Electronic whiteboard system and method

An eraser for use on an electronic whiteboard with a protrusion area on the erasing surface forming a convex area on the erasing surface for establishing a positive point of contact with the whiteboard; an electronic whiteboard system including such an eraser, a controller for storing data relating to information written on and erased from the whiteboard data, and a filter for preventing the storage of digital data relating to contacts with the whiteboard not attributable to normal writing or erasing actions.

What is claimed is:

1. A control system for an electronic whiteboard, the control system comprising:

means for detecting and storing the location coordinates of an object on the whiteboard as it moves across the whiteboard; and

filtering means, responsive to the means for detecting, including:

means for calculating the distance between first and second sequential location coordinates,

means for determining the time interval between the first and second sequential location coordinates,

means for comparing the calculated distance to a pre-established allowable maximum distance for the time interval, and

means for rejecting the second location coordinate if the calculated distance is greater than the pre-established maximum allowable distance for the time interval to filter out inadvertent contacts with the whiteboard.

2. The control system of claim 1 in which the filtering means further includes:

means for computing the change in velocity between three sequential coordinates, and

means for rejecting the third coordinate if the change in velocity is greater than a pre-established maximum allowable change in velocity.

3. The control system of claim 2 further including:

means for inputting the type of object to be moved across the whiteboard, and

means for changing the maximum allowable change in velocity depending on the type of object.

4. The control system of claim 3 further including means for generating a first sound for a first type of object type and a second sound for a second type of object to provide positive feedback to the user of the whiteboard regarding the type of action occurring on the whiteboard.

5. The control system of claim 1 in which the pre-established maximum allowable distance is between 0.2 and 2 inches for a time interval of approximately 5 milliseconds.

6. The control system of claim 2 in which the pre-established maximum allowable change in velocity is between 40 and 120 inches per second squared when the instrument type is a writing instrument and a pre-established maximum allowable change in velocity is between 320 and 960 inches per second squared when the instrument type is an erasing instrument.

7. The control system of claim 1 in which the means for determining the location coordinates includes means for computing the cartesian coordinates of the object, the means for calculating the distance includes means for computing the distance in the x direction and the distance in the y direction between the first and second sequential location coordinates, and the pre-established maximum allowable distance includes a maximum allowable x distance and a maximum allowable y distance.

8. The control system for claim 7 in which the means for computing includes means for evaluating the distance in the x direction in relation to the maximum allowable x distance and for evaluating the distance in the y direction in relation to the maximum allowable y distance and wherein the means for rejecting includes means for eliminating the second location coordinate if either the maximum allowable x or the maximum allowable y distance is exceeded.

9. The control system of claim 2 in which the means for computing the change in velocity includes means for calculating the change in velocity in the x direction and the change in velocity in the y direction, the pre-established allowable maximum change in velocity includes a maximum allowable change in velocity in the x direction and a maximum allowable change in velocity in the y direction, and the means for rejecting the third coordinate includes means for excluding the third coordinate if either the maximum change in velocity in the x direction or the y direction is exceeded.

10. A control system for an electronic whiteboard, the control system comprising:

means for inputting whether a writing instrument or an erasing instrument is to be used on the whiteboard;

means for detecting contact of the instrument with the whiteboard;

means for detecting and storing the location coordinates of the instrument on the whiteboard as it contacts the whiteboard; and

filtering means, responsive to the means for determining, including:

means for calculating the distance between first and second sequential location coordinates,

means for specifying the time interval between first and second sequential location coordinates,

means for comparing the calculated distance to a pre-established allowable maximum distance for the specified time interval,

means for rejecting the second location coordinate if the distance is greater than a pre-established maximum allowable distance for the specified time interval,

means for computing the change in velocity between three sequential coordinates, and

means for rejecting the third coordinate if the change in velocity is greater than a pre-established allowable change in velocity to filter out contacts made with the whiteboard by objects other than the writing or erasing instruments; and

means, responsive to the means for inputting, for changing the pre-established maximum allowable change in velocity depending on the type of instrument inputted.

11. An electronic filter for an electronic whiteboard comprising:

first rejection means, responsive to sequential contacts on the whiteboard which exceed a maximum allowable distance within an established time period, for rejecting at least one of the contacts; and

second rejection means, responsive to sequential contacts on the whiteboard which exceed an established maximum allowable change in velocity, for rejecting at least one of the contacts.

12. A control method for an electronic whiteboard, the control method comprising:

detecting and storing the location coordinates of an object on the whiteboard as it moves across the whiteboard; and

filtering certain errant contacts with the whiteboard wherein filtering includes:

calculating the distance between first and second sequential location coordinates,

determining the time interval between the first and second sequential location coordinates,

comparing the calculated distance to a pre-established allowable maximum distance for the time interval, and

rejecting the second location coordinate if the calculated distance is greater than the pre-established maximum allowable distance for the time interval to filter out inadvertent contacts with the whiteboard.

13. The control method of claim 12 in which filtering further includes:

computing the change in velocity between three sequential coordinates, and

rejecting the third coordinate if the change in velocity is greater than a pre-established maximum allowable change in velocity.

14. The control method of claim 13 further including:

inputting the type of object to be moved across the whiteboard, and

changing the maximum allowable change in velocity depending on the type of object.

15. The control method of claim 14 further including generating a first sound for a first type of object type and generating a second sound for a second type of object to provide positive feedback to the user of the whiteboard regarding the type of action occurring on the whiteboard.

16. The control method of claim 12 in which the pre-established maximum allowable distance is between 0.2 and 2 inches for a time interval of approximately 5 milliseconds.

17. The control method of claim 13 in which the pre-established maximum allowable change in velocity is between 40 and 120 inches per second squared when the instrument type is a writing instrument and a pre-established maximum allowable change in velocity is between 320 and 960 inches per second squared when the instrument type is an erasing instrument for a time interval of approximately 5 milliseconds.

18. A control method for an electronic whiteboard, the control method comprising:

inputting whether a writing instrument or an erasing instrument is to be used on the whiteboard;

detecting contact of the instrument with the whiteboard;

determining and storing the location coordinates of the instrument on the whiteboard as it contacts the whiteboard; and

a filtering process including:

calculating the distance between first and second sequential location coordinates,

specifying the time interval between first and second sequential location coordinates,

comparing the calculated distance to a pre-established allowable maximum distance for the specified time interval,

rejecting the second location coordinate if the distance is greater than a pre-established maximum allowable distance for the specified time interval,

computing the change in velocity between three sequential coordinates, and

rejecting the third coordinate if the change in velocity is greater than a pre-established allowable change in velocity to filter out contacts made with the whiteboard by objects other than the writing or erasing instruments; and

changing the pre-established maximum allowable change in velocity depending on the type of instrument inputted.

19. An electronic filtering process for an electronic whiteboard, the filtering process comprising:

evaluating a plurality of sequential contacts on the whiteboard to ascertain whether a maximum allowable distance between sequential contacts is exceeded within an established time period; and

evaluating a plurality of sequential contacts on the whiteboard to ascertain whether an established maximum allowable change in velocity is exceeded between the contacts.

20. The filtering process of claim 19 further including the step of modifying the established maximum allowable change in velocity depending on the type of device contacting the whiteboard.

21. An electric whiteboard system comprising:

a digitizer including a whiteboard writing surface;

control electronics for detecting and storing the location coordinates of contacts on the whiteboard to keep a digital record of writings and erasures on the whiteboard; and

an electronic filter for preventing the storage of digital data relating to contacts wit the whiteboard writing surface not attributable to writing or erasing actions on the whiteboard writing surface.

22. An electronic whiteboard system comprising:

a digitizer including a writing surface;

control electronics for detecting and storing the location coordinates of contacts on the whiteboard to keep a digital record of writings and erasures on the whiteboard; and

filter means for preventing the storage of digital data relating to contacts with the white board not attributable to writing or erasing actions, said filter means comprising:

means for calculating the distance between first and second sequential location coordinates,

means for determining the time interval between the first and second sequential location coordinates, and

means for comparing the calculated distance to a pre-established allowable maximum distance for the time interval.

23. The system of claim 22 in which the filter means further includes:

means for computing the change in velocity between three sequential coordinates, and

means for comparing the computed change in velocity to a pre-established maximum allowable change in velocity.

24. An electronic whiteboard system comprising:

an electronic whiteboard;

an electronic eraser;

a storage device for storing data relating to information written on and erased from the whiteboard; and

an electronic filter for preventing the storage of digital data relating to contacts with the electronic whiteboard not attributable to writing or erasing actions.

25. The electronic whiteboard system of claim 24 in which the filter comprises a calculator for calculating the distance between a first and second sequential location coordinates, a counter for determining the time interval between the first and second sequential location coordinates, and a distance comparator for comparing the calculated distance to a pre-established allowable maximum distance for the time interval.

26. The electronic whiteboard system of claim 24 in which the filter comprises a velocity computor for computing the change in velocity between three sequential coordinates, and a velocity comparator for comparing the computed change in velocity to a preestablished maximum allowable change in velocity.

27. An electronic whiteboard system comprising:

a digitizer including a whiteboard surface;

control electronics for detecting and storing the location coordinates of a contact on the whiteboard to keep a digital record of writings and erasures on the whiteboard; and

a filter for preventing the storage of digital data relating to a contact with the whiteboard not attributable to writing or erasing actions, comprising a calculator for calculating the distance between a first and second sequential location coordinates, a counter for determining the time interval between the first and second sequential location coordinates, and a distance comparator for comparing the calculated distance to a pre-established allowable maximum distance for the time interval.

28. An electronic whiteboard system comprising:

a digitizer including a whiteboard surface;

control electronics for detecting and storing the location coordinates of a contact on the whiteboard to keep a digital record of writings and erasures on the whiteboard; and

a filter for preventing the storage of digital data relating to a contact with the whiteboard not attributable to writing or erasing actions, comprising a calculator for calculating the distance between a first and second sequential location coordinates, a counter for determining the time interval between the first and second sequential location coordinates, and a distance comparator for comparing the calculated distance to a pre-established allowable maximum distance for the time interval, a velocity computor for computing the change in velocity between three sequential coordinates, and a velocity comparator for comparing the computed change in velocity to a pre-established maximum allowable change in velocity.