Apparatus for recognizing hand printed characters

• US 3,909,785 A
• Filed: 11/12/1973
• Issued: 09/30/1975
• Est. Priority Date: 11/12/1973
• Status: Expired due to Term

• Current Assignee: Joseph A. Howells
• Original Assignee: Joseph A. Howells
• Inventors: Howells, Joseph A.
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/414,700
• Time in Patent Office: 687 Days
• Field of Search: 340/146.3SY,146.3MA,146.3E,146.3J
• US Class Current: 382/187
• CPC Class Codes: G06V 30/347 Sampling; Contour coding; Stroke extraction

Abstract

An apparatus which receives manually formed characters and generates output signals indicative of the characters and their locations. In accordance with the invention there is provided a data surface having a plurality of defined character regions, each region having a plurality of defined sectors. Means are provided for generating digital signals representative of each of a succession of positional coordinates that are traversed when manually entering characters in the character regions. Sector classifying means are responsive to the digital signals for generating a current sector signal which identifies the sector in which the current digital coordinate is located. Memory means are provided for storing a plurality of memory states, each state being representative of a predetermined sequence of sectors which reflect the partial or complete formation of at least one particular character. The memory means are operative in response to the current sector signal as well as to its own previous state for generating state signals which represent its latest state. Means are also provided for indicating the completion of a manually formed character. Finally, output means are responsive to the completion indication for generating character-indicative output signals in accordance with the latest state. In a preferred embodiment of the invention, region classifying means are responsive to the digitial signals for generating a current region signal which identifies the region in which the current digital coordinate is located. In this embodiment, the output means indicates region information as well as character information.

Claims

1. An apparatus which receives manually formed characters and generates output signals indicative of the characters, comprising:

a data surface having a plurality of defined character regions, each region having a plurality of defined sectors;

means for generating digital signals representative of each of a succession of positional coordinates that are traversed when manually entering characters in said character regions;

sector classifying means responsive to said digital signals for generating a current sector signal which identifies the sector in which the current coordinate is located;

memory means for storing a plurality of memory states each of which is representative of an expected predetermined sequence of sectors which reflect the partial or complete formation of at least one particular character, said memory means generating state signals indicative of one of its states;

means for coupling the current sector signal as an input to said memory means;

means for providing the previous output state signals as a further input to said memory means which is operative in response to the current sector signal and to its previous state for generating state signals which represent its latest;

means for indicating the completion of a manually formed character; and

output means responsive to said completion indication for generating the character-indicative output signals in accordance with the latest state.

2. An apparatus as defined by claim 1 further comprising region classifying means responsive to said digital signals for generating a region-indicative signal which identifies the region in which the current coordinate is located.

3. An apparatus as defined by claim 2 wherein said output means is responsive to said completion indication for generating region-indicative signals as well as character-indicative signals.

4. An apparatus as defined by claim 1 wherein said memory means comprises a read-only memory.

5. An apparatus as defined by claim 3 wherein said memory means comprises a read-only memory.

6. An apparatus as defined by claim 1 wherein said memory means is programmed by selecting as the final state for each character the ASCII code digital representation of the character.

7. An apparatus as defined by claim 1 wherein said means for indicating the completion of a manually formed character comprises region change logic circuitry for generating a completion indication each time a new character region is entered.

8. An apparatus as defined by claim 1 further comprising sector change logic circuitry for detecting entry into a new sector and thereupon enabling a change of state of said memory means.

9. An apparatus which receives manually formed characters and generates output signals indicative of the characters, comprising:

a data surface having a plurality of defined character regions, each region having a plurality of defined sectors;

means for generating digital signals representative of each of a succession of positional coordinates that are traversed when manually entering characters in said character regions, said digital signals having most significant bits that represent the current region in which the current coordinate is located and less significant bits that represent the current sector in which the current coordinate is located;

memory means for storing a plurality of memory states, each state being representative of an expected predetermined sequence of sectors which reflect the partial or complete formation of at least one particular character, said memory means being operative in response to the less significant bits and to its previous state for generating state signals which represent its latest state;

means for indicating the completion of a manually formed character; and

output means responsive to said completion indication for generating the character-indicative output signals in accordance with the latest state and region indicative signals in accordance with the most significant bits.

10. An apparatus as defined by claim 9 wherein said memory means is programmed by selecting as the final state for each character the ASCII code digital representation of the character.

11. An apparatus as defined by claim 9 wherein said means for indicating the completion of a manually formed character comprises region change logic circuitry for generating a completion indication each time the most significant bits change.

12. An apparatus as defined by claim 9 further comprising sector change logic circuitry for detecting a change in the less significant bits and thereupon enabling a change of state of said memory means.

13. An apparatus which receives manually formed characters and generates output signals indicative of the characters, comprising:

a data surface having a plurality of defined character regions, each region having a plurality of defined sectors;

means for generating digital signals representative of each of a succession of positional coordinates that are traversed when manually entering characters in said character regions;

sector classifying means responsive to said digital signals for generating a current sector signal whicH identifies the sector in which the current coordinate is located;

region classifying means responsive to said digital signals for generating a region-indicative signal which identifies the region in which the current coordinate is located;

memory means for storing a plurality of memory states, each state being representative of an expected predetermined sequence of sectors which reflect the partial or complete formation of at least one particular character, said memory means being operative in response to the current sector signal and to its previous state for generating state signals which represent its latest state;

means for indicating the completion of a manually formed character; and

output means responsive to said completion indication for generating region-indicative signals and the character-indicative output signals in accordance with the latest state.

14. An apparatus as defined by claim 13 wherein said memory comprises a read-only memory.