Multiple pen stroke character set and handwriting recognition system with immediate response

• US 6,493,464 B1
• Filed: 09/08/1997
• Issued: 12/10/2002
• Est. Priority Date: 07/01/1994
• Status: Expired due to Term

• Current Assignee: Access Company Limited
• Original Assignee: Palm, Inc. (TCL Technology Group Corp.)
• Inventors: Hawkins, Jeffrey Charles, Sipher, Joseph Kahn, Marianetti, Ron II
• Primary Examiner(s): CHANG, JON CARLTON
• Application Number:
  US08/925,563
• Time in Patent Office: 1,919 Days
• Field of Search: 382/187, 382/315, 382/182, 382/229, 382/185, 382/188, 382/227, 382/189, 382/311
• US Class Current: 382/189
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/262 using context analysis, e.g. lexical, syntactic or semantic context
• CPC Class Codes: G06V 30/373 using a special pattern or subpattern alphabet

Abstract

A pen-based computer text input system capable of interpreting a special pre-defined set of single stroke glyphs. Each input stroke is identified with one of three categories: (1) pre-character modifier strokes, (2) character or symbol strokes, or (3) post-character modifier strokes. Pre-character modifier strokes precede character strokes and inform the present recognition system that a subsequently entered character stroke is to be modified by the pre-character modifier stroke in a pre-defined manner. Character strokes cause a character or symbol to be displayed on the display device the moment it is input on the writing tablet, interpreted in accordance with any pre-character modifier stroke. A post-character modifier stroke causes the recognition system to modify, in a pre-defined manner, a character or symbol which was previously entered and displayed. An important advantage of the present invention is its ability to provide immediate recognition of multiple stroke characters without using boxed input.

Claims

1. An electronic handwriting recognition system for interpreting input strokes and displaying corresponding characters, the system having an input writing surface, a pen device for inputting strokes on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with such input writing surface, and a display for displaying characters, the system comprising:

(a) stroke recognition logic for recognizing each individual input stroke after input and assigning each recognized stroke to a corresponding glyph, each glyph being a member of one of a plurality of sets of glyphs, and each glyph being formed by only a single stroke, the sets comprising at least;

(1) a set of character glyphs;

(2) a set of post-character modifier glyphs;

(b) processing logic, coupled to the stroke recognition logic, for;

(1) outputting to the display a first character corresponding to the character glyph to which an initial input stroke is assigned, in response to recognizing the initial input stroke; and

(2) outputting to the display a second character to replace the first character, the second character being uniquely defined by the combination of the first character and the post-character modifier glyph to which a next recognized input stroke is assigned, the second character being outputted in response to the next input stroke being recognized.

7. The invention of claims 1 or 2, wherein the stroke recognition logic and processing logic are embodied in a pen-based portable computer.

2. An electronic handwriting recognition system for interpreting input strokes and displaying corresponding characters, the system having an input writing surface, a pen device for inputting strokes on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with such input writing surface, and a display for displaying characters, the system comprising:

(a) stroke recognition logic for recognizing each individual input stroke after input and assigning each recognized stroke to a corresponding glyph, each glyph being a member of one of a plurality of sets of glyphs, and each glyph being formed by only a single stroke, the sets comprising at least;

(1) a set of pre-character modifier glyphs;

(2) a set of character glyphs;

(3) a set of post-character modifier glyphs;

(b) processing logic, coupled to the stroke recognition logic, for;

(1) outputting to the display a temporary indication of recognition of the pre-character modifier glyph to which an initial input stroke is assigned, in response to the initial input stroke being recognized;

(2) outputting to the display a first character corresponding to the combination of the character glyph to which a next input stroke is assigned and the pre-character modifier glyph, the first character being displayed in response to the next input stroke being recognized; and

(3) outputting to the display a second character to replace the first character, the second character being uniquely defined by the combination of the first character and the post-character modifier glyph to which a second next input stroke is assigned, the second character being displayed in response to the second next input stroke being recognized.

8. The invention of claim 2, wherein the processing logic removes the temporary indication of recognition in response to outputting the character.

3. An automated method for interpreting input strokes and displaying corresponding characters on an electronic handwriting recognition system, the system comprising an input writing surface, a display for displaying characters, and a pen device for inputting strokes on the input writing surface, wherein each stroke comprises a single continuous movement of the pen device while in contact with the input writing surface, the method including the steps of:

(a) recognizing each individual input stroke after input !and assigning each recognized stroke to a corresponding glyph, each glyph being a member of one of a plurality of sets of glyphs that are formed by Only a single stroke, the sets comprising at least;

(1) a set of character glyphs,;

(2) a set of post-character modifier glyphs;

(b) in response to receiving a first input stroke, initially outputting to the display a first character corresponding to the character glyph to which the first input stroke is assigned; and

(c) in response to receiving a second input stroke subsequent to the first input stroke, outputting to the display a second character by recognizing the combination of the displayed character and the post-character modifier glyph to which the second input stroke is assigned.

4. An automated method for interpreting input strokes and displaying corresponding characters on an electronic handwriting recognition system, the system comprising an input writing surface, a display for displaying characters, and a pen device for inputting strokes on the input writing surface, wherein each stroke comprises a single continuous movement of the pen device while in contact with such input writing surface, the method including the steps of:

(a) recognizing each individual input stoke after input and assigning each recognized stroke to a corresponding glyph, each glyph being a member of one of a plurality of sets of glyphs that are formed by only a single stroke, the sets comprising at least;

(1) a set of pre-character modifier glyphs;

(2) a set of character glyphs;

(3) a set of post-character modifier glyphs;

(b) outputting to the displays temporary indication of recognition of the pre-character modifier glyph to which an initial input stroke is assigned;

(c) in response to receiving a next input stroke, outputting to the display a character corresponding to the combination of the character glyph to which the next input stroke and the pre-character modifier glyph are assigned; and

(d) in response to receiving another input stroke subsequent to the next input stroke, outputting to the display a second character to replace-the first character, the second character being uniquely defined by the combination of the first character and the post-character modifier glyph to which the other input stroke is assigned.

9. The invention of claim 4, further including the step of removing the temporary indication of recognition in response to outputting of the first character.

5. A computer program, residing on a computer-readable medium readable by a computer having an input writing surface and a display, for recognizing handwritten strokes of a pen device on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with the input writing surface, and displaying characters as a result of such recognition on a display, the computer program including instructions for causing the computer to:

(a) recognize each individual input stroke after input and assign each recognized stroke to a corresponding glyph, each glyph being a member of one of a plurality of sets of glyphs that are formed by only a single stroke, the sets comprising at least;

(1) a set of character glyphs;

(2) a set of post-character modifier glyphs;

(b) in response to receiving a first input stroke, initially output to the display a first character corresponding to the character glyph to which the first input stroke is assigned; and

(c) in response to receiving a second input stroke subsequent to the first input stroke, output to the display a second character by recognizing the combination of the displayed character and the post-character modifier glyph to which the second input stroke is assigned.

6. A computer program, residing on a computer-readable medium readable by a computer having an input writing surface and a display, for recognizing handwritten strokes of a pen device on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with the input writing surface, and displaying characters as a result of such recognition on a display, the computer program including instructions for causing the computer to:

(a) recognize each individual input stroke after input and assign each recognized stroke to a corresponding glyph, each glyph being a member of one of a plurality of sets of glyphs that are formed by only a single stroke, the sets comprising at least;

(1) a set of pre-character modifier glyphs;

(2) a set of character glyphs;

(3) a set of post-character modifier glyphs;

(b) output to the display a temporary indication of recognition of the pre-character modifier glyph to which an initial input stroke is assigned;

(c) in response to receiving a next input stroke, output to the display a first character corresponding to the combination of the character glyph to which the next input stoke and the pre-character modifier glyph are assigned; and

(d) in response to receiving another input stroke subsequent to the next input stroke, output to the display a second character to replace the first character, the second character being uniquely defined by the combination of the first character and the post-character modifier glyph to which the other input stroke is assigned.

10. The invention of claim 6, further including instructions for causing such computer to remove the temporary indication of recognition in response to output of the first character.

11. An electronic handwriting recognition system for interpreting input strokes and displaying corresponding characters, the system having an input writing surface, a pen device for inputting strokes on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with such input writing surface, and a display for displaying characters, the system including:

(a) input recognition logic for;

(1) recognizing a first input stroke and assigning the first input stroke to a corresponding glyph, the glyph being a member of a set of character glyphs; and

(2) recognizing a second input stroke immediately after the first input stroke and assigning the second input stroke to a corresponding glyph, the glyph being a selected post-character modifier glyph in a set of post-character modifier glyphs;

(b) processing logic, coupled to the input recognition logic, for;

(1) displaying a first character on the display corresponding to the character glyph to which the first input stroke is assigned; and

(2) displaying a second character corresponding to-the combination of the first character and the selected post-character modifier glyph.

12. An electronic handwriting recognition system for interpreting input strokes and displaying corresponding characters, the system having an input writing surface, a pen device for inputting strokes on the input wilting surface, each stroke comprising a single continuous movement of the pen device while in contact wit such input writing surface, and a display for displaying characters, the system including:

(a) input recognition logic for;

(1) recognizing a first input stroke and assigning the first input stroke to a corresponding glyph, the glyph being a member of a set of pre-character modifier glyphs;

(2) recognizing a second input stroke and assigning the second input stroke to a corresponding glyph, the glyph being a member of a set of character glyphs; and

(3) recognizing a third input stroke immediately after the second input stroke and assigning the third input stroke to a corresponding glyph, the glyph being a member of a set of post-character modifier glyphs;

(b) processing logic, coupled to the input recognition logic, for;

(1) outputting to the display a temporary indication of recognition of the pre-character modifier glyph to which the first input stroke is assigned;

(2) displaying a first character on the display corresponding to a combination of the character glyph to which the second input stroke and the pre-character modifier glyph are assigned; and

(3) displaying a second character to replace the first character, the second character corresponding to the combination of the first character and the post-character modifier glyph.

13. An automated method for interpreting input strokes and displaying corresponding characters on an electronic handwriting recognition system, the system including an input writing surface, a pen device for inputting strokes on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with such input writing surface, and a display for displaying characters, the method comprising the steps of:

(a) recognizing a first input stroke and assigning the first input stroke to a corresponding glyph, the glyph being a member of a set of character glyphs;

(b) displaying a character on the display corresponding to the character glyph to which the first input stroke is assigned;

(c) recognizing a second input stroke immediately after the first input stoke and assigning the second input stroke to a corresponding glyph, the glyph being a member of a set of post-character modifier glyphs; and

(d) in response to recognizing the second input stroke, immediately displaying a second character to replace the first character, the second character corresponding to the combination of the displayed character and the post-character modifier glyph.

14. An automated method for interpreting input strokes and displaying corresponding characters on an electronic handwriting recognition system, the system including an input writing surface, a pen device for inputting strokes on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with such input writing surface, and a display for displaying characters, the method comprising the steps of:

(a) recognizing a first input stroke and assigning the first input stroke to a corresponding glyph, the glyph being a member of a set of pre-character modifier glyphs;

(b) outputting to the display a temporary indication of recognition of the pre-character modifier glyph to which the first input stroke is assigned;

(c) recognizing a second input stroke and assigning the second input stroke to a corresponding glyph, the glyph being a member of a set of character glyphs;

(d) displaying a character on the display corresponding to the combination of the character glyph to which the second input stroke is assigned and such pre-character modifier glyph;

(e) recognizing a third input stroke immediately after the second input stroke and assigning the third input stroke to a corresponding glyph, the glyph being a member of a set of post-character modifier glyphs; and

(f) in response to recognizing the second input stroke, immediately displaying a second character to replace the first character, the second character corresponding to the combination of the displayed character and the post-character modifier glyph.

15. A computer program, residing on a computer-readable medium readable by a computer having an input writing surface and a display, for recognizing handwritten strokes of a pen device on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with the input writing surface, and displaying characters as a result of such recognition on a display, including instructions for causing such a computer to:

(a) recognize a first input stroke and assigning the first input stroke to a corresponding glyph, the glyph being a member of a set of character glyphs;

(b) display a character on the display corresponding to the character glyph to which the first input stroke is assigned;

(c) recognize a second input stroke immediately after the first input stroke and assigning the second input stroke to a corresponding glyph, the glyph being a member of a set of post-character modifier glyphs; and

(d) immediately display a second character to replace the first character in response to the second input stroke being recognized, the second character corresponding to the combination of the displayed character and the post-character modifier glyph.

16. A computer program, residing on a computer-readable medium readable by a computer having an input writing surface and a display, for recognizing handwritten strokes of a pen device on the input writing surface, each stroke comprising a single continuous movement of the pen device while in contact with the input writing surface, and displaying characters as a result of such recognition on a display, including instructions for causing such a computer to:

(a) recognize a first input stroke and assigning the first input stroke to a corresponding glyph, the glyph being a member of a set of pre-character modifier glyphs;

(b) output to the display a temporary indication of recognition of the pre-character modifier glyph to which the first input stroke is assigned;

(c) recognize a second input stroke and assigning the second input stoke to a corresponding glyph, the glyph being a member of a set of character glyphs;

(d) display a character on the display corresponding to the combination of the character glyph to which the second input stroke is assigned and such pre-character modifier glyph;

(e) recognize a third input stroke immediately after the second input stroke and assigning the third input stroke to a corresponding glyph, the glyph being a member of a set of post-character modifier glyphs; and

(f) in response to recognizing the third input stroke, immediately displaying a second character to replace the first character, the second character corresponding to the combination of the displayed character and the post-character modifier glyph.

17. A pen based computer comprising:

a memory to store data that references each character in a set of Roman alphabet characters to a corresponding glyph in a set of glyphs, at least a majority of the glyphs in the set of glyphs being individually formed by a single stroke, the set of glyphs as a whole having a graphical appearance that substantially resembles the Roman alphabet characters;

an interactive screen; and

a processor coupled to the memory, the processor being configured to detect a series of strokes caused by contact with the interactive screen, wherein in response to detecting individual strokes in the series of strokes, the processor is configured to;

identify at least one of the strokes as corresponding to one of the glyphs in the set of glyphs; and

for at least the majority of glyphs individually formed by a single stroke, immediately display on the interactive screen the Roman alphabet character that is referenced by the glyph corresponding to the identified stroke in response to detecting completion of that stroke;

wherein the memory is configured to store a data structure that references a set of multi-stroke characters to a combination of glyphs that include a set of post-modifier glyphs, and wherein in response to detecting the series of strokes, the processor is configured to;

identify at least one of the strokes in the series of strokes as corresponding to one of glyphs in the set of post-modifier glyphs; and

in response to completion of the stroke identified as corresponding to one of the glyphs in the set of post-modifier glyphs, immediately replace on the interactive screen a Roman alphabet character with a new character, the Roman alphabet character being referenced in the memory by a previous glyph corresponding to a previously identified stroke in the series of strokes, the new character being referenced in the memory by a combination of the previous glyph and the post-modifier glyph.

18. A pen based computer comprising:

a memory to store data that references each character in a set of Roman alphabet characters to a corresponding glyph in a set of glyphs, at least a majority of the glyphs in the set of glyphs being individually formed by a single stroke, the set of glyphs as a whole having a graphical appearance that substantially resembles the Roman alphabet characters;

an interactive screen; and

a processor coupled to the memory, the processor being configured to detect a series of strokes caused by contact with the interactive screen, wherein in response to detecting individual strokes in the series of strokes, the processor is configured to;

identify at least one of the strokes as corresponding to one of the glyphs in the set of glyphs; and

for at least the majority of glyphs individually formed by a single stroke, immediately display on the interactive screen the Roman alphabet character that is referenced by the glyph corresponding to the identified stroke in response to detecting completion of that stroke;

wherein the memory is configured to store the data structure that references upper case Roman alphabet characters to a combination of glyphs that include a set of pre-modifier glyphs, and wherein in response to detecting the series of strokes, the processor is configured to;

identify at least one of the strokes in the series of strokes as corresponding to one of the glyphs in-the set of pre-modifier glyphs; and

in response to completion of a subsequent stroke to the stroke identified as corresponding to one of the glyphs in the set of pre-modifier glyphs, immediately display on the interactive screen the upper case Roman alphabet character that is referenced by the combination of the pre-modifier glyph and the subsequent glyph.

19. The pen based computer of claim 18, wherein a majority of the glyphs in the set of glyphs have a shape that is different from the shape of all of the other glyphs in the set of glyphs.