Bus-line network communication system

• US 5,550,584 A
• Filed: 02/08/1995
• Issued: 08/27/1996
• Est. Priority Date: 02/19/1992
• Status: Expired due to Term

• Current Assignee: Canopus Corporation
• Original Assignee: Canopus Corporation
• Inventors: Yamada, Hiroshi
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US08/385,463
• Time in Patent Office: 566 Days
• Field of Search: 348/153, 348/159, 348/6, 348/8, 348/10
• US Class Current: 348/153
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

Bus-line network communication system in which changing of adding number or location of monitoring camera can be carried out with easy: A central monitoring device 50 and monitoring cameras C31 to C40 are connected with a communication bus-line 40. The central monitoring device send a request command to the bus-line 40. The request command is received by the selected camera through the bus-line 40. The selected camera which is received the request command, send image data to the-bus line 40. The central monitoring device receives the image data and displays image.

Claims

1. An image obtaining terminal for connection to a network bus-line, comprising:

video convening means for converting an image into a video signal;

analog to digital convening means for converting the video signal into digital image data;

memory means for storing the digital image data;

judging means for determining whether or not a request command on the network bus-line is addressed to a particular image obtaining terminal; and

communication control means for transmitting the digital image data stored in the memory means over the network bus-line when the judging means determines that the request command is addressed to the particular image obtaining terminal, said communication control means including means for adding an identifier to said digital image data before said digital image data is transmitted, indicating that said digital image data is being transmitted from the particular image obtaining terminal.

2. An image obtaining terminal according to claim 1, wherein said video converting means includes a video camera.

3. A central monitoring device for connection to a network bus-line, comprising:

terminal selection means for selecting a particular image obtaining terminal from among a plurality of image obtaining terminals connected to said network bus-line;

transmission means for transmitting a request command over said network bus-line to said particular image obtaining terminal, said request command causing said particular image obtaining terminal to transmit image data and an identifier to said central monitoring device over said network bus-line, said transmission means also including means for adding an identifier before transmitting said request command, indicating that said request command is addressed to said particular image obtaining terminal;

digital to analog converting means for converting the image data from the particular image obtaining terminal into an analog video signal;

image reproducing means for reproducing an image corresponding to said video signal.

4. A central monitoring device according to claim 3, wherein said image reproducing means includes a cathode ray tube.

5. A central monitoring device according to claim 3, wherein said image reproducing means includes a liquid crystal display.

6. A bus-line network communication system comprising:

a plurality of image obtaining terminals, wherein each image obtaining terminal comprises

video convening means for converting an image into a video signal;

analog to digital converting means for converting the video signal into digital image data;

memory means for storing the digital image data;

judging means for determining whether or not a request command on the network bus-line is addressed to a particular image obtaining terminal; and

communication control means for transmitting the digital image data stored in the memory means over the network bus-line when the judging means determines that the request command is addressed to the particular image obtaining terminal, said communication control means including means for adding an identifier to said digital image data before said digital image data is transmitted, indicating that said digital image data is being transmitted from the particular image obtaining terminal;

a central monitoring device comprising

terminal selection means for selecting a particular image obtaining terminal from among a plurality of image obtaining terminals connected to said network bus-line;

transmission means for transmitting a request command over said network bus-line to said particular image obtaining terminal, said request command causing said particular image obtaining terminal to transmit image data to said central monitoring device over said network bus-line, said transmission means also including means for adding an identifier before transmitting said request command, indicating that said request command is addressed to said particular image obtaining terminal;

digital to analog converting means for converting the image data from the particular image obtaining terminal into an analog video signal;

image reproducing means for reproducing an image corresponding to said video signal; and

a single network bus-line connected between said plurality of image obtaining terminals and said central monitoring device.

7. A bus-line network communication system according to claim 6 further comprising a plurality of central monitoring devices connected to said network bus-line.

8. A method for communicating data between a central monitoring device and a plurality of image obtaining terminals over a bus-line network, comprising the steps of:

transmitting over said network bus-line a request command from said central monitoring device to a particular image obtaining terminal selected from among the plurality of image obtaining terminals;

determining in each of said plurality of image obtaining terminals whether or not the request command from the central monitoring device is addressed to the particular image obtaining terminal;

transmitting image data over the network bus-line from the particular image obtaining terminal addressed by said request command;

adding an identifier indicating that the image data is being transmitted from the particular image obtaining terminal; and

reproducing at said central monitoring device an image corresponding to the image data transmitted over the network bus-line.