Handwriting communication system and handwriting input device used therein

• US 6,567,078 B2
• Filed: 01/08/2001
• Issued: 05/20/2003
• Est. Priority Date: 01/25/2000
• Status: Expired due to Fees

• Current Assignee: Xiroku, Inc.
• Original Assignee: Xiroku, Inc.
• Inventors: Ogawa, Yasuji
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): BELL, PAUL A
• Application Number:
  US09/757,727
• Publication Number:
  US 20010050669A1
• Time in Patent Office: 862 Days
• Field of Search: 345/156, 345/173, 345/175, 345/179, 345/764, 345/863, 382/103, 382/186, 382/187, 382/188, 382/189, 382/291, 382/313, 382/314, 382/315, 178/18.03, 178/19.01, 178/20.01, 700/83
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

The present invention relates to a handwriting communication system, a handwriting input device and a handwriting display device used in the system, which can communicate by handwriting among a plurality of computers connected via a network. The communication system includes a handwriting input device which is provided at a transmitting side for inputting the handwriting into a transmitting side computer, and a handwriting display device which is provided at a receiving side for displaying the handwriting based on information transmitted from the transmitting side to a receiving side computer. The present system according to the invention transmits only a contiguous image around the handwritten portion, which reduces the communication volume compared to transmitting the whole image, and which makes the real time transmission and reception of handwriting trace possible.

Claims

1. A handwriting communication system for transmitting and receiving a handwriting by using a plurality of computers, which are connected via a network, said system comprising:

a handwriting input device provided at a transmitting side for inputting a handwriting into a transmitting side computer; and

a handwriting display device provided at a receiving side for displaying said handwriting based on information transmitted from said transmitting side computer to a receiving side computer via said network;

said handwriting input device comprising;

a trace display means for trace information to be written in;

an input means to write said handwriting, to erase said handwriting, or to point out said handwriting on said trace display means;

an image taking means to take a whole image of said trace display means from above;

a position detecting means to detect a pointed position when said input means is placed on said trace display means; and

an image processing means to extract a contiguous image of said pointed position of said input means detected by said position detecting means from said whole image taken by said image taking means;

said handwriting display device comprising;

an image reconstruction means to reconstruct an image based on said contiguous image information extracted by said image processing means, and said pointed position detected by said position detecting means; and

a handwriting display means to store and display the reconstructed image on a display screen,

said position detecting means comprising a retroreflective material which is provided at a tip of said input means, and a light source which is provided adjacent to said image taking means for irradiating said input means;

said position detecting means detecting said pointed position of said input means which is placed on said trace display means by detecting a position of said retroreflective material based on a difference in brightness in said whole image taken by said image taking means.

2. The handwriting communication system as claimed in claim 1, wherein said retroreflective material provided at said tip of said input means, is placed at least at two locations with a space therebetween, said image processing means detecting a direction of said input means from a shape of said retroreflective material taken by said image taking means, and removing an image of said input means from the extracted contiguous image based on said direction of the detected input means.

3. The handwriting communication system as claimed in claim 1, wherein said retroreflective material provided at said tip of said input means, is placed in such a manner as to be reflected to said image taking means as a narrow and long image, said image processing means detecting a direction of said input means from a shape of said retroreflective material taken by said image taking means, and removing an image of said input means from the extracted contiguous image based on said direction of the detected input means.

4. The handwriting communication system as claimed in claim 1, wherein said retroreflective material has one of a shape which is determined in accordance with a kind of said input means, and a shape which is changed in accordance with an operation of an operator, and said image processing means changes sizes of said contiguous image extracted in accordance with said shape.

5. The handwriting communication system as claimed in claim 1, wherein said retroreflective material is equipped with a colored filter in front thereof, said light source emits by switching a plurality of colors of light, and said image processing means recognizes kinds of said input means by detecting reflected light from said retroreflective material.

6. The handwriting communication system as claimed in claim 1, wherein said retroreflective material is equipped with a colored filter in front thereof, said image taking means detects a plurality of colors of light, and said image processing means recognizes kinds of said input means by detecting reflected light from said retroreflective material.

7. The handwriting communication system as claimed in claim 1, wherein said image processing means removes a fourth quadrant portion of said extracted contiguous image.

8. The handwriting communication system as claimed in claim 1, wherein said receiving side computer removes a fourth quadrant portion of said extracted contiguous image.

9. The handwriting communication system as claimed in claim 1, wherein said image reconstruction means has a display memory corresponding to said display screen, and generates an address from said pointed position and data from said contiguous image, thereby storing and displaying on said display screen said trace information on said trace display means by writing said data into said address of said display memory.

10. The handwriting communication system as claimed in claim 1, wherein said image taking means is positioned above an upper left corner of said trace display means for a right-handed operator, or an upper right corner of said trace display means for a left-handed operator.

11. The handwriting communication system as claimed in claim 1, wherein said image processing means is provided in said transmitting side computer.

12. A handwriting input device for transmitting a handwriting by using a computer which is connected via a network, said handwriting input device comprising:

a trace display means for trace information to be written in;

an input means to write, to erase a handwriting, or to point out a handwriting on said trace display means;

an image taking means to take from above a whole image of said trace display means;

a position detecting means to detect a pointed position when said input means is placed on said trace display means;

an image processing means to extract a contiguous image of said pointed position of said input means detected by said position detecting means from said whole image taken by said image taking means,

said position detecting means comprising a retroreflective material which is provided at a tip of said input means, and a light source which is provided adjacent to said image taking means for irradiating said input means;

said position detecting means detecting said pointed position of said input means which is placed on said trace display means by detecting a position of said retroreflective material based on a difference in brightness in said whole image taken by said image taking means.

13. The handwriting input device as claimed in claim 12, wherein said retroreflective material provided at said tip of said input means is placed at least at two locations with a space therebetween, said image processing means detecting a direction of said input device from a shape of said retroreflective material taken by said image taking means, and one of said image processing means, the transmitting side computer and the receiving side computer removing an image of said input means from the extracted contiguous image based on said direction of the detected input means.

14. The handwriting input device as claimed in claim 12, wherein said retroreflective material provided at said tip of said input means is placed in such a manner as to be taken by said image taking means as a narrow and long image, said image processing means detecting a direction of said input device from a shape of said retroreflective material taken by said image taking means, and one of said image processing means, the transmitting side computer and the receiving side computer removing an image of said input means from the extracted contiguous image based on said direction of the detected input means.

15. The handwriting input device as claimed in claim 12, wherein said retroreflective material has one of a shape which is determined in accordance with a kind of said input means, and a shape which is changed in accordance with an operation of an operator, and said image processing means changes sizes of said contiguous image to be extracted in accordance with said shape.

16. The handwriting input device as claimed in claim 12, wherein said retroreflective material is equipped with a colored filter in front thereof, said light source emits by switching a plurality of colors of light, and said image processing means recognizes kinds of said input means by detecting reflecting light from said retroreflective material.

17. The handwriting input device as claimed in claim 12, wherein said retroreflective material is equipped with a colored filter in front thereof, said image taking means detects a plurality of colors of light, and said image processing means recognizes kinds of said input means by detecting reflecting light from said retroreflective material.

18. The handwriting input device as claimed in claim 12, wherein said image processing means removes a fourth quadrant portion of said extracted contiguous image.

19. The handwriting input device as claimed in claim 12, wherein said receiving side computer removes a fourth quadrant portion of said extracted contiguous image.

20. The handwriting input device as claimed in claim 12, wherein said image taking means is positioned above an upper left corner of said trace display means for a right-handed operator, or an upper right corner of said trace display means for a left-handed operator.

21. The handwriting input device as claimed in claim 12, wherein said image processing means is provided in said transmitting side computer.