Touch panel display system

• US 6,690,363 B2
• Filed: 02/16/2001
• Issued: 02/10/2004
• Est. Priority Date: 07/19/2000
• Status: Expired due to Fees

• Current Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Next Holdings Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Newton, John
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): Alphonse, Fritz
• Application Number:
  US09/788,307
• Publication Number:
  US 20020075243A1
• Time in Patent Office: 1,089 Days
• Field of Search: 345/173, 345/175, 345/179, 345/170, 341/13, 178/18-1-
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

Emitters and detectors are positioned in proximity to a display screen. Emitters emit energy beams that are diverged across the surface of the display screen. Emitters may be activated/deactivated in sequence, rapid enough to substantially ensure that several energy beams are interrupted by a touch of the display screen. Detectors receive energy beams over a range of angles and generate detection signals upon detecting energy beams. Detection maps are generated based on detection signals. Detection maps indicate which detector should receive an energy beam from which emitter at any point in time. Detections maps are compared to determine that energy beams have been interrupted by a touch. Based on the interrupted energy beams, the location of the touch on the display screen may be determined. The invention serves to reduce the number of emitters and detectors required in a touch panel display system and/or increase the sensitivity and accuracy thereof.

Claims

1. A touch panel display screen comprising:

a display screen for displaying information;

a plurality of emitters positioned in proximity to the display screen, each of the emitters adapted for emitting energy beams that are diverged across a surface of the display screen according to a cycle; and

a plurality of detectors positioned in proximity to the display screen and adapted to receive the energy beams over a range of angles and to generate detection signals upon detecting any one of the energy beams, wherein the number of detectors is less than the number of emitters, such that not every emitter is aligned on-axis with a corresponding detector.

2. The touch panel display screen of claim 1, wherein the plurality of emitters are positioned in proximity to the display screen in such a manner that the energy beams cover substantially the entire area of the surface of the display screen.

3. The touch panel display screen of claim 1, wherein the energy beams are selected from the group consisting of infrared energy beams, visible light energy beams, microwave energy beams and acoustic wave energy beams.

4. The touch panel display screen of claim 1, wherein the information displayed on the display screen comprises a dynamically changeable image.

5. The touch panel display screen of claim 1, wherein the information displayed on the display screen comprises a static image.

6. The touch panel display screen of claim 1, wherein a touch of the display screen will interrupt at least one of the energy beams and will cause at least one of the detectors to not detect the at least one interrupted energy beam.

7. The touch panel display screen of claim 6, wherein location of the touch on the display screen is calculated based on the interrupted energy beams.

8. The touch panel display screen of claim 1, wherein the display screen comprises a top edge, a left edge, a right edge and a bottom edge;

and

wherein the plurality of emitters positioned in proximity to the display screen comprises a first set of emitters positioned relative to the top side of the display screen, a second set of emitters positioned relative to the left side of the display screen, a third set of emitters positioned relative to the right side of the display screen, and a fourth set of emitters positioned relative to the bottom side of the display screen.

9. The touch panel display screen of claim 8, wherein the plurality of detectors positioned in proximity to the display screen comprises a first set of detectors positioned relative to the top side of the display screen, a second set of detectors positioned relative to the left side of the display screen, a third set of detectors positioned relative to the right side of the display screen, and a first set of detectors positioned relative to the bottom side of the display screen.

10. The touch panel display screen of claim 9, wherein each set of detectors comprises two detectors.

11. A touch panel display system comprising:

a display screen for displaying information;

a plurality of emitters positioned in proximity to the display screen, each of the emitters adapted for emitting energy beams that are diverged across a surface of the display screen;

a plurality of detectors position in proximity to the display screen, each of the detectors adapted to receive the energy beams over a range of angles and to generate detection signals upon detecting any one of the energy beams;

a computer-readable medium for storing detection maps indicating which of the detectors should be receiving one of the energy beams from at least one of the emitters at any point in time; and

a processor for executing computer-executable instructions for;

generating a plurality of detection maps based on the detection signals generated by the detectors over time and storing the plurality of detection maps on the computer-readable medium,

accessing the computer-readable medium to compare a current detection map to a reference detection map in order to determine the absence of at least one expected detection signal from at least one of the detectors,

based on the absence of the at least one expected detection signal, determining that at least one of the energy beams has been interrupted by a touch of the display screen, and

based on the at least one interrupted energy beam, determining the location of the touch on the display screen.

12. The touch panel display screen of claim 11, wherein the processor executes further computer executable instructions for controlling activation of the emitters.

13. The touch panel display screen of claim 12, wherein the processor controls the emitters to emit energy beams in a cycle such that each emitter is activated and deactivated according to a sequence.

14. The touch panel display screen of claim 13, wherein the cycle is rapid enough to substantially ensure that a plurality of energy beams will be interrupted by a touch of the display screen, each of the interrupted energy beams being emitted by different ones of the emitters at different times.

15. The touch panel display system of claim 11, wherein the reference detection map comprises an average of several previously stored detection maps.

16. The touch panel display system of claim 11, wherein at least two pairs of intersecting energy beams are interrupted by the touch of the display screen;

and

wherein determining the location of the touch on the display screen comprises;

determining an intersection point location for each pair of intersecting interrupted energy beams, each intersection point location representing a possible location of the touch on the display screen, and

calculating an average intersection point location by averaging the intersection point locations, the average intersection point location representing an estimation of the location of the touch on the display screen.

17. The touch panel display system of claim 16, wherein determining the location of the touch on the display screen further comprises determining an angle of intersection for each pair of intersecting interrupted energy beams;

and

wherein calculating the average intersection point location comprises weighting each intersection point location based on the corresponding angle of intersection and averaging the weighted intersection point locations.

18. A method for implementing a touch panel display screen comprising:

providing a display screen for displaying information;

providing a plurality of emitters positioned in proximity to the display screen, each of the emitters adapted for emitting energy beams that are diverged across a surface of the display screen according to a cycle; and

providing a plurality of detectors positioned in proximity to the display screen and adapted to receive the energy beams over a range of angles and to generate detection signals upon detecting any one of the energy beams, wherein the number of detectors is less than the number of emitters, such that not every emitter is aligned on-axis with a corresponding detector.

19. A computer-readable medium having stored thereon computer-executable instructions for performing the method of claim 18.

20. The method of claim 18, wherein the plurality of emitters are positioned in proximity to the display screen in such a manner that the energy beams cover substantially the entire area of the surface of the display screen.

21. The method of claim 18, wherein a touch of the display screen will interrupt at least one of the energy beams and will cause at least one of the detectors to not detect the at least one interrupted energy beam.

22. The method of claim 21, further comprising determining a location of the touch on the display screen based on the interrupted energy beams.

23. The method of claim 22, wherein at least two pairs of intersecting energy beams are interrupted by the touch of the display screen;

and

wherein determining the location of the touch on the display screen comprises;

determining an intersection point location for each pair of intersecting interrupted energy beams, each intersection point location representing a possible location of touch on the display screen, and

calculating an average intersection point location by averaging the intersection point locations, the average intersection point location representing an estimation of the location of the touch on the display screen.

24. A computer-readable medium having stored thereon computer executable instructions for performing the method of claim 23.

25. The method of claim 23, wherein determining the location of the touch on the display screen further comprises determining an angle of intersection for each pair of intersecting interrupted energy beams;

and

wherein calculating the average intersection point location comprises weighting each intersection point location based on the corresponding angle of intersection and averaging the weighed intersection point locations.

26. A computer-readable medium having stored thereon computer-executable instructions for performing the method of claim 25.

27. The method of claim 18, wherein the cycle is rapid enough to substantially ensure that a plurality of energy beams will be interrupted by a touch of the display screen, each of the interrupted energy beams being emitted by different ones of the emitters at different times.

28. The method of claim 18, further comprising generating a plurality of detection maps based on the detection signals generated by the at least one detector over time, the detection maps indicating from which of the emitters the at least one detector should receive an energy beam at any point in time.

29. The method of claim 28, further comprising comparing a current detection map to a previously stored detection map in order to determine that at least one of the energy beams has been interrupted by the touch of the display screen.

30. A computer-readable medium having stored thereon computer-executable instructions for performing the method of claim 29.

31. A method for implementing a touch panel display screen comprising:

providing a display screen for displaying information;

providing a plurality of emitters positioned in proximity to the display screen in such manner that ht energy beams cover substantially the entire area of a surface of the display screen, each of the emitters adapted for emitting energy beams that are diverged across the surface of the display screen, the emitters being further adapted to be activated and deactivated according to a sequence that is rapid enough to substantially ensure that a plurality of the energy beams will be interrupted by a touch of the display screen, each of the interrupted energy beams being emitted by different ones of the emitters at different times;

providing a plurality of detectors positioned in proximity to the display screen and adapted to receive the energy beams over a range of angles and to generate detection signals upon detecting any one of the energy beams;

generating a plurality of detection maps based on the detection signals generated by the detectors over time, the detection maps indicating from which of the emitters each of the detectors should receive one of the energy beam at any point in time;

comparing a current detection map to a previously stored detection map in order to determine that the plurality of energy beams has been interrupted by touch of the display screen; and

determining a location of the touch on the display screen based on the interrupted energy beams.

32. A computer-readable medium having stored thereon computer-executable instructions for performing the method of claim 31.

33. The method of claim 31, wherein at least two pairs of intersecting energy beams are interrupted by the touch of the display screen;

and

wherein determining the location of the touch on the display screen comprises;

determining an intersection point location for each pair of intersecting interrupted energy beams, each intersection point location representing a possible location of the touch on the display screen, and

calculating an average intersection point location by averaging the intersection point locations, the average intersection point location representing an estimation of the location of the touch on the display screen.

34. A computer-readable medium stored thereon computer-executable instructions for performing the method of claim 33.

35. The method of claim 33, wherein determining the location of the touch on the display screen further comprises determining an angle of intersection for each pair of intersecting interrupted energy beams;

and

wherein calculating the average intersection point location comprises weighting each intersection point location based on the corresponding angle of intersection and averaging the weighted intersection point locations.

36. A computer-readable medium having stored thereon computer-executable instructions for performing the method of claim 35.

37. A touch panel display screen comprising:

a display screen for displaying information;

a plurality of emitters positioned in proximity to a top edge, a right edge, a left edge and a bottom edge of the display screen, each of the emitters adapted for emitting energy beams that are diverged across a surface of the display screen according to a cycle; and

a plurality of detectors interspersed among the emitters along each of the top edge, the right edge, the left edge and the bottom edge of the display screen, each of the detectors adapted to receive the energy beams over a range of angles and to generate detection signals upon detecting any one of the energy beams, wherein the number of detectors is less than the number of emitters, such that not every emitter is aligned on-axis with a corresponding detector.

38. The touch panel display screen of claim 37, wherein the plurality of detectors comprises two detectors interspersed among the emitters along each of the of the top edge, the right edge, the left edge and the bottom edge of the display screen.

39. The touch panel display screen of claim 37, wherein the plurality of detectors comprises three detectors interspersed among the emitters along each of the of the top edge, the right edge, the left edge and the bottom edge of the display screen.