Hand-held scan data handling system

• US 3,964,022 A
• Filed: 04/18/1975
• Issued: 06/15/1976
• Est. Priority Date: 01/07/1974
• Status: Expired due to Term

• Current Assignee: Recognition International, Inc. (BancTec Incorporated)
• Original Assignee: Recognition Equipment Incorporated
• Inventors: Martin, Charles E.
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/569,692
• Time in Patent Office: 424 Days
• Field of Search: 340/146.3 SY, 340/146.3 H, 340/146.3 AC, 340/146.3 Z, 340/146.3 J, 340/146.3 R, 235/61.11 E
• US Class Current: 382/292
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06K 2207/1018 Source control
• CPC Class Codes: G06K 7/01 Details
• CPC Class Codes: G06K 7/10 by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
• CPC Class Codes: G06K 7/10851 Circuits for pulse shaping, amplifying, eliminating noise signals, checking the function of the sensing device basic electronic circuitry H03
• CPC Class Codes: G06K 7/10881 constructional details of hand-held scanners
• CPC Class Codes: G06V 10/10 Image acquisition document image scanning and transmission H04N1/00; control of digital cameras H04N23/60
• CPC Class Codes: G06V 10/12 Details of acquisition arrangements; Constructional details thereof
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 10/20 Image preprocessing
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image
• CPC Class Codes: G06V 10/28 Quantising the image, e.g. histogram thresholding for discrimination between background and foreground patterns
• CPC Class Codes: G06V 10/7515 Shifting the patterns to accommodate for positional errors
• CPC Class Codes: G06V 10/98 Detection or correction of errors, e.g. by rescanning the pattern or by human intervention; Evaluation of the quality of the acquired patterns
• CPC Class Codes: G06V 30/142 using hand-held instruments; Constructional details of the instruments
• CPC Class Codes: G06V 30/224 of printed characters having additional code marks or containing code marks
• CPC Class Codes: G11B 15/10 Manually-operated control; Solenoid-operated control G11B15/44 takes precedence
• CPC Class Codes: G11B 15/1883 for record carriers inside containers
• CPC Class Codes: G11B 15/29 through pinch-rollers or tape rollsG11B15/295 takes precedence

Abstract

Optically reading and processing alphanumeric data using a hand-held wand by passing a two-dimensional array of photosensitive elements horizontally along a line of data to be read. An optical image of the data is focused upon the array to produce digitized outputs which are thresholded to produce a one bit binary code indicating black cells and white cells. A subset of the binary quantities are combined in terms of black segments and white voids to form a plurality of character images while simulating vertical movement of the subset with character recognition attempted upon each simulated increment of vertical movement.

Claims

1. A method for optically reading and automatically processing alphanumeric data utilizing a hand-held wand, which comprises the steps of:

passing a two-dimensional array of photosensitive elements horizontally along a line of data to be read,

focusing an optical image of the data upon said array,

digitizing the output signals produced by said array,

thresholding said digitized outputs to produce a 1 bit binary code indicating black data cells and white data cells,

storing said binary codes in registers to form a plurality of character images,

shifting the binary codes in the register to simulate vertical movement of said array relative to the line,

combining the binary codes indicating black cells the binary codes indicating white cells to provide an identification of the presence of a character image along the line, and

processing the character images for character recognition at intervals related to the time required for movement of the array a preset distance along the line for each simulated increment of vertical movement.

2. The method for optically reading as set forth in claim 1 including the step of establishing a predetermined restraint condition for inhibiting plural output indications from any character the image of which is captured.

3. An optical character recognition system utilizing a hand-held wand for optically reading alphanumeric characters on a character field and automatically processing and transmitting the data to receiver and/or display devices, which comprises:

a two-dimensional photo sensor array of height in cells greater than the array width in cells to produce optical images of each character as a set of electrical signals during horizontal relative movement between said wand and said field,

means responsive to the electrical signals to produce one bit binary codes representing an image,

means for storing the one bit binary codes as character segments and background segments,

a blanking circuit means to inhibit multiple loading of a single character into said means for storing upon operating of the hand-held wand at a high frame rate and a low hand-swept velocity, and

a line tracker circuit to sense vertical positioning of a character image on said array and to separate character strings which correspond with multiple lines of characters in the field of view of said sensor.

4. A hand-held operated character recognition system as set forth in claim 3 including a character string and storage analysis circuit to analyze nonnumeric characters in a character string to thereby accommodate sensing multiple data field.

5. The combination as set forth in claim 4 wherein said blanking circuit includes a down counter which is reset to a constant k whenever a character is recognized, where K corresponds to frames searched with no character being recognized.

6. The combination as set forth in claim 5 wherein a character is loaded into said character string and storage analysis circuit when the down counter identified with said circuit is in a zero count state.

7. The combination as set forth in claim 4 wherein:

said character string and storage analysis circuit includes a plurality of character string storage registers, and

said line tracker circuit means includes a counter and logic unit which provides a binary number VC corresponding to the vertical position of the character in the field of view, and includes means to identify each of said plurality of character string storage registers by binary number VN corresponding to the vertical positioning of the last character detected for that string, and includes means for determining whether a detected character is to be added to a given string by determining whether VN - VC is less than approximately one-half of the height of a character.

8. The combination as set forth in claim 3 including a counter for counting the number of characters recognized during one sweep across said field.

9. The combination as set forth in claim 3 including means for limit recognition of only a predetermined number of characters in a given sweep across said field.

10. The combination as set forth in claim 3 including means for establishing a time interval within which to recognize the first character during a given sweep across said field.

11. The combination as set forth in claim 3 including means responsive to the end of an initiated time interval to evaluate special character and character count acceptability to indicate success of a given sweep across said field.

12. The combination as set forth in claim 3 including means for setting a delay time and wherein a period exceeding the delay time without a character recognition occurring indicates the end of a character field.

13. An optical character recognition system utilizing a hand-held wand for optically reading alphanumeric characters on a character field and automatically processing and transmitting the data to receiver and/or display devices, which comprises:

a two dimensional optical sensor in said hand-held wand to produce optical images of each said character as a set of electrical signals indicating black cells and white cells in said field during horizontal relative movement between said wand and said field,

means responsive to the electrical signals to produce one bit binary codes indicating black cells and white cells in said field,

means for storing the black cell and white cell binary codes,

means for shifting the codes in said means for storing to simulate vertical movement of the wand relative to the field,

means for processing the black cell codes and the white cell codes to provide an identification of the presence of a character image in the field, and

means for attempting an identification of a character image between the shifting of the binary codes in said means for storing from a plurality of black cell codes and a plurality of white cell codes, the interval between each attempt of identification being related to the time required for the movement of said sensor a preset distance in said field.

14. The system of claim 13 including a counter for counting the number of characters recognized during one sweep across said field.

15. The system of claim 13 including means to limit recognition of only a predetermined number of characters in a given sweep across said field.

16. The system of claim 13 wherein display or transmission means respond to said means for identification to display in real time characters in said field.

17. The system of claim 16 wherein said display or transmission means is disabled unless a predetermined key symbol is recognized at a predetermined location in said field.

18. The combination as set forth in claim 13 including means for establishing a time interval within which to recognize the first character during a given sweep across said field.

19. The combination as set forth in claim 18 including means responsive to the end of an initiated time interval to evaluate special character and character count acceptability to indicate success of a given sweep across said field.

20. The combination as set forth in claim 13 including means for setting a delay time and wherein a period exceeding the delay time without a character recognition occurring indicates the end of a character field.

27. A hand operated optical character recognition system as set forth in claim 19 wherein a two-dimensional array of photosensitive diodes in said sensor is operated at a frame rate sufficiently high to preclude passage of a character past the field of view without the character being centered within the tolerance of the said system during at least one frame thereby to accommodate variable sweep velocity, variable character pitch and unknown direction of sweep and including:

a blanking circuit means to inhibit multiple loading of a single character in said means for storing upon operating at a high frame rate and at low hand-swept velocity,

a character string and storage analysis circuit means to analyze nonnumeric characters in a character string thereby to accommodate sensing multiple data fields, and

a line tracker circuit means to sense vertical positioning of a character image on said array and to separate character strings which correspond with multiple lines of characters in the field of view of said sensor.

28. The combination as set forth in claim 27 wherein said blanking circuit includes a down counter which is reset to a constant K whenever a character is recognized, where K corresponds to frames searched with no character being recognized.

29. The combination of claim 27 wherein K is about 14.

30. The combination set forth in claim 27 wherein:

said character string and storage analysis circuit means includes a plurality of character string storage registers, and

said line tracker circuit means includes a counter and logic unit which provides a binary number V_c corresponding to the vertical position of the character in the field of view, and includes means to identify each of said plurality of character string storage registers by binary number V_n corresponding to the vertical positioning of the last character detected for that string, and includes means to determine whether a detected character is to be added to a given string by determining whether |V_n - V_c | is less than approximately one-half of the height of a character.

31. The combination as set forth in claim 27 including means for setting a specific time interval to be initiated upon recognition of the first character, and the expiration of said time interval constituting a decision that the scanning operation is complete.

32. The combination as set forth in claim 27 including means for setting a specific time interval to be initiated or reinitiated upon recognition of any character, and the expiration of said interval constituting a decision that the scanning operation is complete.

21. An optical character recognition system utilizing a hand-held wand for optically reading alphanumeric characters on a character field and automatically processing and transmitting the data to receiver and/or display devices, which comprises:

a two dimensional optical sensor in said hand-held wand to produce optical images of each said character as a set of electrical signals indicating black cells and white cells in said field during horizontal relative movement between said wand and said field,

means responsive to the electrical signals to produce one bit binary codes indicating black cells and white cells in said field,

means for storing the black cell and white cell binary codes as black character segments and void segments,

means for shifting the codes in said means for storing to simulate vertical movement of the wand relative to the field,

means for combining the black segments and the void segments to provide an identification of the presence of a character image in the field, and

means for attempting an identification of a character image between the shifting of the binary codes in said means for storing from a plurality of black segments and void segments, the interval between each attempt of identification being related to the time required for the movement of said sensor a preset distance in said field.

22. The combination set forth in claim 21 in which said sensor is an LS1 photosensing array.

23. The optical character recognition system as set forth in claim 21 wherein:

said optical sensor is a two-dimensional array of photosensitive diodes, and

said means for storing includes an array of nine serial-input-parallel-output registers of which one is 8 bits wide and 1 bit high while the other eight are 1 bit wide and 16 bits high to simulate the apparent vertical movement of said character image through said array in one cell height increments, and thereby accommodate vertical character misregistration between said sensor and characters in said field.

24. The combination set forth in claim 21 in which means are provided to enable system output utilization of signals from said means for identification only after K consecutive attempts in which no character recognition has occurred.

25. The combination as set forth in claim 21 wherein said means for combing said black segments and void segments includes logical OR circuits responsive to preset patterns of black segments or void segments.

26. The combination set forth in claim 21 in which said patterns comprise horizontal rows or vertical columns corresponding to subsets of said binary codes and wherein members in said horizontal rows or vertical columns are logically ORed to accommodate variations in angle, perspective and field depth during said movement across said field.

33. The system of claim 21 including a counter for counting the number of characters recognized during one sweep across said field.

34. The system of claim 21 including means to limit recognition of only a predetermined number of characters in a given sweep across said field.

35. The system of claim 21 wherein display or transmission means responds to said means for identification to display in real time characters in said field.

36. The system of claim 35 wherein said display or transmission means is disabled unless a predetermined key symbol is recognized at a predetermined location in said field.