Electronic pen device and character recognition method employing the same

• US 6,625,314 B1
• Filed: 09/23/1999
• Issued: 09/23/2003
• Est. Priority Date: 09/25/1998
• Status: Expired due to Term

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Okamoto, Masayoshi
• Primary Examiner(s): Dastouri, Mehrdad
• Application Number:
  US09/401,989
• Time in Patent Office: 1,461 Days
• Field of Search: 382/119, 382/120, 382/121, 382/122, 382/186, 382/187, 382/188, 382/189, 178/18.01, 178/19.01, 738/620.46, 345/173, 455/556
• US Class Current: 382/188
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/03546 using a rotatable ball at the tip as position detecting member
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32

Abstract

An electronic device used to identify loci containing more than one stroke. This electronic device utilizes a ball rotation sensor to detect the position and movement while it is in contact with a surface and an acceleration sensor when the device is not in contact with the surface. Further, this device is able to correct for inaccuracies in the acceleration sensor utilizing data received from the ball rotation sensor. This correction is based on a calculated detection error determined while the ball rotation sensor is active. The correction occurs when the device is again no longer in contact with the surface and again utilizing the acceleration sensor to determine position.

Claims

1. An electronic pen device comprising:

first measuring means for measuring movement loci of a pen point in directions X and Y on the basis of a detection result in a ball rotation sensor detecting rotation of a ball provided on said pen point;

contact state determination means for determining whether said pen point is in a contact state or in a noncontact state with an entry plane;

second measuring means for measuring movement loci of said pen point in said directions X and Y on the basis of acceleration detected by an acceleration sensor;

movement locus operation means for obtaining a contact movement locus of said pen point on the basis of a measurement result in said first measuring means when said contact state determination means determines that said pen point is in said contact state with said entry plane while obtaining a noncontact movement locus of said pen point on the basis of a measurement result in said second measuring means when said contact state determination means determines that said pen point is in said noncontact state with said entry plane;

correction means for correcting said measurement result from said second measuring means when said pen point is in said noncontact state based on a measurement result received from said first measuring means determined when the pen point is in a prior contact state;

a telephone circuit for making communication with the destination of transmission/receiving,

a microphone for inputting a transmission a speaker for outputting a receiving tone, and call control means obtaining a telephone number of the destination of transmission on the basis of a character string recognized, by said character recognition, and

means arid outputting said obtained telephones number to said telephone circuit for allowing said telephone circuit to make a call.

2. The electronic pen device in accordance with claim 1, wherein

said movement locus operation means employs end coordinates of said noncontact movement locus obtained on the basis of a measurement result in said second measuring means in immediately preceding said noncontact state as start coordinates of each, said contact movement locus, and employs end coordinates of said contact movement locus obtained on the, basis of a measurement, result in said first measuring means in immediately preceding said contact state as start coordinates of each said noncontact movement locus.

3. The electronic pen device in accordance with claim 1, wherein

said contact state determination means determines whether said pen point is in said contact state or in said noncontact state with said entry plane on the basis of a measurement result of pressing force applied from said pen point.

4. The electronic pea device in accordance with claim 1, wherein said contact state determination means determines whether said pen point is in said contact state or in said noncontact state with said entry plane on the basis of presence/absence of rotation of said ball detected by said ball rotation sensor and presence/absence of acceleration detected by said acceleration sensor.

5. The electronic pen device in accordance with claim 1, further comprising character recognition means recognizing a character drawn with said pen point on said entry plane on the basis of said contact movement locus for a single character obtained by said movement locus operation means.

11. The electronic pen device in accordance with claim 1, wherein

said contact state determination part determines whether said pen point is in said contact state or in said noncontact state with said entry plane on the basis of presence/absence of rotation of said ball detected by said ball rotation sensor and presence/absence of acceleration detected by said acceleration sensor.

12. The electronic pea device in accordance with claim 1, further comprising a character recognition part recognizing a character drawn with said pen point on said entry plane on the basis of said contact movement locus for a single character obtained by said movement locus operation part.

6. A telephone set employing an electronic pen device, comprising:

first measuring means for measuring movement loci of a pen point in directions X and Y on the basis of a detection result in a ball rotation sensor detecting rotation of a ball provided on said pen point;

contact state determination means for determining whether said pen point is in a contact state or in a noncontact state with an entry plane;

second measuring means for measuring movement loci of said pen point in said directions X and Y on the basis of acceleration detected by an acceleration sensor;

movement locus operation means for obtaining a contact movement locus of said pen point on the basis of a measurement result in said first measuring means when said contact state determination means determines that said pen point is in said contact state with said entry plane while obtaining a noncontact movement locus of said pen point on the basis of a measurement result in said second measuring means when said contact state determination means determines that said pen point is in said noncontact state with said entry plane;

correction means for correcting said measurement result from said second measuring means when said pen point is in said noncontact state based on a measurement result received from said first measuring means determined when the pen point is in a prior contact state;

character recognition for means recognizing a character drawn with said pen point on said entry plane on the basis of said contact movement locus for a single character obtained by said movement locus operation means;

a telephone circuit for making communication with the destination of transmission/receiving;

a microphone for inputting a transmission tone;

a speaker for outputting a receiving tone; and

call control means for obtaining a telephone number of the destination of transmission on the basis of a character string recognized by said character recognition means and outputting said obtained telephone number to said telephone circuit for allowing said telephone circuit to make a call.

7. The telephone set employing an electronic pen device in accordance with claim 6, wherein

said movement locus operation means employs end coordinates of said noncontact movement locus obtained on the basis of a measurement result in said second measuring means in immediately preceding said noncontact state as start coordinates of each said contact movement locus, and employs end coordinates of said contact movement locus obtained on the basis of a measurement result in said first measuring means in immediately preceding said contact state as start coordinates of each said noncontact movement locus.

8. An electronic pen device comprising:

a first measuring part for measuring movement loci of a pen point in directions X and Y on the basis of a detection result in a ball rotation sensor detecting rotation of a ball provided on said pen point;

a contact state determination part determining whether said pen point is in a contact state or in a noncontact state with an entry plane;

a second measuring part for measuring movement loci of said pen point in said directions X and Y on the basis of acceleration detected by an acceleration sensor;

a movement locus operation part for obtaining a contact, movement locus of said pen point on the basis of a measurement result in said first measuring part when said contact state determination part determines that said pen point is in said contact state with said entry plane while obtaining a noncontact movement locus of said pen point on the basis of a measurement result in said second measuring part when said contact state determination part determines that said pen point is in said noncontact state with said entry plane;

correction part for correcting said measurement result from said second measuring part when said pen point is in said noncontact state based on a measurement result received from said first measuring part determined when the pen point is in a prior contact state;

a telephone circuit for making communication with the destination of transmission/receiving,

a microphone for inputting a transmission tone, a speaker for outputting a receiving tone, and a call control part obtaining a telephone number of the destination of transmission on the basis of a character string recognized by said character recognition part and outputting said obtained telephone number to said telephone circuit for allowing said telephone circuit to make a call.

9. The electronic pen device in accordance with claim 8, wherein

said movement locus operation part employs end coordinates of said noncontact movement locus obtained on the basis of a measurement result in said second measuring part in immediately preceding said noncontact state as start coordinates of each said contact movement locus, and employs end coordinates of said contact movement locus obtained on the basis of a measurement result in said first measuring part in immediately preceding said contact state as start coordinates of each said noncontact movement locus.

10. The electronic pen device In accordance with claim 8, wherein

said contact state determination part determines whether said pen point is in said contact state or in said noncontact state with said entry plane on the basis of a measurement result of pressing force applied from said pen point.

13. A telephone set employing an electronic pen device, comprising:

a first measuring part for measuring movement loci of a pen point in directions X and, Y on the basis of a detection result in a ball rotation sensor detecting rotation of a ball provided on said pen point;

a contact, state determination part determining whether said pen point is in a contact state or in a noncontact state with an entry plane;

a second measuring part for measuring movement loci of said pen point in said directions X and Y on the basis of acceleration detected by an acceleration sensor;

a movement locus operation part for obtaining a contact movement locus of said pen point on the basis of a measurement result in said first measuring part when said contact state determination part determines that said pen point is in said contact state with said entry plane while obtaining a noncontact movement locus of said pen point on the basis of a measurement result in said second measuring part when said contact state determination part determines that said pen point is in said noncontact state with said entry plane; and

correction part for correcting said measurement result in said second measuring part when said pen point is in said noncontact state based on a measurement result received from said first measuring part determined when the pen point is in a prior contact state;

a character recognition part recognizing a character drawn with said pen point on said entry plane on the basis of said contact movement locus for a single character obtained by said movement locus operation part;

a telephone circuit for making communication with the destination of transmission/receiving;

a microphone for inputting a transmission tone;

a speaker for outputting a receiving tone; and

a call control part obtaining a telephone number of the destination of transmission on the basis of a character string recognized by said character recognition part arid outputting said obtained telephone number to said telephone circuit for allowing said telephone circuit to make a call.

14. The telephone set employing an electronic pen device in accordance with claim 13, wherein

said movement locus operation part employs end coordinates of said noncontact movement locus obtained on the basis of a measurement result in said second measuring part in immediately preceding said noncontact state as start coordinates of each said contact movement locus, and employs end coordinates of said contact movement locus obtained on the basis of a measurement result in said first measuring part in immediately preceding said contact state as start coordinates of each said noncontact movement locus.