Image data communication system

• US 5,748,898 A
• Filed: 08/12/1996
• Issued: 05/05/1998
• Est. Priority Date: 08/10/1995
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: NEC Corporation
• Inventors: Ueda, Hiroaki
• Primary Examiner(s): Grant, Christopher C.
• Application Number:
  US08/695,415
• Time in Patent Office: 631 Days
• Field of Search: 348/12, 348/13, 348/7, 348/6, 348/10, 348/14, 348/15, 348/16, 348/17, 348/18, 348/19, 455/4.2, 455/5.1, 455/6.1, 455/6.2, 455/6.3
• US Class Current: 709/219
• CPC Class Codes: H04L 65/1059 End-user terminal functionalities specially adapted for real-time communication
• CPC Class Codes: H04L 65/1063 Application servers providing network services systems providing special services to telephonic subscribers H04M3/42
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/4053 without floor control
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The invention provides an image data communication system of a simple construction wherein wasteful processing is eliminated so that desired image data can be transmitted rapidly to a terminal of a source of a request for the image data. A server and a plurality of terminals are interconnected so as to allow communication of image data. A terminal information retrieval section provided in the server discriminates whether or not image data requested from a first terminal have already been transmitted to a second terminal. An image data transfer section provided in the server requests, when a result of the discrimination is that the data have been transmitted already, the second terminal for transmission of the image data and transfers the image data received from the second terminal to the first terminal. A terminal memory provided in each terminal stores image data, and an image data transmission section provided in each terminal reads out image data requested from the server from the terminal memory and transmits the read out image data to the server.

Claims

1. An image data communication system which includes a server and a plurality of terminals and wherein image data are communicated between said server and said terminals, comprising:

transmission discrimination means provided in said server for discriminating whether or not image data requested from a first one of said terminals have already been transmitted to a second one of said terminals;

image data transfer means provided in said server for requesting, when a result of the discrimination of said transmission discrimination means is that the data have been transmitted already, the second terminal for transmission of the image data and transferring the image data received from the second terminal to the first terminal;

terminal side storage means provided in each of said terminals for storing image data; and

image data transmission means provided in each of said terminals for reading out image data requested from said server from each of said terminal side storage means and transmitting the read out image data to said server.

2. An image data communication system as claimed in claim 1, further comprising server side storage means provided in said server for storing a terminal information file including an address number of the second terminal and a name of the image data transmitted to the second terminal and an image data file including a plurality of image data, said transmission discrimination means referring to said terminal information file to discriminate to which one of said terminals the image data have been transmitted.

3. An image data communication system as claimed in claim 2, wherein image data are transferred as packet data together with an address number of a destination and an address number of a source of transmission.

4. An image data communication system as claimed in claim 3, further comprising a router for transmitting the image data toward the terminal of the destination based on the address number of the destination included in the packet data.