Pen sensor coordinate narrowing method and apparatus

• US 20030095109A1
• Filed: 06/26/2002
• Published: 05/22/2003
• Est. Priority Date: 12/28/1999
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Okada, Yukihiro, Ilagiwara, Kunihiko, Suzuki, Manabu, Toda, Seiji, Sasaki, Manabu, Miyaoku, Hiroshi, Horiuchi, Keiko, Fukuda, Takatoshi
• Granted Patent: US 7,259,754 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/0386 for light pen

Abstract

When a user indicates a point on a display screen of a computer using a pen sensor, first the display screen is divided into a plurality of areas and the areas are displayed by mutually different colors or brightnesses. The plurality of colors or brightnesses displayed are scanned by the pen sensor and the colors or brightnesses detected by the light receiver to judge in which area the indicated point is located. Next, the judged area is further divided into a plurality of areas which are displayed by mutually different colors or brightnesses. Next, a routine similar to the above is successively repeated to narrow down the area in which the point indicated by the pen sensor is located and finally determine the position of the point, that is, the XY coordinates on the display screen.

Claims

1. A pen sensor coordinate narrowing method for determining a position indicated by a pen sensor when scanning a display screen by said pen sensor, said pen sensor coordinate narrowing method comprising:

a step of dividing said display screen into a plurality of areas and displaying these areas by mutually different colors or brightnesses when starting to scan said display screen by said pen sensor and

a step of judging which of the plurality of areas the position of the pen sensor on the screen is at based on the single color or brightness of the areas detected by the pen sensor, wherein

the judged area is used as the next scan area, and the display step and the judgement step are repeated several times so as to determine the position indicated by the pen sensor.

2. A pen sensor coordinate narrowing method as set forth in claim 1, further comprising moving a boundary line formed by said areas along a coordinate axis of said screen and using the position of the boundary line when said pen sensor detects a color or brightness changing along with movement of the boundary line.

3. A pen sensor coordinate narrowing method as set forth in claim 1, further comprising predicting a range including a second position which said pen sensor will indicate next after the coordinates of the first position on the screen indicated by the pen sensor are determined and using this range as the next scan area.

4. A pen sensor coordinate narrowing method as set forth in claim 3, wherein the range including the second position predicted is a range including the periphery of the first position.

5. A pen sensor coordinate narrowing method as set forth in claim 3, further comprising using the coordinates of the first position as a starting point and using a range extended toward one corner of the screen as the next scan area.

6. A pen sensor coordinate narrowing method as set forth in claim 3, further comprising using the point where the pen sensor is moved away from the screen as the starting point, predicting the range including a second position next indicated by said pen sensor, and using that range as said next scan area when said pen sensor moves from said first position on said screen.

7. A pen sensor coordinate narrowing method as set forth in claim 3, further comprising computing a direction of movement and speed of movement from said first position based on information up to the point where the pen sensor is moved away from the screen, predicting a position in proximity to said second position, and using the range predicted to include that second position using that proximity position as a starting point as said scan area.

8. A pen sensor coordinate narrowing method as set forth in claim 1, further comprising comparing a color or brightness detected at a position indicated by said pen sensor and a color or brightness displayed on said screen around the position indicated by said pen sensor to prevent erroneous judgement of the coordinates of the pen sensor at said judgement step.

9. A pen sensor coordinate narrowing method as set forth in claim 1, further comprising, after the coordinates of said first position on said screen have been determined, using a periphery of said first position as a movement detection area, displaying a plurality of areas included in that area by mutually differing colors or brightnesses, and judging that said pen sensor has moved when said pen sensor detects a different color or brightness.

10. A pen sensor coordinate narrowing method as set forth in claim 1, further comprising displaying emphasis on the display screen indicating that a narrowing operation is underway at said display step.

11. A pen sensor coordinate narrowing method as set forth in claim 1, further comprising considering the scan operation to have ended when the pen sensor is moved away from the screen for a predetermined time.

12. A pen sensor coordinate narrowing apparatus for determining coordinates of a position indicated by a pen sensor including:

a display means for dividing a screen into a plurality of areas and displaying the areas by different colors or brightnesses;

a pen sensor for detecting colors or brightnesses of said areas displayed on said screen;

a position detecting means for determining a divided area including a position indicated by said pen sensor based on the color or brightness detected when said pen sensor instructs a position on said screen; and

a control means for suitably repeatedly instructing said display means to use an area determined by said position detecting means as the next scan area, divide it into a plurality of areas, and display the areas by different colors or brightnesses.

13. A pen sensor coordinate narrowing apparatus as set forth in claim 12, wherein said display means has a means for displaying the plurality of divided areas on the screen by different colors or brightnesses and moving a boundary line formed by said areas along a coordinate axis of said screen and said position detecting means detects a position of said coordinate axis by a change of the color or brightness detected by said pen sensor.

14. A pen sensor coordinate narrowing apparatus as set forth in claim 12, wherein said control means has a movement range predicting means for predicting a range including a second position which said pen sensor will indicate next after the coordinates of the first position on the screen indicated by the pen sensor are determined and using this range as the next scan area and said display means divides said next scan area into a plurality of areas and displays said areas by different colors or brightnesses.

15. A pen sensor coordinate narrowing apparatus as set forth in claim 14, wherein said movement range predicting means uses the range including the periphery of the first position as the next scan area.

16. A pen sensor coordinate narrowing apparatus as set forth in claim 14, wherein said movement range predicting means uses as said next scan area an area extending toward one corner of said screen using the coordinates of said first position as a starting point.

17. A pen sensor coordinate narrowing apparatus as set forth in claim 14, wherein said movement range predicting means uses as said next scan area the range predicted to include a second position to be next indicated by said pen sensor point using as a starting point the point where the pen sensor moves over said screen from said first position and said pen sensor is moved away from the screen.

18. A pen sensor coordinate narrowing apparatus as set forth in claim 14, wherein said movement range predicting means computes a direction of movement and speed of movement from said first position based on information up to the point where the pen sensor is moved away from the screen, predicts a position in proximity to said second position, and uses the range predicted to include that second position using that proximity position as a starting point as said scan area.

19. A pen sensor coordinate narrowing apparatus as set forth in claim 12, further comprising a first sensor for detecting a color or brightness on said screen at a position indicated by said pen sensor and a plurality of second sensors arranged symmetrically with respect to said first sensor.

20. A pen sensor coordinate narrowing apparatus as set forth in claim 12, wherein said display means, after the coordinates of said first position on said screen have been determined, displays a movement detection area surrounding said first position and comprised of different colors or brightnesses and detects movement or direction of movement of said pen sensor when said pen sensor detects the colors or brightnesses of said movement detection area.

21. A pen sensor coordinate narrowing apparatus as set forth in claim 20, wherein said movement detection area forms a contoured part including the range of the first position.

22. A pen sensor coordinate narrowing apparatus as set forth in claim 12, wherein said display means stops the display of said scan area when there is no instruction for display of the next scan area even after the elapse of a predetermined time from the display of said scan area.

23. A pen sensor coordinate narrowing apparatus as set forth in claim 12, wherein said display means displaying emphasis on the display screen indicating that a narrowing operation is underway.