Videoconferencing Systems, Inc.

Hayes Microcomputer Products, Inc.

Acis

Richard C Mays

Curtis M Smith

Leo M Cortjens

Kenneth A Franklin

Martin H Sauser, Jr

Karen G Hazzah

A kernel for enforcing a hierarchical invocation structure prevents upcalls by executing kernel operations during each invocation of code unit of application by another code unit. Kernel operations determine the priority of the invoking unit of code based on the hierarchy of the invocation structure. Only invocations by either lower priority units, or the unit itself are allowed. Once invoked, the kernel operates to establish a priority for the invoked task. The kernel provides various event mechanisms to provide for priority based preemption concurrently with the enforced invocation structure, thus allowing the handling of asynchronous events in a multitasking environment. The event mechanisms allow a unit of code to signal the occurrence of a condition, which may be captured by other code units. The kernel determines the proper code unit for responding to the condition, and employs scope rules to further define the handling operation. Scheduling and tasking mechanisms schedule the handling of the condition and dispatch the handling of the event on a prioritized basis.

Method for enforcing a hierarchical invocation structure in real time

A method for automatically adjusting the pan and tilt of a camera, such as used in a videoconferencing system. A pointer and a picture of the camera's field of view are provided on a display device, such as a television set or a monitor. The pointer is moved on the display device in response to user commands from a user control device, such as a mouse or a joystick. When the user determines that the pointer is in the correct position the user uses the user control device to send a designation command. Then, in response to the designation command, the pan and/or tilt of the camera are adjusted to center the desired object in the picture. The method also provides: for ignoring the designation command if the amount of panning and/or tilting does not exceed a predetermined value; for zooming out prior to panning and/or tilting and then zooming in after panning and/or tilting if the amount of panning and/or tilting exceeds a predetermined value; and for adjusting the rates of panning and/or tilting so as to complete panning and tilting at approximately the same time.

Method for automatically adjusting a video conferencing system camera

A videoconferencing system including error detection, monitoring, and reporting. A controller (10) controls the operation of a camera (17) or a peripheral device, such as a video cassette recorder (20), or a modem (22). A user input device, such as a mouse (12) or a joystick (18), is connected to the controller to allow the user to control the camera or the peripheral device via the controller. The controller sends the user's commands and then monitors status signals to determine whether the commands were properly executed or errors occurred. The controller stores indications of the errors and the command signals associated with the errors and automatically provides notice of the errors associated with the operation of the camera and the peripheral devices. The controller also provides notice of any errors to remote locations via the modem. The user may print out a report listing the errors and the command signals associated with the errors. The controller also identifies a command associated with an error and provides the reverse command in an attempt to correct the error.

Method of determining an error in a video conferencing system camera

A videoconferencing system which is easy to use. A camera unit (17) provides a picture which is displayed on the display screen of a monitor (21A, 21B). A controller (10) controls the operation of the camera and also causes a pointer or other indicator to be displayed on the display screen along with the picture. A user input device, such as a mouse (12) or a joystick (18), is connected to the controller. The mouse or joystick is used to position the pointer at a desired location on the picture or to designate an area of interest on the picture. The controller then causes the camera to pan and/or tilt in order to center the desired point or area of interest on the display screen, and to zoom, if appropriate, in order to fill the display screen with the desired area of interest. The range of operation of the camera is divided into a plurality of regions. The controller determines the selected region, that is, the region in which the selected picture occurs, and determines a focus setting for the camera based on the selected region. If a focus setting has not previously been determined for that region then the controller uses the focus setting for a parent region which encompasses the selected region.

Method for automatically adjusting the pan and tilt of a video

A videoconferencing system which readily accommodates new devices and new features. A plurality of devices ( 10, 12-18, 20-22) are connected to a network (23) by a plurality of network converters (11). A controller (10) contains software pertinent to each type of converter and the device to which it is connected. The controller (10) loads the appropriate software into each converter (11) so that each converter is then configured for the device (10, 12-18, 20-22) to which it is connected. User instructions are provided by a mouse (12), a control panel (13), or a joystick (18) to the controller (10). The controller (10) interprets the instructions to determine the action required and sends an appropriate command to the selected device. The present invention also provides a method for automatically positioning the camera, automatically zooming and focusing the camera, and for automatically adjusting the pan and tilt rates, and the zoom and focus during pan and tilt operations.

Network videoconferencing system

A videoconferencing system which is easy to use. A camera unit (17) provides a picture which is displayed on the display screen of a monitor (21A, 21B). A controller (10) controls the operation of the camera and also causes a pointer or other indicator to be displayed on the display screen along with the picture. A user input device, such as a mouse (12) or a joystick (18), is connected to the controller. The mouse or joystick is used to position the pointer at a desired location on the picture and to draw a rectangular area of interest on the display screen, for example by depressing a mouse button when the pointer is at a first location, dragging the mouse to a second location, and then releasing the button. Upon an indication from the user that a desired area of interest has been drawn, for example by a click of the mouse button, the camera pans and/or tilts in order to center the desired area of interest on the display screen and zooms in order to fill the display screen with the desired area of interest. Because the shape of the rectangular area of interest drawn by the user may not correspond to the shape of the display screen, one dimension, such as the larger dimension or the smaller dimension, of the rectangular area of interest is selected to fill the display screen. To avoid the annoying effect of very small camera adjustments, the camera pan and/or tilt is not adjusted unless the amount of adjustment exceeds a predetermined value. To avoid the annoying effect of a rapidly changing field of view, the camera is zoomed out prior to panning and/or tilting, and then zoomed in after panning and/or tilting, if the amount of camera panning and/or tilting exceeds a predetermined value.

Method for automatically adjusting a videoconferencing system camera to

A videoconferencing system for remotely controlling a peripheral device such as a VCR (20). A controller (10) controls the operation of the peripheral device by transmitting a conversion program to a converter (11G) via a network. The converter stores the conversion program in a memory and then uses the conversion program to convert subsequently transmitted network standard control signals into device specific control signals for controlling the peripheral device and also converts signals from the peripheral device into network standard control signals. The controller, or any other device in the network capable of using network standard control signals, may then remotely control and monitor the peripheral device by transmitting network standard control signals to the converter and receiving network standard control signals from the converter. The videoconferencing system thus allows a peripheral device to be remotely controlled and monitored by any device that is capable of transmitting and receiving network standard control signals.

Method for remotely controlling a peripheral device in a

A videoconferencing system which is easy to use. First and second video devices, such as a camera unit (17) or a videocassette recorder (20), provide first and second pictures, respectively. A video control unit (15) combines these pictures to provide a combined picture, such as a split screen display, which is displayed on a monitor (21A, 21B). A controller (10) controls the operation of the video devices and the video control unit, and also causes the video control unit to display a pointer or other indicator on the combined picture. A user input device, such as a mouse (12) or a joystick (18), is connected to the controller. The mouse or joystick is used to position the pointer at a desired location on the combined picture, and also to select the function which a video device is to perform. The controller automatically selects the video device which is to perform the selected function by determining which video device is providing the part of the combined picture in which the pointer is positioned. The controller then instructs that video device to perform the selected function. Thus, by placing the pointer in the desired portion of a combined picture, the user automatically controls the video device which provides that portion of the combined picture. Thus, the user does not need to know what video device is providing the desired portion of the combined picture or have to take any steps to directly select that video device.

Video conferencing system controlled by menu and pointer

Method and apparatus for reducing latency delay associated with converting asynchronous, serial digital data to packet data. The number of data characters received before a time-out occurs are counted; the last character received before a time-out occurs is recognized; or the number of data characters transmitted before a signal is received from the destination terminal are counted. The information thus gathered is used to predict the occurrence of future latency delay. Data packets are transmitted immediately upon the subsequent receipt of a number of data characters equal to the number of data characters received before the time-out occurred; receipt of a character identical to the last character received before a time-out; or receipt of a number of data characters equal to the number of data characters transmitted before another signal is received from the destination terminal, respectively. By transmitting immediately when a latency delay is expected, the latency delay is completely avoided.

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Atlanta, GA, United States of America

Richard C Mays