanning the image of the bullseye acquisition target, the scan control circuitry further including means operative in response to the control signal from the control means to cause the image dissector to scan the image in a circular scan pattern, the image dissector producing the second electrical signals representative of the data encoded in the label in response to scanning the image of the radial data-representing code elements.