Computer graphics processing and selective visual display system – Display peripheral interface input device – Touch panel
Reexamination Certificate
1999-04-05
2001-12-04
Lao, Lun-Yi (Department: 2673)
Computer graphics processing and selective visual display system
Display peripheral interface input device
Touch panel
C345S179000, C178S018010, C178S018030
Reexamination Certificate
active
06326954
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to electronic writeboards and in particular to a method and editor for erasing on an electronic writeboard.
BACKGROUND OF THE INVENTION
Electronic writeboards or whiteboards (EWBs) are known in the art and have been used in conjunction with host computers executing applications software to provide enhanced multimedia and teleconferencing capabilities. An example of an electronic writeboard of this nature is sold by SMART Technologies Inc. of Calgary, Alberta, Canada under the name SMART Board. The SMART Board electronic writeboard includes a touch sensitive panel, a tool tray accommodating a plurality of tools such as coloured pens and an eraser as well as a driver and an associated controller.
In use, the electronic writeboard is connected to a host processor such as a personal computer operating in a Windows® environment and executing applications software, via a serial data connection. The electronic writeboard can be operated in one of three modes, namely a projected mouse mode, a projected mark-up mode and a non-projected mode.
In the projected mouse mode, the image displayed on the monitor of the personal computer is projected onto the touch sensitive panel. In this case, the electronic writeboard functions as a giant mouse providing input to the personal computer in response to user contact with the touch sensitive panel. Specifically, the electronic writeboard generates mouse events in response to user contact with the touch sensitive panel, which are conveyed to the personal computer for processing. Thus, by contacting the touch sensitive panel, the personal computer can be conditioned to open and display menus, to activate displayed menus, to drag icons, to execute software and to switch applications by changing input focus. The latter event of course is achieved by contacting the touch sensitive panel outside of the window of the active application running on the personal computer.
In the projected mark-up mode the coloured pens and eraser are used to contact the touch sensitive panel. The active application running on the personal computer tracks where writing and erasing has occurred and maintains a computerized image of what is drawn on and erased from the touch sensitive panel. The computerized image includes one or more objects, each of which represents writing on the touch sensitive panel. The computerized image is projected onto the touch sensitive panel so that the user can see the computerized image.
In the non-projected mode, no images are displayed on the touch sensitive panel. Dry-erase markers are used to contact the touch sensitive panel. The application running on the personal computer tracks where writing and erasing has occurred and maintains a computerized image of what is drawn on the touch sensitive panel. However, since no image is displayed on the touch sensitive panel, the electronic writeboard is not interactive when operated in this mode.
Currently there are two prior art erasing techniques used in electronic writeboards during operation in the projected mark-up mode. One technique is to detect when the eraser touches an object representing writing that is displayed on the electronic writeboard and delete the entire object touched by the eraser. This approach is unsatisfactory due to the fact that the erased area often has little bearing with respect to the location of the eraser on the touch sensitive panel. Also, this technique does not allow part of an annotation represented by an object to be erased.
Another technique, currently implemented by the SMART Board, describes the size and shape of the eraser as a circular mask. When the eraser contacts annotations displayed on the touch sensitive panel that are represented by an object, the parts of the annotations within the circular mask are removed. During movement of the eraser, the mask is repeatedly applied to the object to erase the appropriate parts of the annotations represented by the object. Unfortunately, these erase operations require a significant amount of time to complete and therefore, the eraser may move a large distance during the time a single erase operation is performed. As a result, the mask is applied to the object at spaced locations resulting in disjointed parts of annotations being removed instead of a continuous swatch representing the eraser stroke. It is possible to save the intermediate eraser positions and apply the mask retroactively; however, this results in the erase operations falling further and further behind the actual eraser position. Accordingly, improvements to erase operations in electronic writeboards are desired.
It is therefore an object of the present invention to provide a novel method and editor for erasing on an electronic writeboard.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a method for erasing objects representing writing on an electronic writeboard comprising the steps of:
describing an eraser as a mask;
monitoring movement of said eraser over said electronic writeboard;
detecting overlap between said mask and writing on said electronic writeboard represented as an object and erasing writing within said mask; and
adjusting the shape of said mask to compensate for the speed at which said eraser is moved over said electronic writeboard.
Preferably, movement of the eraser is detected at intervals and the shape of the mask is adjusted when the distance traveled by the eraser between successive eraser events exceeds a threshold. It is also preferred that at the adjusting step, the mask is changed from a generally circular configuration to a generally rectangular configuration when the eraser is moved over the electronic writeboard at a speed above a threshold rate. In a preferred embodiment, the threshold rate is determined by measuring the distance between two contact points of the eraser on the electronic writeboard after a predetermined amount of time has elapsed.
Preferably, the size and shape of the rectangular mask is calculated by extending line segments from the eraser contact points in opposite directions and perpendicular to a line joining the eraser contact points. The line segments have a length equal to the radius of the circular mask. The ends of the line segments define the corners of the rectangular mask.
According to another aspect of the present invention there is provided an editor for removing writing on an electronic writeboard represented as an object comprising:
means for describing an eraser as a mask;
means for monitoring movement of said eraser over said electronic writeboard;
means for detecting overlap between said mask and writing on said electronic writeboard represented as an object and erasing writing within said mask; and
means for adjusting the shape of said mask to compensate for the speed at which said eraser is moved over said electronic writeboard.
According to yet another aspect of the present invention there is provided an interactive display system comprising:
a touch sensitive panel responsive to user contact in the form of writing and erasing and generating signals representing the location of writing and erasing thereon;
a projector to project images on said touch sensitive panel reflecting the writing and erasing on said touch sensitive panel; and
a computer executing an applications program, said applications program being responsive to writing signals to create objects representing writing on said touch sensitive panel and providing updated image output to said projector, said applications program also being responsive to erasing signals and including means for describing an eraser as a mask; means for monitoring movement of the eraser over said touch sensitive panel; means for detecting overlap between the mask and writing on said touch sensitive panel and erasing writing within said mask; and means for adjusting the shape of said mask to compensate for the speed at which said eraser is moved over said touch sensitive panel, said applications program providing updated image output to said project
Lao Lun-Yi
Smart Technologies Inc.
Zavis Katten Muchin
LandOfFree
Method for erasing on an electronic writeboard does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for erasing on an electronic writeboard, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for erasing on an electronic writeboard will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2565507