Synchronized cursor shared among a number of networked computer systems

• US 6,115,027 A
• Filed: 02/23/1998
• Issued: 09/05/2000
• Est. Priority Date: 02/23/1998
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Hao, Ming C., Lee, Dongman, Sventek, Joseph S.
• Primary Examiner(s): Bayerl, Raymond J.
• Assistant Examiner(s): Nguyen, Thomas T.
• Application Number:
  US09/028,172
• Time in Patent Office: 925 Days
• Field of Search: 345/329, 345/339, 345/145, 345/157, 345/332, 345/331, 345/330, 709/201, 709/202, 709/205, 709/237, 709/248
• US Class Current: 715/858
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/04892 Arrangements for controlling cursor position based on codes indicative of cursor displacements from one discrete location to another, e.g. using cursor control keys associated to different directions or using the tab key arrangements for controlling cursor position based on coordinate signals G06F3/038
• CPC Class Codes: G06F 3/1454 involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay

Abstract

A non-intrusive cursor synchronization system is described that does not change or modify the existing system or application. The cursor synchronization system is used for synchronously displaying a cursor on a plurality of display systems connected together via a network without requiring database or shared memory. The cursor synchronization system includes a plurality of agents, each being coupled to one of the display systems to cause the respective display system to display a consistent cursor movement, and to trigger concurrent execution among a number of existing applications. The cursor synchronization system also includes a cursor synchronizer that captures and compresses the cursor movement generated from one of the display systems within a time interval that is adjustable based on the speed at which the user moves the cursor. The cursor synchronizer synchronously sends the compressed cursor movement to each of the agents such that the cursor movement is synchronously displayed on each of the display systems with minimized network traffic through the network. A method for synchronously displaying a cursor on a plurality of display systems connected together via a network is also described.

Claims

1. A cursor synchronization system for synchronously displaying a cursor on a plurality of display systems connected together via a network, comprising:

(A) a plurality of agents, each being coupled to one of the display systems to cause the respective display system to display a compressed cursor movement wherein each of the agents does not generate any control request;

(B) a cursor synchronizer coupled to the agents wherein the cursor synchronizer captures and compresses the cursor movement generated from an external cursor generator within a predetermined time interval, wherein the cursor synchronizer synchronously sends the compressed cursor movement to each of the agents such that the cursor movement is synchronously displayed on each of the display systems with minimized network traffic through the network, wherein the agents only receive the compressed cursor movement from the cursor synchronizer and do not provide any cursor movement or control request input to the cursor synchronizer.

2. The cursor synchronization system of claim 1, wherein each of the agents also triggers concurrent execution among a plurality of existing applications within the display systems without requiring sharing of memory or database.

3. The cursor synchronization system of claim 1, wherein the cursor synchronizer compresses the cursor movement within the predetermined time interval by defining the predetermined time interval as a plurality of time periods and using a last cursor location of the cursor movement within each of the time periods to represent the cursor movement.

4. The cursor synchronization system of claim 3, wherein the cursor synchronizer synchronously sends the compressed cursor movement to each of the agents by sending all the last cursor locations within each of the time periods, one period at a time, to the agents.

5. The cursor synchronization system of claim 4, wherein after the cursor synchronizer sends all the last cursor locations of the cursor movement within a particular time period to all the agents, the cursor synchronizer does not send all the last cursor locations of the cursor movement within an adjacent time period of the particular time period unless the cursor synchronizer receives a completion message from each of the agents.

6. The cursor synchronization system of claim 5, wherein each of the agents sends the completion message to the cursor synchronizer once the agent has received and displayed all the last cursor locations of the cursor movement within anyone of the time periods.

7. The cursor synchronization system of claim 4, wherein if a button/keyboard action occurs within one of the time periods, the cursor synchronizer treats the cursor location right before the button/keyboard action as another last cursor location within that time period such that the button/keyboard action occurs at the same location on all of the display systems.

8. The cursor synchronization system of claim 1, wherein the cursor synchronizer further comprises

(a) a module that defines the predetermined time interval as a plurality of time periods;

(b) a compressor that compresses the cursor movement by only transmitting the last cursor locations of the cursor movement within each of the time periods of the predetermined time interval to each of the agents;

(c) a to-location synchronizer that, if a button/keyboard action occurs within one of the time periods, causes a cursor location right before the button/keyboard action as another last cursor location within that time period such that the button/keyboard action occurs at the same location on all of the display systems.

9. The cursor synchronization system of claim 1, wherein the predetermined time interval is approximately fifty milliseconds.