IMAGE FORMING APPARATUS, COMMUNICATION CONTROL METHOD THEREOF AND RECORDING MEDIUM

1 . An image forming apparatus that has a server cooperation function to transmit data to a data processing server connected therewith via a network and receive processed data after the server performs data processing, and is capable of communicating with a plurality of external apparatuses via the network by establishing concurrent connections, comprising:

a judger that judges whether or not the number of the currently established connections with the external apparatuses reaches a limit number of connections that is an allowable upper limit of concurrent connections, during execution of the server cooperation function; and

a controller that reserves a connection with the server if the judger judges that the number of the currently established connections does not reach the limit number of connections, and cancels the reserved connection after the end of the execution of the server cooperation function.

2 . The image forming apparatus recited in claim 1 , wherein the controller cancels the reserved connection, if the execution of the server cooperation function is not ended within a predetermined period of time after the start of the execution of the server cooperation function.

3 . The image forming apparatus recited in claim 1 , wherein the controller keeps going the execution of the server cooperation function until any of the currently established connections is terminated, if the judger judges that the number of the currently established connections reaches the limit number of connections.

4 . The image forming apparatus recited in claim 1 , wherein the maximum number of connections with the server, which are reserved to be established by executing the server cooperation function, is set to a value smaller than the limit number of connections.

5 . An image forming apparatus that has a server cooperation function to transmit data to a data processing server connected therewith via a network and receive processed data after the server performs data processing, and is capable of communicating with a plurality of external apparatuses via the network by establishing concurrent connections, comprising:

a detector that detects a connection request that is transmitted by the server in order to transmit the processed data subsequently;

a judger that judges whether or not the number of the currently established connections with the external apparatuses reaches a limit number of connections that is an allowed upper limit of concurrent connections; and

a controller that terminates any of the currently established connections, if the detector detects a connection request from the server and the judger judges that the number of the currently established connections reaches the limit number of connections.

6 . The image forming apparatus recited in claim 5 , wherein the controller preferentially terminates a connection established by a user who instructed to execute the server cooperation function.

7 . The image forming apparatus recited in claim 5 , wherein the controller preferentially terminates an idle connection not currently used for data communication.

8 . The image forming apparatus recited in claim 5 , wherein the controller preferentially terminates a connection having the longest connection time.

9 . A communication control method of an image forming apparatus that has a server cooperation function to transmit data to a data processing server connected therewith via a network and receive processed data after the server performs data processing, and is capable of communicating with a plurality of external apparatuses via the network by establishing concurrent connections, comprising:

judging whether or not the number of the currently established connections with the external apparatuses reaches a limit number of connections that is an allowable upper limit of concurrent connections, during execution of the server cooperation function; and

reserving a connection with the server if it is judged in the judgment step that the number of the currently established connections does not reach the limit number of connections, and cancelling the reserved connection after the end of the execution of the server cooperation function.

10 . The communication control method of the image forming apparatus, recited in claim 9 , wherein the reserved connection is cancelled, if the execution of the server cooperation function is not ended within a predetermined period of time after the start of the execution of the server cooperation function, in the reservation and cancellation step.

11 . The communication control method of the image forming apparatus, recited in claim 9 , wherein the execution of the server cooperation function is kept going until any of the currently established connections is terminated, if it is judged in the judgment step that the number of the currently established connections reaches the limit number of connections.

12 . The communication control method of the image forming apparatus, recited in claim 9 , wherein the maximum number of connections with the server, which are reserved to be established by executing the server cooperation function, is set to a value smaller than the limit number of connections.

13 . A communication control method of an image forming apparatus that has a server cooperation function to transmit data to a data processing server connected therewith via a network and receive processed data after the server performs data processing, and is capable of communicating with a plurality of external apparatuses via the network by establishing concurrent connections, comprising:

detecting a connection request that is transmitted by the server in order to transmit the processed data subsequently;

judging whether or not the number of the currently established connections with the external apparatuses reaches a limit number of connections that is an allowable upper limit of concurrent connections;

terminating any of the currently established connections, if a connection request from the server is detected in the detection step and it is judged in the judgment step that the number of the currently established connections reaches the limit number of connections.

14 . The communication control method of the image forming apparatus, recited in claim 13 , wherein a connection established by a user who instructed to execute the server cooperation function is preferentially terminated in the connection termination step.

15 . The communication control method of the image forming apparatus, recited in claim 13 , wherein an idle connection not currently used for data communication is preferentially terminated in the connection termination step.

16 . The communication control method of the image forming apparatus, recited in claim 13 , wherein a connection having the longest connection time is preferentially terminated in the connection termination step.

17 . A computer readable recording medium having a communication control program recorded therein to make a computer of an image forming apparatus that has a server cooperation function to transmit data to a data processing server connected therewith via a network and receive processed data after the server performs data processing, and is capable of communicating with a plurality of external apparatuses via the network by establishing concurrent connections, execute:

judging whether or not the number of the currently established connections with the external apparatuses reaches a limit number of connections that is an allowable upper limit of concurrent connections, during execution of the server cooperation function; and

reserving a connection with the server if it is judged in the judgment step that the number of the currently established connections does not reach the limit number of connections, and cancelling the reserved connection after the end of the execution of the server cooperation function.

18 . A computer readable recording medium having a communication control program recorded therein to make a computer of an image forming apparatus that has a server cooperation function to transmit data to a data processing server connected therewith via a network and receive processed data after the server performs data processing, and is capable of communicating with a plurality of external apparatuses via the network by establishing concurrent connections, execute:

detecting a connection request that is transmitted by the server in order to transmit the processed data subsequently;

judging whether or not the number of the currently established connections with the external apparatuses reaches a limit number of connections that is an allowable upper limit of concurrent connections; and

terminating any of the currently established connections, if a connection request from the server is detected in the detection step and it is judged in the judgment step that the number of the currently established connections reaches the limit number of connections.