Abstract:
An apparatus, method, and computer program product for instant document sharing. In one embodiment, referred to as “document sharing,” a file is converted to a “shared document” which is distributed to the members of a data conference for review. In another embodiment, referred to as “application viewing,” the “owner” of a document shares the screens created by an application associated with the document. The other members of the data conference can view the screens, but cannot interact with the application. In another embodiment, referred to as “application sharing,” the “owner” of a document shares the screens created by an application associated with the document. The other members of the data conference can view the screens and interact with the application.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/109,026, filed Nov. 18, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to data conferencing, and more particularly to instant document sharing in a data conference. 
     2. Related Art 
     Whenever two or more people are involved in the preparation of a document, whether it be a financial spread sheet, a CAD design, a circuit schematic layout, an organization report, a bit map image, etc., succeeding drafts of the document are prepared, circulated, and modified in the process. Each person annotates his or her remarks on the document and forwards it to the next person. Typically, several drafts of the document will be circulated before a final draft is produced. This is a very time-consuming process. 
     In the case where the reviewers involved in this document preparation process are at different geographical locations, getting the document from one location to another location and back becomes another tedious and time-consuming task. The document must be mailed or faxed to that person, further complicating the entire process. 
     One alternative method to this process is to hold meetings where the reviewers gather and comment on the document with the hope to reduce the number of drafts needed before a final draft is produced. The shortcoming with this method is that there may be significant travel time and travel cost in getting everyone to the same location. In addition, the final draft of the document is usually circulated again for final comments. 
     One solution to this problem is to use a teleconferencing software program to share the document among the geographically dispersed reviewers. This process is often referred to as “data conferencing.” By using computer network connections, modem-connected phone lines, and the like, everyone can be connected via his or her computer. By using the teleconferencing software program, everyone&#39;s computer screen displays the same document. In addition to using the software program and network or modem connections, conference calling over the voice phone lines or through the software program creates a dynamic and live atmosphere where everyone can participate in the discussion and refer to the document displayed on the screen. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus, method, and computer program product for instant document sharing. In one embodiment, referred to as “document sharing,” a file is converted to a “shared document” which is distributed to the members of a data conference for review. The method of this embodiment includes printing the file, on a local computer, to a virtual printer from an application associated with the file, thereby creating the shared document; and sending the shared document to one or more remote computers, where the shared document is displayed by a viewer application. 
     In another embodiment, referred to as “application viewing,” the “owner” of a document shares the screens created by an application associated with the document. The other members of the data conference can view the screens, but cannot interact with the application. Only the owner can interact with the application. The method of this embodiment includes invoking the application on a local computer, thereby generating an application screen. The application screen is sent to a virtual device, thereby creating a “shared screen.” The shared screen is sent to a remote server for distribution to remote computers, where the shared screen is displayed by a viewer application. The user of the local computer (referred to as the “owner”) provides user input while editing the shared screen. The user input drives the application to edit the application screen based on the user input. In response, the application provides an application screen update. The application screen update is sent to the virtual device, thereby creating a shared screen update. The shared screen update is sent to the remote server for distribution to the remote computers, thereby updating the display of the application screen by the viewer applications. 
     In another embodiment, referred to as “application sharing,” the “owner” of a document shares the screens created by an application associated with the document. The other members of the data conference can view the screens and interact with the application. The method of this embodiment includes invoking the application on a local computer, generating an application screen. The application screen is sent to a virtual device, creating a shared screen. The shared screen is sent to a remote server for distribution to the remote computers used by the members of the data conference, where the shared screen is displayed by a viewer application. The members edit the shared screen, thereby generating user input that is sent to the local computer. The user input drives the application to edit the application screen based on the user input. In response, the application provides an application screen update. The application screen update is sent to the virtual device, thereby creating a shared screen update. The shared screen update is sent to the remote server for distribution to the remote computers, thereby updating the display of the application screen by the viewer applications. 
     In all embodiments, an annotation mode is available, where a transparent window is displayed over the shared document. Users can create objects to be displayed in the transparent window, thereby annotating the document. 
     One advantage of the present invention is that, by sharing documents in a client-server system, it provides robust, scalable, instant document sharing. 
     Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described with reference to the accompanying drawings. 
     FIG. 1 depicts an example client-server system in which the present invention may be used. 
     FIG. 2 depicts two clients engaged in a data conference using a server. 
     FIG. 3 is a block diagram of document sharing application according to a preferred embodiment of the present invention. 
     FIG. 4 depicts the software layers in a structured system environment. 
     FIG. 5 depicts the software layers in a structured system environment as modified by a preferred embodiment of the present invention. 
     FIG. 6 is a flow diagram depicting the operation of document sharing mode according to a preferred embodiment of the present invention. 
     FIG. 7 is a flowchart depicting the operation of document sharing mode according to a preferred embodiment of the present invention. 
     FIG. 8 is a flow diagram depicting the operation of application viewing mode according to a preferred embodiment of the present invention. 
     FIGS. 9A and 9B constitute a flowchart depicting the operation of application viewing mode according to a preferred embodiment of the present invention. 
     FIG. 10 is a flow diagram depicting the operation of application sharing mode according to a preferred embodiment of the present invention. 
     FIGS. 11A and 11B constitute a flowchart depicting the operation of application sharing mode according to a preferred embodiment of the present invention. 
     FIG. 12 depicts an example computer system capable of carrying out the functionality of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is described in terms of the above example. This is for convenience only and is not intended to limit the application of the present invention. In fact, after reading the following description, it will be apparent to one skilled in the relevant art how to implement the present invention in alternative embodiments. 
     Introduction 
     The present invention is an apparatus, method, and computer program product for sharing documents and applications in a client-server system having multiple remote clients. FIG. 1 depicts an example client-server system  100  in which the present invention may be used. System  100  includes a server  102  and a plurality of clients  104 A,  104 B,  104 N. The present invention is usually invoked after a data conference has been established. Methods for establishing data conferences among clients are well-known in the relevant arts. 
     The present invention provides four modes to support different kinds of data sharing and collaboration: document sharing mode, application viewing mode, application sharing mode, and annotation mode. In each mode, a document is shared among the clients. 
     In each mode, a client assumes one of four roles: owner, host, editor, and spectator. The owner is client that provides the document. The host is the client that has control of the data conference. An editor is a client that is allowed to edit the document. An annotator is a client that can edit a transparent window that overlays the document. A spectator is a client that can view the document and transparent window, but cannot edit them. 
     FIG. 2 depicts two clients  204  engaged in a data conference using a server  102 . One key advantage of using a client-server architecture rather than a peer-to-peer architecture is that no client is burdened with communicating with all of the other clients. It merely communicates with the server. This advantage permits the system to be highly scalable, for example, to serve a data conference involving a large number of clients. 
     Referring to FIG. 2, each client includes an operating system  206 , such as Windows, a memory  208 , and a document sharing application  210 . Client  204 A has assumed the role of owner, and so includes a file editing application  212  that is associated with the document to be shared. For example, the file editing application can be Microsoft Word, and the document to be shared can be a Microsoft Word document. client  204 B has assumed the role of editor. 
     FIG. 3 is a block diagram of document sharing application  210  according to a preferred embodiment of the present invention. In a preferred embodiment, document sharing application  210  is configured as a browser plug-in that can be downloaded from the Internet and installed on a computer running a Windows-type operating system and a browser such as Windows Internet Explorer. 
     In order to share a document, document sharing application  210  first converts the document to another form by “loading” the document, as will be discussed in detail below. Therefore, the document sharing application  210  includes document loader  302 . Depending on the sharing mode, document loading may involve invoking an application associated with the document. Accordingly, document loader  302  includes an application invoker  304 . The present invention also uses virtual devices and drivers in document loading. Accordingly, document loader  302  includes virtual devices and drivers  306 . 
     When a document has been loaded, a viewer application  308  allows the user to view the document. A client shares a loaded document by transmitting data to other clients, and receiving such data, using communication module  310 . Methods for exchanging such data are discussed extensively in U.S. Pat. No. 5,623,603, assigned to the assignee of the present application, and the disclosure thereof incorporated herein by reference in its entirety. 
     An editing module  312  enables users to perform editing functions. Document editor  314  allows users to edit a shared document. Overlay editor  316  allows users to edit the transparent overlay screen. Annotating the transparent window and sending data representing the annotations to a remote computer, where the annotations are drawn on the display, is discussed extensively in U.S. Pat. No. 5,577,188, assigned to the assignee of the present application, and the disclosure thereof incorporated herein by reference in its entirety. 
     Structured System Programming Environment 
     Before proceeding to the discussion of the methods of document sharing, the software layers in a structured system programming environment such as Microsoft Windows are explained. Referring to FIGS. 4 and 5, in starting the document sharing application  210 , the software layers in a structured system programming environment are modified. FIG. 4 depicts the software layers in a structured system environment. In this environment, a running application program  402  interfaces with input and output devices strictly through the operating system&#39;s Window system environment, represented by OS Window system  404 . When the application program requests the OS Window system to write a character to the screen, the OS Window system in turn directs a display driver  406  to write the character to the monitor  408 . A driver such as a display driver is a software program written specifically to handle a specific device or device type, such as monitor  408 . For example, there are several standards of display resolution with computer monitors. A display driver is needed for each standard in order to control and interface with each type of monitor. 
     Display driver  406  tells the monitor  408  specifically how to write a character on the screen. For example, in an application program such as a word processor running on top of OS Window system  404 , when the user inputs a character “a” from the keyboard and when the word processor receives the character “a” as input, the word processor will display the character “a” on the screen at the right place to reassure the user that he or she has input a character “a”. To write the character “a” to the screen, the word processor calls a OS Window system  404  write-to-screen routine, specifying the character “a” and the location on the screen to place the character. The OS Window system  404  routine in turn calls the display driver with the given information, and the display driver specifically tells the computer screen the placement of dots on the screen to compose the visual image resembling the character “a”. 
     In activating document sharing application  210 , referring to FIG. 5, the software layer structure is modified. The application call to OS Window system  404  is redirected to a virtual display device  504 . Virtual display device  504  is one of the virtual devices and drivers  306  within document loader  302 . 
     In a preferred embodiment, redirection of the application calls to OS Window system is accomplished by renaming the appropriate OS Window System calls with predefined alternate calls and naming the virtual display device to the OS Window system&#39;s original calls. When the application calls the OS Window System via its name, it is calling the virtual display device rather than the OS Window System. The virtual display device calls the OS Window system through its predefined names. The virtual display device calls the OS Window system with the information to place on the screen as requested by a file editing application  502 , which can be any application such as a word processor. 
     In one embodiment, virtual display driver  504  reports the screen updates to document sharing application  210  via dynamic link library  506 . When the screen updates are finished, document sharing application  210  reads the screen updates stored in dynamic link library  506 . In annotation mode, document sharing application  210  checks for overlapping screen objects and re-draws the annotation objects if necessary. This process is fully explained in U.S. Pat. No. 5,577,188. 
     In another embodiment, document sharing application  210  creates a shared screen  508 , or a shared screen update  510 , which is passed directly to document sharing application  210  for display, and for transmission to other clients in the data conference for display to other users. This embodiment is used in the application viewing and application sharing modes, as described in detail below. 
     In document sharing mode, a representation of the entire document is sent to each client&#39;s viewer application  308 . In one embodiment, this is accomplished by using a virtual printer driver  512 , rather than a virtual display driver. The document to be shared is printed from its associated file editing application  502  to virtual printer driver  512 , creating a shared document  514  in a predefined format. Shared document  514  is passed directly to document sharing application  210  for display, and for transmission to other clients in the data conference for display to other users. 
     Document Sharing Mode 
     FIG. 6 is a flow diagram depicting the operation of document sharing mode according to a preferred embodiment of the present invention. FIG. 6 depicts the data flows between file editing application  212 , document sharing application  210 A running on owner client  204 A and document sharing application  210 B running on editor client  204 B. FIG. 7 is a flowchart depicting this operation. 
     Referring to FIG. 7, the user of owner client  204 A selects a file to share in step  702 . In response, the application invoker of document sharing application  210 A invokes the file editing application  212  associated with the selected file in step  704 . In a preferred embodiment, the application invoker employs automatic application association to select the associated file editing application based on associations established by the operating system according to methods well-known in the relevant arts. If the file editing application is already running, step  704  merely involves opening the selected file using the associated file editing application. However, if the file editing application is not open when the file is selected, the file editing application is launched first. 
     The default printer associated with file editing application  212  or Windows is checked in step  706 . If the default printer is not set to be the virtual printer associated with virtual printer driver  512 , then the default printer is saved in step  710  and the virtual printer is selected as the default printer in step  712 . Otherwise, steps  710  and  712  are skipped. 
     The selected file is then printed to the virtual printer in step  714 . Referring to FIG. 5, this operation entails redirecting the print call from file editing application  502  at the OS Window System  404  to virtual printer driver  512 , thereby creating shared document  514 . Shared document  514  is then passed to document sharing application  210  for viewing and distribution. If necessary, the default printer is restored in step  716 . If file editing application  502  was launched in step  704 , then it is closed in step  718 . 
     Document sharing application  210 , on receipt of shared document  514 , sends the shared document to server  102  for distribution to the other clients in the data conference. All of the clients in the data conference then display the shared document using viewer application  308 , as shown in step  722 . 
     In FIG. 6, time flows from top to bottom. Referring to that figure, virtual printer driver  512  generates printer file  602  which is modified by document sharing application  210 A to create a shared document  514 . Document sharing application  210 A then displays shared document  514  and forwards it to document sharing application  210 B for display. Using annotation mode, the two document sharing applications can exchange user input  604  to draw various objects upon a transparent window overlaying the shared document  514 . 
     Application Viewing Mode 
     FIG. 8 is a flow diagram depicting the operation of application viewing mode according to a preferred embodiment of the present invention. FIGS. 9A and 9B constitute a flowchart depicting that operation. 
     A user of document sharing application  210 A selects a file editing application to view in step  902 . In response, the file editing application is invoked, generating an application screen  802 , as shown in step  904 . Document sharing application  210 A causes application screen  802  to be sent to virtual display driver  504 , thereby generating a shared screen  508  as shown in step  906 . The shared screen is passed back to document sharing application  210 A, which sends the shared screen to server  102  in step  908 . Server  102  distributes the shared screen to the other clients in the data conference in step  910 . In step  912 , the other clients in the data conference, such as the client running document sharing application  210 B, display the shared screen using viewer application  308 . 
     Referring to FIG. 8, the users in the data conference that have been granted the role of editor can exchange user input in the form of annotations  804 . However, in application viewing mode, the application is controlled only by the owner&#39;s user input  806 . The other clients in the data conference are not permitted to control the application directly. When document sharing application  210 A receives input from the local user in step  914 , it forwards this user input  806  to file editing application  502  to drive the application to edit the application screen based on that input, as shown in step  916 . In response, the application provides an application screen update  808 , which is received by the owner document sharing application  210 A in step  918 . Document sharing application  210 A sends application screen update  808  to virtual display driver  504 , thereby creating a shared screen update  510 , as shown in step  920 . Referring to FIG. 5, shared screen update  510  is passed to document sharing application  210 B. 
     Document sharing application  210 A forwards the shared screen update to server  102  in step  922 . The server distributes the shared screen update to the other clients in the data conference, as shown in step  924 . In response, the clients revise the shared screen currently being displayed using the shared screen update, and display the revised shared screen in step  926 . 
     Application Sharing Mode 
     FIG. 10 is a flow diagram depicting the operation of application sharing mode according to a preferred embodiment of the present invention. FIGS. 11A and 11B constitute a flowchart depicting that operation. 
     A user of document sharing application  210 A selects an application to view in step  1102 . In response, the application is invoked, generating an application screen  1002 , as shown in step  1104 . Document sharing application  210 A causes application screen  1002  to be sent to virtual display driver  504 , thereby generating a shared screen  508  as shown in step  1106 . The shared screen is passed back to document sharing application  210 A, which sends the shared screen to server  102  in step  1108 . Server  102  distributes the shared screen to the other clients in the data conference in step  1110 . In step  1112 , the other clients in the data conference display the shared screen using viewer application  308 . 
     In application sharing mode, both the owner and editors are permitted to control the file editing application directly. Steps  1114  through  1126  illustrate this process. Referring to FIG. 10, a user of document sharing application  210 B generates editor user input  1004 , which is sent to owner  210 A. Owner  210 A receives the editor user input in step  1114 , and forwards this input to file editing application  212 , thereby driving that application to edit the current application screen based on editor user input  1004  as shown in step  1116 . In response, the file editing application generates an application screen update  1006 , which is received at owner  210 A in step  1118 . Owner  210 A sends the application screen update to virtual display driver  504 , thereby creating a shared screen update  510 A, as shown in step  1120 . 
     Referring to FIG. 5, shared screen update  510 A is passed to document sharing application  210 A, which forwards the shared screen update to server  102 , as shown in step  1122 . The server distributes the shared screen update to the other clients in the data conference, as shown in step  1124 . Each client revises the current shared screen using the shared screen update, and displays the revised shared screen using its viewer application  308 , as shown in step  1126 . The process of steps  1114  through  1126  is repeated as needed for user input from both the local computer and remote computers. 
     FIG. 10 also depicts the process whereby the local user (owner) controls the application. According to this process, owner user input  1008  is sent from owner  210 A to file editing application  212 , thereby driving it to edit the current application screen, and provide an application screen update  1010 . The application screen update is sent to virtual display driver  504 , creating a shared screen update  510 B, which is displayed and forwarded to server  102  for distribution to other clients, which revised their screens accordingly. 
     The present invention may be implemented using hardware, software or a combination thereof and may be implemented in a computer system or other processing system. In fact, in one embodiment, the invention is directed toward one or more computer systems capable of carrying out the functionality described herein. An example computer system  1200  is shown in FIG.  12 . The computer system  1200  includes one or more processors, such as processor  1204 . The processor  1204  is connected to a communication bus  1206 . Various software embodiments are described in terms of this example computer system. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures. 
     Computer system  1200  also includes a main memory  1208 , preferably random access memory (RAM), and can also include a secondary memory  1210 . The secondary memory  1210  can include, for example, a hard disk drive  1212  and/or a removable storage drive  1214 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive  1214  reads from and/or writes to a removable storage unit  1218  in a well known manner. Removable storage unit  1218 , represents a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive  1214 . As will be appreciated, the removable storage unit  1218  includes a computer usable storage medium having stored therein computer software and/or data. 
     In alternative embodiments, secondary memory  1210  may include other similar means for allowing computer programs or other instructions to be loaded into computer system  1200 . Such means can include, for example, a removable storage unit  1222  and an interface  1220 . Examples of such include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units  1222  and interfaces  1220  which allow software and data to be transferred from the removable storage unit  1218  to computer system  1200 . 
     Computer system  1200  can also include a communications interface  1224 . Communications interface  1224  allows software and data to be transferred between computer system  1200  and external devices. Examples of communications interface  1224  can include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via communications interface  1224  are in the form of signals which can be electronic, electromagnetic, optical or other signals capable of being received by communications interface  1224 . These signals  1226  are provided to communications interface  1224  via a channel  1228 . This channel  1228  carries signals  1226  and can be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels. 
     In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage device  1218 , a hard disk installed in hard disk drive  1212 , and signals  1226 . These computer program products are means for providing software to computer system  1200 . 
     Computer programs (also called computer control logic) are stored in main memory  1208  and/or secondary memory  1210 . Computer programs can also be received via communications interface  1224 . Such computer programs, when executed, enable the computer system  1200  to perform the features of the present invention as discussed herein. In particular, the computer programs, when executed, enable the processor  1204  to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system  1200 . 
     In an embodiment where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system  1200  using removable storage drive  1214 , hard drive  1212  or communications interface  1224 . The control logic (software), when executed by the processor  1204 , causes the processor  1204  to perform the functions of the invention as described herein. 
     In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). In yet another embodiment, the invention is implemented using a combination of both hardware and software. 
     While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be placed therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by any of the above-described example embodiments, but should be defined only in accordance with the following claims and their equivalents.