Communication terminal, communication system, method of sharing data, and recording medium

1. A communication terminal comprising circuitry configured to:

transmit a participation request for requesting participation in a remote conference being conducted between one or more other communication terminals, to a communication management apparatus that manages data being shared between the other communication terminals, the remote conference having already been started before the participation request is transmitted;

receive screen data of a display screen being currently displayed at the other communication terminals from the communication management apparatus, the screen data including a stroke data identifier identifying stroke data of the display screen currently being displayed and an image data identifier identifying background image data of the display screen currently being displayed, the screen data of the display screen being one of a plurality of items of screen data generated at at least one of the other communication terminals in the remote conference; and

control a display to display the display screen based on the screen data that is received, wherein the circuitry is configured to:

download the stroke data identified with the stroke data identifier included in the screen data that is received, from the communication management apparatus,

download the background image data identified with the image data identifier included in the screen data that is received, from a memory that stores the background image data, the memory that stores the background image data being separate from the communication management apparatus, and

control the display to display a stroke image generated based on the stroke data, and a background image of the background image data.

2. The communication terminal of claim 1 , wherein the circuitry is further configured to:

receive conference information on the remote conference from the communication management apparatus in response to the participation request;

identify the screen data of the display screen, based on the conference information on the remote conference;

transmit a data acquiring request for acquiring the screen data of the display screen to the communication management apparatus; and

receive the screen data of the display screen, transmitted from the communication management apparatus in response to the data acquiring request.

3. The communication terminal of claim 2 , wherein the circuitry is configured to identify the screen data of the display screen, using an identifier of a particular screen data of the plurality of items of screen data indicated by the conference information.

4. The communication terminal of claim 2 , wherein the identifier of the particular screen data identifies a particular page of a plurality of pages of screen available for display at any one of the other communication terminals.

5. The communication terminal of claim 3 , wherein the circuitry is configured to determine a priority in downloading the plurality of items of screen data, other than the identified screen data of the display screen, based on identifiers of the plurality of items of screen data indicated by the conference information.

6. The communication terminal of claim 1 ,

wherein the plurality of items of screen data are data having been or currently shared between the other communication terminals in the conference.

7. A communication system comprising:

the communication terminal of claim 1 ;

at least one of the other communication terminals; and

the communication management apparatus configured to manage communication between the communication terminal and the other communication terminals.

8. The communication system of claim 7 ,

wherein the other communication terminal is configured to transmit the background image data of a background image being displayed at the other communication terminal to store the background image data in the memory, and transmit stroke data generated at the other communication terminal to the communication management apparatus.

9. A method of sharing data, performed by a communication terminal, the method comprising:

transmitting a participation request for requesting participation in a remote conference being conducted between one or more other communication terminals, to a communication management apparatus that manages data being shared between the other communication terminals, the remote conference having already been started before the participation request is transmitted;

receiving screen data of a display screen being currently displayed at the other communication terminals from the communication management apparatus, the screen data including a stroke data identifier identifying stroke data of the display screen currently being displayed and an image data identifier identifying background image data of the display screen currently being displayed, the screen data of the display screen being one of a plurality of items of screen data generated at at least one of the other communication terminals in the remote conference; and

displaying, on a display, the display screen based on the screen data that is received, wherein the receiving comprises:

downloading the stroke data identified with the stroke data identifier included in the screen data that is received, from the communication management apparatus, and

downloading the background image data identified with the image data identifier included in the screen data that is received, from a memory that stores the background image data, the memory that stores the background image data being separate from the communication management apparatus, and wherein the displaying comprises:

controlling the display to display a stroke image generated based on the stroke data, and a background image of the background image data.

10. A non-transitory recording medium which, when executed by one or more processors, cause the processors to perform a method of sharing data comprising:

transmitting a participation request for requesting participation in a remote conference being conducted between one or more other communication terminals, to a communication management apparatus that manages data being shared between the other communication terminals, the remote conference having already been started before the participation request is transmitted;

receiving screen data of a display screen being currently displayed at the other communication terminals from the communication management apparatus, the screen data including a stroke data identifier identifying stroke data of the display screen currently being displayed and an image data identifier identifying background image data of the display screen currently being displayed, the screen data of the display screen being one of a plurality of items of screen data generated at at least one of the other communication terminals in the remote conference; and

displaying, on a display, the display screen based on the screen data that is received, wherein the receiving comprises:

downloading the stroke data identified with the stroke data identifier included in the screen data that is received, from the communication management apparatus, and

downloading the background image data identified with the image data identifier included in the screen data that is received, from a memory that stores the background image data, the memory that stores the background image data being separate from the communication management apparatus, and wherein the displaying comprises:

controlling the display to display a stroke image generated based on the stroke data, and a background image of the background image data.

11. A communication system comprising:

a communication terminal;

a plurality of other communication terminals; and

a communication management apparatus comprising circuitry configured to manage communication among the communication terminal and the plurality of other communication terminals and to manage data being shared among the communication terminal and the plurality of other communication terminals,

the communication terminal comprising circuitry configured to:

transmit a participation request for requesting participation in a remote conference being conducted between one or more of the plurality of other communication terminals, to the communication management apparatus, the remote conference having already been started before the participation request is transmitted;

receive screen data of a display screen being currently displayed at the other communication terminals from the communication management apparatus, the screen data including a stroke data identifier identifying stroke data of the display screen currently being displayed and an image data identifier identifying background image data of the display screen currently being displayed, the screen data of the display screen being one of a plurality of items of screen data generated at at least one of the other communication terminals in the remote conference; and

control a display to display the display screen based on the screen data that is received, wherein the circuitry of the communication terminal is configured to:

download the stroke data identified with the stroke data identifier included in the screen data that is received, from the communication management apparatus,

download the background image data identified with the image data identifier included in the screen data that is received, from a memory that stores the background image data, the memory that stores the background image data being separate from the communication management apparatus, and

control the display to display a stroke image generated based on the stroke data, and a background image of the background image data.

12. The communication system of claim 11 , wherein the circuitry of the communication terminal is further configured to:

receive conference information on the remote conference from the communication management apparatus in response to the participation request;

identify the screen data of the display screen, based on the conference information on the remote conference;

transmit a data acquiring request for acquiring the screen data of the display screen to the communication management apparatus; and

receive the screen data of the display screen, transmitted from the communication management apparatus in response to the data acquiring request.

13. The communication system of claim 12 , wherein the circuitry of the communication terminal is configured to identify the screen data of the display screen, using an identifier of a particular screen data of the plurality of items of screen data indicated by the conference information.

14. The communication system of claim 12 , wherein the identifier of the particular screen data identifies a particular page of a plurality of pages of screen available for display at any one of the other communication terminals.

15. The communication system of claim 13 , wherein a priority is determined in downloading the plurality of items of screen data, other than the identified screen data of the display screen, based on identifiers of the plurality of items of screen data indicated by the conference information.

16. The communication system of claim 15 , wherein the circuitry of the communication management apparatus is configured to determine the priority.